短波低速调制解调器字同步的实现方案

Implementation of Word Synchronization for HF Low-speed Modem

在无线数字通信系统中,同步是一个非常重要的问题。短波低速数字调制解调器中字同步的实现方案是:发端采用统一的信号格式严格以规定的时间间隔发送,其中字同步码为七位巴克码"1110010";收端则将收到的信号与该巴克码进行相关运算,然后利用字同步码的周期性进行大数判决。

In wireless digital communication system, synchronization is a very important problem. The implementation of word syn- chronization about the short wave low speed digital modem is： the transmit port of the modem adopts uniform signal for- mats strictly to guarantee sending within specified period, in which the word synchronous code is seven bits barker code “1110010”. On the other hand, the receive port implements correlative operation between the received signal and the barker code, then carries out large number judgment using the periodicity of word synchronous code.