Research Of The Mmse Channel Estimation Based On Statistical Information Of Data Field In Td-Scdma System

In recent years, with the development of wireless communication technology, people’s demands for data service and communication quality are also increasing. The second generation of mobile communication system has been difficult to satisfy their requirements. Therefore, the third generation of mobile communication system which have higher data transmission rate and can provide various multimedia service is developed.TD-SCDMA, which is proposed by China, is one of the three3G mainstream technologies. It has adopted a series of new technologies such as joint detection, uplink synchronization, smart antenna and etc. And the realization of these technologies is mainly based on the accurate channel estimation which means their performance depends a lot on the accuracy of channel estimation. Therefore, the performance of channel estimation algorithm is very important to the3G system. At present the uplink of TD-SCDMA system mainly used B.Steiner estimator. However, B.Steiner estimator will enlarge the noise which results in the degradation of accuracy of channel estimation. Although many scholars have proposed improved algorithms to improve its performance, these solutions do not make full use of the spatial information of received signal. The research works of this paper mainly include the realization of simulation platform for TD-SCDMA uplink, wireless channel modeling, channel estimation and so on. And among these works, channel estimation is the research focus.First of all, the development of3G and the current achievements of channel estimation technology are briefly introduced in this paper.Secondly, wireless channel model, physical channel and burst structure of TD-SCDMA system is discussed. Then channel estimation technologies including B.Steiner estimator and some improved algorithms are analyzed in this paper.Finally, based on the B.Steiner estimator, an improved channel estimation algorithm is proposed. It used the statistical information of channel correlation obtained by Midamble code and data field to realize the secondary estimation to improve the accuracy of estimation. Then the paper simulates the TD-SCDMA uplink and compares the performance of single-user and multi-user. What’s more, the complexity of the algorithm is also analyzed. And some methods to reduce the algorithm complexity are given.