Since the seminal paper by Knopp and Humblet that showed that the system throughput of a singlecel l system is maximized if only one terminal transmits at a time, there has been a large interest in opportunistic communications and its relation to various fairness measures. On the other hand, in multicel l systems there is a need to allocate transmission power such that some overall utility function is maximized typically under fairness constraints. Furthermore, in multicell systems the degree of resource allocation freedom includes the serving cell selection that allows for load balancing and thereby the efficient use of radio resources. In this paper we formulate the joint serving cell selection (link selection) and power allocation problem as an optimization task whose purpose is to maximize either the minimum user throughput or the multicell sum throughput. The max-min problem and a simplified max throughput problem are both NP-hard and we therefore propose heuristic solution approaches.We present numerical results that give new and valuable insights into the trade off between fair and sum throughput optimal joint resource allocation strategies.
Mikael Fallgren, Aesa Hildur Oddsdottir, Gabor Fodor