基于循环谱包络的扩谱直序信号的码片 时宽、载频、幅度估计

Chip Width, Carrier Frequency and Amplitude Estimation of DS Signal Based on Cyclic Spectrum Amplitude

扩谱直序信号是二二阶循环平稳信号,其循环谱幅度包含了信号的码片时宽、载频、幅度等信息,通过分析,文中提出利用非零循环频率处谱峰的位置与大小估计这三个参数的算法,算法不需要伪随机码序列和信号参数等先验信息,可实现对信号参数的盲估计;对参数的估计是在非零循环频率上进行两个一维搜索,很大程度避免或减小了平稳噪声和干扰的影响,适用于低信噪比情况,且避免了多维搜索;文中还分析了算法的实现条件,并通过仿真实验对估计算法性能进行评估.

DS signal is a second order cyclostationary signal, where the information of chip width, carrier frequency and amplitude of signal is included in the amplitude of cyclic spectrum. A novel parameter estimation algorithm of DS signal, which makes use of the position and magnitude of non-zero cyclic spectral peaks to estimate the three parameters, is presented. This algorithm can implement blind estimation without a prior knowledge of pseudorandom sequence and signal parameters. This algorithm is suit for the estimation of low input signal-to-noise ratio, which can weaken or avoid the affection of stationary noise and interference by searching in nonzero cyclic frequencies. Moreover, this algorithm is more efficient by reducing multi-dimensional search to three single dimensional searches. The implement condition of the algorithm is analyzed and the performance of parameter estimation is measured by computer simulation.