Adaptive & Blind Equalization in Digital Optical Receivers using Constant Modulus Algorithm (CMA)

Adaptive & Blind Equalization in Digital Optical Receivers using Constant Modulus Algorithm (CMA)

Bandana MallickBibhu Prasad M. Bandyopadhyay N. Mandal S. Chattopadhyay 

Department of Electronics and Communication Engineering, Gandhi Institute of Engineering

Department of Electronics and Instrumentation Engineering, Gandhi Institute of Engineering

Department of Electrical Engineering, Asansol Engineering College, Asansol India

Department of Electronics Engineering, IIT(ISM) Dhanbad, India

Department of Electrical Engineering, National Institute of Technical Teachers’ Training and Research, Kolkata, India

Corresponding Author Email:;;;;
October 2017
31 December 2017
31 December 2017
| Citation



In this work a high precision adaptive equalization method is proposed and analysed using constant modulus algorithm (CMA). It includes blindand adaptive equalization. This proposed algorithm is described and evaluated using quadrature phase shift keying (QPSK) transmission. The QPSK modulation in combination with frequency-domain constant modulus algorithm (CMA) method, which exhibits remarkable robustness to received signal. Complex-valued communication link utilizes new advanced algorithm for blind equalisation as constant module algorithm. The studied Digital Signal Processing algorithm is considered as important building blocks in digital coherent receivers for the future generation of optical communication systems. The simulated results are different in both based on bandwidth and side lobe suppression ratio.


Adaptive equalizers, blind equalization, CMA equalizer, Constant modulus algorithm, Error measurement, QPSK.

1. Introduction
2. Blind Channel Equalization & CMA
3. Proposed Algorithm
4. Conclusion

[1] C. Pan, H. B¨ulow, W. Idler, L. Schmalen, F.R. Kschischang, “Optical Nonlinear Phase Noise Compensation for 9 × 32-Gbaud PolDM-16 QAM Transmission Using a Code-Aided Expectation-Maximization Algorithm” Journal of light wave technology, vol. 33, no. 17, pp. 3679 – 3686, September 1, 2015.

[2] Alcatel Lucent Inc., “Blind equalization for polarization-switched QPSK optical communications” US Patent December 22, 2011.

[3] C. Behrens, D. Lavery, D.S. Millar, S. Makovejs, B. C. Thomsen, R.I. Killey, S. J. Savory and P. Bayvel, “Ultra-Long-Haul Transmission of 7x42.9 Gb/s PS-QPSK and PM-BPSK,” European Conference on Optical Communication (ECOC) 2011, Mo.2.B.581-B586.

[4] Y. Gao, J. C. Cartledge, J. D. Downie, J. E. Hurley, D. Pikula and S. S.-H.Yam, “Nonlinearity compensation of 224 Gb/s dual-polarization 16-QAM transmission over 2700 km,” IEEE Photonics Technology Letters, vol. 25, no. 1, pp. 14–17, January 2013.

[5] C. Behrens, R. Killey, S. Savory, M. Chen and P. Bayvel, “Nonlinear transmission performance of higher-order modulation formats”, IEEE Photonics Technology Letters, vol. 23, issue-6, pp. 377–379, March 2011.

[6] R. Babu. T.P. Rajesh Kumar, “Blind Equalization using Constant Modulus Algorithm and Multi-Modulus Algorithm in Wireless Communication Systems,” International Journal of Computer Applications (0975 – 8887), vol. 1, no. 3, pp. 40-45, 2010.

[7] F.P. Guiomar, S.B. Amado, A. Carena, G. Bosco, A. Nespola, A.N.Pinto, “Fully Blind Linear and Nonlinear Equalization for 100G PM-64QAM Optical Systems” Journal of light wave technology, vol. 33, no. 7, pp. 1265 – 1274, April 1, 2015.

[8] S. Abrar A.K. Nandi, “Normalised Constant Modulus Algorithm For Blind Channel Equalisation” 16th European Signal Processing Conference (EUSIPCO 2008), pp. 1 – 5, Lausanne, Switzerland, August 25-29, 2008. 

[9] Z. Ding, “Adaptive Filters for Blind Equalization” CRC Press LLC, 2000.

[10] Z. Ding, Y. Li, “Blind Equalization and Identification” Marcel Dekker, Inc., CRC Press New York, Basel (2001).

[11] M. Boulouird, G. Favier and M. M. Hassani, “HOS-based Methods for Blind Identification of MA Models using Communication Signals”, Proceedings of AMSE-International Conference on Modeling and Simulation : General Applications and Models in Engineering Science-ICMS’05 , Marrakesh, Morocco, November 22-24, 2005.

[12] P. Johannisson, Martin Sjodin, Tobias A. Eriksson and Magnus Karlsson, “Four-dimensional modulation formats for long-haul transmission, “ Published in: Optical Fiber Communications Conference and Exhibition (OFC),San Francisco, CA, USA, 9-13 March 2014.

[13] S.J. Savory, “Digital coherent optical receivers: Algorithms and subsystems,” IEEE J. Sel. Topics Quantum Electron, vol. 16, no. 5, pp.1164–1179, September–October 2010. 121