Journal of Broadcast Engineering (방송공학회논문지)

The Korean Institute of Broadcast and Media Engineers (한국방송∙미디어공학회)
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Digitally Modulated Signal Classification based on Higher Order Statistics of Cyclostationary Process

순환정상 프로세스의 고차 통계 특성을 이용한 디지털 변조인식

  • Ahn, Woo-Hyun (Department of Electronics Engineering, Chungbuk National University) ;
  • Nah, Sun-Phil (Agency for Defense Development) ;
  • Seo, Bo-Seok (Department of Electronics Engineering, Chungbuk National University)
  • Received : 2014.01.06
  • Accepted : 2014.03.14
  • Published : 2014.03.30
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Abstract

In this paper, we propose an automatic modulation classification method for ten digitally modulated baseband signals, such as 2-FSK, 4-FSK, 8-FSK, MSK, BPSK, QPSK, 8-PSK, 16-QAM, 32-QAM, and 64-QAM based on higher order statistics of cyclostationary process. The first order cyclic moments and higher order cyclic cumulants of the signal are used as features of the modulation signals. The proposed method consists of two stages. At the first stage, we classify modulation signals as M-FSK and non-FSK using peaks of the first order cyclic moment. At the next step, we apply the Gaussian mixture model-based classifier to classify non-FSK. Simulation results are demonstrated to evaluate the proposed scheme. The results show high probability of classification even in the presence of frequency and phase offsets.

이 논문에서는 순환정상 프로세스의 고차 통계 특성을 바탕으로 2-FSK, 4-FSK, 8-FSK, MSK, BPSK, QPSK, 8-PSK, 16-QAM, 32-QAM, 64-QAM 등 10개의 기저대역 디지털 변조신호를 자동으로 인식하는 방법을 제안하였다. 변조신호의 고유한 성질을 나타내는 특징변수로는 1차 순환 모멘트와 고차 순환 큐뮬런트를 이용하였다. 제안한 변조인식기는 크게 두 단계로 구성되며, 첫 번째 단계에서는 1차 순환 모멘트가 나타내는 첨두치를 이용하여 M-FSK와 비FSK로 변조신호를 분류한다. 두 번째 단계에서는 비FSK를 분류하기 위해 고차 순환 큐뮬런트 값을 이용하는 Gaussian 혼합 모델 기반의 분류기를 적용하였다. 제안한 방법의 성능을 검증하기 위해서 모의실험을 실시하였다. 모의실험 결과 제안한 분류기는 주파수와 위상 옵셋이 존재하는 환경에서도 우수한 분류확률을 나타내었다.

Keywords

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