基于多卫星的GPS中频信号生成方法

A Method of Intermediate Freguency GPS Signal Processing Based on Multi-Satellites

提出一种GPS中频数字信号的生成方法,以实现信噪比和多普勒频移均可调的多卫星GPS信号的模拟,可为软件接收机技术以及基于微弱信号处理的高灵敏度GPS接收机的研究提供可靠的信息源.根据接收机中信号处理模块的功能架构提出GPS中频信号模型,并使用真实伪距和载波相位等GPS原始数据、多卫星的导航信息和强度可调的噪声信号模型等拟合出GPS的中频信号.通过捕获、跟踪和导航电文解调等实验结果表明,生成的信号完全具备GPS信号的所有特征,可用于软件接收机的定位解算.

Thispaper presented a method to generate GPS intermediate freguency （IF） digital signal for simulation of GPS signal based on multi-satellites with adjustable carrier-to-noise ratio and Doppler shift. This GPS IF digital signal can be served as reliable data resource in the research of development of software receiver and high-sensitivity GPS receiver based on weak signal processing. The mathematic model of GPS IF signal was designed according to signal processing module in GPS receiver, then GPS IF signal is generated by navigation data of multi-satellites, modulated noise model with adjustable intensity, and GPS raw data which includes real pseudorange and carrier phase. The experimental results of signal acquisition, tracking and navigation data decoding show that GPS IF signal has all the characteristics of real GPS signal, and it can be used in position estimation in software receiver.