A Study of Pseudo-Range Errors Induced by Group Delays of Intermediate-Frequency Bandpass Filters in the CAPS

A Bandpass Filter (BPF) is an important component of the receiver in the Chinese Area Positioning System (CAPS). Group delays, especially those of wide-frequency ranging codes, are among the major sources of pseudo-range measurement errors. In this paper we present certain analyses of the principle of tracking and processing code signals. We subsequently derive the theoretical formula of a pseudo-range error and describe simulations of effects of a BPF. Based on these we have studied an approach to optimize group delays to improve the design of the CAPS receiver. The results of our study can provide useful references for the design of the GNSS receiver.