Frequency Division Multiple Access (FDMA)

Introduction
Frequency Division Multiple Access Used for AMPS and TACS, the two key analog systems and their variants, this system gives each conversation its own unique radio channel. Division of a radio frequency into several channels by splitting the frequency band into distinct segments, which are assigned to various callers. This allows a single base station to serve many callers. For example, a typical AMPS network will have 832 channels spaced approximately 30 kilohertz apart. - Frequency Div ....etc

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IMPLEMENTATION OF PRECODING FOR SC-FDMA SYSTEMS
Presented by
VISHNUPRIYA L
M3 MTV,
CET ,TRIVANDRUM



CONTENTS
INTRODUCTION
MOTIVATION
LITERATURE REVIEW
BLOCK DIAGRAM
WORK DONE
FUTURE WORKS

ABSTRACT
Single Carrier Frequency Division Multiple Access (SC-FDMA) is a technique for high data rate uplink transmission in cellular technology. It satisfies the demand of requiring higher data rate. This requirement of high data rate results in sig ....etc

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Overview
Code division multiple access (CDMA) is a modulation and multiple-access scheme based on spread-spectrum communication. In this scheme, multiple users share the same frequency band at the same time, by spreading the spectrum of their transmitted signals, so that each user's signal is pseudo-orthogonal to the signals of the other users.

CDMA Signals
In a CDMA system, each signal consists of a different pseudorandom binary sequence (called the spreading code) that modulates a carrier, spreading the spectrum of the waveform. A large ....etc

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Orthogonal Frequency Division Multiple Access (OFDMA) is a multiple access scheme for OFDM systems. It works by assigning a subset of subcarriers to individual users.




OFDMA features

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OFDMA is the 'multi-user' version of OFDM
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Functions by partitioning the resources in the time-frequency space, by assigning units along the OFDM signal index and OFDM sub-carrier index
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Each OFDMA user transmits symbols using sub-carriers that remain orthogonal to those of other users
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More th ....etc

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Frequency Division Multiple Access Used for AMPS and TACS, the two key analog systems and their variants, this system gives each conversation its own unique radio channel. Division of a radio frequency into several channels by splitting the frequency band into distinct segments, which are assigned to various callers. This allows a single base station to serve many callers. For example, a typical AMPS network will have 832 channels spaced approximately 30 kilohertz apart. - Frequency Division Multiple Access, digital transmission technology that ....etc

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Abstract:
Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user version. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This allows simultaneous low data rate transmission from several users, OFDM is sometimes referred to as discrete multi-tone modulation, instead of a single carrier being modulated, a large number of evenly spaced subcarriers are modulated using some m-ary of QAM. This is a spread-spectrum technique that increases the efficiency of data communications by increasin ....etc

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TDMA, or Time Division Multiple Access was one of the first cell phone digital standards available in the United States. It was the first successor to the original AMPS analog service that was popular throughout the country, and was in popular service from the early-mid 1990's up until roughly 2003 when the last of the TDMA carriers, Cingular and AT&T, switched to the GSM digital standard.

TDMA was a significant leap over the analog wireless service that was in place at the time, and it's chief benefit for carriers was that it used the avail ....etc

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A Technique for Orthogonal Frequency Division Multiplexing
Frequency Offset Correction

Abstract:
The Orthogonal Frequency Division Multiplexing (OFDM) is a Multi Carrier Modulation technique employing Frequency Division Multiplexing of orthogonal subcarriers. It is also sometimes called as discrete multitone modulation (DMT). It is better than CDMA in high bit rate and Broadband Communications .It is a multi carrier technique, which is very sensitive to Frequency Offset between transmitter and receiver. Th ....etc

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