Parallel combinatory OFDM signaling

Abstract

A parallel combinatory-orthogonal frequency division multiplexing (PC-OFDM) system is proposed and analyzed. The proposed system selects at each symbol interval a subset of the available subcarriers, and the selected subcarriers are modulated by points from an M-PSK signal constellation, PC-OFDM systems can be designed to have lower peak-to-average power ratio (PAPR), higher bandwidth efficiency, and lower bit error probability on Gaussian channels compared to ordinary OFDM systems. A bit mapping procedure using the Johnson (1993) association, together with a position algorithm for the PSK symbols, is proposed. Good analytical approximations of the BER for PC-OFDM systems are derived for AWGN and Ricean fading channels, and extensive simulation results are presented.