Arbitrary Phase Modulation Waveform Design For High Frequency Radar

There is serious narrowband interference in the application of HF radar. Discrete frequency signals distribute transmission energy into each discrete bands meet the bandwidth of the system and to improve the signal-to-noise-and-interference ratios(SINR) of the echo signal. Compared with those traditional discrete spectrum signals, the arbitrary phase signal has the irreplaceable advantage. Therefore, this paper uses the arbitrary phase-only signal, aiming at the problem of high range sidelobe of echo signal because of the discrete spectrum.Chapter 2 analyses the performance of the arbitrary phase-only signal and the range sidelobe depends entirely on the phase assemblage sequences. The ambiguity performance provides better resolution. In addition, the effect of the frequency band distribution on the autocorrelation of the signal is studied, and some methods for the estimation of the side lobe are given.Chapter 3 analyses the coupling relationship in a conflicting way of power spectrum performance and autocorrelation performance. The derivation of objective functions of signal power spectrum and autocorrelation properties are given. Then the joint objective function is established. The waveform design problem is formulated as an optimization problem. The wave solution is given using circle iteration algorithm. Simulation results show that this method can adjust the weight according to the different situation and has flexibility.However, due to the disadvantage of division of passband and stopband, which influences the further improve of SINR. And it is difficult to directly express the weight factor of the performance objective function. Therefore, based on the actual radar environment and the known interference information, Chapter 4 reconstructs the SINR objective function to further improve t signal-to-noise-and-interference ratios. Then the Pareto optimization of the signal performances is introduced. The maximum SINR and the integral sidelobe level are combined to a joint objective function. The simulation results show that the performance of signal-to-noise-and-interference ratio is improved by analyzing simulation result and comparing with Chapter 3. And the Pareto optimal curve is showed. With the he Pareto optimal curve, the figure can be explained.Finally, the waveform design method is extended to MIMO radar. Through the improvement of the signal model and the related algorithm parameters, the multi-channel waveform based on MIMO can be designed. The simulation results show the feasibility of the method and the method.