一种改进的GPS信号捕获策略的性能分析

Performance Analysis of an Improved GPS Acquisition Strategy

针对一种克服位翻转设计的GPS信号捕获策略缺乏理论评估,以及判决门限计算公式失配的问题,对该策略下的接收机捕获性能做了理论分析及定量评估,给出了虚警概率和检测概率的解析表达式,以及修正的判决门限计算公式。从理论上证明了这种策略在存在数据位翻转时的有效性,并指出当利用传统判决门限计算公式对该策略进行设计时,预期性能与实际捕获性能间存在较大偏差,而给出的修正计算公式可以得到与真实值吻合的分析结果。该结论对接收机研制有指导意义和实用价值。

A GPS signal acquisition strategy designed for overcoming data bit flip lacks the theoretical appraisal,and the corresponding judging threshold calculation formula does not match.By strict mathematical derivation and simulation,the theoretical analysis and the quantitative evaluation of receiver acquisition performance under the strategy are investigated in this paper.The expressions of false-alarm probability and detection probability,and an improved compensational formula of judging threshold are derived.It is shown that,the strategy is effective when there is a data bit flip,and compared with traditional threshold expressions,the derived expressions are more close to the practical results compared with the conventional formula.This conclusion is important for practical engineering application.