基于小波熵的BPSK信号码元速率估计算法

Symbol rate estimation algorithms based on wavelet entropy

为了解决在低信噪比下准确地估计BPSK信号的码元速率问题,提出了基于小波能谱熵和小波时间熵的两种码元速率估计算法.通过一维多尺度小波变换重构高频部分,分别计算重构信号的小波能谱熵和小波时间熵.对于小波能谱熵,可以直接求取码元速率;对于小波时间熵,需要根据进一步叠加运算后的峰值来求取码元速率.仿真实验表明这两种方法都可以很好地处理低信噪比下BPSK信号的码元速率估计问题,并且比瞬时自相关法具有更强的抗噪性和适应性.

To estimate the symbol rate of BPSK signal in low signal-noise ratio environment, two methods based on wavelet energy entropy （ WEE ） and wavelet time entropy （ WTE ） were proposed in this paper.After reconstructing the high bandwidth of the signal’ s multi-scale wavelet transformation, the WEE and WTE were calculated, respectively.For wavelet energy entropy, the symbol rate can be estimated directly.For wavelet time entropy, the symbol rate can be estimated based on the peaks processed by superposition operation.The simulation results showed good performance of both two methods.Furthermore, these two al-gorithms were less influenced by the noise and have better adaptability than instantaneous au-tocorrelation method.