Research And Implementation Of Modulation Identification

Identification of modulation signals is an important technology in the adaptive transmission system. The algorithm based on higher order cumulants and other characteristic parameters to the single carrier signals including both analog and digital signals is studied in this paper. And an improved coherent detection algorithm to frequency offset is also achieved to the actual received radio signals. The structure of the classified machine is another important part of the signal classification process. The machine based on Support vector machine (SVM) is also learned in this paper. SVM is a new pattern recognition method based on structure risk principles from statistic learned theory, which has a good performance when the sample number is limited. An algorithm based on SVM is proposed in this paper to classify the multi-carrier and single carrier signals.We also learned the blind time-parameters estimation scheme for OFDM. Further, we learned a algorithm based on higher order cumulants which can classfied the subcarrier modulation type of the OFDM signal.