Research On A New SOQPSK-MIL Modulation And Demodulation Method

In wireless communication,due to the existence of non-linear amplifiers,the amplitude-phase transition and the deterioration of spectrum will occur in the process of signal transmission.Spectrum performance reflects whether a modulation system is good or not.When choosing a modulation system,constant envelope modulation or continuous phase modulation should be chosen.SOQPSK-MIL is a typical continuous phase modulation signal,which wideband utilization and power utilization are high and can be adapted to non-linear amplifiers.In view of the number of SOQPSK-MIL modulation waveforms and the complexity of demodulation,a new SOQPSK-MIL modulation scheme is studied in this paper.There are two new modulation schemes: based on set A and based on waveform set B.The number of waveform sets of the new modulation scheme is half that of the original modulation scheme,and the new modulation scheme designs corresponding baseband mapping rules and cross-correlation trellis coder based on the new waveform set.We simulate and compare the time domain waveform and power spectrum density of the new SOQPSK-MIL modulation modulation scheme with Simon' scheme.A new state transition diagram is defined when designing the optimum receiver for a new modulation scheme.According to the baseband mapping rules,the transfer output of each state is calculated,and the state transition table is summarized.At the same time,the optimum receiver is designed according to the matched filter and the state transition diagram.At the same time,the Euclidean distance of the new modulation scheme is analyzed,and the BER performance of the new modulation scheme and Simon modulation scheme is compared.In addition,the new state transition table is observed and summarized in this paper,and a simplified receiver is designed based on the idea of average waveform.The new modulation scheme reduces the number of matched filters and the complexity of demodulation,and keeps the BER performance of its optimum receiver and simplified receiver unchanged.Finally,based on Verilog language,a new modulation scheme modulator and demodulator are designed on the simulation platform of FPGA,which verifies the feasibility of the modulation scheme in hardware.