i
應用於離散多載波傳收器之低複雜度時域等化器
學生： 沈柏成 指導教授： 李程輝 博士 國立交通大學電信工程學系碩士班中文摘要
在離散多頻帶（discrete multitone，DMT ）接收器中，使用了一個時域等 化器（time-domain equalizer，TEQ）來縮短通道響應。然而，並非所有的TEQ 設 計方法都是著重於想使傳輸速率變大。近年來，有些學者已注意到這個問題也提 出 了 解 決 這 個 問 題 的 方 法 。 現 今 有 一 個 方 法 即 是 Minimum intersymbol interference (Min-ISI) 。這方法可以使DMT系統的傳輸速率接近通道最大傳輸 速率。然而這方法的缺點是必須耗費相當多的乘法，這在實際上的即時處理器是 不易實現的。因此，我們希望能改進其為一個低複雜度的方法。在本論文中，我 們將要研究這個問題，並提出兩個簡化的演算法。在最後的模擬中，我們可以發現簡化方法所得到的傳輸率與原來的 Minimum intersymbol interference
ii
Reduced Complexity Time-Domain Equalization
Methods for Discrete Multitone Transceivers
Student: Po-Cheng Shen
Advisor: Dr. Tsern-Huei Lee
Department of Communication Engineering
National Chiao-Tung University
Abstract
In the discrete multitone (DMT) receiver, a time-domain equalizer (TEQ) is used
to shorten the channel response. However, not all of the existing TEQ design methods
aim at maximizing bit rates. The minimum intersymbol interference (Min-ISI) method
yields TEQ designs for DMT modulation transceivers that are close to channel
capacity. For eight standard ADSL channels, the Min-ISI design method reaches
within 2% of the matched filter bound at the TEQ output. However, the Min-ISI
method relies on several computation ally expensive multiplications. In this thesis, we
develop low-comp lexity TEQ design algorithms for these multiplications to allow for
real-time implementation of the Min-ISI method on programmable digital signal
processors. Based on simulations using eight different carrier-serving-area loop
channels, we can show that the two proposed modified methods yield high bit rates.
Its performance is very close to the original Min-ISI design method.
iii
Acknowledgements
I am deeply grateful to my advisor, Professor Tsern-Huei Lee, for his continuous
encouragement, support, and enthusiastic discussion throughout this research. His
valuable suggestions help me to the success of this work.
Also this is an opportunity to express my sincere appreciation to all the staff of
the Institute of Communication Engineering, National Chiao Tung University, for
their encouragement and help. Especially, I would like to thank the members of
Network Technologies Laboratory for their stimulating discussion and help.
This thesis is dedicated to my parents for their patience, love, encouragement and
