Research On Far-end Crosstalk Vectorization Cancellation System And Power-control Based G.fast

With the rapid development of high-definition video services, people’s demand of the rate access to the Internet have been increasing, the problem of the high cost of fiber access and the difficult of fiber to the home, make the last kilometer become the one last hurdle between people and the Internet. Therefore copper access to the Internet technology get more and more attention and development.The problem of copper access technical is the presence of far-end crosstalk severely affected the transmission of signals. In order to solve the far-end crosstalk problem, in this paper, we deeply discussed the technique of vectoring cancellation for far end crosstalk, a system model is proposed and a rigorous derivation of the formula is given. In addition, For the problem of power control and power allocation in the system, a corresponding power control algorithm is proposed and the feasibility and effectiveness of the algorithm are proved.First, this paper discusses and proves the principle of Vectoring technology and a system model is proposed to counteract the far end crosstalk. The accuracy of calculate the inverse matrix can be improved as compared with the original algorithm, This model can cancel the far-end crosstalk between lines effectively in the upstream and downstream direction, improve the signal to noise ratio and capacity of the channel.Secondly, this paper declared the necessity of transmit power requirements and power distribution, proposed a power constraint algorithm and Can effectively control the transmission power, and combined with the power water-filling algorithm, it can be reasonably allocated transmit power for each sub channel in the system, and the algorithm execution process is explained in detail. The algorithm can additional increase the total capacity of the channel.Finally, this paper use the collected data of the verification system, analyze the performance of the communication system in the upstream and downstream directions, the results shows that the proposed system can effectively counteract the effects of the far-end crosstalk between lines, power control algorithm can enhance the signal to noise ratio on the lines and promote channel capacity.