对一种移除调制相位信息的算法进行了进一步研究, 使其适用于更高阶调制格式的相干系统。该算法对接收到的复数信号的实部和虚部分别采用绝对值操作, 移除调制的相位信息。通过对28 GBaud的64QAM(64阶正交幅度调制)相干系统进行仿真, 来研究该算法在64QAM系统中的性能。仿真结果表明, 该算法无需乘法器, 而且在频偏估计中的性能与传统的M次幂运算的性能接近。因此, 该算法相比M次幂运算在性能不变的情况下, 降低了算法的复杂度。

An algorithm to remove the modulated phase is further investigated to make the algorithm be suitable for the coherent systems of higher-order modulation format. In the algorithm, the absolute operation is respectively implemented on the real part and imaginary part of received complex signals to remove their modulated phases. The performance of the proposed algorithm in a 28 GBaud coherent 64 ary Quadrature Amplitude Modulation (64QAM) system is investigated through simulation. The simulation results show that the proposed algorithm requires no multiplier and reaches the approximate performance as the M th-power operation in the frequency offset estimation. Therefore, the algorithm reduces the complexity with similar performance compared with M th-power operation.