Reducing the PAPR of OFDM Using a Simplified Scrambling SLM Technique with No Explicit Side Information

Selected Mapping (SLM) is a popular technique used for Peak-to Average Power (PAPR) reduction in OFDM systems. Normally SLM techniques require explicit side information to be transmitted to allow decoding at the receiver. Alternative SLM techniques use shift register scramblers to embed the side information into the transmitted OFDM symbols. In this paper the concept of an SLM Simplified Scrambler is introduced. The advantages of this technique are (a) no explicit side information is transmitted, and (b) the simplified scrambler helps to avoid the problem of shift register error propagation in the receiver descrambler. The Simplified Scrambler SLM-OFDM approach is investigated in terms of PAPR reduction, Power Spectral Density (PSD) and Bit-Error Rate (BER) performance. It is shown that the Simplified Scrambler SLM-OFDM technique exhibits the same PSD and BER as general OFDM as well as improving the BER performance over SLM shift-register scrambler techniques.