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Nonlinear Blind Equalizers: NCMA and NMCMA

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DOI: 10.4236/ijcns.2010.36070    4,125 Downloads   7,387 Views  

ABSTRACT

This paper proposes two nonlinear blind equalizers: the nonlinear constant modulus algorithm (NCMA) and the nonlinear modified constant modulus algorithm (NCMA) by applying a nonlinear transfer function (NTF) into constant modulus algorithm (CMA) and modified constant modulus algorithm (MCMA), respectively. The effect of the NTF on CMA and MCMA is theoretically analyzed, which implies that the NTF can make their decision regions much sharper so that the proposed two nonlinear blind equalizers are more robust against the convergency error compared to their linear counterparts. The embedded single layer in NCMA and NMCMA simultaneously guarantees a comparably speedy convergency. On 16-quadrature amplitude modulation (QAM) symbols, computer simulations show that NCMA achieves an 8dB lower convergency mean square error (MSE) than CMA, and NMCMA achieves a 15dB lower convergency MSE than MCMA.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

D. Wang and S. Chandana, "Nonlinear Blind Equalizers: NCMA and NMCMA," International Journal of Communications, Network and System Sciences, Vol. 3 No. 6, 2010, pp. 523-529. doi: 10.4236/ijcns.2010.36070.

References

[1] J. R. Treichler and B. G. Agee, “A New Approach To Multipath Correction of Constant Modulus Signals,” IEEE Transactions on Acoustics, Speech, and Signal Processing, Vol. 27, No. 10, October 1979, pp. 512-530.
[2] X. H. Dai, “CMA-Based Nonlinear Blind Equalizer Modeled by a Two-Layer Feed forward Neural Network,” IEE Proceedings-Communications, Vol. 148, No. 4, April 2001, pp. 243-248.
[3] S. A. Athuraliya and L. M. Garth, “Quantized CMA Equalization for Shaped Signal Constellations,” IEEE Signal Processing Letters, Vol. 11, No. 2, February 2004, pp. 67-70.
[4] B. Baykal and A. G. Constantinides, “Matched Filtering for CMA-Based Blind Channel Estimation,” IEEE Electronics Letters, Vol. 39, No. 17, August 2003, pp. 1285-1287.
[5] D. L. Wang, H. Leung, K.-C. Kwak and H. Yoon, “Enhanced Speech Recognition with Blind Equalization for Robot “WEVER-R2”,” Proceedings of IEEE Inter- national Symposium on Robot and Human Interactive Communication, Jeju Island, August 2007, pp. 684-488.
[6] G. Gelli and F. Verde, “Two-Stage Interference-Resistant Adaptive Periodically Time-Varying CMA Blind Equali- zation,” IEEE Transactions on Signal Processing, Vol. 50, No. 3, March 2002, pp. 662-672.
[7] K. Wesolowski, “Analysis and Properties Of The Modified Constant Modulus Algorithm for Blind Equalization,” European Transactions on Telecommunications, Vol. 3, No. 3, September 2008, pp. 225-230.
[8] M. Chen, Q. J. Tu and Z. Ding, “A Quadratic Programming Approach to Blind Equalization and Signal Separation,” IEEE Transactions on Signal Processing, Vol. 57, No. 6, June 2009, pp. 2232-2244.
[9] Kyuho Hwang and Sooyong Choi, “Blind Equalization Method Based on Sparse Bayesian Learning,” IEEE Signal Processing Letters, Vol. 16, No. 4, April 2009, pp. 315-318.
[10] I. Santamaria, C. Pantaleon, L. Vielva and J. Ibanez, “Blind Equalization of Constant Modulus Signals Using Support Vector Machines,” IEEE Transactions on Signal Processing, Vol. 52, No. 6, June 2004, pp. 1773-1782.
[11] K. Nam Oh and Y. O. Chin, “Modified Constant Modulus Algorithm: Blind Equalization and Carrier Phase Recovery Algorithm,” Proceedings of IEEE International Conference on Communications, Seattle, June 1995, pp. 498-502.
[12] M. Amin, H. Lin, C. R Reed. Jr. and R. Malkemes, “A Modified Constant Modulus Algorithm For Adaptive Channel Equalization for QAM Signals,” Proceedings of IEEE Signal Processing Workshop, Cannes, August 2001, pp.563-566.
[13] I. Chahed, J. Belzile and A. B. Kouki, “Blind Decision Feedback Equalizer Based on High Order MCMA,” Proceedings of IEEE CCECE, Niagara Falls, Ontario, May 2004, pp. 2111-2114.
[14] Z. X. Jiang, M. Zhang, Z. C. Li and S. L. Lu, “A Newly High-Speed MCMA Algorithm for QAM System,” Proceedings of WiCOM, Dalian, September 2008, pp. 1-4.
[15] D. L. Wang, “A Nonlinear Modified Constant Modulus Algorithm for Blind Equalization,” Proceedings of IEEE CCECE, Calgary, Alberta, May 2010, pp. 1-4.
[16] D. L. Wang and D. G. Wang, “Generalized Derivation of Neural Network Constant Modulus Algorithm for Blind Equalization,” Proceedings of WiCOM, Beijing, September 2009, pp. 1-4.
[17] D. L. Wang, H. Leung, A. P. Kurian, K.-C. Kwak and H. Yoon, “A Deconvolutive Neural Network for Speech Classification with Applications to Home Service Robot,” IEEE Transactions on Instrumentation and Measurement, Vol. 59, No. 9, September 2010, pp. 1297-1303.
[18] C. You and D. Hong, “Nonlinear Blind Equalization Schemes Using Complex-Valued Multilayer Feedforward Neural Networks,” IEEE Transactions on Neural Networks, Vol. 9, No. 11, November 1998, pp. 1442 -1455.

  
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