Research On Time-frequency-space Modulation And Noncoherent Detection

With the deployment of 5G,the widespread application of the Internet of Things,and the increasing development of other high-mobile applications,higher requirements are put forward for high-reliability and high-capacity communications in a Doppler environment.Extending noncoherent time-frequency dispersion waveforms to spatial anti-dispersion waveforms can effectively meet the communication requirements in high-mobility scenarios,but there is currently a lack of clear ideas and methods.Aiming at the space division expansion of the noncoherent time-frequency dispersion waveforms,we combined noncoherent MIMO spatial multiplexing model with the anti-double dispersion fading waveforms,and designed a time-frequency-space modulation signal system.In a high-speed mobile environment,joint multiplexing in the time,frequency and space domains can be obtained,and the robustness in the double dispersion domain can be retained.In addition,in view of the nonlinear mutual interference problem in non-coherent MIMO-MFSK modulation model,a low-complexity linear detection algorithm and signal design are proposed.The main contents of this paper can be summarized as follows:(1)First,it explains the research background and significance of time-frequency-space modulation in high-mobile environments,as well as the research status of Chirp modulation and noncoherent MIMO technology at domestic and abroad.Then,the FCr SK modulation and detection model is given,the noncoherent MIMO-MFSK system model derivation process is explained in detail.Summarizes the idea of noncoherent anti-time and frequency dispersion waveforms extended spatial multiplexing and points out the shortcomings of the detection algorithm of noncoherent MIMO-MFSK detection system.(2)For high-reliability and high-capacity communications in a mobile environment,combined with the MIMO-MFSK system,the noncoherent time-frequency waveforms anti-double dispersion fading are extended to the spatial domain to obtain time-frequency-space modulation signals system and noncoherent detection algorithm.Theoretical derivation and simulation results show that the proposed MIMO-FCr SK time-frequency-space modulation detection system is not sensitive to Doppler frequency shift and inherits the advantages of Chirp signal resistance to time and frequency dispersion.In addition,based on the software radio platform and channel simulator,a set of transceiver system was built to verify its feasibility in a mobile environment.(3)Aiming at the nonlinear mutual interference problem of noncoherent spatial modulation,a low-complexity linearization detection algorithm is proposed,and a signal design that satisfies any number of transmitting and receiving antennas is given,so that MIMO-MFSK energy detection has less stringent requirements for the number of antennas.Then the model is deduced in detail,and a new equivalent general formula of the algorithm is given.The simulation results show that the use of equivalent linear solution can reduce the complexity of the detection operation.