Bit Error Rate Improvement of Orthogonal Frequency and Code Division Multiplexing by Symbols Peak Power Reduction

V.B.Shukla; Goutam Chatterjee

Volume : IV, Issue : VI, June - 2015

Bit Error Rate Improvement of Orthogonal Frequency and Code Division Multiplexing by Symbols Peak Power Reduction

V. B. Shukla, Goutam Chatterjee

Abstract :

As we know, that every technology has some advantages and limitations. OFCDM, which is very promising modulation technique for 4G standard like LTE (Long Term Evolution) and WIMAX (Worldwide Inter–operability for Microwave Access) also has some limitations like frequency offset, high peak power as compared to average power and Orthogonal code allotment etc. In this paper, peak power to average power issue has been raised, that limits the performance of OFCDM or other multi–carrier system, if not handled properly. Due to increase of symbols peak power as compared to their average power non–linear distortion occurs, which causes orthogonality of OFCDM sub–carriers get lost, so Inter Carrier Interference (ICI) and Inter Symbol Interference (ISI) both arises. So it is necessary to reduce peak power. Several Peak power reduction techniques have been proposed in literature. These techniques are divided into two groups (i) signal scrambling techniques and (ii) signal distortion techniques. But both have some types of disadvantages. Here is a proposed technique known as sub–career processing (SCP) technique, that is used to reduce peak power by more than 5 dB and remove rigorous requirement for power amplifier and digital to analogue converter. Due to reduction in peak power as compared to average power, Inter carrier interference (ICI) and Inter symbol interference (ISI) both can be reduces considerably, so bit error rate (BER) performance of the system get improved.