基于瞬时频率累积的FSK扩频信号检测方法

Detection Method for FSK Spread Spectrum Signal Based on Instantaneous Frequency

针对低信噪比环境下FSK扩频信号检测性能较差的问题,提出一种基于瞬时频率累积的检测方法。该方法首先利用瞬时自相关估计信号的瞬时频率,然后利用扩频码的结构特点构造归一化瞬时频率累积平均和,并通过消除中心频率影响和做等间隔滑动累积处理得到检测统计量;最后根据瞬时频率累积峰的峰值大小和间隔判断是否存在FSK扩频信号。仿真结果表明,所提方法受频率偏差影响小,在低信噪比环境下具有较好的检测性能和较低的计算复杂度。

In order to improve the detection performance of frequency shift keying(FSK)spread spectrum(SS)signals in low signal to noise ratio(SNR)environment,a detection method based on instantaneous frequency accumulation is proposed.Firstly,the instantaneous frequency is estimated by using the instantaneous autocorrelation,and then the normalized instantaneous frequency sum is constructed by using the structural characteristics of the spread spectrum code.The detection statistics are obtained by eliminating the influence of central frequency and doing the equal interval sliding cumulant.Finally,the value and interval of the instantaneous frequency cumulant are determined.The simulation results show that the proposed method is less affected by frequency deviation,and has better detection performance in low SNR environment and lower computational complexity.