基于DMT的HDSL／ADSL系统中的回波抵消技术

高比特率数字用户环路是在光纤用户网普及之前向用户提供宽带业务的一种过渡手段。ＤＭＴ（离散多音频调制）是一种多载频调制，由于性能优越，被广泛应用于ＨＤＸＳＬ和ＡＤＳＬ系统中。采用加波抵消的方法，可以提高系统传输速率、增加传输距离。本文着 基于ＤＭＴ的ＨＤＳＬ和ＡＤＳＬ系统中的回波抵消技术－－ＴＡＦＤＥＣ方法，即将频域的回波抵消器（ＥＣ）和时域的回波合成器（ＣＥＳ）结合起来，以达到减少运算量，降低复杂

Echo Cancellation Technology in DMT-based HDSL/ADSL Systems

The high-bit-rate digital subscriber line technology used to be a transitional means to provide subscribers with broadband sefores prior to the popularization of light-fiber subscriber networks. With its superior performance, DMT, a kind of multicarrierfrequency modulation, has found wide applications in HDSI, and ADSL Systems. In addition, the echo cancellation method can ellhance the transmission rate of the system and lengthen the distance of transhassion. This paper aims to give an introduction of the echo. cancellation technology in the DMT-based HDSL and ADSL system, of the TAFDEC (Time and Frequency Domain Echo canceller) method, which combines the frequency domain echo canceller (EC) with the time domain echo canceller (CES) to achieve the qurpose of lessening operations and reducing complexity.An imprond scheme that can further reduce complekity is then proposed.