AWGN和FEXT噪声下铜双绞传输线的信道容量

On the Capacity of the Copper Twisted Pairs in the Presence of AWGN and FEXT

本文研究加性白高斯噪声和远端串音两种噪声并存时铜双绞传输线的信道容量，用数值方法给出了不同线路长度和不同输入功率时的信道容量，研究了达到信道容量时的最优输入功率谱密度分布。计算结果表明，在加性白高斯噪声和远端串音同时存在时，信号的输入功率谱不再为均匀分布，这种不均匀性随着输入功率的增加更为明显。这与干扰为纯白高斯噪声时，最优输入功率谱近似为均匀分布的结果是不同的。

This paper studies the capacity of the copper twisted pairs in the presence of additive white Gaussian noise (AWGN) and far end crosstalk (FEXT), gives the channel capacity in different lengths and different input powers by numerical methods, studies the optimum input power spectral density distribution at achieving the channel capacity. The calculating results show that the distribution of the optimum input power spectral density in the presence of AWGN and FEXT is not uniform anymore. With increasing of the input power, this characteristic is more clear. This is difference from the situation where AWGN is the only interference, where the distribution is approximately uniform.