基于数字变频处理的GPS/BDS双模捕获

GPS/BDS Dual Mode Acquisition Based on Digital Frequency Conversion

全球定位系统(Global Positioning System,GPS)与“北斗”定位导航系统(Beidou Navigation Satellite System,BDS)的双模导航能够提高定位稳定性与精确性,但通常在前端硬件设计中需要建立双通道对GPS和BDS射频信号分别进行处理,极大地增加了硬件设计复杂度以及功率的消耗。针对双通道硬件设计的复杂性问题,提出了在Matlab环境下对GPS/BDS双频信号进行数字变频处理的方法。该方法将硬件中的变频功能在软件中实现,从而降低了硬件设计的复杂度且保证了算法与不同全球卫星导航系统(Global Navigation Satellite System,GNSS)以及前端硬件的兼容性。实验结果表明,在不同的单通道硬件设计下,利用该方法能够成功在软件中消除与L1或B1的频偏得到捕获信号,并捕获到GPS/BDS可见卫星信息。

Even though dual mode navigation based on global positioning system(GPS)and Beidou navigation satellite system(BDS)can increase positional stability and accuracy,two channels are built in front-end firmware to respectively process GPS and BDS radio frequency signals.Therefore,the complexity of firmware design and power consumption are significantly increased.For the complexity problem of dual channel firmware design,a method based on digital frequency conversion is proposed to process GPS/BDS dual frequency signal under the Matlab environment.The method can achieve the same frequency conversion performance in software as achieved in firmware design.In this way,the firmware design complexity is reduced,the compatibility with global navigation satellite system(GNSS)and different front-end firmwares can be guaranteed.As the results illustrate,through using different single-channel firmwares,the method can successfully wipe off offset from channel center to L1 or B1 carrier and acquire the visible information of GPS and BDS.