Transmit Diversity versus Beamforming System in Correlated Fading Channel

Abdul W. Umrani, Yong L. Guan, Fahim A. Umrani

.

DOI: 10.4236/ijcns.2010.38089                

Abstract

The performance analysis, using outage capacity for a forward link cellular communications system is presented. The effects of correlated fading, the distribution of angle of arrivals, and the array configurations are considered. The objective is to examine the effect of angle of arrival (AOA) energy distributions on two systems (transmit diversity and beamforming) with angle spread. We do so by comparing the performance of transmit diversity with a system that uses beamforming to point a relatively narrow beam at the mobile station. Analytical results show that the transmit diversity system using uniform linear arrays (ULA) and uniform circular arrays (UCA) with truncated Laplacian AOA, performs better even at smaller angle spreads as compared to other energy distributions. The ULA geometry is a preferable configuration for transmit diversity system as compared to UCA.

Keywords

Antenna Arrays, Angle Spread, Fading Correlation, Diversity Performance, Fading Channels, Cellular Radio

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	J. H. Winters, “The Diversity Gain of Transmit Diversity Technique in Wireless Systems with Rayleigh Fading,” IEEE Transactions on Vehicular Technology, Vol. 47, No. 4, 1998, pp. 119-132.
[2]	S. Zhou and G. B. Giannakis, “Optimal Transmitter Eigen-Beamforming and Space Time Block Coding Based on Channel Correlations,” IEEE Transactions on Information Theory, Vol. 49, No. 7, 2003, pp. 1673-1690.
[3]	C. Chauah, D. Tse, J. Kahn and R. Valenzuala, “Capacity Scaling in MIMO Wireless Systems under Correlated Fading,” IEEE Transactions on Information Theory, Vol. 48, No. 3, 2002, pp. 637-650.
[4]	S. Siwamogsatham and M. P. Fitz, “Robust Space-Time Codes for Correlated Rayleigh Fading Channels,” IEEE Transactions on Signal Processing, Vol. 50, No. 10, 2002, pp. 2408-2416.
[5]	E. A. Jorswieck and A. Sezgin, “Impact of Spatial Correlation on the Performance of Orthogonal Space-Time Block Codes,” IEEE Communications Letters, Vol. 8, No. 1, 2004, pp. 21-23.
[6]	C. Rensburg and B. Friedlander, ‘Transmit Diversity for Arrays in Correlated Rayleigh Fading,” IEEE Transactions on Vehicular Technology, Vol. 53, No. 6, 2004, pp. 1726-1734.
[7]	K. I. Pedersen, P. E. Mogensen and B. H. Fleury, “Power Azimuth Spectrum in Outdoor Environments,” IEE Electronics Letters, Vol. 33, No. 18, 1997, pp. 1583-1584.
[8]	B. Friedlander and S. Scherzer, “Beamforming versus Transmit Diversity in the Downlink of Cellular Communication System,” IEEE Transactions on Vehicular Tech- nology, Vol. 53, No. 4, 2004, pp. 1023-1034.
[9]	A. W. Umrani and V. K. Dubey, “Effect of Angle of Arrival on Transmit Diversity and Beamforming Systems under Correlated Fading,” IEE Electronics Letters, Vol. 41, No. 6, 2005, pp. 293-294.
[10]	A. W. Umrani and V. K. Dubey, “Effect of Angle of Arrival on Transmit Diversity and Beamforming Systems under Correlated Fading,” IEEE Sarnoff Symposium on Advances in Wired and Wireless Communication, Prince- ton, 18-19 April 2005, pp. 109-112.
[11]	J.-A. Tsai, M. Buehrer and B. D. Woerner, “BER Perfor- mance of a Uniform Circular Array versus a Uniform Li- near Array in a Mobile Radio Environment,” IEEE Trans- actions on Wireless Communications, Vol. 3, No. 3, 2004, pp. 695-700.
[12]	N. L. Johnson, S. Kotz and N. Balakrishnan, “Continuous Univariate Distributions,” Wiley Series, Hoboken, Vol. 1, 1994.
[13]	J. Salz and J. H. Winters, “Effect of Fading Correlation on Adaptive Arrays in a Digital Mobile Radio,” IEEE Transactions on Vehicular Technology, Vol. 43, No. 4, 1994, pp. 1049-1057.
[14]	A. W. Umrani and V. K. Dubey, “Correction to BER Per- formance of a Uniform Circular Array versus a Uniform Linear Array in a Mobile Radio Environment,” IEEE Transactions on Wireless Communications, Vol. 5, No. 4, 2006, p. 732.
[15]	J.-A. Tsai, M. Buehrer and B. D. Woerner, “The Impact of AOA Energy Distribution on Spatial Fading Correlation of Linear Antenna Arrays,” Proceedings of IEEE 55th Vehicular Technology Conference, Birmingham, Vol. 2, 6-9 May 2002, pp. 933-937.
[16]	J.-A. Tsai, M. Buehrer and B. D. Woerner, “Spatial Fading Correlation Function of Circular Antenna Arrays with Laplacian Energy Distribution,” IEEE Communications Letters, Vol. 6, No. 5, 2002, pp. 178-180.
[17]	X. Li and Z. P. Nei, “Comments on Spatial Fading Correlation of Circular Antenna Arrays Laplacian Energy Distribution,” IEEE Communications Letters, Vol. 8, No. 5, 2004, p. 295.
[18]	Y. Wang, Z. Zhou and J. Wang, “Analysis of Spatial Fading Correlation for Different Antenna Arrays,” Proceedings of 2004 IEEE Wireless Communications and Net- working Conference, Atlanta, 21-25 March 2004, pp. 700- 705.
[19]	A. Forenza and R. W. Heath, Jr., “Impact of Antenna Geometry on MIMO Communication in Indoor Clustered Channels,” Proceedings of Antennas and Propagation Society International Symposium, Monterey, 20-26 June 2004, pp. 1700-1703.