The Research And Implementation Of Channel Estimation In The Downlink Of 3GPP-LTE Ststem

With the development of the mobile telecommunication technologies, it is required that the telecommunication systems supply better communication service to more customers even in complicated environment. As one of the most important standards in next generation wireless system, LTE has been widely recognized as significant status in the future communication industry, so it is valuable to research on LTE technologies. Channel estimation is critical in the downlink of LTE system based on MIMO-OFDM structure. Our study involves building LTE downlink simulation platform, modeling wireless channel and channel estimation.It's very important to understand wireless channel's mechanism and set up effective channel model for the evaluation of wireless mobile communication technologies. SCME channel model based on SCM is proposed for broadband mobile communication systems by Eoupean Union WINNER Project.Channel estimation has a great influence on the performance of LTE downlink system. In this paper, we design channel estimation methods according to the pilot pattern in the LTE downlink system. In the aspect of non-adaptive channel estimation, the pilot assisted channel estimation algorithms based on LS and LMMSE criteria, together with channel interpolation based on linear interpolation and DFT based interpolation are studied. In the terms of adaptive channel estimation, two-dimensional LMS, RLS, and SVD adaptive algorithms based on traditional channel estimation are realized, and then we analyze the complexities of these algorithms.Finally, we build simulation platform of LTE downlink system according to the standards. Then we evaluate the performance of different channel estimation algorithms through simulation by taking MSE and BER as the performance metrics.