BER enhanced receiver for PHO-OFDM-based optical wireless communications

Abstract

In this paper, a soft-equalization-based single iterative receiver is proposed for the recently proposed PAM-DMT-based hybrid optical orthogonal frequency division multiplexing (PHO-OFDM) system to enhance its bit error rate (BER) performance. The interlayer interference and clipping noise of the pulse amplitude modulated discrete multitone (PAM-DMT) branch and DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) branch are first reduced by a soft-equalization method in the frequency domain. Then, the pairwise clipping (PC) and pairwise averaging (PA) are further introduced to correct the regenerated time-domain branch signals according to the corresponding branch symmetry properties. Numerical simulations demonstrate that the proposed receiver can realize improved BER performance over the conventional counterpart under both the linear and nonlinear transmission model.