Research On Uplink MIMO Technology In LTE-A

With the rapid development of mobile Internet and the rapid update of the intelligent terminal,the requirements of the uplink service in the mobile communication network are becoming higher and higher.LTE as the main technology of the fourth generation mobile communication,MIMO,OFDM and other key technologies have been adopted,so the system performance has been greatly improved.In order to maintain the leading position of the global mobile broadband standard,3GPP launched a research project based on LTE-Advanced.In LTE-Advanced,the enhanced multi-antenna technology is introduced to solve the problem of the future wireless communication greater capacity of demand.As an important component of the multi-antenna enhancement technology,uplink MIMO technology plays an important role in improving the peak speed and reliability of information transmission,expanding coverage,restraining interference,increasing the system capacity and improving the system throughput.The increase in the number of uplink transmission antennas,brings some new problems and new technologies.LTE previous version only supports 2 antennas,and is to choose one of the antennas to transmit;in the LTE enhanced version,that is,version after the Release10,extended to the uplink maximum support four antennas,and SU-MIMO has been applied in PUSCH,can transmit two codebooks word and four layers.In this technical background,the system throughput can be improved according to the change of antenna configuration and transmission environment.According to the shortcomings of the existing adaptive schemes,an adaptive method for uplink transmission mode is introduced to improve the performance of the system.Considering the effect of user's equipment power,the orthogonality of the channel,the real-time performance and stability of switching,an improved MIMO adaptive algorithm is realized.At the same time,due to the introduction of uplink multiple antenna technology,MIMO user's pairing algorithm also has more choices.According to the antenna selection,a kind of uplink MIMO user pairing method is introduced,and the higher system capacity and throughput are obtained by a more suitable pairing.Through the system level simulation,the results show that the improved adaptive algorithm can effectively reduce the block error rate and improve the system throughput.Based on the characteristics of LTE-Advanced uplink multiple antenna,a kind of uplink MIMO user paring algorithm is designed,and the target of improving system throughput is also achieved.