PAPR analysis of DHT-precoded OFDM system for M-QAM

High Peak to Average Power Ratio (PAPR) is one of the major drawbacks in Orthogonal Frequency Division Multiplexing (OFDM). The High PAPR increases the complexity of Analogue to Digital (A/D) and Digital to Analogue (D/A) convertors and also reduces the efficiency of RF High Power Amplifier (HPA). In this paper we present an analysis of Discrete Hartley Transform (DHT) precoded OFDM system using M-QAM (where M=16, 32, 64, 256). We compare the computer simulation results of DHT precoded OFDM system with DFT precoded OFDM system, Walsh Hadamard Transform (WHT) precoded OFDM system, Selected Mapping (SLM) based OFDM system and OFDM conventional. Simulation results show that the PAPR of DHT precoded OFDM system is lower than WHT precoded OFDM system, SLM-OFDM system and OFDM conventional. We also concluded in this paper that DFT precoded OFDM system has zero PAPR.