Spatial Modulation Research For Broadband Massive MIMO Systems

As one of the key technologies in the 5th generation mobile communication systems(5G),massive mul-tiple input multiple output(MIMO)technology can provide significant improvements on spectral efficiency and energy efficiency by using a large number of antennas at the base station.Spatial modulation(SM)tech-nology is a recently proposed novel multiple antenna transmission technique with only one radio-frequency(RF)chain at the transmitter.Compared with conventional MIMO technologies,SM can avoid inter-channel interference and inter-antenna synchronization,improve energy efficiency without sacrificing spectral effi-ciency.This thesis investigates SM related technologies in broadband massive MIMO systems,focusing on the optimal design of data transmission methods at the transmitter and the low complexity detection methods at the receiver.Firstly,we study massive MIMO SM technology.To start with,the massive MIMO SM system is de-scribed in detail,including the principle of SM scheme,the system model of massive MIMO SM system,and the detection methods at the receiver.Then,the massive MIMO SM system is compared with conventional massive MIMO system in terms of energy efficiency and bit error ratio(BER)performance,analyses and simulation results indicate that massive MIMO SM systems can provide higher energy efficiency and better BER performance while achieving same spectral efficiency.In addition,various detection methods for SM are simulated and analyzed in terms of BER performance and complexity,and the merits and drawbacks are summarized at last.Then,we propose massive MIMO subcarrier index modulation(SIM)orthogonal frequency division multiplexing(OFDM)technology.Considering the problem of spectrum waste in existing SIM schemes,the method of transmitting data is improved and applied to massive MIMO OFDM systems.Furthermore,based on the signal model of massive MIMO SIM-OFDM system,the generalized approximate message passing(GAMP)iterative detection methods for massive MIMO SIM system are proposed in two scenarios,which are ideal channel state information(CSI)and existence of channel estimation error.By multiple numeric analyses and simulations,the performance of massive MIMO SIM-OFDM system is evaluated in terms of spectrum efficiency,energy efficiency,PAPR and BER performance.The results show that the improved SIM-OFDM technology can improve energy efficiency and PAPR performance while guaranteeing spectral efficiency and BER performance.In addition,simulation results show that the GAMP detection methods proposed for massive MIMO SIM-OFDM systems in the two CSI scenarios can effectively improve the signal detection performance with low computational complexity compared with MMSE detection methods.Finally,we propose massive MIMO space-frequency modulation(SFIM)technique.The SFIM scheme is proposed by combining SM technology with SIM-OFDM technology and applied to massive MIMO OFDM systems.Then,based on the massive MIMO SFIM system model,the minimum mean square error(MMSE)detection method and the GAMP detection method for massive MIMO SFIM system are derived respectively in two scenarios,which are ideal CSI and existence of channel estimation error.By many experiments to evaluate the proposed transmission scheme,we obtain a conclusion that that the proposed massive MIMO SFIM system can improve energy efficiency without loss of spectral efficiency and BER performance com-pared with conventional massive MIMO SM OFDM systems.In addition,simulation results show that the GAMP detection methods proposed for massive MIMO SFIM systems in the two CSI scenarios can effec-tively improve the signal detection performance with low computational complexity compared with MMSE detection methods.