PAPR analysis of coded-OFDM system and mitigating its effect with clipping, SLM and PTS

Abstract

In wireless communication, parallel transmission of symbols using multi carriers is applied to achieve high efficiency in terms of throughput and better transmission quality. Orthogonal Frequency Division Multiplexing (OFDM) is one of the techniques for parallel transmission. In multipath environment the performance of orthogonal frequency division multiplexing (OFDM) is improved by introducing some kind of channel coding. Coded OFDM (COFDM) is the new candidate for application such as DAB and DVB-T due to its better performance in fading environment. However high peak to average power ratio (PAPR) is a major demerit of OFDM system, it leads to increased complexity of circuit and reduced efficiency of RF amplifier. In this paper our aim is to evaluate the PAPR of COFDM system and reducing its effect by clipping, Selected Mapping (SLM) and Partial Transmit Sequence (PTS) techniques. COFDM system used here comply with IEEE 802.11a specifications and Reed Solomon (RS) codes along with convolution codes are used for channel coding purpose. Channel used for consideration is AWGN. The performance is evaluated in terms of PAPR value and BER.