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Joint Scheduling and Resource Allocation in the OFDMA Downlink: Utility Maximization under Imperfect Channel-State Information (2011)
| Content Provider | CiteSeerX |
|---|---|
| Author | Aggarwal, Rohit Assaad, Mohamad Koksal, C. Emre Schniter, Philip |
| Abstract | We consider the problem of simultaneous user-scheduling, power-allocation, and rate-selection in an orthogonal frequency division multiple access (OFDMA) downlink, with the goal of maximizing expected sum-utility under a sum-power constraint. In doing so, we consider a family of generic goodput-based utilities that facilitate, e.g., throughput-based pricing, quality-of-service enforcement, and/or the treatment of practical modulationand-coding schemes (MCS). Since perfect knowledge of channel state information (CSI) may be difficult to maintain at the base-station, especially when the number of users and/or subchannels is large, we consider scheduling and resource allocation under imperfect CSI, where the channel state is described by a generic probability distribution. First, we consider the “continuous ” case where multiple users and/or code rates can time-share a single OFDMA subchannel and time slot. This yields a nonconvex optimization problem that we convert into a convex optimization problem and solve exactly using a dual optimization approach. Second, we consider the “discrete ” case where only a single user and code rate is allowed per OFDMA subchannel per time slot. For the mixed-integer optimization problem that arises, we discuss the connections it has with the continuous case and show that it can solved exactly in some situations. For the other situations, we present a bound on the optimality gap. For both cases, we provide algorithmic implementations of the obtained solution. Finally, we study, numerically, the performance of the proposed algorithms under various degrees of CSI uncertainty, utilities, and OFDMA system configurations. In addition, we demonstrate advantages relative to existing state-of-the-art algorithms. |
| File Format | |
| Volume Number | 59 |
| Journal | IEEE TRANSACTIONS ON SIGNAL PROCESSING |
| Language | English |
| Publisher Date | 2011-01-01 |
| Access Restriction | Open |
| Subject Keyword | Resource Allocation Imperfect Channel-state Information Optimal Joint Scheduling Continuous Case Orthogonal Frequency Division Multiple Access Time Slot Obtained Solution Convex Optimization Problem Channel State Sum-power Constraint Quality-of-service Enforcement Mixed-integer Optimization Problem Ofdma System Configuration Nonconvex Optimization Problem Single Ofdma Subchannel Index Term Bisection Algorithm Perfect Knowledge Single User Utility Maximization Generic Goodput-based Utility Multiple User Csi Uncertainty Code Rate State-of-the-art Algorithm Channel State Information Algorithmic Implementation Imperfect Channel State Information Imperfect Csi Optimality Gap Practical Modulationand-coding Scheme Mixed Integer Optimization Dual Optimization Approach Various Degree Generic Probability Distribution Ofdma Subchannel Throughput-based Pricing Discrete Case |
| Content Type | Text |
| Resource Type | Article |
