导航卫星多数表决恒包络技术研究

摘要

In order to improve the efficiency of frequency, modern satellite navigation systems often transmit several signals via one channel. The direct linear combined signal , which is not a constant envelope one, will make a distorted wave shape when through high power amplifier (HPA) ,and it will also affect the performance of the navigation system. It is necessary to research the constant envelope technology for solving this problem. The majority voting , which has been used in deep space domain successfully, is a constant envelope technology for binary signal. Because of the characteristic of constant envelope, it allows the signal to go through C class HPA. This paper introduces the meaning of using the constant envelope technology and criteria of evaluating the constant envelope technology. The majority voting technology is also studied, including uniform weighting, nonuniform weighting and generalized majority arithmetic. Therefore, the simulation result of multiplexing efficiency and the power spectral density function are given. This paper could play a role of theoretical reference for satellite navigation signal desigr.%为了提高频带的利用率,现代卫星导航系统往往在一个信道内发送多路信号.直接的线性组合信号不是恒包络的信号,在通过功率放大器时会产生失真,影响信号的性能.为解决这一问题,引入了恒包络生成技术.多数表决算法是针对二进制信号的一种恒包络算法,目前已经成功应用于深空通信中的信号处理;其恒包络特性允许信号通过效率较高的C类功率放大器且不引起信号崎变.文章首先介绍了使用恒包络算法的意义和衡量恒包络算法优劣的评价准则,然后分别介绍了等功率、非等功率、通用的多数表决算法,并给出了复用技术效率变化的仿真结果、典型情况下的功率谱密度,可为卫星导航系统的信号设计提供理论参考.