摘要
研究了一种数字中频GPS信号生成方法。给出了数字中频信号数学模型,模型考虑了各种因素对信号的影响。通过导航电文分析,提出信号传播时延、多普勒频移以及信号入射方向的估计方法。给出了中频信号产生的流程,对其中时延的设置,信号的上变频、信号幅度设置以及方向信息的导入进行了阐述。对所生成的信号模型进行了仿真分析,给出了信号产生各个阶段的频谱,对所生成的信号进行了相关捕获。仿真结果表明频谱特征符合理论分析,能够被捕获并找出信号时延从而实现定位。证明该信号模型能作为信号源应用于GPS接收机研制中。
The paper discusses a digital IF GPS signal generation method, gives the mathematic model of digital IF signal. This mathematic model takes into account the influence of various factors. Based on analysis of the navigation data, the method to estimate signal propagation time, Doppler frequency shift and the coming angle of signal is proposed. The flow to generate IF signal is given, in which the setting of time delay, the up-frequency conversion, the setting of signal magnitude and the introduction of direction information are expounded. The signal generation model is simulated and analyzed, the spectrum of signal in each stage given, and the correlation capture of the generated signal also done. Simulation indicates that the spectrum is in accord with theoretical analysis; the signal could be captured, thus find the time delay, accomplish the orientation. The signal model is proved applicable in the research and development of GPS receiver.
出处
《通信技术》
2012年第6期124-127,130,共5页
Communications Technology
