摘要
研究了基于DSP实现的卫星跳频调制解调器的实现方案,介绍了系统的基本组成结构和调制解调原理,着重探讨了解调的同步算法的选取。卫星跳频通信的同步包括频率估计、位同步和跳频同步等多方面。首先讨论了频率同步,针对卫星通信频差较大的特点,采用了两个阶段的前馈式频率同步,分别完成对频差的粗略估计和精确估计,并对其同步性能做出了具体分析。位同步选用了数字锁相环法以忍受小的剩余频差。最后简单介绍了基于跳频同步的跳频信号的拼接。
A frequency-hopping modem based on DSP concept for satellite communication is studied. The basic architecture of the system and the basic theory of modem are introduced. A special analysis of modem synchronization algorithm is made. The synchronization of satellite frequency-hopping communication includes frequency estimation, symbol timing and frequency-hopping synchronization. In this paper, the frequency estimation is discussed first. A two-step feed-forward method is adopted to adapt to the big frequency offset of the satellite communication. One step is to achieve the coarse estimation and the other the accurate estimation. The performance of the method is analyzed in detail. Finally, the patching-up of the frequency-hopping signal based on frequency-hopping synchronization is introduced briefly.
出处
《电子工程师》
2006年第12期18-21,共4页
Electronic Engineer
关键词
卫星通信
跳频通信
调制解调器
DSP
同步
satellite communication
frequency-hopping communication
modem
DSP
synchronization
