Spectrum Signal Code Estimation Algorithm And Program Design

Electronic countermeasure is an oppositional action that both sides of enemies use the signals being in available electromagnetic spectra and weapon to win the war. Spread-spectrum communication was firstly applied in military communications due to its good immunity to interference and security.The frequency hopping and the direct sequence spread spectrum are the main communication way of the spread-spectrum. The code estimation of the frequency hopping and the direct sequence spread spectrum signals are mainly discussed in the dissertation. The dissertation also discuss the realizing of the estimation of the spread-spectrum code in the fast digital signal processor. The main content and works of the dissertation are present as follows:(1) Studying the characteristic of the frequency hopping code estimation algorithm. According to the characteristic of the algorithm, the algorithm is realized with the software on the hardware platformof the TMS320C6713. The algorithm is optimized when it is the presented with the form of software. The test with the other parts of the system of frequency hopping is finished.(2) A fast operate of tabu search in PN sequence based on the maximum likelihood estimation is suggested. It's compared to the original algorithm of tabu. The operations of these two algorithm are analyzed, and I get the time of each algorithm that they estimate the code to use.Experiments have testified the theory. Experiments show that the new algorithm is faster than the algorithm of tabu, lower the operations from M 5 to M 2 ,and has the same function.(3) The new algorithm isrealized on the hardware platform of ADSP-TS101. A demo of operation is designed based on the hardware and MATLAB including the function of dynamic display. Experiment results are shown in the end of this dissertation, which indicate that the code estimation of the spread-spectrum signal has the high speed and good accuracy under required precision of experiment, can do well in code estimation of spread-spectrum signal. The conclusion and data that gained from the fast operate of tabu search in PN sequence based on the maximum likelihood estimation in this dissertation, has theoretical value and practicality in code estimation of spread-spectrum signal.The algorithm of the frequency hopping code estimation is a forword researching project of national defense. It has been adopted by the experts. The result of the testing has reached the demands of the contract. The fast operate of tabu search in PN sequence based on the maximum likelihood estimation is a 863 project of corps.