Transmission Systems Performance enhancement approach of the Wiener beamforming in DS/CDMA systems

An efficient performance enhancement scheme using the persymmetric covariance matrix structure to enhance the performance of the Wiener beamforming in DS/CDMA systems is proposed. The main idea of the proposed scheme is to reduce the interference-plus-noise effect from the pre-correlation array covariance matrix using the persymmetric covariance matrix in a weight vector calculation for the Wiener beamforming. Generally, the persymmetric covariance matrix has the theoretical properties such as Toeplitz structure matrix or a positive semidefinite matrix. The persymmetric covariance matrix structure is obtained from the pre-correlation array covariance matrix using one of three methods, which are Toeplitz matrix approximation (TMA) method, forward/backward averaging (FBA) method and Toeplitz-plus-Hankel approximation (THA) method. Simulation results are shown with the various parameters that demonstrate the superiority of the proposed scheme. Copyright © 2005 AEIT.

[1]  S. Saunders,et al.  Adaptive antenna array using real symmetric array covariance matrix , 2001 .

[2]  Emad K. Al-Hussaini,et al.  Performance of MRC Diversity Systems for the Detection of Signals with Nakagami Fading , 1985, IEEE Trans. Commun..

[3]  Don H. Johnson,et al.  Array Signal Processing: Concepts and Techniques , 1993 .

[4]  Richard D. Gitlin,et al.  The impact of antenna diversity on the capacity of wireless communication systems , 1994, IEEE Trans. Commun..

[5]  Arogyaswami Paulraj,et al.  Performance of Wireless CDMA with M-ary Orthogonal Modulation and Cell Site Antenna Arrays , 1996, IEEE J. Sel. Areas Commun..

[6]  Arogyaswami Paulraj,et al.  Recursive adaptive beamforming for wireless CDMA , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[7]  D. Mitchell Wilkes,et al.  A Hermitian Toeplitz matrix is unitarily similar to a real Toeplitz-plus-Hankel matrix , 1991, IEEE Trans. Signal Process..

[8]  Oishi Yasuyuki,et al.  Adaptive array for wideband DS-CDMA with decision feedback channel estimation , 1998, ICUPC '98. IEEE 1998 International Conference on Universal Personal Communications. Conference Proceedings (Cat. No.98TH8384).

[9]  Giovanni Romano,et al.  UMTS W-CDMA: evaluation of radio performance by means of link level simulations , 2000, IEEE Wirel. Commun..

[10]  John Thompson,et al.  Performance of antenna array receiver algorithms for CDMA , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[11]  S. Haykin,et al.  Adaptive Filter Theory , 1986 .

[12]  Hamid Aghvami,et al.  Performance of optimum and suboptimum combining at the antenna array of a W-CDMA system , 1999, IEEE J. Sel. Areas Commun..

[13]  Guanghan Xu,et al.  Performance of CDMA smart antenna systems , 1995, Conference Record of The Twenty-Ninth Asilomar Conference on Signals, Systems and Computers.

[14]  S. Unnikrishna Pillai,et al.  Forward/backward spatial smoothing techniques for coherent signal identification , 1989, IEEE Trans. Acoust. Speech Signal Process..

[15]  Laurence B. Milstein,et al.  Coherent DS-CDMA performance in Nakagami multipath fading , 1995, IEEE Trans. Commun..

[16]  Kap Seok Chang,et al.  Chip-level 2-D RAKE receiver with symbol-level searcher beamforming , 1999, Gateway to 21st Century Communications Village. VTC 1999-Fall. IEEE VTS 50th Vehicular Technology Conference (Cat. No.99CH36324).