Wcdma Space-time Coding And Space Diversity Technology Research

With the internet and Multimedia generalization, more and more applications need high data rate access. Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency .MIMO(multiple input and multiple output)can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing.The 3th generation mobile communication WCDMA is coming,with the purpose of putting MIMO,STBC(space time block coding),space diversity into practice of WCDMA systems, in order to lay the foundation of 3G toward 4G, this dissertation has done some research under this background.This dissertation introduced the development of mobile communication firstly, then given out the key technology of next generation communication, discussed the promising diversity technology.MIMO and STBC is given out in the next chapter, simulation results proved the benefitial of MIMO and STBC.Some channel estimation methods are introduced subsequently, the channel estimation method based on orthogonal design is proved better than LS(least square ) algorithm. Antenna selection is used to reduce systems complexity without efficient great loss under coherent channel situation.some selection algorithms are given out in this chapter.The different transmit and receive diversity schemes of WCDMA are given out in the fifth chapter, and pay much attention to STBC application in WCDMA specially, compared the sequence of spectrum spreading and STBC, give out the conclusion: spectrum spreading firstly is better than later.The various multiuser detection schemes are studied in the next chapter, considering the deficiency of traditional linear detection algorithm, this dissertation proposed a nonlinear multiuser detection(MUD) algorithm, because it used the high order statistic property, its beneficial is proved by the simulation results.