GPS软件接收机信号的快速捕获与跟踪

根据GPS软件接收机对数据块进行信号处理的工作方式，研究基于快速傅里叶变换的循环相关法伪码快速捕获与跟踪技术。基于实测GPS中频数据，采用循环相关法在频域计算输入信号与本地信号的相关值，由相位关系得到精细载频。仿真结果表明，该技术能减少运算量，缩短捕获时间。得到的载频能满足跟踪环对频率分辨率的要求。对跟踪结果进行子帧匹配和奇偶校验后，可以获得导航电文信

Fast Acquisition and Tracking for Signal of GPS Software Receiver

According to the working mode of GPS software receiver to do signal process on data block, this paper studies fast acquisition and tracking technology for fake code of circular correlation method based on Fast Fourier Transform(FFT). Based on CPS intermediate frequency data getting by operational test, circular correlation method is used to calculate correlation value of input signal and local signal in frequency domain.Fine carrier frequency is obtained by phase relation. Simulation results show that this technology can reduce computation quantity and shorten acquisition time. The obtained carrier frequency can meet the tracking loop's demand about frequency resolution. Navigation information can be obtained through sub frame match and parity check of tracking result.