Low-complexity two-stage equalizer for receiver IQ imbalance compensation and polarization demultiplexing for real-time System

Abstract

Reducing the complexity of adaptive equalizer is significant for realizing real-time hardware systems. In this paper, we propose a low-complexity two-stage equalizer that can be used in real-time systems. The performance of the proposed equalizer was verified through a 112 Gbit/s polarization multiplexing quadrature phase shift keying (PM-QPSK) back-to-back experiment with a receiver IQ impairment emulation module. The results revealed that, as for FIR module, compared with the conventional 2 × 2 MIMO, the number of multipliers in the proposed equalizer can be reduced by approximately 70% by use of 21 taps, while this equalizer is less sensitive to IQ impairment.