On the Practical Aspects of Joint Passive Phase Conjugation and Equalization in Underwater Communication Systems
محورهای موضوعی : Majlesi Journal of Telecommunication Devices
Azizollah Jamshidi
1
(Electrical and Computer Engineering School, Shiraz University)
Samaneh Moezzi
2
(Electrical and Computer Engineering School, Shiraz University)
کلید واژه: en,
چکیده مقاله :
Abstract- Underwater acoustic communication is suffered from the channel effects which results in time spreading of the transmitted signal. In underwater environment multiple replicas of the transmitted signal are received at the receiver through different paths, which causes significant Inter-Symbol Interference (ISI). Decision Feedback Equalizers (DFE) was utilized to overcome this type of interference in digital communications so many years ago. However, because of the complexity of adaptive equalizers Passive Phase Conjugation (PPC) was widely exploited in underwater communications in the recent years. Because of the poor performance of the PPC method, adaptive equalizers are jointed to improve the PPC performance. In this paper, experimental results conducted in Shiraz Electronic Industrials’ pool are reported. Three different approaches are compared in terms of Symbol Error Rate (SER) versus the number of used channels at the pool: 1) the PPC method; 2) DFE equalizer for only a single channel; 3) the PPC method combined with adaptive DFE. The experimental results showed that the third approach outperforms the others while a simpler receiver is obtained.
[1] M. Stojanovic, J. A. Catipovic, and J. G. Proakis, “Phase-coherent digital communications for underwater acoustic channels,” IEEE J. Ocean. Eng., vol. 19, no. 1, pp. 100–111, Jan. 1994.
[2] M. A. Chitre, S. Shahabudeen, and M. Stojanovic, “Underwater acoustic communications and networking: Recent advances and future challenges,” J. Mar. Technol. Soc., vol. 42, no. 1, pp. 103–116, 2008.
[3] D. Rouseff, J. A. Flynn, J. A. Ritcey, W. L. J. Fox, “Acoustic Communication Using Time-Reversal Signal Processing: Spatial and Frequency Diversity”, AIP conference, 2004.
[4] Zhang, Guosong; Dong, Hefeng. “Joint passive-phase conjugation with adaptive multichannel combining for coherent underwater acoustic communications”, Vol. 73, Issue 4, pp: 433-439, 2012
[5] G. Edelmann, T. Akal, W. Hodgkiss, S. Kim, W. Kuperman, H. Song, and T. Akal, “An initial demonstration of underwater acoustic communication using time reversal mirror,” IEEE J. Ocean. Eng. 27, 602–609, 2002.
[6] T. Yang, “Temporal resolutions of time-reversed and passive-phase conjugation for underwater acoustic communications,” IEEE J. Ocean. Eng. 28, 229–245, 2003.
[7] Zhang, G., J.M. Hovem, H. Dong, and L. Liu, Coherent underwater communication using passive time reversal over multipath channels, Applied Acoustics, Vol. 72, No. 7, pp. 412-419, 2011.
[8] M. Stojanovic. “Retro focusing techniques for high rate acoustic communications”. J. Acoust. Soc. Am., 117:1173–1185, March 2005.
[9] G. F. Edelmann, H. C. Song, S. Kim, W. S. Hodgkiss, W. A. Kuperman, T. Akal, ‘Underwater Acoustic Communications Using Time Reversal’, IEEE Journal of Oceanic Engineering, vol. 30, NO. 4, pp. 852-864, OCT. 2005.
[10] H.C. Song, W.S. Hodgkiss, W.A. Kuperman, M. Stevenson and T. Akal. “Improvement of time-reversal communications using adaptive channel equalizers”. IEEE J. Ocean, Eng., 31, no. 2:487–496, April 2006.
[11] J. Gomes, A. Silva, S. Jesus, “Joint passive time reversal and multichannel equalization for underwater communications”, OCEANS'06 - Boston, USA, Sept. 2006.
[12] H. C. Song, A. Dotan, “Comments on “Retro focusing techniques for high rate acoustic communication”[J. Acoust. Soc. Am., 117, 1173 –1185] (L),” J. Acoust. Soc. Amer., 2006
[13] H.C. Song, W.S. Hodgkiss, W.A. Kuperman, W.J. Higley, K. Raghukumar, , T. Akal and M. Stevenson, “Spatial diversity in passive time reversal communications” , J. of the acoustical society of America ,July, 2006.
[14] H. C. Song, W. S. Hodgkiss, S. Kim, “Performance prediction of passive time reversal communications”, J. Acoust. Soc. Am. Vol. 122, No. 5, November 2007.
[15] J. Gomes, A. silva, S. Jesus, “Adaptive spatial combining for passive time-reversed communications”, J. Acoust. Soc. Am. 124 _2, pp. 1038–1053, May 2008.
[16] U. Vilaipornsawai, A. J. Silva, S. M. Jesus, “Combined adaptive time reversal and DFE technique for time-varying underwater communications”, ECUA Istanbul Conference, 2010.
[17] G. Zhang, H. Dong, “Experimental research on adaptive multichannel equalization for underwater communications”, IEEE, 2011.
[18] G. Zhang, H. Dong, “Spatial diversity in multichannel processing for underwater acoustic communications”, Ocean Engineering 38, pp. 1611–1623, 2011.
[19] G. Zhang, J. M. Hovem and H. Dong, "Experimental Assessment of Different Receiver Structures for Underwater Acoustic Communications over Multipath Channels ", Sensors 2012, 12, 2118-2135, 2012.
[20] Song H.C., Hodgkiss W.S. , “Efficient use of bandwidth for underwater acoustic communication”, J. Acoust Soc. Am., Aug. 2013; 134(2), pp:905-908.
