Spectrum sharing in heavy loaded networks

Spectrum is one of the most precious radio resources that we have in communication networks, which should be utilized very efficiently. In this paper, we propose some admission control algorithms that activates users in the network, such that total sum rate of the network is maximized. In these algorithms, we try to find the best users among the many users requesting for service in the network. At the same time, we allocate each sub-channel to as many of the users as possible while the desirable Quality of Service (QoS) for all active users is satisfied. We present a Greedy algorithm; which performs close to the optimum solution; and sub-optimal algorithm with low complexity. The performance of these algorithms have been simulated and compared with existing methods.