Utilizing multiuser diversity for efficient support of quality of service over a fading channel

We consider the problem of quality of service (QoS) provisioning for K users sharing a downlink time-slotted Rayleigh fading channel. We develop simple and efficient schemes for admission control, resource allocation, and scheduling, which can yield substantial capacity gain. The efficiency is achieved by virtue of multiuser diversity. A unique feature of our work is explicit provisioning of statistical QoS, which is characterized by a data rate, delay bound, and delay-bound violation probability triplet. The results show that compared with a fixed-slot assignment scheme, our approach can substantially increase the statistical delay-constrained capacity of a fading channel (i.e., the maximum data rate achievable with the delay-bound violation probability satisfied), when delay requirements are not very tight, while yet guaranteeing QoS at any delay requirement.