High spectral efficiency and flexible data rate access are the main focus o
f future wireless networks. Multiple channel allocation schemes have the po
tential of achieving this goal. By assigning multiple slots and/or multiple
carriers to one user, it is possible to provide a flexible data rate with
quite low complexity. In this article we propose a simple allocation scheme
where each user is assigned a fixed group of carriers. These carriers are
adaptively used depending on the interference situation within the system.
The system performance in terms of average throughput is investigated for t
wo different types of allocation schemes: a fully centralized scheme and a
distributed one that uses frequency diversity as a mean of improving the us
er link quality. The obtained results show that both schemes improve the sy
stem throughput over single carrier allocation without affecting the capaci
ty of the system in terms of number of users per cell.