EURASIP Journal on Wireless Communications and Networking 
Volume 2006 (2006), Article ID 60681, 18 pages
doi:10.1155/WCN/2006/60681

A General Theory for SIR Balancing

Holger Boche1,2,3 and Martin Schubert2

 1Heinrich Hertz Chair for Mobile Communications, Faculty of Electrical Engineering and Computer Science, Technical University of Berlin, Berlin 10587, Germany
2Fraunhofer German-Sino Lab for Mobile Communications (MCI), Einsteinufer 37, Berlin 10587, Germany
3Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut (HHI), Einsteinufer 37, Berlin 10587, Germany
Received 12 May 2005; Revised 28 December 2005; Accepted 19 January 2006

Recommended by Stefan Kaiser

Abstract

We study the problem of maximizing the minimum signal-to-interference ratio (SIR) in a multiuser system with an adaptive receive strategy. The interference of each user is modelled by an axiomatic framework, which reflects the interaction between the propagation channel, the power allocation, and the receive strategy used for interference mitigation. Assuming that there is a one-to-one mapping between the QoS and the signal-to-interference ratio (SIR), the feasible QoS region is completely characterized by the max-min SIR balancing problem. In the first part of the paper, we derive fundamental properties of this problem for the most general case, when interference is modelled with an axiomatic framework. In the second part, we show more specific properties for interference functions based on a nonnegative coupling matrix. The principal aim of this paper is to provide a deeper understanding of the interaction between power allocation and interference mitigation strategies. We show how the proposed axiomatic approach is related to the matrix-based theory.