Research On Simulation Of Non-orthogonal Multi-Modulation In Field Phone Line Channel

Modulation is a basic part in the digital communication system, which plays an important role for the transmission performance. In wire communication, the advanced line coding techniques are PAM, QAM and DMT. Professor Liang Dequn proposed Non-orthogonal Multiple Modulation Technology, which could have huge influence on the development of digital communication.The defense communication network of a country includes military communication network, a part of nationality commonality communication network and the other special network. The military communication includes strategy communication network and field communication network. The technology construction of strategy communication network and national public communication network is similar. But the technology construction of field communication network is different from the national public communication network.To study the performance of NMT, the thesis designs and simulates the communication system based on NMT with SIMULINK in MATLAB. The network analysis instrument, hp8753D, is used to test the channel model of Field Phone Line channel. The principle of this test is demonstrated in detail. At the same time the mathematic formula by the method of least squares is built, finally these two channel models are analyzed. Under the condition of different transmission rate, the relationship between Signal to Noise Ratio and Bit Error Ratio are analyzed. The experiment results indicate that both transmission distance and rate are satisfied. On the foundation of basic NMT construction, the encoding technology is the additive wave, which solves problems of transmission distortion used primary NMT encoding technology and ill-conditioned system of equations. In addition, the simulation is a convenient visualized tool for other performance's testing.