Middle Childhood Development Essay

Middle childhood development is a big time in a child life. They begin to become more independent and rely more on themselves without the help of their parents. This is also a great time to still create solid bonds with your child before they enter the adolescence stage which begins at 13 (Dr.Laura Markham, 2013). With the peer pressure from friends and associates having a good foundation with your child early can save you a ton of stress. During middle childhood stage, children develop more independence from parents and family. They understand more and can differentiate between right and wrong. Children at this age give more attention to friendship and teamwork, but continue to be strongly influence by their parents’ judgment. At this age children have the ability to experience and describe feelings and thoughts with parents and friends. Middle childhood is a time when children develop social relationships. The social skills learned through family and peers give them ability to participate in meaningful communication that later provide foundation for challenges as adolescence. This improves their relationship and encourages them to be successful in future. According to Piagets theory of Cognitive Development between the ages of 6-11 children are at the stage of concrete operational thought. This involves a growing ability for children to use logic and thought. For example, a child age 8 will understand that it is wrong to steal even if they only did it because they were hungry. A toddler may take the food and eat it while knowing that it was wrong but not feel bad because in their mind they only did it because they were hungry. Same situation but different thought processes because of the age and development of the child. Stable and supportive families are crucial during middle childhood development  stage. Supportive family members and friends improve social development and children’s self-concept is basically shaped by relationships with parents, teachers and peers. Often they have little concern about their physical appearance though certain pressure during the later years 9-11 to look like the traditional boy and girls’ body image declines, especially with puberty. At this stage lower self-control and emotional stability may be observed. At this stage parents should be very careful about how they say and do things because children especially look to their parents at this age for confirmation on how to act as such. Culture also plays a major role in child self esteem because if influence your children to be strong and independent as children they take that into adolescence and early adulthood. In conclusion, middle childhood is an important stage in a person’s development in life. These are the crucial years that you start to see a change in your child and you can either change with them or have a hard time adjusting to them. I myself have a child that is 11, and I can honestly say that she has grown so much over years both physic al and emotionally. References Berk, L. E. (2012) Infants, Children, and Adolescents. (7th Ed). Boston, MA: Pearson. www.health.gov.sk.ca/middle-childhood

Leadership: Theory, application, skill development Essay

Over the past one year, the concept and skills that I have been able to learn is that of leadership. Leadership is an important aspect of life because in every situation in life, there is a form of leadership, although minor in some case that is observed. It is often experienced in homes, schools, businesses, organizations, and even governments among other areas in life. Although as an individual I have never been involved in any form of leadership, I believe that leadership plays a very important role in the existences of human beings in the world since through leadership, people are able to know what to do, at what time, how to do it, and what results to achieve in the long run. It was my belief that leadership is meant for the male gender and the females were not suitable for any leadership positions, be it political leadership, at homes, schools or any other place in life. There has been stereotyping in the society that women cannot hold leadership positions except for men (Steinberg, 2008). However, one Sadhana Smiles, who is a chief executive officer of Harcourts Victoria, a real estate group, disapproves this notion that men are the only people who can take top leadership positions. She however, says that a lot of women are rarely considered for roles in leadership since men prefer to deal with their fellow men and are more comfortable in transacting business with other men more than with women. At first, I knew that there is no difference in leadership. For me, anybody who gave commands and issued instructions was a leader. I was wrong. During the year, I read about different types of leadership styles and did my research through observation in several organizations, one being our school as well as my church. I discovered that the frequently applied leadership styles in many organizations across the globe include transformational leadership and the transactional form of leadership (Kippenberger, 2002). Under the transformational leadership I learned that the leaders get an opportunity to give inspiration to the employees, so that the employees can perform beyond their normal duties. I also learned that leaders are people who are capable of performing the functions of showing direction, aligning, influencing, motivating and inspiring of the people they lead. On the other hand manager is simply someone who is capable of planning, budgeting, organizing and allocating resources and can control and resolve problems easily. In addition, leadership can be explained by use of many theories such as the traits theory, behavioural theory, and the contingency or situational theory which include theories such as the path-goal theory (Lussier, & Achua, 2010). Therefore, with the considerations of the above aspects and example on leadership, I realised that leadership is a very important at all levels in an organisation, and within the society. In addition, I realised that in leadership, what can work in one context may not be applicable in another. Culture is also another issue that I got to understand plays a great role in application of the theories of leadership. It is therefore, recommendable that women should be given equal chances in leadership as men without any form of discrimination, something that I really support since women can perform just like men or even better. References Kippenberger, T. (2002). Leadership Styles. Chichester: Capstone Pub. Lussier, R. N., & Achua, C. F. (2010). Leadership: Theory, application, skill development. Australia: SouthWestern/Cengage Learning. Steinberg, B. S. (2008). Women in power: The personalities and leadership styles of Indira Gandhi, Golda Meir, and Margaret Thatcher. Montreal: McGill-Queen’s University Press. Source document

Studies in Maltese Architecture

Surveies in Maltese Architecture The Manoel Theatre jpg/640px-Manoel_theatre_%2812843882153%29.jpg" src="https://s3-eu-west-1.amazonaws.com/aaimagestore/essays/1463861.001.jpg">The Manoel Theatre, or as normally referred to in the Maltese linguistic communication, ‘Teatru Manoel ‘ , is one of the most of import and important memorials shacking in Malta since it a really old theater amongst the other few in all of Europe. This Theatre stretches back to the eighteenth century when it was inaugurated in January of 1732 in the bosom of Valletta, which means it has survived a long period of histories and now it holds within it a heritage which is unreplaceable and alone. Dating back to the early old ages of the eighteenth century, the Grandmaster of the Order of Malta at that clip was Grandmaster Antonio Manoel de Vilhena. As a swayer, he planned and constructed assorted military and civil edifices, such as the garrison in Marsamxett known as Fort Manoel. Fortunately, at that clip, the Grandmaster started to admit theatrical public presentations by the Italian knights of the Order of St. John ( in their hostel ) , every bit good as a Maltese group that used to play comedies and musical amusement, ( in the same hostel ) some of which were rather successful. Therefore Grandmaster Antonio Manoel de Vilhena set up a foundation (Fondazione Manoel) which decided to buy two houses in Strada del Carmine, now known as ‘Triq it-Teatru l-Antik ‘ , at the cost of 2,186scudiso that a new theater could be built at this location. Francois Mondion is said to hold been one of the senior designers employed by Grandmaster Vilhena, that designed and built the new theater, but there is still doubt and uncertainness regarding who the existent designer of the theater was. On the 16th of March 1731, work started on site which was of an country of 94.5 square canes, which was a Maltese unit of measuring used at that clip and consequences to about 414 m? . Since many old ages have passed since the twenty-four hours it was built, the aesthetics, frontage and form are without any uncertainty different from what had been originally constructed in 1732. However, it can still be pointed out that there is a great chance that it might hold been influenced by two theaters in Palermo at that clip. Besides, it is clear that the original form of the auditorium was in the signifier of a U, being described ( by De Lucca and Tonna ) as somewhat retrograde for its clip, with the phase being projected by two consecutive sides. The modern-day papers Cabreo Vilhena describes the interior portion of the theater as it was formatted originally, holding a sum of 39 boxes and a cavity furnished with benches. The boxes were divided into three grades: the first grade being used by the grandmaster ‘s pages ; the 2nd grade was used by the grandmaster and his cortege ; and the 3rd grade was known as ‘the Gods ‘ where the seats are rather high and distant from the phase. A figure of appliances and machines used to do scenes even more Godhead and spectacular where found on the same degree of ‘the Gods ‘ grade. The Manoel Theatre was and still is a theater which maps like many others with some of its parts being the wings and background, every bit good as â€Å"a shop room for the lamps that illuminated the auditoriumâ€Å" . The wing is the country and portion of the phase which is used by the performing artist to fix to come in and is besides used as a storage infinite for set scenery and proficient equipment. Obviously, this portion of the theater is masked by legion long curtains for privateness. On the other manus, the background was the background to any scene of a phase set. Manoel Theatre besides had: the chief entryway ; the phase ; a little room for invitees (saletta) ; a corridor in the signifier of a U-shape ; and a basement found below the phase. As can be seen by the exposure of the original frontage of the theater below, two olympian pillars flanked the front door and supported the balcony above it. The whole Manoel Theatre was surprisingly finished and completed after a sp eedy 10 months. At the early times of Manoel Theatre ‘s startup, the Baroque manner was booming and at its highest point in Europe. Architecture was non the lone of import factor during churrigueresque clip but other factors should be considered. Performing humanistic disciplines such as opera itself were going really of import during this clip and could be categorized into two parts:‘opera seria ‘and‘operabuffa ‘. This means that great public presentations and composings were expected to come with this new theater, besides with the reaching of celebrated composers. The 19th of January 1732 marked an of import day of the month for the Manoel Theatre since the first public presentation was held on this day. ‘Merope ‘( as it was called ) depicted calamities of that century and was acted by the Italian knights of the Order themselves as a mark of regard and baronial work chosen for the startup of the theater. Following this public presentation, were two comedies traveling by the name of ‘Il Giocatore Disperato ‘and ‘Don Pilone ‘. Besides, other public presentations were held during this clip, largely comedies, but unluckily their names are unknown so non much information is available about them. It is of import to observe that from such early times the theater started to be used for other activities such as a locale for carnival balls. During the regulation of Vilhena, there are no more histories of theatrical composings and public presentations but we do hold the memoirs of Carlo Goldoni which do give us an thou ght of how it felt like to be in the Manoel Theatre. Sequence to Vilhena ‘s regulation was Despuig who ne'er attended the theater for his ain grounds, but after him there was the powerful Grandmaster Manoel de Pinto Fonseca who was so in love with theater and public presentation humanistic disciplines that three yearss after he was elected he attended an opera at the theater. It is cardinal to retrieve that during the eighteenth century Manoel Theatre was one of the really few topographic points where the knights and certain types of people could be entertained. Priests were besides acute on keeping their ain public presentations and dramas, even though at these times they merely accepted work forces to go to their dramas. Grandmaster Pinto de Fonseca went to the theater for the last clip at the age of 92 demoing the great love and regard he had for this type of art. Giovanni Artuffo presented and introduced legion operas by three different composers in the early 1750s. All of their plants were admired by the knights and the Maltese people ( less sophisticated but still enthusiastic about the opera itself ) . Just one or really few non-operatic plants were performed during this period. It is besides noteworthy that the old ages 1768-70 a adult female was given the impresa which happens really seldom, in fact she was the lone adult female to be given such power during that century. Besides, a few old ages subsequently Natale Marini made a program and theoretical account of the theater ‘s interior and phase since the theater was under uninterrupted wear but there is no record demoing renewing work. This century marks the debut of a immature endowment Nicolo Isuoard who was set to go one of Paris ‘ most popular composers of amusing opera subsequently on. In 1796 the Gallic arrived and took over Malta, and Napoleon expelled the Order of St. John from Malta in 1798, so the theater had been leased to four individuals. The invasion of the French caused some immediate jobs since the Italian vocalists and instrumentalists organizing portion of the opera of Manoel Theatre were obliged to remain in Malta, so they wanted an addition in their pay. The monetary values and rewards which were making the jobs were shortly fixed and taken attention of. In September 1798, Nicolo Isouard was appointed commissioner for theatre whilst Pietro Paolo Muscat became the exclusive showman as he bought all the portions. During this period, Manoel Theatre was confronting a batch of jobs and was at a clip of crisis, with the attending at the theater most likely worsening since the vocalists were non being changed and the fort started to lose involvement. With all these debatable state of affairss, Isouard was kept busy most of the clip seeking to happen a solut ion to better the state of affairs. In 1799 the theater got involuntarily involved in a atrocious episode in Maltese history when the Maltese were be aftering to assail and scupper the Gallic within the walls of Valletta itself. Manoel Theatre got involved in the narrative because Vaubois ordered Isouard to set on a show on a Friday ( a twenty-four hours when no operas or comedies were of all time performed ) to move as a distraction for the Gallic. However, the program was discovered and several plotters were executed in the square in forepart of the Magisterial Palace. By the early 1800s, the Italian company had had plenty and did non desire to execute any longer, and so the theater was forced to shut with the going of the Italians from Valletta. Manoel Theatre was so reopened and a important event occurred when it was decided that a Maltese play group was to execute on a regular basis inside the theater. This was rather a important measure in Maltese history. In 1800, the Gallic were driven to a point where they cou ld non shack in Malta any longer, ( with the aid of the British ) so they decided to go forth, taking with them Nicolo Isuardo who was regarded as a treasonist and ne'er to return to Malta. After helping to throw out the Gallic, the British found themselves crowned head of the Maltese Islands. Unfortunately, during the going of the Gallic and the early 1801, no public presentations seem to hold taken topographic point inside Theatre Manoel but at least it was surely used for the organisation of balls since Aeneas Anderson tells us that he attended a public ball at the Opera House during this period. Italian opera is reintroduced one time once more and the public presentations are described as great amusement with merely a few little jobs. Besides the fact that non everyone could come in the theater or take his topographic point was acquiring on some people ‘s nervousnesss. In 1812, George Whitmore of the Royal Engineers was â€Å" to reconstruct the edifice exhaustively, to increase the figure of boxes†¦ and to adorn the full edifice in a modern, simple and elegant manner † . Oakes and Whitmore had a big influence on the aesthetics of the theater as it is nowadays since they did hole and alteration rather a batch of parts. In fact, the tallness of the edifice was raised higher with a new roof being built, the floor of the cavity was re-laid, the brackets were removed and the boxes were opened up for better visibleness, and a 4th grade was added. Besides, the dressing suites for performing artists was increased and the phase enlarged. This resulted in the auditorium holding an egg-shaped form, which is still present with that same form presents. The British made sure to re-introduce theprotettore, which was occupied by a citizen of high standing, and the besides reintroduced the system of naming an showman, with the first showmans being three. Showmans had rather a hazardous concern with the hazard of hardly doing any money since they had provide amusement and public presentations all the clip throughout the whole twelvemonth. These apart from holding to pay the rent, had to engage vocalists and terpsichoreans to come to Malta which could take to economical battles. In fact, during 1817-18 the fundss for Manoel Theatre were so bad that both the rent and the admittance monetary values were reduced. The immature British officers, as were the knights, needed to utilize the free clip they had, so for some of them theatre was their interest. We do hold histories of information about legion dramas in English which were held at the Manuel Theatre such as the celebrated workThe Clandestine Marriageby Colman and Garrick. The nineteenth century besides marks another of import milepost in native Maltese play because dramas started to be performed in Maltese linguistic communication as described by the British officer Anderson. The first full length drama was called ‘Caterina, ix-Xbejba tal-Irdum ‘ . Opera, on the other manus, was deemed as more of import during the British regulation, it was the reigning genre. The figure of new operas to be performed per twelvemonth settled at four and bothopera seriaandopera buffaperformed in the early decennaries. A figure of vocalists were so loved and respected a batch by the audience as were Camilla Darbois and Lorenzo Del Riccio amongs t some others, to the point that they ended up settling in Malta ( as they were foreign ) . One should besides retrieve that during their reign, Manoel theater was used for a figure of great occasions as was done for the return of Governor Sir Thomas Maitland. Subsequently along the nineteenth century, Manoel Theatre had become such a load on the authorities because of showmans and the fact that the theater was now an aged edifice with excessively many fixs to be done, it was agreed that a new opera house ( The Royal Opera house ) was to be built. This led to the Manoel Theatre falling into private custodies when Anacleto Conti decided to purchase Mifsud ‘s half portion and go the exclusive proprietor. By 1866 the Royal Opera House was ready to be used and Manoel Theatre ready to be abandoned for good. Manoel Theatre was besides stripped from its rubric ( Theatre Royal ) and named after the Grandmaster Antonio Manoel de Vilhena. Between 1866 and 1873, Manoel Theatre had its ruin, it was hardly used and when used merely for dramas by Maltese amateurs. Since it was hardly used, no care, fixs or renovating were done and it continued to deteriorate. In 1873, a calamity occurred in Valletta when the Royal Opera House was unluckily destroyed and beyond fix. At least from this calamity, Malta regained back a forgotten treasure, that is the Manoel Theatre. Since operas and dramas urgently needed a moderately good topographic point to be performed, what better pick was at that place than the Manoel Theatre? Conti ( the proprietor of the theater ) could non believe his fortune when his theater started to be used and after some clip besides repaired. What really did salvage the theater from traveling downhill for good was the new genre of theater, called ‘operetta ‘ . Since Manoel Theatre had long been unused as a proper theater, its proprietors had to do a figure of efforts at re-establishing it as an opera house. Fortunately, they managed to set up the theater for a figure of seasons and the plants started to increase, accordingly taking to a successful and positive season. In 1882, Arpa decided to buy the Manoel Theatre from Conti and after some clip realized that something had to be done to vie with the Rjal, so many fixs and redecorations were undertaken. On a positive note, Manoel Theatre had some really successful seasons at the terminal of the 1880s, one of the most of import dramas being‘Birichino Al Teatro‘ . After some old ages, Arpa could non pay back the financess he borrowed from G. Gollcher, and so Gollcher decided to take legal actions and purchase the theater himself. The Gollchers did do some few changes and redecorations for the better since they managed the theater themselves for several more old ages. The MADC, which is a popular play group that formed in 1910 with the amalgamation of two groups of play, used to execute a batch in Manoel Theatre and inspired many other groups. In the twentieth century,‘Romanticismo ‘was repeated a figure of times in the theater and after some clip Manoel Theatre besides became a film but unrecorded theater was non banished. The Second World War did somewhat decelerate down Manoel Theatre, but surprisingly composings were still being shown and people were still go toing the theater to be entertained. The Maltese Government, at that clip Malta Labour Party, decided to purchase back Manoel Theatre so as to continue it and its historical heritage. When the theater was acquired, Vera Lindsay and Richard Southmen were commissioned to give recommendations on the resurgence of the Manoel Theatre. Numerous sum of alterations and changes had to be done so refurbishment started instantly. In 1960 the first Manoel Theatre direction commission was set up and they had to do certain that the gap would be a genuinely great one. Fortunately, the gap was a successful event. Presents, Manoel Theatre has continued to populate up to its outlooks and better since it continues to expose many theatrical productions and public presentations both in the Maltese and English linguistic communication, with opera being basically of import, play, dancing, musical shows, and the one-year MADC Christmas dumb show. The Manoel Theatre has been home to countless famous persons and astonishing endowments such as Joseph Callejla, Boris Christoff, Louis Kenter, John Neville and many others. The theatre direction commission president right now is Michael Grech and the deputy president Kenneth Zammit. The theater besides has a museum ( which shows the history of the topographic point ) , and a gift store. It is astonishing to see that this theater managed to survived through all these old ages, all this history shacking within merely one edifice. It has such great intrinsic value, non merely to us but besides to the whole of Europe, that it should be taken attention of and pr eserved for the longest clip possible.

Sales promotions Essay Example | Topics and Well Written Essays - 250 words

Sales promotions - Essay Example Managers’ tendency to rely on sales promotion has increased over the passage of time because sales promotion triggers the buyer action serving as a short-term tool while advertising shapes the attitude of market toward the brand in the long-run (Kotler, 2003). A very effective way of sales promotion is the use of coupons. In this strategy, customers either cut the coupons from newspapers or receive them on their own so as to be able to buy products at discounts (Rikey, 2012). Rebates are of two kinds; â€Å"an instate rebate, where the discount is taken immediately at the store register, or a mail-in rebate, or MIR, where the customer must fill out documentation, and mail it in order to receive their refund† (Miller, 2014). Cooperative advertising programs and sales training programs are means of effecting the support of retailers. Different sales promotion techniques attract professional buyers in the business market. Continuity programs are of huge significance in the travel industry and also have propagated to the advertisers of business-products (O’Guinn, Allen, and Semenik, 2011, p. 568). Repeat purchase is rewarded by continuity programs and

McCabe on Faith and Reason Essay Example | Topics and Well Written Essays - 1000 words

McCabe on Faith and Reason - Essay Example Indeed, Christianity or Islam operate with rather complex notions and require their followers to have a strong faith. In this paper I will argue that Herbert McCabe fails to draw a good connection between faith and reason because his arguments are too ambiguous. This represents the major drawback of his position when it comes to explaining what role the latter plays in the former. In order to demonstrate this, I will first explore his position on the connection between faith and reason; then pay attention to the merits of it and, afterwards, put emphasis on the deficiencies that can be found in it. To begin with, it may be particularly important to outline the view of McCabe on the way faith and reason are connected. He points out that there are two extreme positions when it comes to faith: on the one hand, some might argue that to practice it one should not have any reasons at all which means that faith is above any reasoning; on the other hand, others are firm in that their faith can hardly be disproved logically. The scholar notes that true understanding of faith lies somewhere in between as â€Å"the first extreme makes the notion of truth inapplicable. The other makes the notion of faith inapplicable† (McCabe 5). In addition McCabe notes that people who dismiss the importance of the relationship between faith and reasons fail to â€Å"take sufficiently seriously the point that faith means holding something as true – they think of faith as more an act of courage or trust in a very general sense† (McCabe 6). So, he proves that it is essential to make th is relationship clear. There are several merits of such an approach. First of all, McCabe shows that faith should not be perceived as some kind of a metaphysical knowledge that is beyond common sense and is incompatible with logic. Quite the opposite, he draws several examples, as in the case of marrying for money, which show that faith is a rather difficult complex and any

Database Management system project (MIS) Assignment

Database Management system project (MIS) - Assignment Example With the help of an entity relation diagram (ERD), normalized relations are displayed using Crows Foot notation. Further, relational tables and the ERD are translated and displayed in Access with a focus on integrity and referential rules during the design of the tables. Finally, the project will perform querying processes that summarizes the key data and give justifications for them. With the help of screenshots, the database components will be shown in the report to illustrate the functionality of the database. This is a project that entails the development of a database for an airline company referred as Fly Dubai. The company operates from Dubai and serves regions in Asian Pacific, Middle East, Africa and Europe. The system for an airline company should be up to date, accurate, secure, and responsive to frequent changes and should integrate the use of decision making and management tools for the day to day operation of the company. Airline industry comprise of a number of stakeholders which include passengers, airline employees, airport and crew service providers and government regulators among others. A database is anticipated that documents the details of all the interested parties and meets their needs effectively. This paper documents the creation of a database using database tools such as Access and subsequent management processes that ensure efficient delivery of service. Fly Dubai is a no-frills airline company that is based in United Arab Emirates. The company serves low income consumers in UAE and other Asian countries. It has also developed partnerships and collaborations with other airlines operating outside UAE and into Asian Pacific regions, Europe, South America and Africa. The airline is headquartered in Dubai and is a vital transport option for UAE residents and beyond. Since the inception of the airline a few years ago, the key challenge has been the booking, scheduling and office

Unit 1 Lab 2 Using Command Line Help Case Study Example | Topics and Well Written Essays - 250 words

Unit 1 Lab 2 Using Command Line Help - Case Study Example It shows the general commands including the tools and utilities. These commands mostly comprise of the BSD user environment (Lewis, 2013). Most are command shell interpreters, commands for manipulating files, commands for the mail, and tools for formatted output and text editors. All of these commands set a value for status so that it can be used to ascertain if the command executed successfully upon completion. The above is in line that a value of zero shows a successful conclusion of the command while, and a value is greater than zero means that an error occurred. Note: With Solaris, it is necessary to run the catman utility before search the man pages by keyword. This can take considerable time on some systems and is generally completed by the instructor prior to class. Enter the following command: $ man –k grep a. List some of the man pages where the grep command was found . Step 10. Interpret man Page Headings There are a number different headings or informational areas in a typical man page. The more common ones are: NAME Name accomplish the same thing SYNOPSIS Shows the syntax arguments DESCRIPTION Gives an overview of what the what the command will take effect on such that can change the function or effect of They are by a dash (-) or minus sign SEE ALSO Refers the user to other related commands and subjects These headings are displayed in the man page output using all capital letters. Depending on the command and its purpose, the man page may not contain all headings. For instance, the pwd (Print Working Directory) command does not have Options or Operands information heading since there are no options or operands that can be with the command. All commands will have at least a Name, Synopsis, and

Calvins View of the Biblical Doctrine of the Fall of Man, Resistence Essay

Calvins View of the Biblical Doctrine of the Fall of Man, Resistence to Tyrannical Government and argument for Limited Governmen - Essay Example Irresistible Grace†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..5 D. Perseverance of the Saints†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 6 E. Limited Atonement †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ 6 III. Christian Community and the Christian Government †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ 7 - 9 IV. Conclusion †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢ € ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦9 Introduction The Reformation was a religious movement intended to rectify the teachings of the Catholic Church on human salvation. It abolished the systematized view on attaining salvation by emphasizing on human faith alone. Thus, for the Reformists, it is enough for man to believe in order to be saved. One of the most influential theologians during the Reformation period was John Calvin. Claimed by many as the founder of Calvinism, he shared some definitive teachings on the nature of man and on the significance of a Christian community. His lectures greatly contributed in the establishment of some religious and socio-political ideologies of today. In this light, we will examine the teachings of John Calvin by highlighting on two important aspects: firstly, his view on the nature of man in relation to the divine intellect; and secondly; his notion of the ideal socio-political community. I. Human Sin and Salvation All of the teachings of John Calvi n are grounded on his unique conception of human nature, which according to him, is corrupt and wicked. 1 As underscored in most of works, the spiritual downfall of man was caused by the sin of Adam and Eve. As a result of this sin, man became spiritually dead. Thus, John Calvin believes that the spiritual downfall of man has made him unworthy to go to heaven, thus, he has to be essentially chosen by God to be saved. The choice, however, depends not on his actions on earth but on the destiny that has been arbitrarily assigned to him by God. In this light, the salvation of man rests heavily on the arbitrary and preordained judgment of God, for He has the right, the power, and the wisdom to do whatever he pleases. This sets forth the central tenet of Calvinism, which is predestination. The catechism of Calvinism is summarized into Five Points (Christ Covenant Sunday School 2009). An examination of each point will help elucidate some of the key issues related to Calvinism: firstly, the inherent nature of sin in relation to the work of Satan; secondly, the justification for the selection of the Elect; and lastly, Calvary and notion of limited atonement. 1. Total Depravity As described earlier, the whole being of man has been tainted by sin—his body, soul, intellect, will, and emotions. And because of this, man has lost his direct relation to God. Sin is deemed to be the activity of Satan. According to the bible, Satan is a fallen angel who lost his status due to perversion. His rebellion to God caused him to become the irreconcilable enemy of God. It can be stated, moreover, that Satan’s nature is marked by lies.2 His basic strategy of falsehood is intended not only to injure God, but also to destroy man. According to Calvin, however, the fall of man is his own responsibility. Although the conception of sin is formed by Satan, it is man that ultimately executed the act. As a result, man now bears the image of Satan and is now

Bombing Hiroshima and Nagasaki Essay Example | Topics and Well Written Essays - 1000 words

Bombing Hiroshima and Nagasaki - Essay Example The situation was similar to the initial years of World War II when Germany was annexing one country after another without any equitable resistance. Had not America dropped the two atomic bombs, in all likelihood, the war could have continued for weeks or months, adding to the miseries worldwide. Except for Russia, European powers had almost come to a standstill. The involvement of Russia in Japan had America not dropped the bombs, could easily have made the conflict bloodier and more widespread. It is debatable whether so many lives could have been lost had Russia invaded Japan. However, it is certain the conflict could have dragged on longer in such an eventuality. While other powers of the Axis viz, Germany and Italy had been vanquished, the battle with Japan was far from over. Japan was holding to ransom the rest of the world through its brazen show of power. Nothing seemed to hold the Japanese march. In spite of suffering reverses, Japan held on and was in no hurry to surrender. The Japanese juggernaut was so strong that it held most of Far East Asia. However, at the closing stage, Japan was losing its grip although it was not ready to admit defeat. Japan was given enough time and incentive to surrender. The Potsdam Proclamation issued on July 26, 1945, was very clear about the ramifications in the event of no surrender. The ultimatum declared, "We call upon the government of Japan to proclaim now the unconditional surrender of all Japanese armed forces, and to provide proper and adequate assurances of their good faith in such action. The alternative for Japan is prompt and utter destruction" (Bill Gordon, 2000). But Japan did not surrender. The Japanese, or those at the helm in Japan, were in no mood to listen. They may have been materially demolished, but mentally they had enough capacity to fight on. It took two atomic bombs and a week later, Japan surrendered and that too on the prompting of the emperor. I am not condoning the horrors of the atomic bombs. America had other alternatives besides the atomic bombs. But it is debatable if these alternatives could have worked and produced the same results that the atomic bombs did. The alternatives were these: "(1) use in manner most effective from a military point of view to bring about prompt Japanese surrender while minimizing the loss of American lives, (2) give military demonstration to Japan with opportunity for surrender before full use of weapon, (3) give experimental demonstration in this country with opportunity for surrender before full use of weapon, (4) do not use militarily but make public the experimental results, or (5) maintain as secret as possible and refrain from using the bombs in the war. President Truman chose alternative 1, even though only 15 percent of the scientists supported it" (Bill Gordon, 2000). President Truman's choice of alternative 1 was at best akin to mercy killing. However beastly this alternative might have appeared, it is difficult to fathom the efficacy of any other alternative. Japan needed a live demonstration. Even after the atomic bombs were dropped Japan dithered on the decision to surrender. It was only at the intervention of the Japanese

I am not sure about the subject that i used, but you have to put the Assignment

I am not sure about the subject that i used, but you have to put the right subject for each - Assignment Example This comes in the wake of different cases around the nation where officers are seen to manhandle or mistreat people from minority groups, with some even leading to the death of the said individuals (Schmidt 1). The issue of hate crimes has been a topic that is often discussed in hushed tones in various areas in the United States. In yet another different online article, The Guardian dated 10 Feb. 2015, three individuals were sentenced to prison for alleged hate crimes that led to the death of one James Craig Anderson. In the wake of these allegations, it later emerged that a group of white people would go to Jackson to pester, harass, and assault black people. Others were waiting sentencing stemming from the same hate crimes and conspiracy to do the same against nonwhites (AP 1). After a series of attacks by both white police officers and civilians, it has become necessary for major newspapers around the nation to highlight what is happening, and what should be done about it. It is clear that race is still an issue that most people are battling with, and with the rising number of cases, the attitude and mentality of everyone involved needs to change. This is for the betterment of society and everyone involved in making it prosper. It is my belief that whenever minority groups hear of such cases, there is bound to be traces of anger, bitterness, and resentment towards the other race, especially when perpetrators are not brought to book. It is about time people realize that society is made up of all races, and not just the whites. Associated Press, Jackson Mississippi. â€Å"Three sentenced in Mississippi for ‘Hate Crime’ Murder of Black Man.† The Guardian 10 Feb. 2015. Print. Schmidt, Michael S. â€Å"F.B.I. Director to Give Speech Addressing Relations between Police and

AMERICAN HISTORY SINCE 1865 TO 1900 Essay Example | Topics and Well Written Essays - 1250 words

AMERICAN HISTORY SINCE 1865 TO 1900 - Essay Example Nikon and Kennedy was elected president. John F. Kennedy and his vice president, Lyndon B. Johnson took the office in 1961. There has always been a power struggle between the left and right wing of politics, the political left stood up for social policies that would help the working class, the business and industry where as the political right is all for the conservative Christian values and support a free market system. The democrats who had won the election in 1960 were the party at the center; they faced a lot of opposition from the republicans including the most significantone that the elections were rigged and Kennedy falsely won the elections. Posner in one of his article mentioned that when the Kennedy votes suddenly rose by 40,000 in Texas the republicans cried that this was election fraud, he also wrote, â€Å"while he was careful not to put a public imprimatur on the concerted Republican effort to challenge the election results, he privately not only authorized it, but act ively encouraged it† (Posner). After the assassination of Kennedy his vice president Lyndon B. Johnson took the oval office by defeating Barry Goldwater; a nominee of the Republican Party in 1964. After the New Deal Coalition collapsed in the mid-sixties, the riots and the Vietnam War and the opposition of the civil rights movement by many southern democrats the republicans found a way to gain power, this shifted the southern power that Democrats had into the laps of the republicans as many African Americans were now supporting the Democratic Party. This power shift was also due to the Johnson’s increasing interest in The Vietnam war, which leaded to conflicts inside the Democratic Party. And in the election of 1968 the Republican Party won; Richard Nixon defeated Huber H. Humphrey and became the president of United States. It was in the final years of the American Civil War, when congress started to debate for the rights of the former freed

The second World War Essay Example for Free

The second World War Essay D-day was heralded as first enormous invasion of the allied on German claimed soil. The army generals and the government wanted to give the impression of complete power and might in their final push to abolish the Nazi slavery of Europe now they had the backing of America and Canada. It was perceived as almost a religious crusade, as though God was supporting their every move so it couldnt possibly fail. This confidence and sense of glory made the war seem more justifiable as people felt they were serving the righteous side. People on the home front were well informed of the fact the British were not defending but were on the offensive, this change in situations inspired people on the home front who were growing tired of the continuing news on the Atlantic battles and artillery battles. This mighty push was seen as courageous and raised peoples hope that the end was nigh. Churchill was in charge and was organising the campaign at this crucial juncture so the whole nation was on tenterhooks to receive his commands. The nation was made to feel everything depended on this mission, as it flooded the press. This encouraged the country to work even harder to achieve this goal and also worry less about the long-term situation as they were focusing on the present. When the troops landed on the coast of France and Normandy it was seen as histories greatest oversees operation which was true, but also glossed over the fact that they still had a bloody battle at a disadvantaged position once they reached mainland. Evacuation The war was expected several years before 1939 and preparations were already taking place before its declaration to move children into more rural and predicted safer areas. Away from the densely populated cities and industrial places where German bombers would likely target when the war commenced. Other preparations were made to limit causalities in the of air raids and predicted gas attacks; gas masks were compulsory items to have, thousands of Anderson shelters were erected for people to hide in during raids, rationing began to help soldiers and make sure everyone was kept healthy, the local defence volunteers and many other similar organisations were established to help and warn people in raids, signals e. g.sirens were created and the blackout was enforced to prevent German pilots from pinpointing a certain location. The community were encouraged to be involved in all these preparations, which also made them aware of the imminent threat posed by bombing thus persuading them to leave their children in the houses of strangers. In 1939 there was the largest mass evacuation of people in Britains history, from major cities and 3. 5 million people were arranged to be evacuated to reception areas. Most were normal children, others from schools and hospitals etc. This huge amount of people who were confused and uneducated about the situation inevitably posed many problems to the process. For a start most people had no idea of where they were heading, for they were not told before hand and the number of evacuees far out numbered the people willing to house them. This was all due to poor organisation by the government, despite notifying people about the plans months before. But considering the sheer amount of people involved the process run smoothly in the governments perspective and many evacuations worked with out a hitch. The government had also set up first aid stations showing they were obviously attempting to cope with all the inevitable problems that would arise. Many very poor children would arrive at reception areas with various health conditions such as scabies, lice and due to cold weather and lack of adequate clothing cold burns often formed. The clinics provided basic care before they were sent to hosts. On their identity cards they has health related information and often the kids that appeared unhealthy would be unfairly treated and hosts would be less likely to want them. The government tried to persuade families to separate from their loved ones by using propaganda. The predictions of casualties e. g. 4,000,000 in London far surpassed the actual figures and were there fore grossly exaggerated. Britain had been expecting air attacks for many years as the hostilities and threats had been building for several years before the war. Leaflets and Posters were important techniques of spreading their message about the evil extent Hitler would undertake to achieve his aims. This, initially discouraging and potential fear mongering way, proved to be effective as people were more intensely willing to participate in order to save their people and foil Hitlers plans to destroy public morale. The fact they used propaganda so wide spread proves people obviously needed a lot of convincing and the dark nature of the propaganda ( as in source B7 ) suggests the government were desperate to make an impact in order to attain their goal of the complete evacuation of children from cities. Subsequently when dealing with three million people there were many cases of disaster where the propaganda had inflicted panic instead of the hoped controlled movement. Sir John Anderson who as organising evacuation did not help this emotional upheaval, as he had a cold and detached not understanding nature. Evacuation was established to firstly protect people especially children from the threat of bombing. Children were obviously the most crucial group of people for they would continue the next generation. This also kept morale high as people in battle and working at home knew their children were safe and didnt have to worry about them being killed or injured in air raids. It also allowed rural communities not involved so much in the war effort feel occupied and of use thus supporting positive morale in these areas too. However, the fact that children were sent to random homes meant that they had to deal with whatever situation they were landed in, often their were clashes of class and social statue, sometimes this resulted in a positive outcome as poor children found themselves in welcoming circumstances. This sudden mix of classes had never occurred before, as people who lived totally separate and different life styles had to live side by side and deal with the prejudice that had been fed to them through society over countless generations. This new perspective to life sometimes highlighted the conflicts between people but often created a sense of unity in the face of a common enemy. This mystery of a new experience often initially excited children and many had a very interesting and free time when away from the city and the stress and restraints that went with it. Others, particularly younger children missed their homes and parents dreadfully and did not enjoy the peculiar circumstances they were forced into. The children themselves were all labelled so they could be identified and told to take a few essential possessions. When they reached the trains stations and bus stations they were filed onto the transport and many were separated from their parents and placed into groups with a guardian of one of the 100,000 teachers participating. Over 3,000,000 were evacuated in the first 4 days of September, which by any terms is an astonishing feat of organisation and co-ordination. When the order was sent at 11:07 August 31st few imagined that within a week a quarter of the population would have been evacuated. The stations were dense with people saying their good byes or finding luggage or lost siblings, this caused great confusion and the distress of moving to an unknown location built up tensions of fear resulting in anger. Smaller children who didnt understand the situation must have felt distraught at leaving their parents, these early traumatic experiences must have left deep impressions, especially as many were ignorant to when they would return. Others simply found it an exhilarating adventure and treated it like a holiday, particularly those who went to boarding schools. Those in the poverty stricken slums of the cities jumped at the opportunity to go to the country. Obviously in a movement this massive there was a great variation in opinions and attitudes towards evacuation but the underlying intension was similar for most people as they had seen the effects of severe bombing in other parts of the world-; do whats best for the country and its future unsurprisingly seemed the most important plan of action. This overall idea allowed stereotypical images to develop in peoples minds over how children had to deal with the situation e. g. Grin and bear it and dont complain. When reaching the reception areas local councils would line up the children and hosts simply picked their favourite. As this was often based on superficial first impressions many children were left feeling rejected and humiliated, this seemed a rudimentary way of selecting people, but in the end left no muddle over names and identities and matching people up. This random selection and the lack of restriction to who hosts could be occasionally left vulnerably children in dangerous hands of abusers. Because it was simply luck of the draw some had equally great experiences as expected and it is clear that only a minority, once settled had a miserable time. Ministry of health reporters issued statements declaring a glossy positive outlook of evacuation, so as not to worry the people and also the government, allowing people to begin concentrating no the more imminent problems of combat in war. Generally this statement is true as the main motivation to evacuate such large numbers was to save lives and this certainly worked, as the millions of estimated causalities did not happen and the country could run more smoothly because of this conclusion. In most cases people were more at ease with their childrens safety and there fore could focus on work and soldiers on the battle front. Women The Second World War affected the lives of women dramatically. Since the late 1800s women like the suffragettes had been protesting for womens rights as they were discontented with societies attitude to women as being inferior and demanded more equality between the sexs. Although through the early 1920s women did gain the right to vote and became more acceptable in some work arenas e. g. nurses clerks typists (jobs considered appropriate for women), the opportunities had only opened slightly, but the reality was most women performed exactly the same role as previously. However, many women were settled in the traditional way of life they led and felt the home was their first priority and there fore didnt particularly feel the necessity to change. The government realised that due to the unusual circumstances it would be most practical to enrol the services of women to fill the occupation vacancies in industry whilst vast numbers of men were recruited into war. Originally many government ministers were reluctant to conscript women in to work, arguing that a womans responsibilities were in the home caring for children. However, as more men left it became more important to keep the country producing munitions etc. instead of women simply staying at home, so the government lead by chamberlain agreed to ask for womens volunteer assistance. They made a national campaign advertising for help in a huge range of jobs, using posters, billboards, leaflets etc and encouraged applicants by saying it was imperative for the war effort. Many people were initially surprised at the unprecedented mass surge of women who signed up for industry working and the land army. Particularly after the depression of the thirties many working class women jumped at the new opportunities that had aroused and were motivated by the promise of money of their own. A minority of women objected to war work believing it detracted from their house work and others detested the prejudice that occurred and the lack of equal treatment; the fact women were paid 60% of an equivalent male employer, this proves how women were seen as less productive and skilled as a man. It also shows how society expected women to work for the good of the nation even with lower wages and how most women just accepted this. Many women who enrolled for work had never been away from home or worked for an income before and took on the new opportunities with enthusiasm and determination. The country was finally willingly giving women the chance to show their capability to perform in areas they had never had access to previously, this encouraged women to work to their limits. Government officials made reports of the exceptional standard of work occurring in the factories by newly appointed women and how it equalled if not excelled that of the prior male labourers. The new work and money entitled women to be more independent and opinionated. As they become more liberated and confident in their positions, some began to demand more equality for they realised the worth of their aid. The whole population became more and more involved in the war effort and the new workforce was described as soldiers with different weapons, hence the name given to this condition total war. Women in the home looking after the family also found themselves in new situations as the head of the family was always the man or husband and in most cases he had been sent to war. These women now had to organise and take the responsibilities of the man; they were now the dominant figure in the family, which had hardly ever occurred before. The decisions women made were complicated by the limitations of the rationing of food, clothing and general materials. They were in charge of the ration booklets for the family and had to pool all the coupons they received to obtain food and other items. Because civilians were targeted during the war they also had to deal with temporary housing, evacuation and ensuring everyone was safe during bombing raids. Often women like this joined the local civil defence or nursing posts to help their community. They were depended on to manage serious situations in bombing raids and such like, that before the war would have been considered too important to be arranged by a woman. Many women there fore felt more appreciated and occupied than previously, so wanted to contribute. The government enthused this attitude by using positive propaganda suggesting how useful and essential womens work was. Posters of physically fit women doing hard jobs and showing satisfaction in their work were often used. This rose the morale of many women and made them more unified with the war effort which obviously helped in the manufacturing of munitions, saving food for soldiers, keeping the economy stable and saving lives on the home front. Many were encouraged to attend USO balls where they danced and befriended lonely soldiers, young women had freedom social as well, and this also allowed them to enjoy the war and the new experiences it entailed. Due to the new independence women had acquired some found themselves more sexually liberated and due to their uneducated and ignorant ideas of sex found themselves in difficult positions with no one to understand or express their feeling to. The government at the time did not think to inform women about sex and its possibly consequences, so occasionally there were cased of illegitimate children being born and mothers being shamed by their peers. However, the government did publish leaflets containing information on ways to become self sufficient e. g.growing vegetables making food that was healthy and of good value, being resourceful with all house hold equipment, making suitable cloths and recycling materials etc. all these suggestions aided women in their duties and showed how they could be generally more efficient. Government posters were used to make people, especially women aware of the consequences of wasting products in a time of shortages e. g. the cartoon character squander bug. Posters were also produced highlighting the significance of not discussing the war in public in case German secret agents were listening. All these legitimate warnings kept peoples minds focused on why they were doing what they were doing and there fore prevented opposition from other people who didnt agree with women having the authority they did. All the concerns and anxieties over what was socially acceptable made the war an exciting yet confusing time for women. They had to combine their traditional values with this new independence, but also keep in mind it was a temporary situation and whatever happened in their lives now was likely to change again when the men returned from war.

Digital Signal Processing (DSP) and CDMA Advantages

Digital Signal Processing (DSP) and CDMA Advantages INTRODUCTION ANALOG AND DIGITAL SIGNALS The signal is initially generated is in the form of an analog electrical voltage or current, produced for example by a microphone or some other type of transducer. The output from the readout system of a CD (compact disc) player, the data is already in digital form. An analog signal must be converted into digital form before DSP techniques can be applied. An analog electrical voltage signal, for example, can be digitized using an electronic circuit called an analog-to-digital converter or ADC. This generates a digital output as a stream of binary numbers whose values represent the electrical voltage input to the device at each sampling instant. Digital signal processing (DSP)-digital representation of signals and the use of digital processors to analyze, modify, or extract information from signals. Many signals in DSP are derived from analogue signals which have been sampled at regular intervals and converted into digital form. The key advantages of DSP over analogue processing are Guaranteed accuracy (determined by the number of bits used) Perfect reproducibility No drift in performance due to temperature or age Takes advantage of advances in semiconductor technology Greater flexibility (can be reprogrammed without modifying hardware) Superior performance (linear phase response possible, and filtering algorithms can be made adaptive) Sometimes information may already be in digital form. There are however (still) some disadvantages Speed and cost (DSP design and hardware may be expensive, especially with high bandwidth signals) Finite word length problems (limited number of bits may cause degradation). Application areas of DSP are considerable: Image processing (pattern recognition, robotic vision, image enhancement, facsimile, satellite weather map, animation) Instrumentation and control (spectrum analysis, position and rate control, noise reduction, data compression) Speech and audio (speech recognition, speech synthesis, text to speech, digital audio, equalisation) Military (secure communication, radar processing, sonar processing, missile guidance) Telecommunications (echo cancellation, adaptive equalisation, spread spectrum, video conferencing, data communication) Biomedical (patient monitoring, scanners, EEG brain mappers, ECG analysis, X-ray storage and enhancement). INTRODUCTION TO CDMA Code Division Multiple Access (CDMA) is a radically new concept in wireless communications. It has gained widespread international acceptance by cellular radio system operators as an upgrade that will dramatically increase both their system capacity and the service quality. It has likewise been chosen for deployment by the majority of the winners of the United States Personal Communications System spectrum auctions. It may seem, however, mysterious for those who arent familiar with it. CDMA is a form of spread-spectrum, a family of digital communication techniques that have been used in military applications for many years. The core principle of spread spectrum is the use of noise-like carrier waves, and, as the name implies, bandwidths much wider than that required for simple point-to-point communication at the same data rate. Originally there were two motivations: either to resist enemy efforts to jam the communications (anti-jam, or AJ), or to hide the fact that communication was even taking place, sometimes called low probability of intercept (LPI). It has a history that goes back to the early days of World War II. The use of CDMA for civilian mobile radio applications is novel. It was proposed theoretically in the late 1940s, but the practical application in the civilian marketplace did not take place until 40 years later. Commercial applications became possible because of two evolutionary developments. One was the availability of very low cost, high density digital integrated circuits, which reduce the size, weight, and cost of the subscriber stations to an acceptably low level. The other was the realization that optimal multiple access communication requires that all user stations regulate their transmitter powers to the lowest that will achieve adequate signal quality. CDMA changes the nature of the subscriber station from a predominately analog device to a predominately digital device. Old-fashioned radio receivers separate stations or channels by filtering in the frequency domain. CDMA receivers do not eliminate analog processing entirely, but they separate communication channels by means of a pseudorandom modulation that is applied and removed in the digital domain, not on the basis of frequency. Multiple users occupy the same frequency band. This universal frequency reuse is not fortuitous. On the contrary, it is crucial to the very high spectral efficiency that is the hallmark of CDMA. Other discussions in these pages show why this is true. CDMA is altering the face of cellular and PCS communication by: Dramatically improving the telephone traffic capacity Dramatically improving the voice quality and eliminating the audible effects of multipath fading Reducing the incidence of dropped calls due to handoff failures Providing reliable transport mechanism for data communications, such as facsimile and internet traffic Reducing the number of sites needed to support any given amount of traffic Simplifying site selection Reducing deployment and operating costs because fewer cell sites are needed Reducing average transmitted power Reducing interference to other electronic devices Reducing potential health risks Commercially introduced in 1995, CDMA quickly became one of the worlds fastest growing wireless technologies. In 1999, the International Telecommunications Union selected CDMA as the industry standard for new third-generation (3G) wireless systems. Many leading wireless carriers are now building or upgrading to 3G CDMA networks in order to provide more capacity for voice traffic, along with high-speed data capabilities. DS_CDMA Multiple access systems based on DS CDMA have achieved increasing significance for mobile communications applications. A promising concept is based on DS_CDMA applying MRC at the receiver. MRC takes advantage of the channel diversity to combat the multipath fading. However the capacity of a DS_CDMA system is limited by both multi-user interference and inter symbol interference ISI in high data rate applications. OFDM is applied to combat the frequency selectivity of the channel using a simple one tap equalizer Further more OFDM prevents the ISI and inter carrier interference ICI by inserting a guard interval between adjacent OFDM symbols OFDM is typically used for audio TV and HDTV transmission over terrestrial channels and achieves high spectral efficiency. The CMDA Technology overview FDMA In Frequency Division Multiple Access, the frequency band is divided in slots. Each user gets one frequency slot assigned that is used at will. It could be compared to AM or FM broadcasting radio where each station has a frequency assigned. FDMA demands good filtering. TDMA In Time Division Multiple Access, the frequency band is not partitioned but users are allowed to use it only in predefined intervals of time, one at a time. Thus, TDMA demands synchronization among the users. CDMA CDMA, for Code Division Multiple Access, is different from its traditional ways in which it does not allocate frequency or time in user slots but gives the right to use both to all users simultaneously. To do this, it uses a technique known as Spread Spectrum . In effect, each user is assigned a code,which spreads its signal bandwidth in such a way that only the same code can recover it at the receiver end. This method has the property that the unwanted signals with different codes get spread even more by the process, making them like noise to the receiver . Spread Spectrum Spread Spectrum is a mean of transmission where the data occupies a larger bandwidth than necessary. Bandwidth spreading is accomplished before the transmission through the use of a code, which is independent of the transmitted data. The same code is used to demodulate the data at the receiving end. The following figure illustrate the spreading done on the data signal x(t) by the spreading signal c(t) resulting in the message signal to be transmitted, m(t). Originally for military use to avoid jamming (interference created on purpose to make a communication channel unusable), spread spectrum modulation is now used in personal communication systems for its superior performance in an interference dominated environment . Definition of Spread Spectrum: A transmission technique in which a pseudo-noise code, independent of the information data, is employed as a modulation waveform to â€Å"spread† the signal energy over a bandwidth much greater than the signal information bandwidth. At the receiver the signal is â€Å"despread† using a synchronized replica of the pseudo-noise code. Basic Principle of Spread Spectrum System: The Principal types of Spread Spectrum are Direct Sequence (DS), and Frequency Hopping (FH). An over view of these systems is hereby given: Pseudo shift of the phase pseudo shift of the frequency Coherent demodulation noncoherent Direct Sequence Spread Spectrum (DSSS) A pseudo-noise sequence pnt generated at the modulator, is used in conjunction with an M-ary PSK modulation to shift the phase of the PSK signal pseudo randomly, at the chipping rate Rc (=1/Tc) a rate that is integer multiple of the symbol rate Rs (=1/Ts). The transmitted bandwidth is determined by the chip rate and by the base band filtering. The implementation limits the maximum chip rate Rc (clock rate) and thus the maximum spreading. The PSK modulation scheme requires a coherent demodulation. PN code length that is much longer than a data symbol, so that a different chip pattern is associated with each symbol. Frequency Hopping Spread Spectrum A Pseudo-noise sequence pnt generated at the modulator is used in conjuction with an M-ary FSK modulation to shift the carrier frequency of the FSK signal pseudurandomly, at the hopping rate Rh. The transmitted signal occupies a number of frequencies in time, each for a period of time Th (= 1/Rh), referred as dwell time. FHSS divides the available bandwidth into N channels and hops between these channels according to the PN sequence. At each frequency hop time the PN generator feeds the frequency synthesizer a frequency word FW (a sequence of n chips) which dictates one of 2n frequency position fhl . Transmitter and receiver follows the same frequency hop pattern. The transmitted bandwidth is determined by the lowest and highest hop position by the bandwidth per hop position (à ¢Ã‹â€ Ã¢â‚¬  fch). For a given hop, instantaneous occupied bandwidth is the conventional M-FSK, which is typically much smaller than Wss. So the FHSS signal is a narrowband signal, all transmission power is concentrated on one channel. Averaged over many hops, the FH/M-FSK spectrum occupies the entire spread spectrum bandwidth. Because the bandwidth of an FHSS system only depends on the tuning range, it can be hopped over a much wider bandwidth than an DSSS system. Since the hops generally result in phase discontinuity (depending on the particular implementation) a noncoherent demodulation is done at receiver. With slow hopping there are multiple data symbol per hop and with fast hopping there are multiple hops per data symbol. 3.3 Basic principle of Direct Sequence Spread Spectrum For BPSK modulation the building blocks of a DSSS system are: Input: Binary data dt with symbol rate Rs = 1/Ts (=bitrate Rb for BPSK) Pseudo-noise code pnt with chip rate Rc = 1/Tc (an integer of Rs) Spreading: In the transmitter, the binary data dt (for BPSK, I and Q for QPSK) is ‘directly multiplied with the PN sequence pnt , which is independent of the binary data, to produce the transmitted baseband signal txb: txb = dt . pnt The effect of multiplication of dt with a PN sequence is to spread the baseband bandwidth Rs of dt to a baseband bandwidth of Rc. Despreading: The spread spectrum signal cannot be detected by a conventional narrowband receiver. In the receiver, the baseband signal rxb is multiplied with the PN sequence pnr . If pnr = pnt and synchronized to the PN sequence in the received data, than the recovered binary data is produced on dr. The effect of multiplication of the spread spectrum signal rxb with the PN sequence pnt used in the transmitter is to despread the bandwidth of rxb to Rs . If pnr ≠  pnt , than there is no dispreading action. The signal dr has a spread spectrum. A receiver not knowing the PN sequence of the transmitter can not reproduce the transmitted data. Performance in the presence of interference: To simplify the presence of interference, the spread spectrum system is considered for baseband BPSK communication (without filtering). The received signal rxb of the transmitted signal txb plus an additive inteferance i (noise, other users, jammer,†¦Ã¢â‚¬ ¦): rxb = t xb + i = dt . pnt + i To recover the original data dt the received signal rx0 is multiplied with a locally generated PN sequence pnr that is an exact replica of that used in the transmitter (that is pnr = pnt and synchronized) The multiplier output is therefore given by: dr = rxb . pnt = dt . pnt . pnt + i . pnt The data signal dt is multiplied twice by the PN sequence pnt , where as the unwanted inteferance i is multiplied only once. Due to the property of the PN sequence: pnt + pnt = +1 for all t The multiplier output becomes: dr = dt + i . pnt The data signal dr is reproduced at the multiplier output in the receiver, except for the inteferance represented by the additive term i . pnt . Multiplication of the inteferance by the locally generated PN sequence, means that the spreading code will affect the inteferance just as it did with the information bearing signal at the transmitter. Noise and inteferance, being uncorrelated with the PN sequence, becomes noise-like, increase in bandwidth and decrease in power density after the multiplier. After dispreading, the data component dt is narrow band (Rb) whereas the inteferance component is wideband (Rc). By applying the dr signal to a baseband (low-pass) filter with a band width just large enough to accommodate the recovery of the data signal, most of the inteferance component i is filtered out. The effect of inteferance is reduced by processing gain (Gp). Narrowband inteferance: The narrowband noise is spread by the multiplication with the PN sequence pnr of the receiver. The power density of the noise is reduced with respect to the despread data signal. Only 1/Gp of the original noise power is left in the information baseband (Rs). Spreading and dispreading enables a bandwidth trade for processing gain against narrow band interfering signals. Narrow band inteferance would disable conventional narrow band receivers. The essence behind the inteferance rejection capability of a spread spectrum system: the useful signal (data) gets multiplied twice by the PN sequence, but the inteferance signal get multiplied only once. Wideband interference: Multiplication of the received signal with the PN sequence of the receiver gets a selective despread of the data signal (smaller bandwidth, higher power density). The inteferance signal is uncorrelated with the PN sequence and is spread. Origin of wideband noise: Multiple Spread Spectrum user: multiple access mechanism. Gaussian Noise: There is no increase in SNR with spread spectrum: The large channel bandwidth (Rc instead of Rs) increase the received noise power with Gp: Ninfo = N0 . BWinfo à   Nss = N0 . BWss = Ninfo .Gp The spread spectrum signal has a lower power density than the directly transmitted signal. Code division multiple access (CDMA) is a methode of multiplexing (wireless) users distinct (orthogonal) codes. All users can transmit at the same time, and each is allocated the entire available frequency spectrum for transmission. CDMA is also known as Spread-Spectrum multiple access (SSMA). CDMA dose not require the bandwidth allocation of FDMA, nor the time synchronization of the individual users needed in TDMA. A CDMA user has full time and full bandwidth available, but the quality of the communication decreases with an increasing number of users (BER ). In CDMA each user: Has its own PN code Uses the same RF bandwidth Transmits simultaneously (asynchronous or synchronous) Correlation of the received baseband spread spectrum signal rxb with the PN sequence of user 1 only despreads the signal of user 1. The other user produces noise Nu for user 1. ACCESS SCHEMES For radio systems there are two resources, frequency and time. Division by frequency, so that each pair of communicators is allocated part of the spectrum for all of the time, results in Frequency Division Multiple Access (FDMA). Division by time, so that each pair of communicators is allocated all (or at least a large part) of the spectrum for part of the time results in Time Division Multiple Access (TDMA). In Code Division Multiple Access (CDMA), every communicator will be allocated the entire spectrum all of the time. CDMA uses codes to identify connections. MULTIPATH AND RAKE RECEIVERS One of the main advantages of CDMA systems is the capability of using signals that arrive in the receivers with different time delays. This phenomenon is called multipath. FDMA and TDMA, which are narrow band systems, cannot discriminate between the multipath arrivals, and resort to equalization to mitigate the negative effects of multipath. Due to its wide bandwidth and rake receivers, CDMA uses the multipath signals and combines them to make an even stronger signal at the receivers. CDMA subscriber units use rake receivers. This is essentially a set of several receivers. One of the receivers (fingers) constantly searches for different multipaths and feeds the information to the other three fingers. Each finger then demodulates the signal corresponding to a strong multipath. The results are then combined together to make the signal stronger. Difference between TDMA vs CDMA. TDMA is Time Division Multiple Access, while CDMA is Code Division Multiple Access. Both technologies achieve the same goal of better utilization of the radio spectrum by allowing multiple users to share the same physical channel, but by using different methods and that is why the three of the four words in each acronym are identical. Both allow more than one person to carry out a conversation on the same frequency without causing interference. The two technologies differ in the way in which users share the common resource. In TDMA the channel is chopped up into sequential time slices. The data of each user is put on the channel in a round-robin fashion. In reality, only one user actually uses the channel at any given point of time, but he uses it only for short bursts. He then gives up the channel for a short duration to allow the other users to have their turn. This is similar to how a computer with just one processor runs multiple applications simultaneously. CDMA on the other hand allows everyone to transmit at the same time. With conventional methods of modulation techniques it would hav been simply not possible. What makes CDMA to allow all users to transmit simultaneously is a special type of digital modulation called Spread Spectrum. In this modulation technique users stream of bits is taken and splattered them across a very wide channel in a pseudo-random fashion. The pseudo part is very important here as at the receiver end the randomization must be undone in order to collect the bits together in a coherent order. For example consider a room full of couples, and each couple trying to carry on one-on-one conversations. In TDMA each couple takes their turn for talking and they keep their turns short by speaking only one sentence at a time. As there is always more one person speaking in the room at any given point of time, no one has to worry about being heard over the background din. In CDMA assume each couple talks simultaneously, but they all use different languages. The background din doesnt cause any real problem as none of the listeners understand any language other than that of the individual to whom they are listening. Voice Encoding At this point many people confuse two distinctly different issues involved in the transmission of digital audio. The first is the WAY in which the stream of bits is delivered from one end to the other. This part of the air interface is what makes one technology different from another. The second is the compression algorithm used to squeeze the audio into as small a stream of bits as possible. This latter component is known at the Voice Coder, or Vocoder for short. Another term commonly used is CODEC, which is a similar word to modem. It combines the terms COder and DECoder. Although each technology has chosen their own unique CODECs, there is no rule saying that one transmission method needs to use a specific CODEC. People often lump a technologys transmission method with its CODEC as though they were single entities. Voice encoding schemes differ slightly in their approach to the problem. Because of this, certain types of human voice work better with some CODECs than they do with others. The point to remember is that all PCS CODECs are compromises of some sort. Since human voices have such a fantastic range of pitch and tonal depth, one cannot expect any single compromise to handle each one equally well. This inability to cope with all types of voice at the same level does lead some people to choose one technology over another. All of the PCS technologies try to minimize battery consumption during calls by keeping the transmission of unnecessary data to a minimum. The phone decides whether or not you are presently speaking, or if the sound it hears is just background noise. If the phone determines that there is no intelligent data to transmit it blanks the audio and it reduces the transmitter duty cycle (in the case of TDMA) or the number of transmitted bits (in the case of CDMA). When the audio is blanked your caller would suddenly find themselves listening to dead air, and this may cause them to think the call has dropped. To avoid this psychological problem many service providers insert what is known as Comfort Noise during the blanked periods. Comfort Noise is synthesized white noise that tries to mimic the volume and structure of the real background noise. This fake background noise assures the caller that the connection is alive and well. However, in newer CODECs such as EVRC (used exclusively on CDMA systems) the background noise is generally suppressed even while the user is talking. This piece of magic makes it sound as though the cell phone user is not in a noisy environment at all. Under these conditions, Comfort Noise is neither necessary, nor desirable. DS-CDMA-INTRODUCTION While multiple access interference (MAI) by other users has been recognized as the capacity-limiting factor in direct sequence code-division multiple-access (DS-CDMA)-based cellular communication systems, multiuser approaches have largely alleviated the problem when the noise process is additive Gaussian. With the availability of multiuser detectors, inaccurate or inappropriate noise modelling assumptions seem to have become the issue again. Whereas multiuser detection has much to offer in the mobile- to-base station uplink, it does not at present appear to be feasible for the downlink due to the complexity involved and the lack of resistance against adjacent cell interference. Moreover, the few multiuser proposals for the downlink require the knowledge of all spreading codes, which is not possible in the tactical military environment, for instance. Enhanced single-user receivers equipped with adaptive filter banks deliver promising performance with reasonable complexity, especially in slowly varying channels. Thus, the performance of single-user detectors is still of interest, particularly in the presence of non-Gaussian noise. In both urban outdoor and indoor mobile radio environments, electromagnetic interference generated by man-made sources such as factories or power lines causes the noise to be of non-Gaussian nature. Large noise magnitudes are deemed very improbable by linear receivers, and consequently performance deterioration is experienced. It is therefore desirable to build systems that can maintain respectable functionality under a broad class of noise distributions, rather than strictly optimizing for the unrealistic Gaussian assumption. Such is the goal of robust detection and estimation theory, which aims to design systems that are suboptimal under nominal channel conditions (e.g., Gaussian channel) and yet do not face catastrophy when the noise distribution is not nominal (e.g., unlike linear schemes). Note that suboptimality here refers to very good performance that is slightly worse than that of the nominal-optimal detector/estimator. The direct sequence code division multiple access (DS-CDMA) technique has been favourably considered for application in digital mobile cellular networks due to its potential to provide higher system capacity over conventional multiple access techniques. Unlike FDMA and TDMA capacities which are mostly limited by the bandwidth, the capacity of a CDMA system is mainly restricted by its interference level. Any reduction in interference produces a direct and linear increase in system capacity. Multiple access interference (MAI) caused by non-zero cross-correlation between different spreading sequences is the major type of interference limiting the CDMA system capacity. Much work has been done to characterize MAI, and to analyze and evaluate the CDMA system performance in the presence of MAI. Since the cross-correlation properties of most sets of spreading codes are either too complex to analyze or very difficult to compute when different transmissions are not synchronized, a random seque nce model. In the case of moderate to large processing gains, Gaussian distribution with variable variance is a good approximation for the MAI distribution. One of the approaches to reduce MAI is to employ orthogonal spreading sequences, and try to synchronize the transmissions at the chip level (quasi-synchronization). However, this is generally difficult to achieve in multipoint-to-point systems, such as the reverse link (mobile-to-base) of a cellular system, due to a lack of synchronization of the various mobile terminals, and the variable transmission delays. In this paper, a multi-carrier DS-CDMA (MCDS-CDMA) scheme is employed to facilitate the synchronization process, and thus reduce MAI. SYSTEM MODEL A model of the MS-DS-CDMA system for the kth user of a CDMA system is shown in the figure 1. TRANMSITTER MODEL At the transmitter the user‘s data stream dk(t) is divided into M interleaved sub streams and spread by a spreading sequence ck(t) to a fraction 1/M of the entire transmission bandwidth W. The resultant chip sequences are then used to modulate M carrier. The carrier frequencies ωm,m=1,2,M are equally spaced by the chip rate so that they are mutually orthogonal over one channel symbol interval T. Let R be the information rate and Rc be the carrier control code rate then the channel symbol interval is BER PERFORMANCE: MC-DS-CDMA system performance measured by bit error rate through analysis and simulation. Analysis: The BER is analysed based on the following: Ortoganal spreading sequences with rectangular pulse shape are applied. ÃŽ ¶k,k=1†¦K are independent of random variables distributd in (-ÃŽ ¶D,ÃŽ ¶D) WHERE ÃŽ ¶D=ÃŽ µD+Ï‚D.Given W and ÃŽ ¶D,M is chosen so that ÃŽ ¶D It is assumed that the fading parameters of the desired user . It is perfectly estimated so that the coherent detection and optimum soft decision decoding could be carried out at the receiver to make the problem analytically tractable. The fading amplitudes as independent Rayleigh random variables with equal second moments. The model is MATLAB INTRODUCTION: Matlab is a commercial Matrix Laboratory package which operates as an interactive programming environment. It is a mainstay of the Mathematics Department software lineup and is also available for PCs and Macintoshes and may be found on the CIRCA VAXes. Matlab is well adapted to numerical experiments since the underlying algorithms for Matlabs builtin functions and supplied m-files are based on the standard libraries LINPACK and EISPACK. Matlab program and script files always have filenames ending with .m; the programming language is exceptionally straightforward since almost every data object is assumed to be an array. Graphical output is available to supplement numerical results. IMREAD Read image from graphics file. A = IMREAD(FILENAME,FMT) reads a grayscale or color image from the file specified by the string FILENAME. If the file is not in the current directory, or in a directory on the MATLAB path, specify the full pathname. The text string FMT specifies the format of the file by its standard file extension. For example, specify gif Digital Signal Processing (DSP) and CDMA Advantages Digital Signal Processing (DSP) and CDMA Advantages INTRODUCTION ANALOG AND DIGITAL SIGNALS The signal is initially generated is in the form of an analog electrical voltage or current, produced for example by a microphone or some other type of transducer. The output from the readout system of a CD (compact disc) player, the data is already in digital form. An analog signal must be converted into digital form before DSP techniques can be applied. An analog electrical voltage signal, for example, can be digitized using an electronic circuit called an analog-to-digital converter or ADC. This generates a digital output as a stream of binary numbers whose values represent the electrical voltage input to the device at each sampling instant. Digital signal processing (DSP)-digital representation of signals and the use of digital processors to analyze, modify, or extract information from signals. Many signals in DSP are derived from analogue signals which have been sampled at regular intervals and converted into digital form. The key advantages of DSP over analogue processing are Guaranteed accuracy (determined by the number of bits used) Perfect reproducibility No drift in performance due to temperature or age Takes advantage of advances in semiconductor technology Greater flexibility (can be reprogrammed without modifying hardware) Superior performance (linear phase response possible, and filtering algorithms can be made adaptive) Sometimes information may already be in digital form. There are however (still) some disadvantages Speed and cost (DSP design and hardware may be expensive, especially with high bandwidth signals) Finite word length problems (limited number of bits may cause degradation). Application areas of DSP are considerable: Image processing (pattern recognition, robotic vision, image enhancement, facsimile, satellite weather map, animation) Instrumentation and control (spectrum analysis, position and rate control, noise reduction, data compression) Speech and audio (speech recognition, speech synthesis, text to speech, digital audio, equalisation) Military (secure communication, radar processing, sonar processing, missile guidance) Telecommunications (echo cancellation, adaptive equalisation, spread spectrum, video conferencing, data communication) Biomedical (patient monitoring, scanners, EEG brain mappers, ECG analysis, X-ray storage and enhancement). INTRODUCTION TO CDMA Code Division Multiple Access (CDMA) is a radically new concept in wireless communications. It has gained widespread international acceptance by cellular radio system operators as an upgrade that will dramatically increase both their system capacity and the service quality. It has likewise been chosen for deployment by the majority of the winners of the United States Personal Communications System spectrum auctions. It may seem, however, mysterious for those who arent familiar with it. CDMA is a form of spread-spectrum, a family of digital communication techniques that have been used in military applications for many years. The core principle of spread spectrum is the use of noise-like carrier waves, and, as the name implies, bandwidths much wider than that required for simple point-to-point communication at the same data rate. Originally there were two motivations: either to resist enemy efforts to jam the communications (anti-jam, or AJ), or to hide the fact that communication was even taking place, sometimes called low probability of intercept (LPI). It has a history that goes back to the early days of World War II. The use of CDMA for civilian mobile radio applications is novel. It was proposed theoretically in the late 1940s, but the practical application in the civilian marketplace did not take place until 40 years later. Commercial applications became possible because of two evolutionary developments. One was the availability of very low cost, high density digital integrated circuits, which reduce the size, weight, and cost of the subscriber stations to an acceptably low level. The other was the realization that optimal multiple access communication requires that all user stations regulate their transmitter powers to the lowest that will achieve adequate signal quality. CDMA changes the nature of the subscriber station from a predominately analog device to a predominately digital device. Old-fashioned radio receivers separate stations or channels by filtering in the frequency domain. CDMA receivers do not eliminate analog processing entirely, but they separate communication channels by means of a pseudorandom modulation that is applied and removed in the digital domain, not on the basis of frequency. Multiple users occupy the same frequency band. This universal frequency reuse is not fortuitous. On the contrary, it is crucial to the very high spectral efficiency that is the hallmark of CDMA. Other discussions in these pages show why this is true. CDMA is altering the face of cellular and PCS communication by: Dramatically improving the telephone traffic capacity Dramatically improving the voice quality and eliminating the audible effects of multipath fading Reducing the incidence of dropped calls due to handoff failures Providing reliable transport mechanism for data communications, such as facsimile and internet traffic Reducing the number of sites needed to support any given amount of traffic Simplifying site selection Reducing deployment and operating costs because fewer cell sites are needed Reducing average transmitted power Reducing interference to other electronic devices Reducing potential health risks Commercially introduced in 1995, CDMA quickly became one of the worlds fastest growing wireless technologies. In 1999, the International Telecommunications Union selected CDMA as the industry standard for new third-generation (3G) wireless systems. Many leading wireless carriers are now building or upgrading to 3G CDMA networks in order to provide more capacity for voice traffic, along with high-speed data capabilities. DS_CDMA Multiple access systems based on DS CDMA have achieved increasing significance for mobile communications applications. A promising concept is based on DS_CDMA applying MRC at the receiver. MRC takes advantage of the channel diversity to combat the multipath fading. However the capacity of a DS_CDMA system is limited by both multi-user interference and inter symbol interference ISI in high data rate applications. OFDM is applied to combat the frequency selectivity of the channel using a simple one tap equalizer Further more OFDM prevents the ISI and inter carrier interference ICI by inserting a guard interval between adjacent OFDM symbols OFDM is typically used for audio TV and HDTV transmission over terrestrial channels and achieves high spectral efficiency. The CMDA Technology overview FDMA In Frequency Division Multiple Access, the frequency band is divided in slots. Each user gets one frequency slot assigned that is used at will. It could be compared to AM or FM broadcasting radio where each station has a frequency assigned. FDMA demands good filtering. TDMA In Time Division Multiple Access, the frequency band is not partitioned but users are allowed to use it only in predefined intervals of time, one at a time. Thus, TDMA demands synchronization among the users. CDMA CDMA, for Code Division Multiple Access, is different from its traditional ways in which it does not allocate frequency or time in user slots but gives the right to use both to all users simultaneously. To do this, it uses a technique known as Spread Spectrum . In effect, each user is assigned a code,which spreads its signal bandwidth in such a way that only the same code can recover it at the receiver end. This method has the property that the unwanted signals with different codes get spread even more by the process, making them like noise to the receiver . Spread Spectrum Spread Spectrum is a mean of transmission where the data occupies a larger bandwidth than necessary. Bandwidth spreading is accomplished before the transmission through the use of a code, which is independent of the transmitted data. The same code is used to demodulate the data at the receiving end. The following figure illustrate the spreading done on the data signal x(t) by the spreading signal c(t) resulting in the message signal to be transmitted, m(t). Originally for military use to avoid jamming (interference created on purpose to make a communication channel unusable), spread spectrum modulation is now used in personal communication systems for its superior performance in an interference dominated environment . Definition of Spread Spectrum: A transmission technique in which a pseudo-noise code, independent of the information data, is employed as a modulation waveform to â€Å"spread† the signal energy over a bandwidth much greater than the signal information bandwidth. At the receiver the signal is â€Å"despread† using a synchronized replica of the pseudo-noise code. Basic Principle of Spread Spectrum System: The Principal types of Spread Spectrum are Direct Sequence (DS), and Frequency Hopping (FH). An over view of these systems is hereby given: Pseudo shift of the phase pseudo shift of the frequency Coherent demodulation noncoherent Direct Sequence Spread Spectrum (DSSS) A pseudo-noise sequence pnt generated at the modulator, is used in conjunction with an M-ary PSK modulation to shift the phase of the PSK signal pseudo randomly, at the chipping rate Rc (=1/Tc) a rate that is integer multiple of the symbol rate Rs (=1/Ts). The transmitted bandwidth is determined by the chip rate and by the base band filtering. The implementation limits the maximum chip rate Rc (clock rate) and thus the maximum spreading. The PSK modulation scheme requires a coherent demodulation. PN code length that is much longer than a data symbol, so that a different chip pattern is associated with each symbol. Frequency Hopping Spread Spectrum A Pseudo-noise sequence pnt generated at the modulator is used in conjuction with an M-ary FSK modulation to shift the carrier frequency of the FSK signal pseudurandomly, at the hopping rate Rh. The transmitted signal occupies a number of frequencies in time, each for a period of time Th (= 1/Rh), referred as dwell time. FHSS divides the available bandwidth into N channels and hops between these channels according to the PN sequence. At each frequency hop time the PN generator feeds the frequency synthesizer a frequency word FW (a sequence of n chips) which dictates one of 2n frequency position fhl . Transmitter and receiver follows the same frequency hop pattern. The transmitted bandwidth is determined by the lowest and highest hop position by the bandwidth per hop position (à ¢Ã‹â€ Ã¢â‚¬  fch). For a given hop, instantaneous occupied bandwidth is the conventional M-FSK, which is typically much smaller than Wss. So the FHSS signal is a narrowband signal, all transmission power is concentrated on one channel. Averaged over many hops, the FH/M-FSK spectrum occupies the entire spread spectrum bandwidth. Because the bandwidth of an FHSS system only depends on the tuning range, it can be hopped over a much wider bandwidth than an DSSS system. Since the hops generally result in phase discontinuity (depending on the particular implementation) a noncoherent demodulation is done at receiver. With slow hopping there are multiple data symbol per hop and with fast hopping there are multiple hops per data symbol. 3.3 Basic principle of Direct Sequence Spread Spectrum For BPSK modulation the building blocks of a DSSS system are: Input: Binary data dt with symbol rate Rs = 1/Ts (=bitrate Rb for BPSK) Pseudo-noise code pnt with chip rate Rc = 1/Tc (an integer of Rs) Spreading: In the transmitter, the binary data dt (for BPSK, I and Q for QPSK) is ‘directly multiplied with the PN sequence pnt , which is independent of the binary data, to produce the transmitted baseband signal txb: txb = dt . pnt The effect of multiplication of dt with a PN sequence is to spread the baseband bandwidth Rs of dt to a baseband bandwidth of Rc. Despreading: The spread spectrum signal cannot be detected by a conventional narrowband receiver. In the receiver, the baseband signal rxb is multiplied with the PN sequence pnr . If pnr = pnt and synchronized to the PN sequence in the received data, than the recovered binary data is produced on dr. The effect of multiplication of the spread spectrum signal rxb with the PN sequence pnt used in the transmitter is to despread the bandwidth of rxb to Rs . If pnr ≠  pnt , than there is no dispreading action. The signal dr has a spread spectrum. A receiver not knowing the PN sequence of the transmitter can not reproduce the transmitted data. Performance in the presence of interference: To simplify the presence of interference, the spread spectrum system is considered for baseband BPSK communication (without filtering). The received signal rxb of the transmitted signal txb plus an additive inteferance i (noise, other users, jammer,†¦Ã¢â‚¬ ¦): rxb = t xb + i = dt . pnt + i To recover the original data dt the received signal rx0 is multiplied with a locally generated PN sequence pnr that is an exact replica of that used in the transmitter (that is pnr = pnt and synchronized) The multiplier output is therefore given by: dr = rxb . pnt = dt . pnt . pnt + i . pnt The data signal dt is multiplied twice by the PN sequence pnt , where as the unwanted inteferance i is multiplied only once. Due to the property of the PN sequence: pnt + pnt = +1 for all t The multiplier output becomes: dr = dt + i . pnt The data signal dr is reproduced at the multiplier output in the receiver, except for the inteferance represented by the additive term i . pnt . Multiplication of the inteferance by the locally generated PN sequence, means that the spreading code will affect the inteferance just as it did with the information bearing signal at the transmitter. Noise and inteferance, being uncorrelated with the PN sequence, becomes noise-like, increase in bandwidth and decrease in power density after the multiplier. After dispreading, the data component dt is narrow band (Rb) whereas the inteferance component is wideband (Rc). By applying the dr signal to a baseband (low-pass) filter with a band width just large enough to accommodate the recovery of the data signal, most of the inteferance component i is filtered out. The effect of inteferance is reduced by processing gain (Gp). Narrowband inteferance: The narrowband noise is spread by the multiplication with the PN sequence pnr of the receiver. The power density of the noise is reduced with respect to the despread data signal. Only 1/Gp of the original noise power is left in the information baseband (Rs). Spreading and dispreading enables a bandwidth trade for processing gain against narrow band interfering signals. Narrow band inteferance would disable conventional narrow band receivers. The essence behind the inteferance rejection capability of a spread spectrum system: the useful signal (data) gets multiplied twice by the PN sequence, but the inteferance signal get multiplied only once. Wideband interference: Multiplication of the received signal with the PN sequence of the receiver gets a selective despread of the data signal (smaller bandwidth, higher power density). The inteferance signal is uncorrelated with the PN sequence and is spread. Origin of wideband noise: Multiple Spread Spectrum user: multiple access mechanism. Gaussian Noise: There is no increase in SNR with spread spectrum: The large channel bandwidth (Rc instead of Rs) increase the received noise power with Gp: Ninfo = N0 . BWinfo à   Nss = N0 . BWss = Ninfo .Gp The spread spectrum signal has a lower power density than the directly transmitted signal. Code division multiple access (CDMA) is a methode of multiplexing (wireless) users distinct (orthogonal) codes. All users can transmit at the same time, and each is allocated the entire available frequency spectrum for transmission. CDMA is also known as Spread-Spectrum multiple access (SSMA). CDMA dose not require the bandwidth allocation of FDMA, nor the time synchronization of the individual users needed in TDMA. A CDMA user has full time and full bandwidth available, but the quality of the communication decreases with an increasing number of users (BER ). In CDMA each user: Has its own PN code Uses the same RF bandwidth Transmits simultaneously (asynchronous or synchronous) Correlation of the received baseband spread spectrum signal rxb with the PN sequence of user 1 only despreads the signal of user 1. The other user produces noise Nu for user 1. ACCESS SCHEMES For radio systems there are two resources, frequency and time. Division by frequency, so that each pair of communicators is allocated part of the spectrum for all of the time, results in Frequency Division Multiple Access (FDMA). Division by time, so that each pair of communicators is allocated all (or at least a large part) of the spectrum for part of the time results in Time Division Multiple Access (TDMA). In Code Division Multiple Access (CDMA), every communicator will be allocated the entire spectrum all of the time. CDMA uses codes to identify connections. MULTIPATH AND RAKE RECEIVERS One of the main advantages of CDMA systems is the capability of using signals that arrive in the receivers with different time delays. This phenomenon is called multipath. FDMA and TDMA, which are narrow band systems, cannot discriminate between the multipath arrivals, and resort to equalization to mitigate the negative effects of multipath. Due to its wide bandwidth and rake receivers, CDMA uses the multipath signals and combines them to make an even stronger signal at the receivers. CDMA subscriber units use rake receivers. This is essentially a set of several receivers. One of the receivers (fingers) constantly searches for different multipaths and feeds the information to the other three fingers. Each finger then demodulates the signal corresponding to a strong multipath. The results are then combined together to make the signal stronger. Difference between TDMA vs CDMA. TDMA is Time Division Multiple Access, while CDMA is Code Division Multiple Access. Both technologies achieve the same goal of better utilization of the radio spectrum by allowing multiple users to share the same physical channel, but by using different methods and that is why the three of the four words in each acronym are identical. Both allow more than one person to carry out a conversation on the same frequency without causing interference. The two technologies differ in the way in which users share the common resource. In TDMA the channel is chopped up into sequential time slices. The data of each user is put on the channel in a round-robin fashion. In reality, only one user actually uses the channel at any given point of time, but he uses it only for short bursts. He then gives up the channel for a short duration to allow the other users to have their turn. This is similar to how a computer with just one processor runs multiple applications simultaneously. CDMA on the other hand allows everyone to transmit at the same time. With conventional methods of modulation techniques it would hav been simply not possible. What makes CDMA to allow all users to transmit simultaneously is a special type of digital modulation called Spread Spectrum. In this modulation technique users stream of bits is taken and splattered them across a very wide channel in a pseudo-random fashion. The pseudo part is very important here as at the receiver end the randomization must be undone in order to collect the bits together in a coherent order. For example consider a room full of couples, and each couple trying to carry on one-on-one conversations. In TDMA each couple takes their turn for talking and they keep their turns short by speaking only one sentence at a time. As there is always more one person speaking in the room at any given point of time, no one has to worry about being heard over the background din. In CDMA assume each couple talks simultaneously, but they all use different languages. The background din doesnt cause any real problem as none of the listeners understand any language other than that of the individual to whom they are listening. Voice Encoding At this point many people confuse two distinctly different issues involved in the transmission of digital audio. The first is the WAY in which the stream of bits is delivered from one end to the other. This part of the air interface is what makes one technology different from another. The second is the compression algorithm used to squeeze the audio into as small a stream of bits as possible. This latter component is known at the Voice Coder, or Vocoder for short. Another term commonly used is CODEC, which is a similar word to modem. It combines the terms COder and DECoder. Although each technology has chosen their own unique CODECs, there is no rule saying that one transmission method needs to use a specific CODEC. People often lump a technologys transmission method with its CODEC as though they were single entities. Voice encoding schemes differ slightly in their approach to the problem. Because of this, certain types of human voice work better with some CODECs than they do with others. The point to remember is that all PCS CODECs are compromises of some sort. Since human voices have such a fantastic range of pitch and tonal depth, one cannot expect any single compromise to handle each one equally well. This inability to cope with all types of voice at the same level does lead some people to choose one technology over another. All of the PCS technologies try to minimize battery consumption during calls by keeping the transmission of unnecessary data to a minimum. The phone decides whether or not you are presently speaking, or if the sound it hears is just background noise. If the phone determines that there is no intelligent data to transmit it blanks the audio and it reduces the transmitter duty cycle (in the case of TDMA) or the number of transmitted bits (in the case of CDMA). When the audio is blanked your caller would suddenly find themselves listening to dead air, and this may cause them to think the call has dropped. To avoid this psychological problem many service providers insert what is known as Comfort Noise during the blanked periods. Comfort Noise is synthesized white noise that tries to mimic the volume and structure of the real background noise. This fake background noise assures the caller that the connection is alive and well. However, in newer CODECs such as EVRC (used exclusively on CDMA systems) the background noise is generally suppressed even while the user is talking. This piece of magic makes it sound as though the cell phone user is not in a noisy environment at all. Under these conditions, Comfort Noise is neither necessary, nor desirable. DS-CDMA-INTRODUCTION While multiple access interference (MAI) by other users has been recognized as the capacity-limiting factor in direct sequence code-division multiple-access (DS-CDMA)-based cellular communication systems, multiuser approaches have largely alleviated the problem when the noise process is additive Gaussian. With the availability of multiuser detectors, inaccurate or inappropriate noise modelling assumptions seem to have become the issue again. Whereas multiuser detection has much to offer in the mobile- to-base station uplink, it does not at present appear to be feasible for the downlink due to the complexity involved and the lack of resistance against adjacent cell interference. Moreover, the few multiuser proposals for the downlink require the knowledge of all spreading codes, which is not possible in the tactical military environment, for instance. Enhanced single-user receivers equipped with adaptive filter banks deliver promising performance with reasonable complexity, especially in slowly varying channels. Thus, the performance of single-user detectors is still of interest, particularly in the presence of non-Gaussian noise. In both urban outdoor and indoor mobile radio environments, electromagnetic interference generated by man-made sources such as factories or power lines causes the noise to be of non-Gaussian nature. Large noise magnitudes are deemed very improbable by linear receivers, and consequently performance deterioration is experienced. It is therefore desirable to build systems that can maintain respectable functionality under a broad class of noise distributions, rather than strictly optimizing for the unrealistic Gaussian assumption. Such is the goal of robust detection and estimation theory, which aims to design systems that are suboptimal under nominal channel conditions (e.g., Gaussian channel) and yet do not face catastrophy when the noise distribution is not nominal (e.g., unlike linear schemes). Note that suboptimality here refers to very good performance that is slightly worse than that of the nominal-optimal detector/estimator. The direct sequence code division multiple access (DS-CDMA) technique has been favourably considered for application in digital mobile cellular networks due to its potential to provide higher system capacity over conventional multiple access techniques. Unlike FDMA and TDMA capacities which are mostly limited by the bandwidth, the capacity of a CDMA system is mainly restricted by its interference level. Any reduction in interference produces a direct and linear increase in system capacity. Multiple access interference (MAI) caused by non-zero cross-correlation between different spreading sequences is the major type of interference limiting the CDMA system capacity. Much work has been done to characterize MAI, and to analyze and evaluate the CDMA system performance in the presence of MAI. Since the cross-correlation properties of most sets of spreading codes are either too complex to analyze or very difficult to compute when different transmissions are not synchronized, a random seque nce model. In the case of moderate to large processing gains, Gaussian distribution with variable variance is a good approximation for the MAI distribution. One of the approaches to reduce MAI is to employ orthogonal spreading sequences, and try to synchronize the transmissions at the chip level (quasi-synchronization). However, this is generally difficult to achieve in multipoint-to-point systems, such as the reverse link (mobile-to-base) of a cellular system, due to a lack of synchronization of the various mobile terminals, and the variable transmission delays. In this paper, a multi-carrier DS-CDMA (MCDS-CDMA) scheme is employed to facilitate the synchronization process, and thus reduce MAI. SYSTEM MODEL A model of the MS-DS-CDMA system for the kth user of a CDMA system is shown in the figure 1. TRANMSITTER MODEL At the transmitter the user‘s data stream dk(t) is divided into M interleaved sub streams and spread by a spreading sequence ck(t) to a fraction 1/M of the entire transmission bandwidth W. The resultant chip sequences are then used to modulate M carrier. The carrier frequencies ωm,m=1,2,M are equally spaced by the chip rate so that they are mutually orthogonal over one channel symbol interval T. Let R be the information rate and Rc be the carrier control code rate then the channel symbol interval is BER PERFORMANCE: MC-DS-CDMA system performance measured by bit error rate through analysis and simulation. Analysis: The BER is analysed based on the following: Ortoganal spreading sequences with rectangular pulse shape are applied. ÃŽ ¶k,k=1†¦K are independent of random variables distributd in (-ÃŽ ¶D,ÃŽ ¶D) WHERE ÃŽ ¶D=ÃŽ µD+Ï‚D.Given W and ÃŽ ¶D,M is chosen so that ÃŽ ¶D It is assumed that the fading parameters of the desired user . It is perfectly estimated so that the coherent detection and optimum soft decision decoding could be carried out at the receiver to make the problem analytically tractable. The fading amplitudes as independent Rayleigh random variables with equal second moments. The model is MATLAB INTRODUCTION: Matlab is a commercial Matrix Laboratory package which operates as an interactive programming environment. It is a mainstay of the Mathematics Department software lineup and is also available for PCs and Macintoshes and may be found on the CIRCA VAXes. Matlab is well adapted to numerical experiments since the underlying algorithms for Matlabs builtin functions and supplied m-files are based on the standard libraries LINPACK and EISPACK. Matlab program and script files always have filenames ending with .m; the programming language is exceptionally straightforward since almost every data object is assumed to be an array. Graphical output is available to supplement numerical results. IMREAD Read image from graphics file. A = IMREAD(FILENAME,FMT) reads a grayscale or color image from the file specified by the string FILENAME. If the file is not in the current directory, or in a directory on the MATLAB path, specify the full pathname. The text string FMT specifies the format of the file by its standard file extension. For example, specify gif