Research On Algorithm Of Channel Estimation In Ofdm System

In the wireless mobile channel, to realize high speed and high quality service is the target and requirement of wireless communications. Orthogonal Frequency Division Multiplexing has attracted much attention for its high spectrum efficiency and strong immunity to frequency selective fading availably. Nevertheless, channel estimation is one of the key technologies for reliable transmission in OFDM system. In order to correctly demodulate information from sending terminal, it is therefore needed to estimate channel information accurately from receiving data. The accuracy of channel estimation will directly affect the performance of the whole system.Firstly, this text analyzes some kinds of algorithms based on channel estimation using pilot symbols. Based on research of channel estimation applying m-sequence, using the mismatched sequence and sequence pairs channel estimation algorithm has been put forward in the circumstances of low complexity and higher accuracy. It compared with applying m-sequence and traditional algorithm by computer simulation.Secondly, based on decision feedback channel estimation, this text directed towards the shortcoming of inaccuracy on traditional decision feedback. It put forward new algorithm that uses mismatched sequence or m-sequence to combine decision feedback respectively. Using the mismatch sequence and m-sequence could accurately estimate performance as the initial estimate for decision feedback. It is compared with applying mismatch sequence channel estimation and m-sequence channel estimation and decision feedback channel estimation. The result of simulation by MATLAB verified the feasibility of the paper. It summarized disadvantage and advantage about seveval methods, and provided the direction of the further research aspects.