Research On Spatial Modulation For Massive MIMO Systems

In recent years,with the popularity of smart mobile devices and the emergence of new data services,such as 4K high-definition video,VR,etc.,the requirements of people on the rate and capacity of wireless communications are increasing.Due to its high data transmission rate and spectral efficiency,Multiple-input Multiple-output(MIMO)technology has become a key technology in mobile communication system.Therefore,in order to meet the requirements of higher spectral efficiency and mobile user data in the future,massive MIMO technology which improved from MIMO has become one of the key technologies in the fifth generation mobile communication system.Spatial Modulation(SM),a new technique of MIMO transmission technology proposed in recent years,can solve the problems of high channel interference and high system complexity in MIMO compared with traditional MIMO technology.Meanwhile,transmitting a part of information data through the selection of the activated transmission antenna ensures a certain spectral efficiency.In addition,the detection complexity of the receiver is reduced as well.Therefore,SM technique is very suitable for an asymmetric antenna system.In this thesis,starting from the transmitter and receiver,the mapping method in the correlated channel and the low-complexity detection algorithm of Generalized Spatial Modulation(GSM)was studied respectively in the point-to-point massive MIMO system.The main work of this thesis is as follows:1.Since high channel correlation will reduce the GSM system's BER performance,the block grouping and interval grouping schemes at the transmitter are proposed to reduce the influence of channel correlation on the performance of GSM system.2.Based on the Maximum-Likelihood Detection(MLD)algorithm and the Receiver-centric Sphere Decoding(Rx-SD)detection algorithm,the improved algorithm with low complexity is proposed.The improved algorithm taking the space exchange time as the idea which can reduce the detection complexity by decreasing the large number of intermediate redundancy calculations.3.The multiplexing GSM system combined with GSM and V-BLAST is introduced.The idea of space exchange time is used to reuse the multiplexing GSM detection algorithm,and two kinds of storage methods are proposed.Simulation results show that the improved algorithm combined with two kinds of storage methods can reduce the computational complexity greatly.