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 the instantaneous phase distribution of sinusoidal signals under additive Gaussian white noise, a new BPSK (Signal-to-Noise Ratio) estimation method is proposed. The variance of instantaneous phase of the noisy signal and the signal-to-noise ratio There is an approximately linear one-to-one correspondence, based on which the signal-to-noise ratio estimate is obtained by comparing the estimated variance of the noisy signal with the theoretical value. This method directly processes the baseband over-sampled signal without the need for prior symbol Timing and synchronization.Compared with high-order cumulant method and subspace decomposition method, the performance of the proposed algorithm was tested by computer simulation. The results show that this algorithm has higher estimation accuracy.