A combined weighting and PTS technique for PAPR reduction in OFDM signals

At present for high data rate transmission, Orthogonal Frequency Division Multiplexing (OFDM) is the best and efficient modulation and multiplexing scheme adapted for 4G wireless communication applications. As an attractive technology for wireless communications, OFDM which is one of multi-carrier modulation (MCM) techniques, offers a considerable high spectral efficiency, multipath delay spread tolerance, immunity to the frequency selective fading channels and power efficiency. As a result, OFDM has been chosen for high data rate communications. One of the challenging issues for Orthogonal Frequency Division Multiplexing (OFDM) system is its high Peak-to-Average Power Ratio (PAPR). In this paper we present methods for reduction of PAPR in multi-carrier OFDM through the joint use of weighting, and Partial Transmit Sequence(PTS). In the proposed scheme, initially a weight is imposed on each discrete OFDM signal via a certain kind of a band limited signal, and PTS is done on weighted discrete data and is then considered before a high power amplifier (HPA). All the simulations are conducted in MATLAB over AWGN channel using Quadrature Phase Shift Keying (QPSK) modulation scheme. The simulation results show that the proposed scheme significantly provides better PAPR reduction and high performance on Bit Error Rate (BER) compared to weighting and PTS technique.