Research And Application Of Signal Modulation Recognition Based On Labview

In order to transmit information more effectively and reliably in current complex communication environment, varieties of signal modulation technologies have been applied to the communication system. At the same time, the use of signal modulation recognition technology in the military and civilian field gradually attracts people’s attention and how to effectively recognize modulated signals also causes people’s concern. In this paper, in order to compensate for defects of the signal modulation recognition algorithms based only on high-order cumulants or signal instantaneous characteristics, a method of modulated signal characteristic parameters extraction based on high-order cumulants and signal instantaneous characteristics is proposed after the study of modulated signal characteristic parameters extraction and classification. In addition, a good method of modulated signal classification and recognition based on decision tree is proposed using the obtained characteristic parameters. In order to well apply the proposed signal modulation recognition algorithm to the actual projects, a system of signal modulation recognition based on LabVIEW is designed and developed.The main work of this paper can be summarized as follows:1. A detailed analysis of the modulation principle of analog modulation signals and digital modulation signals is introduced, and the corresponding time domain and frequency domain waveforms and features are given. In addition, the time domain waveforms of nine analog and digital signals including AM,2ASK,4ASK,2FSK,4FSK,8FSK,2PSK,4PSK and16QAM in the ideal case and5db SNR case are studied. 2. The key technologies of signal modulation recognition like characteristic parameters extraction and classification are studied. A method of modulated signal characteristic parameters extraction based on high-order cumulants and signal instantaneous characteristics is proposed, and a method of modulated signal classification and recognition based on decision tree is proposed using the decision tree classifier. Simulation results show that the proposed signal modulation recognition algorithm is simple in design and can effectively recognize nine analog and digital signals including AM,2ASK,4ASK,2FSK,4FSK,8FSK,2PSK,4PSK and16QAM.3. The key technologies of system development based on Lab VIEW are studied. A system of signal modulation recognition based on LabVIEW is designed and developed using the proposed signal modulation recognition algorithm. In addition, the construction and verification of the system is conducted and the verification results show that the system can run accurately, thus proving the correctness of the proposed signal modulation recognition algorithm and the effectiveness of applying the algorithm to actual projects.