提出一种基于线性相位插值(LPI)的增强型载波相位估计(CPE)算法，并对其在112 Gb/s偏振复用16进制正交幅度调制（DP-16QAM）系统中的性能进行了仿真和实验研究。该算法在基于数据块平均的CPE算法基础上，通过对其获得的估计相位噪声进行LPI，实现相位噪声估计准确度的大幅提升。仿真结果显示，基于CPE的增强型CPE算法的相位估计误差的方差比基于数据块平均的算法降低了26%。同时，其线宽容忍度是基于数据块平均算法的2倍。在112 Gb/s DP-16QAM实验系统中对增强型算法进行了测试。实验结果表明，在误码率(BER)为3.8×10-3处，采用增强型算法时所需光信噪比(OSNR)比基于数据块平均算法降低了0.7 dB。仿真与实验结果显示，基于LPI的CPE算法性能与基于窗口扫描算法相当，但增强型算法的硬件复杂度降低了99.2%。

An improved carrier phase estimation (CPE) algorithm based on linear phase interpolation (LPI) is proposed, and simulation and experiment are conducted for evaluating the performance of the proposed algorithm in a 112 Gb/s dual-polarization 16-ary quadrature amplitude modulation (DP-16QAM) system. A LPI function is used to deal with the obtained estimated phase noise in the algorithm based on CPE of block averaging for significantly improving the accuracy of CPE. Compared with the normal block averaging method, the variance of estimated phase error of the proposed algorithm is reduced by 26%, and the linewidth tolerance is 2 times compared with the algorithm based on block averaging. For a 112 Gb/s DP-16QAM experimental system, at 3.8×10-3 bit error rate (BER), a 0.7 dB reducement in terms of the required optical signal-to-noise ratio (OSNR) is demonstrated using the proposed algorithm based on CPE algorithm with respect to the normal block averaging algorithm. The performance of the proposed algorithm is comparable to the algorithm based on sliding window. However, hardware complexity is reduced by 99.2% in comparison with the algorithm based on sliding window.