Research On Enhanced Spatial Modulation Transmission Schemes In Massive Mimo Communication Systems

The MIMO (Multiple Input Multiple Output) systems becomes a key technique in wireless commu-nication systems for its high throughput and high spectrum efficiency during the development of wireless communication techniques. However, MIMO has evident drawbacks in dealing with the MIMO's ICI (inter channels interface) and spectrum efficiency improvement. Spatial modulation provides a new method to pre-vent ICI and improve spectrum efficiency obviously for that it actives only one transmitting antenna on each time slot and convenes information through antenna's location.The present researches of spatial modulation are the interleaving or coding for bits stream before spa-tial modulation symbol mapping in transmitter, the symbol detection in receiver and the spatial modulation in massive MIMO systems. In present researches, the interleaving before mapping doesn't considering the characteristics of spatial modulation mapping; the NMRC detection doesn't considering the influence of noise maximum. And in the multi-users under spatial modulation transmission uplink communication mode with BS configuring with a large number of antennas doesn't imply the low complexity sphere decoding detec-tion.Based on the discussion above, in this paper, the generalized enhanced spatial modulation technologies in large-scale MIMO communication system are researched. The main work are as follows:1. Research on many kinds of enhanced SM technologies in MIMO systems. Firstly, we give the S-M system mode. And then we conduct a study of independent channel Maximal Ratio Combining (MRC) detection algorithm. Based on above, we study the transmitting and receiving enhanced SM technologies, re-spectively. For transmitter, we introduce the schemes of error correction coding for bits before SM mapping, combing of SM and STBC and so on. For receiver, we introduce the schemes of NMRC detecting algorithm, Maximum Likelihood (ML) detecting algorithm in SM systems.2. This paper proposes the scheme of Dual-Interleaving in MIMO-OFDM SM system, and concludes that the system implying proposed scheme outperforms the system without interleaving obviously through sim-ulation results in BER. Study the system of MIMO-OFDM and the implementation of dual-Interleaving SM technology. Details of the focus is on how to achieve the above-described Dual-Interleaving SM technique, and give an implicit interpretation about this scheme based on the characteristics of SM mapping. Based on the above scheme, the simulation results are presented finally. Simulation results reveal that the performance of SM system implies proposed scheme is much better than the conventional SM system without interleaving obviously.3. This paper proposes the Angle detection and Minimum Mean-Squared Error (MMSE) equalization detection algorithm in SM system which adopts to ordinary channels condition, and points that the perfor-mance of system implying proposed algorithm is better than the system implying NMRC detection through simulation results in BER. On one hand, we make a research on the advantages and shortcomings of MRC and NMRC detection algorithm. This leads to an explicit description of our proposed Angle detection and MMSE equalization detection algorithm. On the other hand, based on above algorithm, we propose an Angle detection and MMSE equalization detection algorithm based on condition modify. Finally, we give these two algorithm's simulation results and corresponding analyses together with the conclusion.4. This paper proposes the low complexity SD detection algorithm for massive MU-MIMO systems, and reveals that the system implying proposed algorithm has close performance to ML detection algorithm with a low implementation complexity through simulation results in BER. At first, we study two massive MIMO modes used in SM systems, including the single-user downlink communication mode with Base Station (BS) configuring with a large number of antennas and the multi-users under spatial modulation transmission uplink communication mode with BS configuring with a large number of antennas. Afterwards, we explain SD detection algorithms in present single-user mode massive SM MIMO systems. Based on the single-user mode, we propose the low complexity SD detection algorithm for massive MU-MIMO systems and give its illustration and simulation results together with analyses.