Research On Channel Estimation Technology For Downlink In LTE System

LTE is a long term evolution scheme of 3GPP, as a using extensively communiction standrands, it has higher data rate and higher quality. Channel estimation plays a quite important role in the LTE system which requires the high data rate and quality.The article introduces rudiments of LTE systerm. Because channel estimation is a key technology of physical layer, the article pay attention to the knowledge above physical layer. The article introduces frame structure, timeslots structure for downlink, channel structure for LTE downlink and common structure of phisical channel. The article also introduces characteristics of wireless channel, common channel modols, MIMO and OFDM , the pilot devising for LTE downlink and so on.As channel estimation be key point. Firstly, we main investigate some common channel estimation algorithm, such as LS channel estimation, MMSE channel estimation, SVD-LMMSE channel estimation and a denoise method for LS channel estimation. Secondly, we investigate some interpolation algorithms, such as linear interpolation, Gaussian interpolation and DFT interpolation algorithm. Finally, we change the denoise method for LS channel estimation and a iteration algorithm above LMMSE.All channel estimation algorithms are simulated. The simulation conlusion is that the new channel estimations are more efficient.