Transmission Channel Modeling And Noise Analysis Of VDSL

The purpose of this paper is to do analysis and simulation on various noises probably produced in the process of transmission or in the transmission channel of VDSL.VDSL technology is considered as the next generation product of the Asymmetrical Digital Subscriber Loop (ADSL), which is the conception expansion of ADSL, so it is in the research stage. The VDSL models and some basic criterion are introduced; the advantages of VDSL are compared and analyzed, and the developing actuality is shown in this paper.The performance simulation analysis of VDSL system can provide theoretical foundation to some work such as VDSL system designing, standard establishing, etc, therefore, it has very important significance. The process of performance simulation analysis is to set up exact channel model and interference model first, which is according to the characteristics of twisted-pair channel and various interference; then can get the transmission performance by the computer simulation program, basing on the coding and modulating methods of VDSL transmission. Therefore, it is first to simulate the channel condition of VDSL and various kinds of interference in VDSL's practical work, no matter in the process of analyzing the performance of VDSL or test it. VDSL is the connecting technology realizing the final transmission by the twisted-pair, so the simulating process of channel condition is the modeling process of twisted-pair channel, which shows that the modeling of twisted-pair channel is more important. Identically, the influences of various noises on system in the transmission process can't be ignored either. Various interference which influencing the DSL system performance are introduce in this paper, including background noise, cluster interference, wireless electromagnetism interference and impulse noise, etc. This paper has done deeper theoretical analysis according to the transmission channel characteristics and various noises interference in the transmission process ofVDSL, at the same time, the channel modeling and noise simulation analysis are carried through by using MATLAB tool.The result of the modeling simulation is to know which coding method is to adopt, to get best transmission velocity in the twisted-pair transmission and the lowest interference and wastage, extending its transmission distance as far as possible.The significance of this paper is to bring forward some improvements to practical VDSL system, by doing a series of research on the theoretical foundation, implementing standard, concrete achievement and application of it.