.fsk / Psk Signal Sidelobe Suppression

This dissertation is sponsored by National Natural Science Foundation of China (NSFC), and is based on the project"The producing and processing of new hybrid signal of the sensor with strong delectability and recognition". Some methods and algorithms were studied for FSK/PSK radar signal sidelobe suppression in this paper.The hybrid signals are the combined signals with multi-modulation mode. With multi-modulation, the disadvantages of single-modulation (such as FSK, PSK and PPM) can be eliminated. By taking the advantages of different modulations, the performance of range resolving, Doppler resolving and low probability of intercept (LPI) of the signal can be improved. FSK/PSK radar signal is the signal with both FSK and PSK modulation at one time. It is with large Bandwidth Time product (BT), thumbtack-like ambiguity function and well ability of Anti-EMI.The FSK/PSK signals of which the frequency-hopping and bi-phase sequences were randomly chosen often have high sidelobe level. With the simulation and analysis using MATLAB, this paper studied a method to design low sidelobe FSK/PSK radar signal with Genetic Algorithm and three algorithms for pseudo-random FSK/PSK radar signal sidelobe suppression. Lastly, this paper discussed the realization of the three sidelobe algorithms mentioned above using ADSP 21160 which is a product of ADI SHARC serial digital signal processor.The main results are as follows:1. A method to design low sidelobe FSK/PSK radar signals using genetic algorithm.2. Three algorithms for pseudo-random FSK/PSK radar signals'sidelobe suppression such as spectrum modifying, direct mismatch filters and neural network.3. Using ADSP 21160 to design DSP programs with assembly and C languages for the three algorithms mentioned above on VisualDSP++3.5 integrated development environment.