一、引言为了构成灵活的数字通信网,以传输数字信息,除了需要传输、交换等设备外,还需要一种能够把若干低速数字流组合成为一个较高速率数字流的设备,这种设备就是数字复接设备。它是数字通信网的基础设备之一。大家知道,各种数字传输信道都有一定的数字传输速率。为了有效地利用这些传输信 I. INTRODUCTION In order to form a flexible digital communication network for the transmission of digital information, there is a need for a device capable of combining several low-speed digital streams into a higher-rate digital stream, in addition to the equipment required for transmission, exchange, and the like Digital multiplexing equipment. It is one of the basic equipment of digital communication network. We all know that a variety of digital transmission channels have a certain digital transmission rate. In order to effectively use these transmission letters