基于瞬时相位的BPSK信噪比估计算法

Instantaneous phase based SNR estimation algorithm for BPSK signals

通过对加性高斯白噪声条件下正弦型信号瞬时相位分布情况进行研究,提出了一种新的BPSK(Binary Phase Shift Keying)信噪比估计方法.含噪信号瞬时相位的方差与信噪比之间存在近似线性的一一对应关系,以此为基础通过将含噪信号的估计方差与理论值相比较获得信噪比估计值.该方法直接对基带过采样信号进行处理,不需要事先进行符号定时与同步.使用计算机仿真测试了算法的估计性能,并与高阶累积量方法和子空间分解方法进行了比较,结果表明该算法具有更高的估计精度.

By studying of the characteristics of the instantaneous phase of the mixed signals of sinusoidal signal and additive white Gaussian noise （AWGN）, a novel signal-to-noise ratio （SNR） estimation algorithm for binary phase shift keying（BPSK） signal was proposed. There is a nearly linear one to one relationship between the variance of instantaneous phase and the SNR, based on which the estimation of SNR was acquired by comparing the variance of instantaneous phase of the received signal with the theoretical one. The algorithm treated directly with the over sampled baseband signal, so symbol timing and synchronization, which were hard to acquire when symbol-rate is unknown or in accurate, are not needed. Computer simulations were used to test the performances of the SNR estimation algorithm. Results show that the proposed algorithm is more accurate in precision than the high-order cumulants based method and the subspace decomposition based method.