一种新型双线全双工数字电话机

A New Full Duplex Digital Phone Used in a Single Twisted Pair

介绍了一种新型双线全双工数字电话机,采用目前最先进的自适应回波抵消工作方式,克服了部分国家普遍采用的乒乓方式传输距离短的缺陷. 电路部分采用了MITEL公司最新推出的数字接口芯片MT9172和带HDLC协议控制器的数字电话专用芯片MT9092,并用MCS-51单片机控制.

This paper introduces a new full duplex digital phone which can be used in single twisted pair wires. A modern adaptive echo-cancelling technique is applied to this phone, which can overcome the shorter maximum loop shortcome of TCM(Time Compression Modulation) technique adopted by some countries. It is designed with a digital subscriber interface circuit MT9172 and a digital telephone with HDLC circuit MT9092 controlled by a MCS-51 microprocessor.