Design And Research Of Double Joint Transceiver Spatial Modulation Scheme Based On Relay Selection

In this society where science and technology are constantly developing and progressing,people are no longer satisfied with the existing communication speed and communication quality.Therefore,the multiple-input multiple-output(MIMO)technology has been developed rapidly.By setting multiple antennas in the transmitter and receiver,the transmission rate of the communication system can be greatly increased.However,the use of multiple antennas in MIMO also incurs inter-channel interference(ICI)and inter-antenna synchronization(IAS),which affect the system performance.Spatial modulation(SM),as a special MIMO technology,uses both signal domain and spatial domain to transmit information.SM can use a part of the information bits to activate one antenna for information transmission,while the other antennas keep silent.The other information bits are used for traditional signal modulation.Therefore,SM overcomes ICI,IAS and other problems in MIMO technology,and further improves the system effectiveness and reliability.For the classical SM technology,its diversity gain will be seriously limited because only one transmit antenna is activated for data transmission.Meanwhile,due to channel fading and shadow effect during transmission,the communication quality of the SM system becomes worse.Cooperative relay technology utilizes the relay nodes between the transmitter and the receiver to form a virtual MIMO system.Therefore,it obtains the corresponding diversity gain,overcomes the influence of channel fading and shadow effect,and significantly improves the overall system performance.In addition,due to the existence of relay nodes,the coverage of the system is expanded.This thesis mainly investigates the antenna selection in the SM system and selects the transmit antenna,receive antenna,and modulation symbol jointly.At the same time,it uses the principle of the angle rotation of constellation points to complete two independent spatial modulation processes at the transmitter so as to realize the design and research of the double joint transceiver spatial modulation.Finally,the proposed scheme is combined with cooperative relay to obtain their advantages and.improve the system performance.The detailed research contents are as follows:Firstly,the basic principle of traditional spatial modulation technology is introduced,and its superiority over MIMO technology is explained.Based on the characteristics of traditional SM,several extended SM technologies and their basic principles are introduced,including generalized spatial modulation(GSM)and quadrature spatial modulation(QSM).Then the thesis introduces the system model and communication principle of the basic cooperative communication technology,analyzes the relay behavior and the classical relay protocol,and compares their advantages and disadvantages.Secondly,to further improve the performance of spatial modulation,this thesis presents a double joint transceiver spatial modulation(DJSM)scheme.It carries out two independent SM at the transmitter and distinguishes the two spatial modulation processes by the angle rotation of the constellation points in the constellation diagram.In this thesis,the optimal rotation angle under different modulation order is obtained through the principle analysis and simulation verification of rotation angle selection,which further reduces the error probability of the system.Besides,the theoretical analysis of the proposed scheme is carried out,and the derivation and expression of the average bit error probability(ABEP)of the system are given,and the MATLAB simulation of the double joint transceiver spatial modulation based on angle rotation is carried out.By comparing with the traditional spatial modulation scheme,the obvious performance advantages of the proposed scheme are proved.Finally,considering the influence of shadow fading and noise in the wireless communication environment,a DJSM scheme based on relay selection is proposed,which combines the DJSM scheme with cooperative communication technology.Aiming at the multi-relay environment,the information bits are used to select the relay to forward the information,which improves the system's spectral efficiency and obtains the cooperative diversity gain.In addition,this thesis also carries out simulation verification and comparative analysis to prove its advantages in improving the spectral efficiency and system performance.