GPS软件接收机中一种新的弱信号捕获算法  

Algorithm for weak signal acquisition in GPS software receiver

作　　者：李源明[1] 张波[1] 李署坚[1] 张彦仲[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191

出　　处：《电子测量技术》2012年第11期13-17,共5页Electronic Measurement Technology

基　　金：国家"863"计划基金资助项目(2008AA04A104)

摘　　要：在软件GPS接收机中,捕获是接收机最先启动的工作模块,为保证接收机的高灵敏度,对捕获模块的指标要求严格。为了在弱信号环境下捕获GPS(global positioning system)信号,提出一种新的算法。该算法首先对1ms的数据进行分块和补零处理,然后通过对导航数据跳转沿的估计,延长了相干累积时间,综合考虑捕获时间和灵敏度,处理数据长度设置为280ms。仿真结果表明,这种算法能够捕获信噪比为-44dB的信号,同时确保较少的运算量和较高的灵敏度。Capturing is the first started working module in the software GPS receiver. To ensure high sensitivity of the receiver,the property requirements of the capturing module is strict. In order to capture the GPS（global positioning system）signals in the weak surrounding successfully,a new algorithm is proposed in this paper. Firstly,the data of 1 ms are processed using the method of block breaking and zero padding. Then by estimating the navigation data bit transitions, the coherent cumulation time is prolonged. By considering the capturing time and sensitivity synthetically, the length of the processing data is set as 280 ms. Simulation results show that this algorithm is able to capture the signals whose signal-to-noise ratio （SNR） is --44 dB. Meanwhile,the algorithm can ensure less amount of computation and higher sensitivity.

关 键 词：弱信号捕获 软件GPS接收机 相干累积 分块 补零 

分 类 号：TP228.4[自动化与计算机技术—检测技术与自动化装置]