直接序列扩频信号的信噪比估计

Signal-noise-ratio estimation for direct sequence spread spectrum signals

准确可靠地估计直接序列扩频信号的信噪比,对于辅助完成通信过程中扩频信号的同步捕获及在电子对抗中都具有很重要的意义。针对直接序列扩频信号工作中信噪比较低的特点,提出了一种通过求解接收信号相关矩阵的特征值来估计信号信噪比的方法。分析了在相同数据和随机数据扩频调制条件下接收信号信噪比估计的计算方法,并对于有频差情况下的计算方法进行了说明。计算机仿真结果表明,该方法在低信噪比的条件下具有较强的可靠性。

It is significant to accurately and reliably estimate the SNR of the DSSS signal for synchronization capturing as well as in electronic counter measures （ECM ）. In consideration of the low signal-noise-ratio （SNR） of DSSS signals, a method of estimating the SNR was given by resolving the eigenvalue of the received signal correlation matrix. The two cases of pilot modulated data and random modulated data were theoretically analyzed, and the calculating method was also presented when the frequency offset existed. The computer simulation results show the reliability and robustness of this algorithm in the estimation of the low SNR DSSS signals.