Title :
Using Polymatroid Structures to Provide Fairness in Multiuser Systems
Author :
Maddah-Ali, Mohammad A. ; Mobasher, Amin ; Khandani, Amir K.
Author_Institution :
Dept. of Elec. & Comp. Eng., Waterloo Univ., Ont.
Abstract :
For a wide class of multiuser systems, a subset of capacity region which includes the corner points and the sum-capacity facet has a special structure known as polymatroid. Any interior point of the sum-capacity facet can be achieved by time-sharing among corner points or by an alternative method known as rate-splitting. The main purpose of this paper is to find a point on the sum-capacity facet which satisfies a notion of fairness among active users. In one case, the corner point for which the minimum rate of the active users is maximized (max-min corner point) is computed for signaling. In another case, the polymatroid properties are exploited to locate a rate-vector on the sum-capacity facet which is optimally fair in the sense that the minimum rate among all users is maximized (max-min rate). It is shown that the problems of deriving the time-sharing coefficients or rate-splitting scheme can be solved by decomposing the problem to some lower-dimensional subproblems. In addition, a fast algorithm to compute the time-sharing coefficients to attain a general point on the sum-capacity facet is proposed
Keywords :
channel capacity; minimax techniques; multiuser channels; wireless channels; capacity region subset; lower-dimensional subproblems; max-min corner point; max-min rate; multiuser systems; polymatroid structures; rate-splitting method; sum-capacity facet; time-sharing coefficients; Decoding; Game theory; Laboratories; Throughput; Time sharing computer systems; Transmitters;
Conference_Titel :
Information Theory, 2006 IEEE International Symposium on
Conference_Location :
Seattle, WA
Print_ISBN :
1-4244-0505-X
Electronic_ISBN :
1-4244-0504-1
DOI :
10.1109/ISIT.2006.261694