Research On Real-time Detection And Recognition Of Morse Signal

In this thesis, the Morse telegraph code real-time detection and recognition in strong noise background is investigated. It is inevitable that the communication system is disturbed by noises, especially in the short wave communication. This is great disadvantage for people who engaged in receiving signals artificially. Realization of short Morse automatic detection and recognition by computer can lighten relevant people's burden and improve their work environment.First, all kinds of Morse signal and noise are separately introduced. Second, the signal characters are analyzed. Detection of Morse Signals using complex number Variance is introduced in order to solve the sudden changes in energy when Morse telegraph code appear in this paper. In this algorithm, treating with variance image is used to achieve the purpose of detection. Some familiar noises are also analyzed and dealt with. Adaptive threshold and second are used in the process.In recognition algorithm, the character that there is obvious correspondence between position of peak in variance image and that of Morse frequency is used to wipe off noises. FFT and RFFT are referred in this algorithm. Then Morse code is transformed to texts by making use of adaptive threshold and character coding using Binary Tree. Corrective method is introduced in decoding.At last, programming design of Morse signal detection and recognition system is briefly introduced. Theory analysis and experiments for Morse signal with noises shows that the whole algorithm is effective and feasible.