Development And Research On Ethernet Over DSL

In this paper what is mainly discussed is how to solve the problem of "the last kilometer" network bottleneck by VDSL technology and Ethernet exchange technology, which supplies broad network serve for highly dense habitations. Firstly, the comparison between VDSL technology and other access technologies is presented. Secondly, the VDSL system that had been realized is introduced. Thirdly, the analyses are focused on the development process of the net terminal. Finally the modulation theory about VDSL technology is analyzed and a lot of arithmetic researches and emulate validation are made for ASIC realization of VDSL technology. The two important conclusions are gotten: 1. Plural feed forward equalizer and plural decision feedback equalizer have a phase emendation function. If plural equalizers in the QAM system are used, phase removing circumvolution module can be removed. 2. Two samples in a symbol has no request for sampling phase, but for sampling frequency. And better constellation can be gotten back though. The two conclusions economize the cost of ASIC realization of VDSL technology and simplified arithmetic.