Research And Implementation Of VDSL2Crosstalk Process Engine

In2006, ITU launched VDSL2, a new generation of DSL technology, which frequencyrange increased to30MHz and can provide up to100Mbps symmetric rate in theory.Unfortunately, operating at high frequencies, leads to crosstalk between the differenttwisted-pair. Crosstalk is the main factor of affect the transmission rate and performancequality in VDSL2. Therefore, How to suppress crosstalk interference and increase thetransmission data rates of VDSL2system is an important research topic in the area of acessnetwork currently.This paper studied the zero-forcing algorithm and the first-order algorithm for traditionalcrosstalk cancellation, and comparison between the two algorithm for the basic principles andcharacteristics have been carried out. Based on the algorithm, a crosstalk process engine havebeen designed on the VCE chip. The crosstalk process engine meets both the requirements ofthe chip area and delay during operations with many functions, such as achieving the systemlevel all crosstalk cancellation, partial crosstalk cancellation and supports up to384userlines in center office. Secondly, The crosstalk process engine whose operating clockfrequency is468MHz uses a method that combining parallel and serial operation to split the384x384x4096matrix, and is able to complete the minimum matrix cell (32x16x4)multiplication. Finally, the crosstalk process engine is programmed by Verilog HDL andverified under the Verilog Compile Simulator platform. The simulation results show that thecrosstalk process engine can properly implement the crosstalk cancellation under the controlof the controller, comparing the results with C model, correctness is satisfied.The crosstalk process engine implemented in the VCE chip can well implements thecrosstalk cancellation function in high speed communication VDSL2system, This shows thatthe crosstalk process engine has good practical value and application prospects.