Research On The Key Technologies Of Receive-spatial Modulation

The transmission principle of the spatial modulation(SM)technique is to map a part of the information bits to be transmitted to an antenna index,while the other part is mapped to a conventional amplitude phase modulation(APM)symbol.As a new multi-antenna technology,since it activates only one transmit or receive antenna in each time slot,it can effectively avoid the problems of inter-antenna interference(IAI),inter-antenna synchronization(IAS)and reduce detection complexity in the conventional multi-input multi-output(MIMO)system.Also,it can improve the spectrum efficiency of the system by introducing the spatial domain to the system.Hence,it has great application potential in the field of 5G communication.This thesis first studies the improved offset spatial modulation(OSM)transmission principle,which can reduce the RF link switching frequency by introducing an offset between the connected RF chain and the activated antenna index.However,its transmiter must calculate the normalization coefficient of transmit power by acknowledging the channel state information(CSI),which should be sent to the receiver to realize the detection of the receive signal,making the detection complexity high.In this thesis,a radio frequency offset spatial modulation system based on constellation rotation is proposed.The constellation point is rotated at a certain angle in the constellation diagram to perform precoding processing,and the RF chain with the largest channel gain is selected for transmission.Since the precoding process does not change the transmission power of the transmitted signal,it is not necessary to calculate the normalization coefficient of the power,which reduces the transmission information required by the receiver to complete detection and the complexity of the receiver.Simulation results show that this new scheme achieves a better bit error rate(BER)performance than that in OSM in the case of low-order modulation and high signal-to-noise ratio(SNR).Receive-spatial modulation system usually needs precoding technology to concentrate the transmission power to one of the multiple antennas at receiver.Compared with traditional transmit spatial modulation,the advantage is that the design of the mobile terminal device can be simplified by reducing the system complexity of the receiver.In this thesis,based on minimum mean square error(MMSE)precoding,the BER performance of the spatial modulation system at the receiver is studied.A fast calculation method of the average bit error probability(ABEP)upper bound is derived.The complexity of the receiver is compared with the MIMO transmitting spatial modulation system under the same conditions.Simulation results verify the accuracy of the upper bound of theoretical upper bound of the bit error rate,and prove that the BER performance of PSM based on MMSE is better than that based on zero forcing(ZF),and its complexity at receiver is lower than the MIMO transmit spatial modulation under the same conditions.Receive-differential spatial modulation(R-DSM)technique utilizes the differential modulation between the time-space transmission information blocks at the transmitter to eliminate the constraint that the channel state information must be known for spatial modulation detection,which avoids channel estimation.In this thesis,the BER performance of the precoding aided differential spatial modulation(PDSM)system based on MMSE is studied.And a theoretical upper bound calculation method of ABEP is derived.Simulation results show that the system can achieve a better compromise between system complexity and bit error performance compared with the non-differential receive spatial modulation based on MMSE precoding.