基于XFAST自适应的直接捕获算法

摘要

针对采用XFAST(Extended replica folding acquisition search technique)方法会额外造成恒定信噪比损失的缺点,提出一种基于XFAST方法的自适应捕获方法,结合非相关累加的性质进行自适应组合,对P码信号进行直接捕获.研究结果表明:此自适应捕获方法仍然可以保留XFAST计算量较小的优点,同时可以克服XFAST无法捕获到较弱信号的不足,对实际GPS P码直接捕获接收机的设计以及我国自主北斗长码直接捕获接收机的发展均具有一定的参考价值.%Based on the fact that XFAST method causes additional SNR loss, an adaptive direct acquisition algorithm which uses none-correlation accumulation was proposed. The results show that this method can retain the advantages of less computation as XFAST, and overcome the disability of XFAST acquisition for weaker signal. The adaptive direct acquisition algorithm based on XFAST has certain reference value for GPS P-code receiver and Compass long code receiver design.