| It is increasing that the demand of higher data rates,better quality of service,the fully move and connect to wirless networks,and researchers are striving to find new solutions beyond 4G wireless systems.Spatial modulation(SM)technology has become one of the research hotspots in the field of wireless communications today.This technology uses the activated antenna as digital modulation,making the transmitting antenna index information an additional data carrying method,achieving high speed and reliability transmission.The combination of SM and space-time coding technology can not only improve diversity gain of the system but also achieve higher spectrum efficiency.In this thesis,based on two techniques of space modulation and space-time coding,the spatial modulation signal detection algorithms and space-time coding based on space modulation have been studied in depth.The specific work is summarized as follows:1.The basic principle and system model of spatial modulation and space-time coding are researched.Theoretical analysis and performance comparison of two multi-antenna transmission technologies are given.2.The receiver of the spatial modulation system needs to jointly detect the transmitting antenna and the transmitted symbol,and there is a great correlation between the transmitting antenna and the transmitted symbol on the antenna in the system,which failures to achieve optimal performance during signal detection.This thesis proposes a bit-interleaved coded spatial modulation system.Then,on the basis of the fact that the traditional signal detection algorithms have high complexity and can not output soft output,this thesis proposes a low-complexity soft output detection algorithm for the coded spatial modulation system.Finally,the proposed new algorithm and other detection algorithms perform performance simulation and result analysis,verifying that the proposed algorithm can further improve the overall system performance while greatly reducing the complexity.3.The traditional space-time block coded spatial modulation scheme has a higher data transmission rate than spatial modulation system,but can not obtain a full-diversity gain.This thesis proposes a full-diversity space-time coding scheme based on spatial modulation through the preprocessing of transmission symbols and the design of constellation rotation for transmission codewords,and proves that the scheme can obtain a full diversity.The new proposed scheme is compared with SM and several space-time coding schemes based on spatial modulation,and it is proved that the proposed scheme can obtain better performance than the traditional transmission scheme under the same spectrum efficiency. |
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