Robust Downlink Power Control in Wireless Cellular Systems
EURASIP Journal on Wireless Communications and Networking 2004:2, 261–272 c 2004 Hindawi Publishing Corporation
Robust Downlink Power Control in Wireless Cellular Systems
Mehrzad Biguesh
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Email: biguesh@sent5.uni-duisburg.de
Shahram Shahbazpanahi
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Department of Electrical & Computer Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1 Email: shahbaz@mail.ece.mcmaster.ca
Alex B. Gershman
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Department of Electrical & Computer Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1 Email: gershman@ieee.org Received 30 November 2003; Revised 13 July 2004 A serious shortcoming of current downlink power control methods is that their performance may be severely degraded when the downlink channel information is known imprecisely at the transmitter. In this paper, a computationally and implementationally simple centralized downlink power control method is proposed for cellular wireless communication systems using code division multiple access (CDMA) or space division multiple access (SDMA). Our method provides a substantially improved robustness against imperfect knowledge of the wireless channel by means of maintaining the required quality of service for the worst-case channel uncertainty. In the SDMA case, the proposed technique can be straightforwardly combined with any of the existing transmit beamforming methods. Simulation results validate substantial robustness improvements achieved by our approach. Keywords and phrases: power control, cellular system, CDMA, SDMA, downlink beamforming.
1.
INTRODUCTION
Power control is an intelligent way of adjusting the
Robust Downlink Power Control in Wireless Cellular Systems
Mehrzad Biguesh
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Email: biguesh@sent5.uni-duisburg.de
Shahram Shahbazpanahi
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Department of Electrical & Computer Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1 Email: shahbaz@mail.ece.mcmaster.ca
Alex B. Gershman
Department of Communication Systems, University of Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany Department of Electrical & Computer Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1 Email: gershman@ieee.org Received 30 November 2003; Revised 13 July 2004 A serious shortcoming of current downlink power control methods is that their performance may be severely degraded when the downlink channel information is known imprecisely at the transmitter. In this paper, a computationally and implementationally simple centralized downlink power control method is proposed for cellular wireless communication systems using code division multiple access (CDMA) or space division multiple access (SDMA). Our method provides a substantially improved robustness against imperfect knowledge of the wireless channel by means of maintaining the required quality of service for the worst-case channel uncertainty. In the SDMA case, the proposed technique can be straightforwardly combined with any of the existing transmit beamforming methods. Simulation results validate substantial robustness improvements achieved by our approach. Keywords and phrases: power control, cellular system, CDMA, SDMA, downlink beamforming.
1.
INTRODUCTION
Power control is an intelligent way of adjusting the
References: Manuscript Due Acceptance Notification Final Manuscript Due Publication Date December 1, 2006 April 1, 2007 June 1, 2007 4th Quarter, 2007