全球导航定位系统接收机的跟踪环路带宽设计

为实现全球导航定位系统(GPS)软件接收机对卫星信号灵活稳定的跟踪,采用非相干延迟锁定环和科斯塔斯环来实现伪码跟踪和载波跟踪;选择环路的带宽,利用最优化的设计理念,设计了GPS软件接收机的最优环路带宽,并且根据所估计的信噪比来确定跟踪环路的最优带宽,以达到总的误差最小.采用GPS卫星中频信号采样器采集实际的GPS数据,并通过Visual C及MATLAB进行了仿真实验,结果表明,接收机成功地跟踪上了7路信号,并以通道1中的数据计算出了同相和正交相信号,所设计的搜索和跟踪方法灵活有效,为接收机能够快速地对GPS信号实现捕获和跟踪提供了一定的保障.同时也使得GPS软件接收机对信号处理改用软件来实现,拥有了极大的灵活性.

Design of tracking loop bandwidth of global positioning system receiver

Based on the principle of global positioning system（GPS） signal tracking, noncoherent delay- locked loop and costas loop were used for the realization of flexible and stable tracking＇to pseudo random noise code and carrier. Considering the thermal noise and dynamic stress error, the optimization method was adopted to design an optimal loop bandwidth for GPS software receiver. According to estimation of the signal to noise ratio, the optimal bandwidth was determined to achieve the minimum error. GPS intermediate frequency signal sampler was used for GPS data. Through the experiments of Visual C and MATLAB simulation, the results show that seven signals are successfully tracked, and the data of channel 1 in the calculated in-phase and quadrature phases are verified. The results proves that the method is flexible and effective. And a guarantee is provided for GPS software receiver to quickly realize the acquisition and tracking of GPS signal. At the same time, the function of using software to realize processing signal of GPS software receiver has great flexibility.