Dong Liang, Cao Xiu-ying, Bi Guang-guo. VCMA Blind Equalizer with Improved Convergence Performance for MIMO-OFDM Systems[J]. Journal of Electronics & Information Technology, 2007, 29(6): 1356-1360. doi: 10.3724/SP.J.1146.2005.01593
Citation:
Dong Liang, Cao Xiu-ying, Bi Guang-guo. VCMA Blind Equalizer with Improved Convergence Performance for MIMO-OFDM Systems[J]. Journal of Electronics & Information Technology, 2007, 29(6): 1356-1360. doi: 10.3724/SP.J.1146.2005.01593
Dong Liang, Cao Xiu-ying, Bi Guang-guo. VCMA Blind Equalizer with Improved Convergence Performance for MIMO-OFDM Systems[J]. Journal of Electronics & Information Technology, 2007, 29(6): 1356-1360. doi: 10.3724/SP.J.1146.2005.01593
Citation:
Dong Liang, Cao Xiu-ying, Bi Guang-guo. VCMA Blind Equalizer with Improved Convergence Performance for MIMO-OFDM Systems[J]. Journal of Electronics & Information Technology, 2007, 29(6): 1356-1360. doi: 10.3724/SP.J.1146.2005.01593
In MIMO-OFDM systems, data streams of multiple users can be simultaneously recovered up to a phase ambiguity when a VCMA criterion combined with a user decorrelation criterion is considered. Since a low complexity LMS algorithm is used in the iteration, the convergence speed and the steady state MSE performance become a contradiction. In this paper, a variable step size iteration method is proposed which has good performance in both convergence speed and steady state MSE. Moreover, the impact of channel noise on the tap refreshing process of the transverse filters is analyzed, and a simple method to remove the effect of noise is induced. As a result the convergence performance of the blind equalizer is further improved.
Godard D N. Self-recovering equalization and carrier tracking in two dimensional data communication systems. IEEE Trans. on Commun., 1980, COMM-28(11): 1867-1875.[2]Papadias C B and Paulraj A J. A space-time constant modulus algorithm for SDMA systems. in IEEE/VTS 46th Veh. Tech. Conf. (VTC-96), Atlanta, GA, Apr. 28-May 1, 1996: 86-90.[3]Papadias C B and Paulraj A J. A constant modulus algorithm for multiuser signal separation in presence of delay spread using antenna arrays[J].IEEE Signal Processing Lett.1997, 4(6):178-181[4]Johnson R Jr, Schniter P, and Endres T J, et al.. Blind equalization using the constant modulus criterion: a review[J].Proc. IEEE.1998, 86(10):1927-1949[5]Yang V Y and Jones D L. A vector constant modulus algorithm for shaped constellation equalization[J].IEEE Signal Processing Lett.1998, 5(4):89-91[6]Abrudan T, Sirbu M, and Koivunen V. A block-Toeplitz VCMA equalizer for MIMO-OFDM systems. in ACSSC 2003, Pacific Grove, California, Nov. 2003, vol.1: 1037-1041.[7]Abrudan T, Hjorungnes A, and Koivunen V. Toeplitz method for blind equalization in MIMO OFDM systems. in IZS 2004, ETH Zurich, Switzerland, Feb. 2004: 212-215.[8]Kwong R H and Johnston E W. A variable step size LMS algorithm[J].IEEE Trans. on Signal Processing.1992, 40(7):1633-1642[9]Slock D T M. Blind joint equalization of multiple synchronous mobile users using oversampling and/or multiple antennas. in 28 ACSSC, San Diego, USA, Oct. 1994, vol.2: 1154-1158.