The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Detection Probability Improvement Scheme Optimized for Frequency-Hopping Signal Detection

주파수 도약 신호 탐지에 최적화된 탐지 확률 향상 기법

  • Lee, In-Seok (Department of Computer Science and Engineering, Korea University) ;
  • Oh, Seong-Jun (Graduate School of Information Security, Korea University)
  • 이인석 (고려대학교 컴퓨터.전파통신공학과) ;
  • 오성준 (고려대학교 정보보호대학원)
  • Received : 2018.01.08
  • Accepted : 2018.10.12
  • Published : 2018.10.31
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Abstract

The frequency-hopping technique is one of the spread-spectrum techniques. Frequency hopping is a communication system in which the carrier frequency channel is hopped within the wideband. Therefore, a frequency-hopping system has such advantages as antijamming and low probability of intercept. This system is often used in military communications. Because frequency-hopping signal detection is difficult, it is an important research issue. A novel detection technique is proposed that can improve detection probability. When the received signal is transformed to a frequency domain sample by fast Fourier transform, spectral leakage lowers the detection probability. This problem can be solved by using the Hamming window, and the detection probability can be increased. However, in a frequency-hopping environment, the windowing technique lowers the detection probability. The proposed method solves this weakness. The simulation results show that the proposed detection technique improves the detection probability by as much as 13 %.

주파수 도약(frequency hopping) 기법은 대역확산(spread spectrum) 방법 중 하나로, 광대역 상에서 반송파의 주파수가 고정되어 있지 않고, 다양한 주파수 채널로 도약하는 통신방식이다. 이러한 특성으로 인해 뛰어난 항재밍 성능, 낮은 탐지율 등의 장점을 가지고 있어, 군 통신에 자주 사용되고 있으며, 상용 통신에도 종종 사용되고 있다. 바꿔 말하면, 이런 주파수 도약 신호를 잘 탐지해내는 것은 매우 어려우며 중요한 연구분야 중 하나이다. 본 논문에서는 FFT를 이용한 신호 탐지를 할 때, 주파수 도약 신호의 탐지율을 증가시킬 수 있는 기법을 제안한다. 수신한 신호를 FFT를 이용하여 주파수 성분으로 변환시킬 경우, 스펙트럼 누설(spectral leakage)이 발생하여 탐지율이 낮아진다. 이때, 해밍 윈도우(hamming window)를 이용하여 문제를 해결하고 탐지율을 증가시킬 수 있는데, 주파수가 도약하는 환경에서는 윈도우가 오히려 성능 저하를 가져오기도 한다. 제안하는 기법은 주파수 변화에 대응하여 이러한 약점을 해결하였으며, 기존에 비해 최대 13 % 정도의 탐지율 향상을 얻을 수 있다.

Keywords

References

  1. D. J. Torrieri, Principles of Spread-Spectrum Communication Systems, 2nd ed. Heidelberg, Springer, 2004.
  2. R. C. Dixon, Spread Spectrum Systems with Commercial Applications, 3rd ed. New York, John Wiley & Sons, 1994.
  3. H. Ahn, C. Kim, J. S. No, J. Park, H. Y. Song, and S. W. Han, "The higher-order-modulated slow-frequencyhopping spread-spectrum system over AWGN under partial- band jamming," The Journal of Korean Institute of Communications and Information Sciences(KICS), vol. 42, no. 1, pp. 14-24, Jan. 2017. https://doi.org/10.7840/kics.2017.42.1.14
  4. C. Kim, P. Yang, J. S. No, J. S. Park, H. Y. Song, and S. W. Han, "Construction of anti-jamming partially regular LDPC codes for follower jamming under frequency hopping spread spectrum system," in Proceedings of Symposium of the Korean Institute of Communications and Information Sciences, Nov. 2015, pp. 595-596.
  5. J. Park, I. Kim, H. Y. Song, P. Yang, J. S. No, and S. W. Han, "Erasure insertion and clipping for LDPC coded frequency-hopping non-coherent BFSK system over partial- band jamming channel," The Journal of Korean Institute of Communications and Information Sciences(KICS), vol. 40, no. 8, pp. 1492-1499, Aug. 2015. https://doi.org/10.7840/kics.2015.40.8.1492
  6. N. C. Beaulieu, W. L. Hopkins, and P. J. McLane, "Interception of frequency-hopped spread-spectrum signals," IEEE Journal on Selected Areas in Communications, vol. 8, no. 5, pp. 853-870, Jun. 1990. https://doi.org/10.1109/49.56391
  7. C. D. Chung, "Generalised likelihood-ratio detection of multiple- hop frequency-hopping signals," IEEE Proceedings-Communications, vol. 141, no. 2, pp. 70-78, Apr. 1994. https://doi.org/10.1049/ip-com:19941050
  8. J. E. Dunn, "Detection and classification of frequencyhopped spread spectrum signals," Ph.D. dissertation, Iowa State University, 1991.
  9. A. Polydoros, K. Woo, "LPI detection of frequency-hopping signals using autocorrleation technuques," IEEE Journal on Selected Areas in Communications, vol. 3, no. 5, pp. 714-726, Sep. 1985. https://doi.org/10.1109/JSAC.1985.1146255
  10. F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," in Proceedings of the IEEE, Jan. 1978, vol. 66, no. 1, pp. 51-83. https://doi.org/10.1109/PROC.1978.10837
  11. J. Joo, J. Won, C. Lee, S. Park, and K. Lee, "Detection of an unknown FH signal using scanning receiver and DF receiver in practical environments," in 2007 IEEE Wireless Communications and Networking Conference, Kowloon, Mar. 2007, pp. 1226-1230.
  12. J. O. Kim, J. S. Bae, and K. W. Song, "A method and apparatus to improve anti-jamming and to eliminate jamming in a GPS system by adjusting additional threshold value in the frequency domain," Patent application: 10-2010-0014870, Aug. 2010.
  13. P. T. Capozza, B. J. Holland, T. M. Hopkinson, and R. L. Landrau, "A single-chip narrow-band frequency- domain excisor for a global positioning system(GPS) receiver" IEEE Journal of Solid-State Circuits, vol. 35, no. 3, pp. 401-411, Mar. 2000. https://doi.org/10.1109/4.826823