Resource allocation for non-real-time services in OFDM-based cognitive radio systems

We study the resource allocation (RA) problem in a multiuser OFDM-based cognitive radio (CR) system for non-realtime (NRT) applications in which average user data rates are to be maintained proportionally. In contrast to existing algorithms designed for multiuser OFDM systems, which are unable to guarantee users proportional rates when applied in a CR system, the proposed optimal RA algorithm ensures that CR user rates are maintained in proportion to predefined target rates while at the same time providing an improved system throughput.