Resource allocation to multi-application users in wireless systems

Abstract

In next generation mobile communication systems, a mobile user may choose to enjoy multiple applications simultaneously. In a multiuser system, for the same launched application, different users may have different quality of service (QoS) requirements and different priorities. Under such conditions, no system-defined user-satisfaction parameter can maximize each and every individual user`s satisfaction. Radio resource allocation to users and applications should, in turn, match the utility-maximization conditions. In this work, a user-centric utility maximization problem is formulated for a single user environment. From the formulated optimization problem, an optimum algorithm is derived to perform rate allocation to user-applications. The scheme maximizes user-satisfaction under application-specific rate constraints, and is applicable to both downlink and uplink transmissions. Orthogonal frequency division multiple access (OFDMA) seems to be the most favored multiple access technique for new generation mobile systems. In OFDMA systems, for given satisfation-maximization rates or applications` minimum rates, not only do power and subcarriers need to be allocated to users, but each user`s subcarriers, symbols and power must also be optimally allocated to user-applications, in order to maximize resource efficiency. Appropriate transmission-power minimization problems are formulated and optimum resource unit (RU) and power allocation algorithms are derive for both single user and multiuser cases. These problem formulations and solutions differ from existing works in several aspects. Two applications from the same user may have different bit-errorrate (BER) constraints. In order to achieve resource efficiency and depending on the multi-user multiple access technology in use, the symbols of these applications need to be transmitted using, either different frequency sub-bands, or different times, or different codes, or different combinations of these. Achie...