Recursive Least Squares Adaptive Filter a better ISI Compensator

Authors: O. P. Sharma, V. Janyani, S. Sancheti

Abstract:

Inter-symbol interference if not taken care off may cause severe error at the receiver and the detection of signal becomes difficult. An adaptive equalizer employing Recursive Least Squares algorithm can be a good compensation for the ISI problem. In this paper performance of communication link in presence of Least Mean Square and Recursive Least Squares equalizer algorithm is analyzed. A Model of communication system having Quadrature amplitude modulation and Rician fading channel is implemented using MATLAB communication block set. Bit error rate and number of errors is evaluated for RLS and LMS equalizer algorithm, due to change in Signal to Noise Ratio (SNR) and fading component gain in Rician fading Channel.

Keywords: Least mean square (LMS), Recursive least squares(RLS), Adaptive equalization, Bit error rate (BER), Rician fading channel, Quadrature Amplitude Modulation (QAM), Signal to noiseratio (SNR).

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1060601

References:

[1] S. Haykin, "Adaptive Filter Theory", Third Ed., Upper Saddle River, N.J., Prentice-Hall, 1996.
[2] R. W. Lucky, "Techniques for adaptive equalization of digital communication system", Bell System Tech. Journal, Vol. 45, pp. 255- 286, 1966.
[3] S. U. H. Qureshi, "Adaptive Equalization", IEEE Procs., Vol. 73. No. 9, pp. 1349-1387, Sept. 1985.
[4] J. G. Proakis, "Digital Communication", Fourth Ed., McGraw-Hill International Ed., 2001.
[5] M. K. Simon and M. S. Alounini, "Digital communication over fading channels: A unified approach to performance analysis", Wiley, New York, 2000.
[6] R. Prasad and A. Kegel, "Effect of Rician fading and log-normal shadowing signals on spectrum efficiency in microcellular radio", IEEE Trans. Veh. Tech., PP. 274-81, August 1993.
[7] M. S. Alouini and A. J. Goldsmith, "Capacity of Rayleigh fading channel underdifferent adaptive transmission and diversity combining techniques", IEEE Trans. Veh. Tech., PP. 1165-81, July 1999.
[8] J. A. Daniel, Heejong Yoo, Venkatesh krishnan, Walter Huang and David V. Anderson, "LMS Adaptive Filters Using Distributed Arithmetic for High Throughput", IEEE Trans. On circuit and systems-I: Regular paper, Vol. 52, No. 7, pp. 1327-1337, July 2005.
[9] R. W, Lucky, "Automatic Equalizer for Digital Communication", Bell syst. Tech. J., Vol. 44, pp. 547-588, April 1965.
[10] J. G. Proakis, "Adaptive Equalization for TDMA Digital Mobile Radio",IEEE Trans. On Vehicular Tech., Vol. 40, No. 2, pp. 333-341 May 1991.
[11] O. P. Sharma and S. Sancheti, "Performance analysis of Gray coded MPSK", 22nd National Convention of Electronics and Telecommunication Engineers and National Seminar on Advances in Electronics and Telecommunication Technologies Vision-2020, Souvenir Technical session V, Sr. No. 09, August 04-05, 2006.
[12] K. Banovic, A. R. Esam and M. A. S. Khalid,, "A Novel Radius- Adjusted Approach for Blind Adaptive Equalization", IEEE Signal Processing Letters, Vol. 13, No. 1, Jan. 2006.
[13] R. A. Valenzuela, "Performance of Adaptive Equalization for Indoor Radio Communications", IEEE Tran. On Commun., Vol. 31, No. 3, pp. 291-293, March 1989.
[14] X. Tang, M. S. Alounini and A. Goldsmith, " Effect of channel estimation error on M-QAM BER performance in Rayleigh fading", IEEE Trans. Commun., PP. 1856-64, December 1999.
[15] C. R. Johnson Jr., "Admissibility in blind adaptive channel equalization", IEEE Control System Mag., PP. 3-15, January 1991.
[16] W. Lu, "4-G mobile research in Asia", IEEE commun. Mag., PP. 104-6, March 2003.
[17] D. D. Falconer and L. Ljung, "Application of Fast Kalman Estimation to adaptive Equalization", IEEE Trans. Commun., Vol. Com-26, pp. 1439- 1446, Oct. 1978.
[18] O.P. Sharma, V. Janyani, S. Sancheti and S. Bhardwaj, "Channel Modeling and Security Issues for Wireless Healthcare System", VOYAGER, The Journal of Computer Science and Information Technology, ISSN 0973-4872 Vol.5, No.1, pp. 37-41, Jan-June, 2007.