Journal of the Institute of Electronics and Information Engineers (전자공학회논문지)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Design of the Optimal Phase for the Interpolant Filter in the Second-order Bandpass Sampling System

2차 BPS 시스템의 interpolant 필터에 대한 최적 위상 설계

  • Baek, Jein (Department of Information and Communication, Hannam University)
  • 백제인 (한남대학교 정보통신공학과)
  • Received : 2015.09.06
  • Accepted : 2016.02.24
  • Published : 2016.03.25
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Abstract

In the bandpass sampling(BPS), the sampling frequency for the analog-to-digital converter is lower than that of the signal to be sampled. Since the BPS operation results in the signal spectrum to be copied on the baseband, it is possible for the frequency down-converter to be conveniently omitted. The second-order BPS system is introduced in order to cancel the aliased interference components from the BPS output that may be generated by the BPS processing. In this paper, we introduce a design method for the optimal phase of the interpolant filter in the second-order BPS system which enables to maximally cancel the aliased components. Being mathematically derived, this method can always be applied independently to the spectral characteristics of the BPS input signal. The performance improvements by the suggested method has been measured statistically with various power spectra of the received signal, and it has been shown that the maximal amount of the improvements reaches up to 5~20 [dB] in comparison with the previous suboptimal algorithm.

대역통과 표본화(BPS: bandpass sampling) 기술은 아날로그 신호를 디지털 신호로 변환할 때 표본화하고자 하는 신호의 주파수보다 낮은 주파수로 표본화하는 것을 말한다. BPS 처리만으로도 수신 신호의 스펙트럼이 기저대역에 나타나게 되기 때문에 주파수 하향변환기를 사용하지 않을 수 있어 편리하다. 2차 BPS 시스템은 BPS 과정으로 인하여 발생될 수 있는 aliasing 간섭 성분을 제거하고자 2개의 표본화기를 사용하는 장치이다. 본 논문에서는 2차 BPS 시스템의 aliasing 간섭 성분을 최대로 제거하도록 interpolant 필터의 위상을 최적 설계하는 방식을 제시하였다. 이 방식은 수학적으로 유도된 것으로서, BPS 입력 스펙트럼의 어떠한 조건에서도 항상 성립한다. 수신 신호 전력 스펙트럼을 다양하게 변화시키면서 제안된 방식에 따른 성능 개선 효과를 통계적으로 조사하였고, 기존의 준최적 방식과 비교할 때 최대 5~20 [dB]의 성능 개선이 있음을 확인하였다.

Keywords

References

  1. Rodney G. Vaughan, Neil L. Scott, and D. Rod White, "The theory of bandpass sampling," IEEE Trans. Signal Processing, vol. 39, no. 9, pp.1973-1984, Sept. 1991. https://doi.org/10.1109/78.134430
  2. Vito Giannini, Jan Craninckx, and Andrea Baschirotto, Baseband Analog Circuits for Software Defined Radio, Springer, 2008.
  3. G. Hueber and R. B. Staszewski, Multi-Mode /Multi-Band RF Transceivers for Wireless Communications, John Wiley & Sons, 2011.
  4. A. Kohlenberg, "Exact interpolation of band-limited functions," J. Appl. Phys., vol. 24, no. 12, Dec. 1953.
  5. Hyung-jung Kim, Study and Implementation of a BPS Receiver for SDR/CR, Ph. D., dissertation, Chungbuk National Univ., 2010.
  6. Alan J. Coulson, "A generalization of nonuniform bandpass sampling," IEEE Trans. Signal Processing, vol. 43, no. 3, pp.694-704, Mar. 1995. https://doi.org/10.1109/78.370623
  7. Alan J. Coulson, Rodney G. Vaughan, and Mark A. Poletti, "Frequency-shifting using bandpass sampling," IEEE Trans. Signal Processing, vol. 42, no. 6 pp.1556-1559, June 1994. https://doi.org/10.1109/78.286975
  8. Alan J. Coulson, Rodney G. Vaughan, "Signal combination using bandpass sampling," IEEE Trans. Signal Processing, vol. 43, no. 8, pp.1809-1818, 1995. https://doi.org/10.1109/78.403340
  9. Hyung-jung Kim, Jin-up Kim, Jae-Hyung Kim, Hongmei Wang, and In-Sung Lee, "The design method and performance analysis of RF subsampling frontend for SDR/CR receivers," IEEE Trans. Industrial Electronics, vol. 57, no. 5, pp.1518-525, 2010. https://doi.org/10.1109/TIE.2009.2033491
  10. Hyung-jung Kim, Jin-up Kim, Jae-Hyung Kim, Hongmei Wang, and In-Sung Lee, "RF band-pass sampling for multiband access CR/SDR receiver," ETRI Journal, vol. 32, no. 2, pp.214-221, 2010. https://doi.org/10.4218/etrij.10.1409.0073
  11. Hyuk Kim and Jein Baek, "The multiband interpolant filter in the second-order BPS system," Journal of the IEEK, vol. 50, no. 7, pp. 225-230, July 2013.
  12. Jein Baek, "Design of second-order BPS systems for the cancellation of multiple aliasing," Journal of the IEEK, vol. 52, no. 3, pp. 544-552, March 2015.