Abstract
The paper investigates a single-cell multiuser system with a linear antenna array at the base station. We consider both the down-link and the up-link. The quality of service (QoS) parameter of interest depends monotonically on the signal to interference+noise ratio (SINR) through a given QoS-SINR mapping. In the studied case of no power constraints, the set of all QoS parameter values that can be supported by the system is determined by the spectral radius of a certain nonnegative irreducible matrix. The main result of this paper shows that if the spectral radius is required to be a convex function of the QoS parameter values for an arbitrary link gain matrix, then the inverse of the QoS-SINR mapping must be log-convex, which is in general stronger than the convexity property. We show that the log-convexity requirement can be dropped in two special cases of link gain matrices. These results provide a theoretical framework for the design of medium access control strategies.
| Original language | English |
|---|---|
| Pages (from-to) | 689-694 |
| Number of pages | 6 |
| Journal | IEEE Wireless Communications and Networking Conference, WCNC |
| Volume | 2 |
| State | Published - 2005 |
| Externally published | Yes |
| Event | 2005 IEEE Wireless Communications and Networking Conference, WCNC 2005: Broadband Wirelss for the Masses - Ready for Take-off - New Orleans, LA, United States Duration: 13 Mar 2005 → 17 Mar 2005 |