DOI QR코드

DOI QR Code

An Optimal Space Time Coding Algorithm with Zero Forcing Method in Underwater Channel

수중통신에서 Zero Forcing기법을 이용한 최적의 시공간 부호화 알고리즘

  • Kwon, Hae-Chan (Department of radio Communication Engineering, Korea Maritime and Ocean University) ;
  • Park, Tae-Doo (Hanwha Corporation Gumi Plant(Development Team3)) ;
  • Chun, Seung-Yong (Korea Agency for Defense Development) ;
  • Lee, Sang-Kook (Korea Agency for Defense Development) ;
  • Jung, Ji-Won (Department of radio Communication Engineering, Korea Maritime and Ocean University)
  • Received : 2014.02.26
  • Accepted : 2014.06.30
  • Published : 2014.08.31

Abstract

In the underwater communication, the performance of system is reduced because of the inter-symbol interference occur by the multi-path. In the recent years, to deal with poor channel environment and improve the throughput, the efficient concatenated structure of equalization, channel codes and Space Time Codes has been studied as MIMO system in the underwater communication. Space Time Codes include Space Time Block Codes and Space Time Trellis Codes in underwater communication. Space Time Trellis Codes are optimum for equalization and channel codes among the Space Time Codes to apply in the MIMO environment. Therefore, in this paper, turbo pi codes are used for the outer code to efficiently transmit in the multi-path channel environment. The inner codes consist of Space Time Trellis Codes with transmission diversity and coding gain in the MIMO system. And Zero Forcing method is used to remove inter-symbol interference. Finally, the performance of this model is simulated in the underwater channel.

수중통신에서는 다중경로로 인해 심벌간의 상호간섭이 발생하여 시스템의 성능을 저하시킨다. 최근 수중 통신시스템에서는 이러한 열악한 채널환경을 극복하고 전송률을 향상시키기 위하여 등화기 및 채널 부호화와 시공간 부호화 방식의 효율적인 연접 구조가 수중통신에서 MIMO시스템으로 응용되어 연구되고 있다. 수중 MIMO 환경에서 시공간 부호화 방식 중에서는 시공간 블록 부호화 방식과 시공간 격자 부호화 방식이 있으며, 시공간 격자 부호화 방식이 등화기 및 채널 부호화 방식에 최적이다. 따라서 본 논문에서는 다중경로 채널 환경에서 효율적인 전송을 위해 터보 Pi 부호화기를 외부부호로 사용하고, MIMO시스템에서 전송 다이버시티와 부호화이득을 동시에 가지는 시공간 격자부호를 내부부호로 구성한다. 그리고 심볼간 상호 간섭 제거를 위해 Zero Forcing 등화기법을 사용하여 수중채널에서의 시뮬레이션을 통해 성능을 확인하였다.

Keywords

References

  1. Berrou, C., Glavieux, A. and Thitimajshima, P.(1993), "Near Shanon Limit Error-Correcting Coding and Decoding : Turbo-Codes", in Proc. ICC93.
  2. Calderbank, A. R., Seshadri, N. and Tarokh, V.(1998), "Space-time codes for high data rate wiress communication: performance criterion and code construction", IEEE Trans. Inform. Theory, pp. 744-765.
  3. Foschini, G. J., Gans, M. J.,(1998) "On limits of wireless communication in a fading environment when wsing multiple antennas," Wireless Personal Communication, vol.5, no.3, pp. 311-335.
  4. Kilfoyle, D. B. and Baggeroer, A. B.(2000), "The state of art in underwater acoustic telemetry", IEEE J. Oceanic Eng., Vol. 25, No. 1, pp. 4-27. https://doi.org/10.1109/48.820733
  5. Kienle, F. and Gimmler, C.(2010), "Space-time bit trellis codes", 2010 International ITG Conference, pp. 18-21.
  6. Man-Wai Kwan and Chi-Wah Kok(2006), "FIR zero-forcing equalizer for ISI MIMO channels using space-time modulated codes", IEEE Transcations on Wireless Communication, Vol. 5, No. 1, pp. 123-132. https://doi.org/10.1109/TWC.2006.1576536
  7. Stojanovic, M., Catipovic, J. and Proakis, J.(1994), "Phase coherent digital communications for underwater acoustic channels", IEEE J. Ocean. Eng., Vol. 19, No. 1, pp. 100-111. https://doi.org/10.1109/48.289455
  8. Tarokh, V., Jafarkhani, H. and Calderbank, A. R.(1999), "Space-time block coding for wireless communications: performance results", Selected Areas in Communications, IEEE Journal, Vol. 17, No. 3, pp. 451-460. https://doi.org/10.1109/49.753730
  9. Van Walree, P.(2011), Channel sounding for acoustic communications: techniques and shallow-water examples, FFI(Norwegian Defence Research Establishment) report.