國立臺灣大學電機工程學系暨研究所汪重光2006-07-252018-07-062006-07-252018-07-062001-07-31http://ntur.lib.ntu.edu.tw//handle/246246/7813本文中，主要是在探討以離散多載波 為調變方式的超高速數位用戶迴路傳收機 的架構及其設計。而其所要考慮的雜訊環 境除了一般的白色可加性高斯雜訊之外， 還有近端串音雜訊、遠端串音雜訊、以及 射頻訊號干擾。在發送端，使用反快速傅 利葉轉換來做調變器。因為在超高速數位 用戶迴路傳收機的標準中有五種不同的子 通道數量，為了可以五種都可以支援，所 以採用四級以二為基數，三級以八為基數 的架構的反快速傅利葉轉換。在接收端， 所使用的快速傅利葉轉換和發送端的反快 速傅利葉轉換一樣。除此之外，這個系統 採用一個參數節點的頻域等化器並且配合 Cyclic Prefix 來消除通道效應和預防符元 間的干擾。如果脈衝響應的長度長於所允 許最長Cyclic Prefix 的長度，則用時域等 化器來將其脈衝響應的長度縮短來預防符 元間的干擾。同時，用時序回復電路來回 復正確的類比數位轉化器的取樣頻率。In this paper, a DMT (Discrete Multi-Tone) based VDSL (Very High Speed Digital Subscriber Lines) digital transceiver that can transfer 52Mbps data rate is proposed. The noise environment includes additive white gaussian noise (AWGN), Far-End Cross Talk (FEXT), Near-End Cross Talk (NEXT), and Radio Frequency Interference (RFI). In the transmitter, the Inverse Fast Fourier Transform (IFFT) is designed to modulate the data. There are five sizes of the tones in DMT based VDSL. In order to be compatible with these modes, the architecture that includes four radix-2 stages and three radix2/4/8 stages is proposed. In the receiver, the Fast Fourier Transform (FFT) that has the architecture the same as IFFT is employed to demodulate the incoming signals from channel. Besides, the Cyclic Prefix (CP) and Frequency Domain Equalizer (FEQ) are designed to combat the Inter Symbol Interference (ISI) effects. If the impulse response of the channel is larger than the maximum length of the cyclic prefix, the Time Domain Equalizer (TEQ) is used to shorten the impulse response of this kind of the channel. Mean while the timing recovery system is adopted to provide a stable sampling phase.application/pdf258106 bytesapplication/pdfzh-TW國立臺灣大學電機工程學系暨研究所傳收機VDSLDMTtransceiversreporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/7813/1/892218E002079.pdf