| With the rapid development of modern wireless communication technologies and the popularity of mobile devices such as smart phones,the wireless spectrum resources are becoming increasingly scarce.However,people have still put forward that the future radio communication system can provide high-speed and high-reliability communication quality,which is undoubtedly bringing about new challenges to the development of wireless communications.Multi-input multi-output technology is one of the key transmission technologies in the field of wireless communication research that people are more concerned.This article will take advantage of space-time block coding technique,which can intensify the transmission rate and fortify the reliability of the system.Blind modulation recognition technology,which can make full use of channel capacity and save frequency resources.Golden angle modulation technique,which can improve the system capacity and produce new constellation distinguish from the traditional M-QAM.Spatial modulation technology,which can use the index of transmitting antenna position to carry information in the spatial domain in MIMO communication system.The main research work is as follows:1.Using space-time block coding and blind modulation identification technology,this paper designs an industrial control STBC-MIMO communication system.In order to correctly demodulate the signal detected by the receiver,it is necessary to blindly identify the type of modulation of the received signal,and use the average likelihood ratio detection algorithm to detect and decode.The results of experiments show that the designed system has 2.6d B or d B.4 3 performance gain respectively higher than the traditional wireless industrial control SISO system based on blind modulation identification,when using some different types of modulation combinations of BPSK,QPSK,8PSK and 16 QAM.2.Applying the advantage of Golden angle modulation technique can produce new constellations that are different from traditional M-QAM,a space-time block coding wireless communication system based on GAM is designed in this paper,taking the Alamouti code as an example,the BER simulation experiment is carried out.It is said that,when compared with the traditional systems apply ordinary M-QAM constellation mapping or the systems based on GAM without space-time block coding,the designed system has a better performance more than 2.0d B or1.0d B.3.In order to maximize the diversity gain generated by Spatial modulation and improve the BER performance of MIMO communication system,a spatial modulation mapping scheme with the same bits produced by the transmitted source each time as well as adding auxiliary antennas to assist to transmit modulated symbols is designed in this paper.The experimental results show that(1)when the number of transmitting antennas is the same at the transmitter,the greater the number of receiving antennas at the receiver,the better the system performance is.(2)When the transmission rate of the system is the same,the more bits are used to activate the antenna(i.e.the few bits that are used to generate the modulation symbol for the constellation mapping),the better the system performance is.(3)When the transmission rate of the system is the same but the auxiliary antenna is not added,the system performance will be significantly improved with the increase in the number of transmitting antennas.(4)When the transmission rate of the system is the same and the auxiliary antenna is added,if each transmit slot the total number of antennas under the working state of the terminal is certain,and the performance of the system will be traded off between the influence of the number of transmitting and auxiliary antennas.However,the number of auxiliary antennas obviously has greater influence on the system performance than transmitting antennas. |
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