Research On Some Key Techniques Of MC-CDMA System Based On Visual Simulation

In recent years, wireless communication is rapidly developing, which gives a strong basis for personal communication. Multi-carrier technique is a effective method that decreases the ratio of delay spread to symbol duration in high speed data transmission, which is one of key techniques in wireless data communication and will probably be one of wireless access techniques in the next generation mobile communication network. In this paper we mainly research on multi-carrier technique, including principle of the system, visual simulation of the system and related systems (such as DS-CDMA, OFDM), channel estimation method of the system.In chapter two the paper focuses on the principle of the MC-CDMA system, which combines the CDMA and OFDM, generalizes the system scheme, and analyzes the duality between MC-CDMA system and DS-CDMA system. In chapter three the paper researches on the visual simulation of communication systems. The paper makes main researches on visual simulation method of DS-CDMA, OFDM, and MC-CDMA system, sets up simulation platforms, and gives some useful simulation results. In chapter four the paper researches on the channel estimation method. The paper proposes a new channel estimation method, which is a frequency-domain adaptive filer and takes the fast LMS algorithm. This channel estimation method can rapidly, effectively and adaptively estimates the channel impulse response. And also the paper researches on the two-dimensional pilot-symbol-aided channel estimation, analyzes and realizes the methods that one is realized by the discrete shift-variant 2-D Wiener filter, and the other is realized by the two cascaded orthogonal 1-D Wiener filter.