On the Capacity of Twisted-Wire Pair under AWGN and FEXT Noise Environment

Hua LIN  Takashi YAHAGI  Jianming LU  Xiaoqiu WANG  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E84-A   No.4   pp.1074-1080
Publication Date: 2001/04/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Communication Theory and Signals
asymmetric digital subscriber line (ADSL),  far end crosstalk (FEXT),  channel capacity,  

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The performance of a twisted-pair channel under ADSL environment is assumed to be dominated by far end crosstalk (FEXT) and additive white Gaussian noise (AWGN). In this paper, we study the channel capacity of the copper twisted pair and the optimum input power spectral density distribution at this channel capacity in the presence of ADSL environment. The channel capacity under different loop length and different input power will also be given. The simulation results show that the distribution of the optimum input power spectral density in the presence of AWGN and FEXT is not uniform. This is different from the situation where AWGN is the only interference, where the input power distribution is approximately uniform.