现有的伪噪声(PN)码捕获算法大多是基于相关峰值进行门限判决,而捕获性能依赖于门限实时估计的正确性。针对这种情况,该文提出了一种利用多次PN码相关峰值位置间的相互关系进行判决的算法,避免了对信道噪声的实时估计,并给出了基于频域匹配滤波的实现方法和算法复杂度分析,推导了所提算法的检测概率和虚警概率,并且使用计算机仿真验证了推导结果的正确性;结果表明,所提算法避免了噪声估计的开销,增强了PN码捕获的鲁棒性,提高了捕获性能,适合工程应用。
The existing Pseudorandom Noise (PN) code acquisition algorithms are mostly focused on threshold decision and their acquisition performance depends on the correctness of the real-time estimation of threshold. In this paper, a PN code acquisition algorithm based on multi-correlation-peak value position decision that could avoid the real-time estimation of channel noise power, is proposed. The implementation steps and the computational complexity of the proposed algorithm based on frequency domain match filter are presented. Furthermore, the expressions of detection and false alarm probabili- ties are derived and validated by computer simulations. The theoretical and simulation results show that the proposed algo- rithm is able to avoid the cost of noise estimation, enhance the robustness and improve the acquisition performance. Hence, the proposed algorithm is more suitable for engineering application.