Digital signal processing for training-aided coherent optical single-carrier frequency-domain equalization systems

Abstract

In this paper, we present the design of digital signal processing (DSP) algorithms for training-aided coherent optical single-carrier frequency-domain equalization (SC-FDE) systems. Based on two training-aided channel estimation (TA-CE) schemes, the requirements for training sequence to achieve the minimum mean square error performance of channel estimation (CE) are outlined. Moreover, the practical implementation issues of constant-amplitude zero-autocorrelation sequence and Golay sequences are discussed. We propose to perform time-domain windowing to the CE taps for further noise suppression to improve the CE and achieve large overhead saving with the optimized CE. Furthermore, frame timin..