XFAST长码直捕算法参数优化设计

Optimization of XFAST design

提出一种以单位码相位搜索计算量最小为优化目标,捕获概率和虚警概率确定条件下的XFAST参数优化算法。首先研究存在伪码多普勒条件下的XFAST算法的捕获概率和虚警概率的精确解析表达式,其次对单次XFAST搜索相位数进行分析,在此基础上计算搜索单位相位所需计算量。并给出了在载波多普勒不确定度固定-6^+6 kHz和载噪比固定46 dBHz条件下的捕获单位计算量最小的参数优化设计,可以实现捕获概率为95%,虚警概率为1×10-6的性能,最后通过仿真结果验证了本文理论优化算法的正确性。

An optimization of computations in one unit code phase with restriction of property of detection and false alarm was introduced. The property of detection and false alarm with code Doppler were calculated, then the calculations of searching one code phase were analysed. Two samples with carrier Doppler fixed -6—6 kHz or carrier to noise ratio fixed 46 dBHz are given, the detection probability of 95% and false probability of 10-6 can be achieved. Finally, the results are confirmed by simulation.