应用于GPS接收机的序贯检测器性能分析

Performance analysis of sequential detector for GPS receivers

为了对使用Tong搜索检测器的全球定位系统(GPS)接收机的信号捕获性能进行理论评估,以及在设计中确定该检测器的参数值,推导了该检测器的总虚警概率、总检测概率以及平均驻留时间的计算公式,修正了在此之前研究领域普遍使用的该检测器捕获性能分析公式中的错误,并通过数值验证讨论了该检测器各参数的作用。仿真结果表明:增加Tong搜索检测器内置的计数器初值可以改善捕获性能。在总虚警概率高于0.1%的情况下,降低计数器最大值,同时增加计数器初值可使同等检测概率条件下,平均滞留时间变短。

Tong detectors are widely used in GPS receivers. The established random walk process with two absorbing barriers model was used to develop theoretical formulas for the overall probability of false alarms, the overall probability of detection, and the mean number of dwell times. The functions of the Tong detector parameters are demonstrated by numerical simulations. Experimental results show that increasing the up/down counter initialization in the Tong detector improves the acquisition performance. When the overall probability of false alarms is larger than 0.1 %, increasing the initialization value B and decreasing the maximum value A can shorter the mean number of dwell times on the condition that the overall detection probability is unchanged.