OPTIMUMSCHEDULINGFOR ORTHOGONALMULTIPLE ACCESS OVER FADING CHANNELSUSING QUANTIZEDCHANNEL STATE INFORMATION

The efficiency of multi-access communications over wireless fading links benefits from channel-adaptive allocation of the available bandwidtl) and power resources. Different from most existing approaches that allocate resources based on perfect channel state information (P-CSI), this work optimizes chan­ nel scheduling and resource allocation over orthogonal fad­ ing channels when user terminals and the scheduler rely on quantized channel state information (Q-CSI). The novel uni­ fying approach optimizes an average transmit-performance criterion subject to average quality of service requirements. The resultant optimal policy per fading realization either al­ locates the entire channel to a single (winner) user, or, to a small group of winner users whose percentage of shared re­ sources is found by solving a linear program. Both alterna­ tives become possible by smoothing the allocation scheme. The smooth policy is asymptotically optimal and incurs re­ duced computational complexity.