The Study And Analysis Of Communication System Based On Multipath Fading And Simulation

Radio communication as an important type in the communication system, has been widely used.Among them, the wireless communication compared with cable communication,multipath fading channel environment is the main cause of the error, so the communication system in view of the multipath fading channelis studied.Found in anti-multipath fading technology research, spread spectrum communication system and OFDM communications technology can be used in multipath fading channel. In this paper, we do theoretical analysis on the two kinds of communication system, use the Matlab programming modeling, simulate and verify its ber performance in multipath fading channel. This paper mainly discussed as follows:(1)Complete the design of the direct sequence spread spectrum communication system,the frequency hopping spread spectrum communication system and the orthogonal frequency division multiplexing communication system, programming and simulation analysis. the basic principle and the basic model of those systems are discussed,and the key ability to resist multipath fading of this three systems is studied.(2) Studied the channel estimation and synchronization technology in OFDM communication system.LMMSE channel estimation algorithm is superior,but the complexity is higher.In order to find the simplified method, the SVD algorithm of reducing the complexity of LMMSE algorithm is analyzed and compared. The method is to find the alternative low order matrix. At the same time, some classical synchronization algorithms are improved by optimizing the training symbol structure and improving the synchronization accuracy of the algorithm.(3) The performance of the three communication systems in the multi-path fading channel is studied,that is,the capability of the different communication technology to resist the fading channel fading is studied. For direct sequence spread spectrum and frequency hopping communication system anti multipath fading performance is poor, will spread spectrum systems with FSK modulation and DQPSK modulation combination,improved spread spectrum system in multipath fading channel performance.