一种基于循环谱的突发信号盲检测算法

A Blind Detection Algorithm of Burst Signal Based On Cyclic Spectrum

突发信号盲检测在非合作通信中至关重要。待检测信号特征量的构造与突发信号段起止点的精确捕获是突发信号盲检测技术的关键。文中提出了一种基于循环谱的突发信号盲检测算法,算法首先以循环谱循环频率截面的相对方差作为待检测信号的特征量,该特征量具有优良的抑制突发强噪声干扰性能;然后利用特征量的方差进行信号存在性判决;最后采用基于特征量峰值的突发信号段起止点搜索算法,避免了设置检测门限带来的信噪比估计、噪声功率估计等问题,同时可在一定的检测正确率条件下保证起止点的捕获精度。仿真结果表明,该算法能有效抑制突发强噪声干扰,信号存在性判决准确率高,而且在误差控制要求较严格条件下的检测精度优于双窗能量法。

The blind detection of burst signal is extremely important in the non co-operative communication.The key technology of the blind detection for the burst signal is the features construction and precise start point capture.A new blind detection algorithm based on the cyclic spectrum is proposed in the paper.Firstly it provides the relative variance of cycle frequency profiles data derived from the cyclic spectrum as the detection feature,which can effectively depress the interference caused by the strong noise.Secondly, the variance of the detection feature is used to estimate the existence of the useful signal,and it has a good correct detection ratio. Then,the searching algorithm based on the peak value of detection feature is designed to catch the start point and the end point of proruption signal accurately,and it can avoid many problems caused by the setting of threshold,which is used to distinguish signal from noise.Simulation results show that,the algorithm proposed in the paper has a good performance,it can depress the interference caused by the strong noise,has a good detection ratio of the useful signal,and under the strict error control circumstance,it can catch the start point and the end point of proruption signal more accurately than the algorithm based on the ratio of the energy of two adjacent segment signals.