Design And Verification Of Non-cooperative Receiving Scheme Of CPM Signal

Continuous Phase Modulation(CPM) is a kind of constant-envelope non-linear signal with continuous phase which provides good spectrum and power-efficiency. It is widely used in civil and military communication for efficient transmission in channel of narrowband and limited power. Non-cooperative communication refers to blind demodulation with the modern signal processing technology in the situation of the third party has no priori information. The non-cooperative situation provides a challenge to CPM signals modulation parameter accurate estimation and demodulation for the different modulation parameters produce CPM signals with the different features.This paper took the non-cooperative receiving scheme design and implementation of the CPM signals as the objective, researched the technology of modulation parameter estimation and demodulation, designed a blind receiving scheme which could meet the project requires and indicated the working performance with the actual transceiver data. The main work is described as follows:(1) CPM signal modulation parameter estimation algorithm research. Three symbol rate estimation algorithms that based on cyclic-spectrum and based on square spectrum and joint estimation algorithm be compared. The simulation results indicated that the joint estimation algorithm could apply to all kinds of CPM signal and had good performance and meet the accuracy requires Researched the modulation index estimation algorithm based on the first-order cyclostationary, modulation order recognition algorithm based on the second-order cyclostationary and shaping pulse estimation algorithm based on average autocorrelation function, which simulation results indicated that all the algorithms had good performance and could meet the project requirements.(2) CPM signal demodulation algorithm research. Firstly, researched the blind timing estimation algorithm to ensure the data got into the demodulator at the best timing point and the simulation results showed that the algorithm had high accuracy. Then, researched the optimal coherent detection algorithm based on Viterbi and demodulation algorithm based on multi-symbol detection to compare the bit error performance(BER) and complexity realizing of them, which simulation results showed that BER of the both algorithms achieved anticipant goal, the former algorithm had better performance and the latter algorithm was easier to bring out.(3) CPM signal non-cooperative receiving scheme design. Designed a signal receiving scheme that could correctly estimate modulation parameters of the unknown CPM signals. Validated the scheme through the actual transceiver data processing which showed that the performance met the technology requirements.