Researches On Non-Coherent Transmission Scheme Based On Asymptotic Orthogonality Property Of Channels In Massive MIMO

As wireless communication continues to penetrate all levels of people's lives,technical solutions with greater network capacity,higher transmission,and lower implementation complexity have become the main research directions.At present,the main candidate technologies include large-scale MIMO systems,millimeter-wave transmission,non-orthogonal multiple access,and ultra-dense networks.Among them,large-scale MIMO systems are the most widely studied.The massive MIMO system is an extension of the traditional MIMO system in the spatial dimension,breaking through the limitations of the traditional multiantenna transmission technology and having higher data transmission capability.However,the physical layer transmission scheme of the massive MIMO system still has many bottlenecks,such as the problem of high implementation cost and the difficulty of obtaining accurate channel state information.This thesis focuses on the low-complexity and highefficiency transmission schemes of large-scale MIMO systems in fast time-varying channel environments,mainly for non-coherent signal transmission and processing methods without obtaining accurate channel state information.Based on the statistical properties of the transmission channel of massive MIMO systems,the paper studies the signal design of the transmitter and the signal processing and reconstruction algorithms of the receiver.The work includes:(1)Based on the statistical asymptotic behavior of the transmission channel of large-scale MIMO system(channel hardening characteristics),a non-coherent uplink transmission and reception model based on this property is constructed,and then the optimal non-coherent maximum likelihood detection algorithm is studied.In theory,The pairwise error probability of non-coherent detection is analyzed.(2)In the aspect of user's transmission symbol design,a non-coherent transmission scheme based on energy detection is proposed.The design criteria for transmitting symbols in energy detection using massive MIMO systems are analyzed.A real signal design method based on scaled-constellation is proposed.A corresponding sybol decision method has been issued.(3)In the aspect of user's transmission symbol design,a non-coherent transmission scheme based on energy detection is proposed.The design criteria for transmitting symbols in energy detection using massive MIMO systems are analyzed.A real signal design method based on constellation is proposed.A corresponding judgment method has been issued.In summary,the paper studies the non-coherent transmission method under the condition of unknown precise channel state information for the uplink transmission of massive MIMO systems.The proposed algorithm can alleviate the training in the design of the underlying frame structure of large-scale MIMO systems to some extent.Resource overhead such as sequence and pilot to improve the efficiency of system physical layer transmission.The program is expected to provide reference and reference for the engineering practice of largescale MIMO systems in the future.