A new low complexity DHT based weighted OFDM transmission for peak power reduction

Abstract

Background/Objectives: Orthogonal Frequency Division Multiplexing (OFDM) is an efficient modulation technique that splits a single wideband signal into various narrowband independent signals. It is used in digital audio and video broadcasting, wireless LAN/MAN standards, and WiMAX standards. However, one of the serious problems of OFDM is the high Peak to Average Power Ratio (PAPR), which causes a signal distortion at the High Power Amplifier (HPA) of a transmitter. To reduce the nonlinear distortion, the power efficiency of the HPA has to be significantly decreased. In this work, the influence of combined weighting and Discrete Hartley Transform (DHT) on the OFDM signal is investigated. Methods/Statistical Analysis: A weighted DHT based OFDM system that reduces both the PAPR and the Bit Error Rate (BER) of the OFDM signal is proposed. The effectiveness of the system has been shown through various computer simulated graph. Findings: For 64 subcarriers, the proposed transceiver can achieve 7dB PAPR, which is about 0.9 dB smaller than the conventional DFT based OFDM. Conclusions/Improvements: Presently the DHT based weighted OFDM is proposed for complexity reduction, mainly for lower PAPR. The proposed method can be extended for MIMO system.