Optical carrier phase estimation based on 8-PSK partitioning and modified Viterbi-Viterbi for 32-QAM

In this paper, a carrier phase estimation technique (CPE) based on 8-PSK partitioning and modified Viterbi-Viterbi for 32-QAM is proposed. The proposed algorithm shows 60% linewidth tolerance improvement compared to the already-existed CPE single stage techniques for 1-dB SNR penalty at BER of 1×10
^-2
.