The Simulation Of NMT And NMT Prototype Test On Category 5 Cable

With the increasing popularity of the network, a variety of communication methods have been proposed. However, the modulation technique has not actually changed significantly. DMT used in access network like ADSL, VDSL, and OFDM used in 3G, 4G are based on the principle of multi-carrier invented in the early years. Other traditional modulations such as PAM, MASK, QAM, FSK and PSK are still being used. Professor Liang Dequn invented non-orthogonal multi-modulation technique (NMT), which is a multi-carrier modulation; it breaks through the orthogonal limitation. Theory shows that NMT can be faster than Nyquist rate. Compared with the existing modulation methods, it brings highest spectrum utilization. In order to promote the practical use of NMT, it needs to do sorts of simulation under different environmental conditions.In recent years, people are looking for high speed of broadband access. Fiber to the building, with the LANs which were already constructed in government and enterprises is a great network solution. Fiber to the building could provide 1GHz bandwidth and even more. So how to improve the performance of Category 5 cables to improve the performance of access is of far-reaching significance and commercial value. The performance of the existing Category 5 cables has a number of shortcomings and flaws, NMT technology may be the key to the problems.Based on the past theoretical researches and computer simulations of NMT, this thesis focuses on the computer simulation and prototype test on Category 5 cables to prove the feasibility of NMT. The thesis discusses the NMT simulation on different distances cables, like 100m, 500m and 800m Category 5 cables and the solutions of the incoming problems, for example, pretreatment and phase scrambler. With the same parameters and conditions, the thesis compares NMT with the traditional modulation -DMT to prove the superiority of NMT. And with the toolkit - Simulink of MATLAB, With the same parameters and conditions, the thesis compares NMT with the traditional modulation - DMT to prove the superiority of NMT. And with the toolkit -Simulink of MATLAB, the thesis does the modular simulation for further study and provides a performance simulation platform of NMT. Finally, with the prototype built on the development board - SignalWAVE of Lyrtech Company, the thesis does the test on the real 100 meters Category 5 cable and compares with the computer simulation under the same conditions to prove the NMT engineering feasibility. These works provide theoretical and practical basis for the future of the practical engineering of NMT.