Research on the Influence of Satellite Signal Transmission Channel’s Non-ideal Characteristics on the Quality of Different Envelope Signals

At present, most satellite navigation systems use constant envelope multiplexed signals, in order to reduce the non-linear influence of the power amplifier as much as possible. However, the actual signal transmission channel cannot be purely ideal. Various amplitude-frequency or phase-frequency distortions that may occur will affect the signal envelope characteristics and ranging performance, resulting in a certain difference between the actual signal received by the user and its theoretical design. Research has shown that the performance of the constant envelope signal after passing through the non-ideal channel may not be better than the corresponding non-constant envelope signal. In order to fully understand the specific effects of various non-ideal characteristics of the channel on the non-constant envelope signal and to judge under which non-ideal characteristics the non-constant envelope signal can show better performance, so as to provide new ideas for the design of navigation signals. This article first studies the non-ideal characteristics of the satellite signal transmission channel and establishes five channel distortion models. The BDS-3 B1 constant envelope and non-constant envelope simulation ideal signals are used as the research signals of this article, use the software receiver to evaluate the signal quality of the ideal signal after the distortion model, and use the evaluation index S-curve zero-crossing deviation to express the signal's ranging performance. Finally, the quantitative analysis and comparison of the ranging performance of different envelope signals under the influence of various distortions are realized. The results show that: Inaddition to amplitude ripple distortion, non-constant envelope signals show better ranging performance overall under the same distortion conditions. The research results of this paper have certain reference value for signal design and signal quality evaluation.