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.

本文针对最近提出的基于PAM-DMT的混合光正交频分复用（PHO-OFDM）系统，提出了一种基于软均衡的单迭代接收机，以提高其误码率（BER）性能。首先通过频域中的软均衡方法来降低脉冲幅度调制离散多音（PAM-DMT）分支和DC偏置光正交频分复用（DCO-OFDM）分支的层间干扰和削波噪声。然后，进一步引入成对削波（PC）和成对平均（PA），以根据相应的分支对称特性校正再生的时域分支信号。