Low complexity non decision directed blind carrier phase recovery algorithm for 16-QAM optical coherent receiver

We propose and demonstrate a low complexity non decision directed blind carrier recovery algorithm (NDD-CRA) for 16-QAM optical coherent receivers. Through optimization of step size parameter (μ), we obtained similar performance compared to decision-directed phase estimation algorithm, however, our propose scheme has less complexity compared to the decision directed carrier recovery algorithm (DD-CRA) as the proposed scheme does not require any decision feedback module. From simulation, it is observed that the proposed scheme has less than 1.7 dB OSNR penalty at 10 -3 BER and up to 200-kHz linewidth laser compared with the theoretical performance.