绪论在TDMA卫星通讯方式中,要求由一帧中的少数几个比特建立起钟同步。当地面站不多时,在收端对应每个发站配备一个锁相环的方法是可行的。其原理如图1所示。门_1门_2都受接收的本分帧地址码相关器控制。其开门时间长度,等于比特同步码所占时间长度。比特码以外的信息都被认为是干扰。因此门的主要作用是减小干扰;同时门_2也完成取样保持的功能。在这里,比特同步码采用1 0 1 0二相调相波形式。此波的延迟检波器输出受传输带宽 Introduction In TDMA satellite communication, it is required that clock synchronization be established by a few bits in a frame. When there are not many stations on the ground, it is feasible to provide a phase-locked loop for each sending station at the receiving end. The principle shown in Figure 1. Gate _1 gate _2 are received by the sub-frame address code correlator control. The length of the door opening time is equal to the length of the bit synchronization code. Information other than bit codes is considered as interference. Therefore, the main function of the gate is to reduce the interference; at the same time, Gate_2 also performs the function of sample-and-hold. Here, the bit synchronization code adopts the phase of 10 0 phase bi-phase wave form. This wave delay detector output by the transmission bandwidth