低压电力线信道噪声环境下捕获算法的改进

Improved Acquisition Algorithm in Low-voltage Power Line with Channel Noise

研究一种提高直接序列扩频(DSSS)接收机捕获性能的改进方法,并探讨该方法在低信噪比低压电力线环境下的工作情况。该算法在传统滑动相关捕获算法的基础上,增加一条下通带支路,利用上、下通带内外功率差代替传统的带内信号功率,作为同步门限比较器的输入值,改善扩频接收机的捕获性能。理论证明,具有更优越的捕获性能,并适用于低压电力线环境下。最后,采用Matlab R2006b工具,在低信噪比电力线环境下对扩频系统进行整体仿真。结果表明,在低压电力线等恶劣环境下,该算法与传统的方法相比,具有更好的性能。

A new method to improve the performance of synchronization acquisition on Direct Sequence Spread spectrum （DSSS） system is put forward, and it is also discussed in low- voltage power line with low signal- to- noise. Based on the traditional algorithm of sliding correlation acquisition, this algorithm adds another branch circuit, uses the power difference between in - band and out - of - band signal as the threshold of comparator instead of the traditional in - band signal power, which improves the acquisition performance of spread spectrum receiver. Also, this arithmetic is proved in theory to be applicable to the low - voltage power line with low signal - to - noise. Simulation of spread spectrum system is given under the low signal - to - noise power line environment by using MATLAB R2006b. The results show that the new method is more efficient than the traditional one,especially in low- voltage power line environment.