Frequency Based TEQ Design with Oversampling

• Main Authors: Shao-Lun Hung, 洪紹倫
• Other Authors: Yuan-Pei Lin
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/51866885258756076790

碩士 === 國立交通大學 === 電機與控制工程系所 === 94 === In this paper, we design TEQ (time domain equalizer) for DSL (digital subscriber loops) applications using a frequency domain based approach. In DSL applications, usually frequency division multiplexing is used to separate the upstream and downstream signals. In either direction of transmission, some of the frequency bands are not used for transmission. Interference is formulated and minimized in the frequency domain to take advantage of the unused frequency bands. The frequency domain approach allows us to have a more direct control over the frequency response of the resulting TEQ, which is crucial in the final achievable transmission bit rates. Furthermore we will extend the method to the case when there is oversampling at the receiver to gain additional performance improvement. Oversampling is often used for time synchronization at the receiver and it also arises when the number of tones actually used for transmission is less the maximum possible number. The simulation examples demonstrate that the proposed methods (with or without oversampling) shortens the channel effectively and very good transmission bit rates can be achieved.