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IEEE Transactions on Antennas and Propagation
Volume 46 Number 7, July 1998

Experimental Studies of Spatial Signature Variation at 900 MHz for Smart Antenna Systems

Page 953.

Abstract:

A spatial signature is the response vector of a base-station antenna array to a mobile unit at a certain location. Mobile subscribers at different locations exhibit different spatial signatures. The exploitation of spatial diversity (or the difference of spatial signatures) is the basic idea behind the so-called space-division multiple-access (SDMA) scheme, which can be used to significantly increase the channel capacity and quality of a wireless communication system. Although SDMA schemes have been studied by a number of researchers [1]-[6], most of these studies are based on theoretical analyses and computer simulations with ideal assumptions. Not much experimental study [7], [8] has been reported on spatial signature variation due to nonideal perturbations in a real wireless communication environment. The purpose of this paper is to present, for the first time, extensive experimental results of spatial signature variation using a smart antenna testbed. The results to be presented include the spatial signature variation with time, frequency, small displacement, multipath angle spread and beamforming performance. The experimental results show the rich spatial diversity and potential benefits of using an antenna array for wireless communication applications.

References

1. S. C. Swales, M. A. Beach, D. J. Edwards, and J. P. McGreehan, "The performance enhancement of multibeam adaptive base-station antennas for cellular land mobile radio systems," IEEE Trans. Veh. Technol., vol. 39, pp. 56-67, Feb. 1990.
2. P. Balaban and J. Salz, "Optimum diversity combining and equalization in digital data transmission with applications to cellular mobile radio--Part I: Theoretical considerations," IEEE Trans. Commun., vol. 40, pp. 885-894, May 1992.
3. G. Xu, Y. Cho, A. Paulraj, and T. Kailath, "Maximum likelihood detection of co-channel communication signals via exploitation of spatial diversity," in Proc. 26th Asilomar Conf. Signals, Syst., Comput., Pacific Grove, CA, Oct. 1992, pp. 1142-1146.
4. J. H. Winters, J. Salz, and R. D. Gitlin, "The capacity of wireless communication systems can be substantially increased by the use of antenna diversity," in Proc. 1st Int. Conf. Universal Personal Comun. ICUPC, Dallas, TX, Sept. 29-Oct. 1, 1992, pp. 442-447.
5. B. Suard, A. F. Naguib, G. Xu, and A. Paulraj, "Performance of CDMA mobile communication systems using antenna arrays," in Proc. Int. Conf. Acoust., Speech, Signal Processing, Minneapolis, MN, Apr. 1993, vol. 4, pp. 153-156.
6. L. Tong, G. Xu, and T. Kailath, "Fast blind equalization of multipath channels via antenna arrays," in Proc. Int. Conf. Acoust., Speech, Signal Processing, Minneapolis, MN, Apr. 1993, pp. 272-275.
7. G. Xu, H. Liu, W. J. Vogel, H. P. Lin, S. S. Jeng, and G. W. Torrence, "Experimental studies of space-division-multiple-access schemes for spectral efficient wireless communications," in Proc. Int. Conf. Commun., New Orleans, LA, May 1994, vol. 2, pp. 800-804.
8. S. S. Jeng, H. P. Lin, G. Xu, and W. J. Vogel, "Measurements of spatial signature of an antenna array," in Proc. 6th Int. Symp. Personal, Indoor, Mobile Radio Commun., Toronto, ON, Canada, Sept. 1995, vol. 2, pp. 669-672.
9. A. Paulraj, R. Roy, and T. Kailath, "A subspace rotation approach to signal parameter estimation," Proc. IEEE, vol. 74, pp. 1044-1045, July 1986.
10. T. J. Shan, A. Paulraj, and T. Kailath, "On smoothed rank profile test in eigenstructure methods to direction-of-arrival estimation," IEEE Trans. Acoust., Speech, Signal Processing, vol. 33, pp. 1377-1385, Oct.1987.
11. S. U. Pillai and B. H. Kwon, "Forward/backward spatial smoothing techniques for coherent signal identification," IEEE Trans. Acoust., Speech, Signal Processing, vol. 37, no. 1, pp. 8-15, Jan. 1989.