【摘要】 为解决低信噪比下直扩信号的参数盲估计问题,提出了一种基于模糊函数的直扩信号载频、码率和伪码周期估计新方法。对直扩信号的模糊函数进行了推导和分析,发现直扩信号模糊函数在特定延时和频率上有明显特征对应载频、码率和伪码周期等参数,给出了直扩信号参数估计的具体算法。仿真实验表明在扩频码长为63及码元数为16条件下,载频和码率估计可工作在-12 dB,扩频周期估计可工作在-6 dB低信噪比条件下。该方法可用于非合作通信中直扩信号的参数估计。更多还原

【Abstract】 An ambiguity function(AF) method was developed to estimate the carrier frequency,chip rate and periods of pseudo-random(PN) codes for blind parameter estimates of direct spread spectrum signals(DS-SS) in low signal-to-noise ratio(SNR) environments.The average ambiguity function for DS-SS has simple relationship between the AF characteristics and the carrier frequency,chip rate and PN periods.Simulations with a data set having 63 bit PN codes and 16 symbols show that the carrier frequency and chip rate estimation algorithm works well with SNR=-12 dB and the PN periods estimate is accurate for with SNR=-6 dB.The method can be used to estimate DS-SS parameters in non-cooperative communications.更多还原