Research on the tracking accuracy of fixed-point loop for satellite navigation receiver

Based on the investigation of traditional signal tracking method and accuracy, an improved fixed-point loop control method is proposed to optimize the computation load and resource usage. The theoretical analysis and actual test of the tracking accuracy loss in comparison to ideal loop control is presented from three aspects: quantization error of discriminator, approximation of filter coefficient and computing error of filter. Addition and shift are two main operations of the method. It is obvious that the proposed method can operate easily in real-time with low resources usage and small accuracy loss. The results have verified the correctness of error analyses.