Stimulation Of Non-Orthogonal Multi-Modulation Technology On VDSL Channel

Compared to the digital wide-band communication technologies that have developed rapidly in backbone network and many ways of communications, user access network has developed much more slowly and has become the bottleneck of the entire communications network, especially of the high speed Internet. Since the middle of 1990s, xDSL has been one of the main ways to solve the problem of "the last mile". But the transmission rate of the existing xDSL has been unable to meet the need of increasing on high speed of information transmission.The Non-orthogonal Multi-modulation Technology (NMT) which was brought forward by Professor Dequn Liang breaks through the limitation of orthogonality, brings higher rate-to-bandwidth ratio to traditional orthogonal modulation technologies. Besides, NMT has a more significant advantage than DMT adopted in present xDSL in the aspects of peak-to-average ratio(PAR), anti-phase shift, anti-frequency shift and power demand.In order to carry forward the practical application of NMT, it is necessary to do the research of its stimulation on communication channel to testify the feasibility of NMT. Much research of NMT on communication channel has been done by former postgraduates to prove its feasibility and advantage, but the stimulation of VDSL channel has not been researched yet. Due to the transmission distance getting shorter, the tansmission rate of VDSL is improved on a large scale. According to the fact that NMT has more advantages than DMT in the stimulation of ADSL channel, it's expected that NMT should have a higher transmission rate than DMT on VDSL channel. On the purpose of researching the applications of NMT on VDSL channel, this thesis uses the software of MATLAB to experiment the stimulations of the performances of this system, and makes further efforts to testify the feasibility of NMT and its wide applyingprospect.This thesis introduces the fundamental principle of NMT, foundation of VDSL channel and its analog simulation, and compares the transmission rate with the one by using modulation of DMT in the same conditions. The results of simulation experiments indicate that NMT has higher data rate-to-band-width ratio and transmission rate than DMT. By the end, in order to decrease the high sample rate characteristic of NMT, I make use of the double-side-band that restrains low side band to carry out the twice carrier modulation, and do the research of its affect on the other system performance indexes under this condition.