Channel Modeling And Simulation For G.fast System

With the development of 4K HDTV, 4G technology and other high-speed transmission network application, which cause a sharp increase in demand for voice, data and video digital services, people are increasingly demanding high bandwidth and datarates. Currently the most widely used copper access technology can only provide access rates up to 100 Mbps. Such dararate is increasingly difficult to meet people's needs. If wishes to achieve a qualitative leap, undoubtedly it requires a kind of new technology. G.fast is raised under this kind of backgroud. G.fast technology uses time division multiplexing mode, discrete multi-tone modulation, trellis coding and RS channel coding scheme and Vectoring2.0 technology, which broaden the spectrum to 106 MHz or even 212 MHz. For now, the G.fast technology has been able to make the access speeds of up to 1 Gbps within 50 m, up to 500 Mbps within 100 m and up to 300 Mbps within 200 m.Currently, G.fast technology is still hot for R&D stage. The International Telecommunication Union, British Telecom, Netherlands Telecom, Swisscom and Huawei Company are actively involved in the development of related technology and product research. The twisted wire cable used in various countries and regions are not the same. When covering a variety of scenarios require the use of various types of cable, this is very difficult to complete. To solve this problem, this paper will study the G.fast cable channel model.This paper studied and established the G.fast cable channel model starting from the existing cable channel model. Based on the modeling process, designed a common channel modeling algorithm and another modulus algorithm based on least squares method. These two algorithms are able to quickly build all types of cable channel model. After simulation, it shows that the generic channel modeling algorithm has scalability, modeling accurate, but with high complexity and amount of computation. The least squares algorithm is more quickly but lack of scalability. The generic channel modeling algorithm can not only be applied to the cable channel modeling, but also be applied to calculate circuit, which has a multi-stage filter structure, model parameters. And the method is proved being feasible by simulation.