检测直扩信号载波频率的边带相关算法

Side-correlation Algorithm for Detecting DS Signal's Carrier

载波频率检测是信号频谱监测,侦听的前提。介绍了一种检测直扩信号载波频率的算法,边带相关算法。采用二进制移相键控调制的直扩信号,其频谱的两个边带是以载波频率为中心左右对称的,边带相关算法利用这种对称性,计算直扩信号频谱的边带相关函数,然后求峰值频率,进而确定载波频率。该算法的优点是检测准确率在较低的信噪比条件下仍然很高,因此很适合于工作在低信噪比条件下的直扩信号。计算机仿真结果证明了该算法的有效性。

The detection of DS signal's carrier is important for signal spectrum interception.A algorithm of side-correla- tion for detecting DS signal's carrier is introduced.The two side spectrum of DS signal modulated by 2PSK are sym- metrical by the carrier.The side-correlation can be calculated using algorithm of side-correlation from the symmetry. When the frequency is equal to carrier,the value of the side-correlation is maximum.The advantage of this algorithm is that the probability of detection is high when SNR is low.The algorithm of side-correlation is fit for the detection of DS's carrier because of DS signal often works at low SNR.The algorithm is effective from the results of the computer simulation.