Downlink Scheduling and Resource Allocation for OFDM Systems

Abstract

Abstract-We consider scheduling and resource allocation for the downlink of a cellular OFDM system, with various practical considerations including integer carrier allocations, different subchannelization schemes, a maximum SNR constraint per tone, and "self-noise" due to channel estimation errors and phase noise. During each time-slot a subset of users must be scheduled for transmission, and the available tones and transmission power must be allocated among the selected users. Employing a gradient-based scheduling scheme presented in earlier papers reduces this to an optimization problem to be solved in each time-slot. Using dual decomposition techniques, we give an optimal algorithm for this problem when multiple users can time-share each carrier. We then give several low complexity heuristics that enforce an integer constraint on the carrier allocation. Simulations show that the algorithms presented all achieve similar performance under a wide range of scenarios, and that the performance gap between the optimal and suboptimal algorithms widens when per user SNR constraints or channel estimation errors are considered.

Frequency Selective OFDMA Scheduler with Limited Feedback

“…In our work, we consider equal power allocation across all PRBs, which has been shown to be close to optimal, as described in [4] and [5]. Unlike our work, [4] and [5] do not consider updating the weights after each PRB allocation in a given scheduling instant. A slight variant of the sequential scheduler is also described in [3].…”

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Delay‐aware resource control for device‐to‐device underlay communication systems

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QoS‐aware energy‐efficient resource allocation in OFDM‐based heterogenous cellular networks

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