基于平滑伪维格纳分布和最小熵的BPSK信号参数估计

针对低信噪比环境下二相编码（Binary phase shift keying，BPSK）信号的参数估计性能差问题提出了一种新方法。该方法首先对信号进行平滑伪维格纳分布（Smooth pseudo Wigner-Ville distribution，SPWVD）变换得到时频矩阵S_SPWVD（t_m，f_n），再利用最小熵法对得到的时频矩阵进行处理得到BPSK信号载频的较高精度估计。SPWVD变换将BPSK信号相位突变信息转换为时频域内信号载频处的幅度突变信息，通过搜索相邻负尖峰并进一步处理得到BPSK信号的码宽、码率、码数以及编码序列的估计。仿真结果验证了方法的有效性。

Parameter Estimation of BPSK Signal Based on SPWVD & Minimum Entropy

A new approach is proposed to improve BPSK signal parameter estimation performance under low SNR environment. First, the smooth pseudo Wigner-Ville distribution(SPWVD) is applied to the BPSK signal and time-frequency matrix S_SPWVD (t_m,f_n) is obtained, which can estimate carrier frequency of the signal combined with the minimum entropy criterion. What''s more, the discontinuity of signal phase is mapped to negative magnitude peaks on its carrier frequency in the time-frequency domain. Then,the code width of the BPSK signal can be estimated by searching the interval between adjacent negative peaks, and then the code rate, code number and phase-coded sequence could also be estimated. Finally, simulations show the validity of the proposed approach.