The Smart Antenna And Space-time Code Technology Research Based On TD-SCDMA

With the rapid development of communication technology, the discussion focused on the development of the fourth generation mobile communication technology. Such as multiple-input multiple-output (MIMO), smart antennas, joint detection. MIMO technology can enhance the system with double capacity and spectrum efficiency without increasing system bandwidth, while improving the reliability of the channel, reducing the system error rate. Adaptive beam-forming technique is the core of smart antenna technology, It is linked to the forming of speed and direction of the beam, Smart antenna can improve coveragement, reduce the multiple access interference and improve the handoff efficiency. In China, we has been firstly proposed an international3G standard with independent intellectual property rights--TD-SCMA, As a result of TDD mode, it is more conducive to use smart antenna technology. To further develope TD-SCDMA, it is bound to be associated with advanced technology, this article is based on the above considerations, and carry out the relevant research of combined adaptive beamforming and MIMO technology.Based on the two aspects of beam-forming, the main contents include the following aspects: firstly introduces the physical channel of TD-SCDMA system、key technology and the main research hotspots of multiple-input multiple-output (MIMO), then analyzes the adaptive beam-forming technique, combining with wavelet tansformation, whose received signal is a sparse matrix, not only can improve the algorithm convergence speed, and, after wavelet can also achieve the effect of denoise, thus, this paper puts forward a method based on wavelet transform domain adaptive algorithm, and makes the system simulation test and analysis, get smart antenna beam direction diagram; sencondly, analyzes the channel model, diversity technology, and system capacity of MIMO multiple antennas system, and simulated multiple antenna systems performance, On this basis, this paper introduces the MIMO space-time coding technology, and puts forward the new system of combination MIMO space-time code with the smart antenna, given the essence of fixed beam shaping algorithm is realized by using diversity technology, on the analysis of the system implementation difficulties and the combining site, this paper brings forward channel partition theory, makes the system performance simulation, realized the system performance at different modulation and deduced and the related BER.