Delay Bounds for Resource Allocation in Wideband Wireless Systems

In this paper, the problem of resource allocation in multiuser single-antenna wideband OFDM(A) systems is considered from a cross-layer point of view. The main motivation is to show advantages of such systems with respect to narrowband systems. Despite the maximum normalized average throughput is not increased with respect to that in a narrowband system, a more efficient use of resources is possible by considering frequency as an additional resource to be allocated. It is shown that when the bandwidth is considerably larger than the coherence bandwidth of the channel and the channel is varying slowly with respect to the scheduling period, average delay can significally be improved. In that case, the average delay is only proportional to the scheduling period and not to the channel coherence time (as it is the case in narrowband systems). Furthermore, different reasource allocation policies are analyzed to show average delay improvements when buffer occupancy information is used.