Automatic Recognition of Digital Modulation Types using Wavelet Transformation

웨이브릿 변환을 이용한 디지털 변조타입 자동 인식

  • Published : 2008.04.25

Abstract

In this paper, we deal with modulation classification method using WT capable of classifying incident digital signals without a priori information. These key features should have good properties of sensitive with modulation types and insensitive with SNR variation. The 4 key features for modulation recognition are selected using WT coefficients, which have the property of insentive to the changing of noise. The numerical simulations for classifying 8 digital modulation types using these features are peformed. The numerical simulations of the 3 types (i.e. DTC, MDC, and SVMC) of modulation classifiers are performed the investigation of classification accuracy and execution time to design the modulation classification module in software radio. The simulation result indicated that the execution time of MDC and DTC was best and MDC and SVMC showed good classification performance.

본 논문은 웨이브릿 변환을 이용하여 사전정보 없이 입사하는 디지털 신호의 변조타입 자동식별 방법에 관한 것이다. 변조인식에 사용되는 특징(key features)은 변조타입에 대한 민감도가 우수하고, SNR에 대한 변화가 적은 속성을 가져야 한다. 잡음에 대한 변화가 적은 속성을 가진 웨이브릿 변환 계수에서 변조인식을 위해 4개의 특징(key features)을 선정하였다. 또한 선정된 특징들을 이용하여 총 8종의 디지털변조 신호를 분류하기 위해 시뮬레이션을 수행하였다. 소프트웨어 라디오의 변조인식 모듈 탑재를 고려하여, 3 타입의 변조인식기에 대한 인식 정확도 및 수행시간을 비교 분석하였다. 시뮬레이션 결과 전체 인식시간은 MDC(Minimum Distance Classifier)와 DTC(Decision Tree Classifier)가 빠르게 수행되었고, 인식정확도는 MDC와 SVMC(Support Vector Machine Classifier)가 우수하게 제시되었다.

Keywords

References

  1. M. Vastram Naik et al., "Blind adaptive recognition of different QPSK modulated signals for software defined radio application," in Proc. of COMSWARE, pp. 1-6, Jan. 2006
  2. Bin Le et al, "Modulation identification using neural network for cognitive radios," in Proc. of SDR forum technical conference, 2005
  3. K. C. Ho, W.Prokopiw, and Y. T. Chan, "Modulation Identification By The Wavelet Transformation," in Proc. of MILCOM, pp.886- 890, Nov. 1995
  4. Jian Chen, et al., "Digital Modulation Identificati -on by Wavelet Analysis," in Proc. of ICCIMA, pp.29-34, Aug. 2005
  5. Xin Zhou and Ying Wu, "Automatic Classifica tion of MFSK Signal By The Wavelet Transformations," in Proc. of IEEE ChinaCom06, pp.1-5, Oct. 2006
  6. Ilan Druckmann et al., "Automatic modulation type recognition," in Proc. of IEEE Canadian Conf. on Electrical and Computer Engineering, pp.65-68, May 1998
  7. Hussam Mustafa and Milos Doroslovacki, "Digital modulation recognition using support vector machine classifier," in Proc. of IEEE Conf. on Signals, Systems and Computers, pp.2238-2242, Nov. 2004
  8. Zhilu Wu et al., "Automatic digital modulation recognition based on support vector machine," in Proc. of IEEE Conf. on Neural Networks and Brain, pp. 1025-1028, Oct. 2005
  9. Wu Dan, Gu Xuemai, and Guo Qing, "A new scheme of automatic modulation classification using wavelet and WSVM," in Proc. of Int'l Conf. on Mobile Technology, Applications and Systems, Nov. 2004
  10. B.Q.Hu, J. Yang, and J.L.He, "A multiclassifi cation model based on FSVMs," in Proc. of NAFIPS, pp. 205-209, June 2005
  11. Andrew Webb, Statistical Pattern Recognition, 2nd ed., 2002, John Wiley & Sons, Ltd., pp.144-168