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 than one sub-carrier can be ....etc

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ABSTRACT:

OFDM
otherwise called orthogonal frequency division multiplexing is a modulation and a multiple access technique that can be applied to mobile communications.
OFDM or Multitone modulation as it is sometimes called is the basis for several commercial wireless applications. In OFDM the segments are according to frequency there by dividing the spectrum into a number of equally spaced tones, which are orthogonal with each other and carries a portion of user information on eac ....etc

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Orthogonal Frequency Division Multiplplexing

Multi Carrier Modulation is a technique for data transmission by dividing a high bit rate data stream is several parallel low bit ]rate data streams and using these low bit rate data streams to modulate several carriers. Multi Carrier Transmission has a lot of useful properties such as delay spread tolerance and spectrum efficiency that encourage their use in untethered broadband communications. OFDM is a multi carrier modulation technique with densely spaced sub carriers tha ....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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Orthogonal Frequency Division Multiplexing (OFDM)

ABSTRACT
Orthogonal Frequency Division Multiplexing (OFDM) has recently gained a lot of attention and is a promising candidate for future wireless multimedia communications due to it is resistive to frequency-selective fading and its flexibility for handling multiple data rates for Fourth Generation (4G) wireless systems also it promises data rates up to 10Mbps. A variation of OFDM is Multi-Carrier CDMA (MC-CDMA), in which an OFDM technique and CDM ....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 significant ....etc

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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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Orthogonal Frequency Division Multiplexing


1. INTRODUCTION
1.1. Introduction:-
Orthogonal Frequency Division Multiplexing (OFDM) is one of the latest modulation techniques used in order to combat the frequency-selectivity of the transmission channels, achieving high data rate without inter symbol interference. The basic principle of OFDM is gaining a wide spread popularity within the wireless transmission community. Furthermore,
OFDM is one of the main techniques proposed to be employed in ....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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