Channel Estimation On Related Channel

Channel estimation is a key technology in the MIMO-OFDM system and the accuracy of estimation directly affects the performance of the whole system. When the mobile station moves, time-varying property of the channel will be more severe, therefore fast time-varying channel estimation algorithm is a serious problem. In this paper, the fast time-varying channel estimation based on related channel is discussed.In this paper, we firstly analyze the property of the large-scale fading and small-scale fading channel in the wireless mobile communication system and Jakes model which is used to produce Rayleigh Channel commonly and Rice channel model with multipath delay are introduced. STBC in MIMO and the simulation platform in the MIMO-OFDM system model are introduced. Through the simulations, performance of channel estimation algorithms on pilot is analyzed.According to the correlation of channel, pilot pattern in MIMO-OFDM is designed. The difference between pilot pattern in this paper and the one in the LTE standard is that pilot symbol is continuously set on the adjacent OFDM symbols in the same sub-carrier. Optimal pilot sequence length and interval between pilot sequences are analyzed based on channel estimation performance and correlation of channel. Overhead of pilot is also analyzed. The correlations of m sequence, Gold sequence and ZC sequence are analyzed and the result shows that the ZC sequence is more suitable for this scenario. Process of joint channel estimation algorithm based on designed pilot pattern in this paper is given. Several improved channel estimation algorithms which come from mathematical interpolation models are introduced and the complexity of these algorithm and simulation results are compared and analyzed. According to channel correlation in time domain and frequency domain, linear interpolation algorithm on data symbol and optimal linear interpolation algorithm direction are researched. Through the simulation results, the impact of the estimation algorithm on pilot position, the velocity of mobile station, the length of pilot sequence and the overhead of pilot to the given algorithm is analyzed. Simulation results show that the pilot pattern designed in this paper has a better channel estimation performance with the same overhead of pilot comparing to the pilot pattern in the LTE standard.