Broadband Wireless Communication System Enhanced Multi-antenna Technology Research

Multi-Input Multi-Output (MIMO) multi-antennas technology has been chosen ascore techniques for future mobile communication system because it can enhancespectral efficiency several times without increasing bandwidth. With the furtherdevelopment of multi-antenna technology，enhanced multi-antennas technology basedon large-scale multi-antenna arrays with more transmit/receive antenna has become apopular research.With the Long Term Evolution (LTE) system evolution， Long TermEvolution-Advanced (LTE-A) system configures more transmit antennas and receiveantennas. Especially the asymmetric antenna structure exists in downlink, which is thenumber of transmit antennas is greater than the number of receive antennas. In thiscase, spatial multiplexing MIMO system can onlu use the ML detection algorithm. Thecomplexity will be exponential growth with the number of constellation points and thenumber of transmit antennas. Secondly, with more transmit antennas, the coding matrixof enhanced multi-antennas transmit diversity technology need to be studied under thespatial diversity mode. Besides, the transmit antenna synchronization and theinterchannel interfence will also affect the performance of the spatial multiplexing andspatial diversity MIMO system. Therefore, an enhanced multi-antenna technology–spatial modulation technology, which based on antenna selection theory, is better ableto adapt the downlink configuration of transmit antennas, and the asymmetric antennastructure of downlink.This thesis works for above-mentioned problems in multi-antenna technologysystem.Chapter1is introduced the concept, principle and system models of spatialmultiplexing, spatial diversity and spatial modulation MIMO system, and the mainwork and content of this dissertation.Chapter2is investigated the LTE and LTE-A downlink system. The diversityschemes of two transmit antennas, four transmit antennas and eight transmit antennasare given and evaluated. Chapter3is investigated the detection algorithm of Spatial Modulationmulti-carrier system. On one hand, a lower complexity sphere decoding detection forcentralized Spatial Modulation multi-carrier system is poposed to reduce thecomputational complexity of the optimal detection algorithm. On the other hand, aniterative carrier frequency offset (CFO) compensation algorithm for distributed SpatialModulation multi-carrier system is proposed to eliminate the interfence caused byCFO.Chapter4is investigated the detection algorithm of Spatial Modulationsingle-carrier system, and presents detailed analysis and simulations of the principles,system models and bit error rate (BER) performance for various detection algorithms,including linear frequency domain equalization (FDE) and decision feedback equalizer(DFE). A near maximum likelihood (ML) detection algorithm is proposed. Thesimulation results show that the proposed detection algorithm significantly improve theBER performance of the system.Chapter5is concluded this dissertation and discusses the possible future researchdirections of enhanced multi-antenna technology.