Research On Pilot Optimization And Channel Estimation Algorithm For Massive MIMO Systems

In recent years,with the rapid development of science and technology,the people on the spectrum efficiency and energy consumption in the process of mobile communication rate is gradually improving,and the base station transmits the uplink pilot sequence to the end user through Massive MIMO technology,downlink channel state information terminal users access to the base station through the channel estimation and the CSI to restore the original signal by increasing the base station and the user terminal antenna array,it can increase the channel capacity,by reducing the pilot pollution,reduce channel interference can effectively increase the transmission rate from users,and improve communication spectrum efficiency and energy efficiency,provide the direction for further research and development of mobile communication technology,which will undoubtedly give.Beamforming is one of the most important research directions in Massive MIMO system.Beamforming can effectively suppress channel interference and noise interference,and achieve diversity gain and multiplexing gain by propagating multiple data streams in the channel.In this paper,multi antenna and multi-user Massive MIMO system,the uplink(Uplink,UL)of the maximum signal to leakage and noise ratio(Maximum signal-to-leakage-and-noise,Max-SLNR),zero forcing(Zero forcing,ZF),minimum mean squared error(Minimum mean-squared,error,MMSE)pre encoding algorithm and bit error rate and the rate was analyzed and compared,the results show that Max-SLNR algorithm in speed and better performance than MMSE and ZF algorithm.Secondly,according to the multi cell mass system of pilot frequency pollution and noise problems,proposes a maximum channel allocation based on greedy signal to leakage and noise ratio preencoding algorithm,by selecting the communication link channel minimum interference channel as the transmission channel,in order to reduce the target users in other users on the leakage power,compared with the traditional preencoding algorithm like ZF,Max-SLNR,MMSE,the proposed algorithm is significantly improved in reducing the performance of the pilot pollution.Finally,in the Massive multi cell MIMO system,in order to obtain the channel characteristics of high precision,large number of pilot signals,resulting in low spectrum utilization,pilot pollution is serious,the traditional channel estimation algorithm based on pilot pollution produced by the pilot sequence multiplexing estimation is proposed the improved algorithm of the channel,thealgorithm combined with the strongest user conflict resolution(SUCR)algorithm based on cyclic prefix and maximum likelihood channel estimation of pilot sequences are processed to obtain complete channel state information.