Transceiver Impairment Mitigation by 8×2 Widely Linear MIMO Equalizer With Independent Complex Filtering on IQ Signals

High-order modulation formats with high symbol rates are promising candidates for meeting the growing traffic requirements of digital coherent transmission. In using these formats, impact transceiver impairment on signal quality becomes significant. this paper, we propose an 8×2 widely linear (WL) multiple-input multiple-output (MIMO) equalizer independent complex filtering IQ signals to mitigate impairments. Furthermore, extend subcarrier (SC) multiplexing. Accordingly, a 16×4 WL MIMO is also proposed impairments, through application pair SC inputs. Experimental results show that, transmission 58-GBaud polarization-multiplexing 64 quadrature amplitude (PM-64QAM) single-carrier signal, method effectively compensates various receiver impairments and mitigates transmitter (Tx) Q-penalties 0.1 dB up 10-ps skew, 2.5-dB gain imbalance, 7.2-degree phase error, –15-dB crosstalk in Tx were achieved 100-km standard single-mode fiber Moreover, 29-GBaud PM-64QAM dual-SC 16 × 4 shows mitigation performance similar that case, even though less tolerant laser noise.