This article is part of the series Fairness in Radio Resource Management for Wireless Networks.

Open Access Research Article

On Throughput-Fairness Tradeoff in Virtual MIMO Systems with Limited Feedback

AlexisA Dowhuszko1*, Graciela Corral-Briones1, Jyri Hämäläinen2 and Risto Wichman3

Author Affiliations

1 Digital Communications Research Laboratory, National University of Cordoba (UNC) - CONICET, Avenida Velez Sarsfield 1611, X5016GCA Cordoba, Argentina

2 Department of Communications and Networking, Helsinki University of Technology (TKK), P.O. Box 3000, FIN-02015 TKK, Finland

3 Department of Signal Processing and Acoustics, Helsinki University of Technology (TKK) - Smart and Novel Radios (SMARAD) Centre of Excellence, P.O. Box 3000, FIN-02015 TKK, Finland

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EURASIP Journal on Wireless Communications and Networking 2009, 2009:102064 doi:10.1155/2009/102064


The electronic version of this article is the complete one and can be found online at: http://jwcn.eurasipjournals.com/content/2009/1/102064


Received:1 July 2008
Revisions received:10 December 2008
Accepted:24 January 2009
Published:4 March 2009

© 2009 The Author(s).

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We investigate the performance of channel-aware scheduling algorithms designed for the downlink of a wireless communication system. Our study focuses on a two-transmit antenna cellular system, where the base station can only rely on quantized versions of channel state information to carry out scheduling decisions. The motivation is to study the interaction between throughput and fairness of practical spatial multiplexing schemes when implemented using existing physical layer signaling, such as the one that exists in current wideband code division multiple access downlink. Virtual MIMO system selects at each time instant a pair of users that report orthogonal (quantized) channels. Closed-form expressions for the achievable sum-rate of three different channel-aware scheduling rules are presented using an analytical framework that is derived in this work. Our analysis reveals that simple scheduling procedures allow to reap a large fraction (in the order of 80%) of the sum-rate performance that greedy scheduling provides. This overall throughput performance is obtained without affecting considerably the optimal short-term fairness behavior that the end users would perceive.

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