一种32Q-AM相干光通信系统中相位估算算法

Carrier phase estimation for 32-QAM optical systems using quasi-QPSK-partitioning algorithm

针对相干光纤通信系统中32Q-AM调制格式,提出了一种在第一级使用准QPSK分割的算法来替代传统的QPSK分割的改进相位估计算法。仿真结果显示,在1dB信噪比劣化的情况下当误码率达到1E-2时,该算法相对于传统的QPSK分割算法的激光器线宽带来的相位噪声的容忍度提高了85%。通过与精细的估计算法级联可以获得最大激光器线宽容忍度为5.1E-5。

In this paper, a quasi quadrature phase shift keying （QPSK） partitioning method is proposed to replace the conventional QPSK partitioning method in the first stage of the carrier phase estimation （CPE） algorithms for the 32-QAM coherent optical syste^m. By simulation, for 1 dB SNR penalty at bit error rate （BER） of 1E-2, the proposed method can achieve an improving of 85% for combined linewidth symbol duration product tolerance compared with conventional method for single stage. Combined with the fine stage, the maximum tolerable combined linewidth symbol duration product can be up to 5.1E-5.