Study On Generalized Spatial Permutation Modulation System And Signal Detection Algorithm

As a key technology in wireless communication field,MIMO(Multiple Input Multiple Output,MIMO)technology can improve system capacity and reliability without increasing bandwidth,compared with traditional SISO(Signal Input Signal Output,SISO)technology.However,due to the multiple antennas at the transmitting end,problems such as ICI(Inter Channel Interference,ICI),high receiving end cost and IAS(Inter Antenna Synchronization,IAS)difficulties also exist in the MIMO system.Based on the above problems,SM(Spatial Modulation,SM)came into being.SM technology activates only one transmitting antenna in a time slot,and solves the problems of ICI,RF(Radio Frequency,RF)and IAS by introducing spatial dimension and using the serial number of the activated antenna to carry part of binary bit information.However,SM technology still has some problems such as low antenna utilization,low spectrum efficiency and integer idempotent that the number of transmitting antennas must be 2.In order to solve the limitations of SM technology,a large number of new technologies based on SM technology were proposed,including GSM(Generalized Spatial Modulation,GSM)technology and SPM(Spatial Permutation Modulation,SPM)technology.Compared with SM technology,GSM technology can activate multiple antennas in one time slot,which greatly improves the spectral efficiency,but also leads to the reduction of bit error rate performance of the system.SPM,on the other hand,controls the sequence number of the activated antenna by introducing a time dimension to form a sequence vector with a hamming distance large enough to control the sequence number of the activated antenna,which improves the bit error rate performance of the system,but also leads to the reduction of spectral efficiency due to the sequence vector.In this paper,a GSPM(Generalized Spatial Permutation Modulation,GSPM)system is introduced into GSM.The system by way of cyclic shift sequence vector,to keep the hamming Distance between SPM sequence vector satisfy DCM(Distance Conserving Mapping,DCM)requirements under the premise of activated multiple transmitting antenna.The simulation results show that the spectrum efficiency of GSPM system is improved with the increase of the number of activated antennas and the modulation order.The bit error rate performance of GSPM system is better than that of GSM system.However,as the ML(Maximum Likelihood,ML)detection algorithm of GSPM system needs to jointly detect the transmission vectors of multiple time slots,its computational complexity will increase exponentially with the increase of the number of transmitting antennas.In this paper,a low complexity detection algorithm named TDML(Time Division Maximum Likelihood,TDML)is proposed.The algorithm can greatly reduce the complexity of the receiver by detecting the transmission vector through dividing time slot.Simulation results show that compared with ML algorithm,TDML detection algorithm can greatly reduce the computational complexity of detection algorithm without the performance loss of bit error rate.