OFDM: Principles and Challenges (original) (raw)

OFDM

Orthogonal frequency division multiplexing (OFDM) is a special case of multicarrier transmission, where a single datastream is transmitted over a number of lower rate subcarriers. In July 1998, the IEEE standardization group decided to select OFDM as the basis for their new 5-GHz standard, targeting a range of data stream from 6 up to 54 Mbps. This new standard is the first one to use OFDM in packet-based communications, while the use of OFDM until now was limited to continuous transmission systems.

Overview of the Key Advantages of OFDM System and its Effects of Drawbacks

2018

Due to increasing data traffic worldwide, the demands on optical communication systems in terms of bit rate, spectral efficiency and bandwidth flexibility will increase in the coming years. To cope with this, among other things, the multi-carrier orthogonal frequency division multiplexing (OFDM) in combination with coherent reception is under discussion for future systems. However, as OFDMS systems are sensitive to nonlinear perturbations, this work presents Procedures that reduce such influences. Thus, impairments of the channel estimation are examined by transmitter-side quantization errors and possibilities are shown of reducing them or even eliminating them altogether. In addition, the influence of the non-linear characteristic of the electro-optical modulator is studied and demonstrated that nonlinear distortions can be significantly reduced by digital preprocessing of the transmission signal. On the receiver side, this work deals with synchronization procedures for frame detec...

A Review on Orthogonal Frequency Division Multiplexing (OFDM

Orthogonal frequency division multiplexing (OFDM) is a special case of multicarrier transmission where a single DataStream is transmitted over a number of lower rate subcarriers. In July 1998, the IEEE standardization group decided to select OFDM as the basis for their new 5-GHz standard aiming a range of data stream from 6 up to 54 Mbps. This new standard is the first one to use OFDM in packet-based communications. In wireless communication, concept of parallel transmission of symbols is used to achieve high throughput and better transmission quality. Orthogonal Frequency Division Multiplexing (OFDM) is one of the techniques for parallel transmission. The idea of OFDM is to split the total transmission bandwidth into a number of orthogonal subcarriers in order to transmit the symbols using these subcarriers in parallel. In this paper we will discuss the basics of OFDM technique, role of OFDM in this era, its benefits and losses and also some of its application.

Realization of OFDM Communication System

2016

The process of successfully recovering data back after being transmitted is an important task in communication systems. OFDM proves to be a streamlined but complex alternative amidst all the option there are however it also proves to be reliable. In this system, the transmission of information is considered on multiple carriers that is contained within the allocated channel bandwidth. The key motivation for transmitting data is to reduce ISI and thus, eliminate the performance degradation which is incurred to implement the system. The signal undergoes various processes before it is transmitted and then the AWGN is added to corrupt the signal and fed to the receiver unit.

OFDM for High Data Rate, High-Mobility, Wide-Area Wireless Communications

In recent years, there has been considerable growth in interest in wireless access to wide area data networks at high data rates. This growth has been fuelled by the simultaneous development of the high-speed wired data networks (e.g., the Internet), wide-spread availability of powerful mobile computing devices, rapidly dropping prices for increasingly sophisticated electronic devices, plus the global deployment of wireless voice systems. High-mobility wireless data access at near-LAN rates is likely to be an attractive option. The harsh cellular radio environment creates significant challenges when trying to provide access at high data rates, especially if high-mobility and wide-area availability are expected -even more so when considering the constraints placed on the system design by terminal size and power constraints. This paper describes research into Orthogonal Frequency Division Multiplexing (OFDM) techniques addressing high data rate access in representative mobile cellular...

An Overview: OFDM Technology an Emerging Trend in Wireless Communication

With the expansion of information interchanges innovation, the interest for Higher Data Rate Services, for example, interactive media, voice, and information over both wired and remote connections is likewise expanded OFDM is transmission strategy created to take care of the expanding demand for higher information rates in interchanges, which can be utilized as a part of both wired and remote situations. New strategies to enhance data rates are required to exchange the broad measure of information which existing procedures can't bolster. These strategies must have the capacity to give high Data rate, bit error rate (BER), maximum delay. In this paper, We have presented a survey of QoS in OFDM wireless networks along with resource allocation and scheduling algorithms, its impact and how this modulation scheme can be utilised to enhance the performance of data transmission in the future of wireless networks.