The Performance Research For Spatial Modulation And Precoding MIMO Transmission Technology

Multiple Input Multiple Output (MIMO) transmission technology is currently one of the key technologies in the area of wireless communications. In order to improve the bit error rate (BER) and spectral efficiency, the performance of communication systems applied spatial modulation (SM) and precoding transmission technology was studied in this paper.SM is a novel MIMO transmission technology, which not only use the conventional M-dimensional modulation symbol, but the spatial location of the selected antennas to transmit information. A linear list detection algorithm for Multiple Active Spatial Mod-ulation (MA-SM) was proposed in this paper. The detection of the sub-set of the transmit antennas was first performed, resulting in a list of the best candidates. Then the constellation symbol detection was performed for each selected subset in the list. The numerical anal-ysis of complexity and the BER simulation experiments were performed. The complexity analysis together with simulation results show that:The proposed list detection algorithm can improve the Bit Error Rate (BER) performance compared with the existing detection algorithm without list but incurs not too much complexity increase.Precoding technology is a preprocessing technique in the transmission side, which can improve the BER performance and spectral efficiency of the communication system. The spatial multiplexing transmission scheme was discussed. Generated a diagonal matrix based on the SVD (Singular Value Decomposition) decomposition of the real-time channel matrix. Then construct a joint optimization of precoding matrix according to the principle of X pre-coder and Y precoder. The analysis of error probability in pairs and the BER performance simulation experiments were performed. The analysis of error probability in pairs and the simulation results show that:The BER performance of adaptively joint optimization algo-rithm is better than X precoder, and slightly better than Y precoder at larger SNR (Signal to Noise Ratio). Beamforming is another transmission scheme of the precoding technol-ogy. Based on the reciprocity of LTE (Long Term Evolution) communication system for High-speed Railway, Kerdock codes, which require less memory, can be stored online and have low signal processing complexity, were implemented as the precoding codebook to apply the beamforming with Kerdock Codes (called KBF) on LTE system for High-Speed Railway. And then the analysis of complexity and the performance of simulation for this communication system were presented in this paper. The complexity analysis and simu- lation results show that:The KBF system needs less memory capacity when process the signal online and has low search complexity. The BER performance is better than the Op-portunistic Beamforming (OBF) system and better than the Location Information-assisted Opportunistic Beamforming (L-OBF) system at larger SNR; the achievable rate of KBF system is better than OBF system but worse than L-OBF system. The KBF in LTE system for High-speed Railway can get a tradeoff between the complexity and performance.