This paper proposes a dynamic fractional frequency reused cell architecture that simplifies the problem of subcarrier allocation with frequency reuse in multicell OFDMA networks. The architecture divides the cell surface into two overlapping geographical regions and orthogonally allocates subcarriers, which are called super and regular group of subcarriers, to the regions. The proposed architecture allows a frequency reuse factor of 1 with reduced inter-cell interference and increased trunking gain, while satisfying minimum data rate requirements. We also propose an efficient hierarchical solution to realize the proposed architecture. The solution first allocates subcarriers to the groups so that long term performance is maximized and next opportunistically schedules subcarriers to the users. The opportunistic scheduling is performed at the base stations considering the fairness requirements of the users. Simulation results illustrate the performance improvements of the proposed solution in comparison to the traditional frequency allocation schemes.

This paper considers the problem of scheduling multiple users in the downlink of a time-slotted cellular data network. For such a network, opportunistic scheduling algorithms improve system performance by exploiting time variations of the radio channel. We present novel optimal and approximate opportunistic scheduling algorithms that combine channel fluctuation and user mobility information in their decision rules. The algorithms modify the opportunistic scheduling framework of Liu et al., (1993) with dynamic constraints for fairness. These fairness constraints adapt according to the user mobility. The adaptation of constraints in the proposed algorithms implicitly results in giving priority to the users that are in the most favorable locations. The optimal algorithm is an offline algorithm that precomputes constraint values according to a known mobility model. The approximate algorithm is an online algorithm that relies on the future prediction of the user mobility locations in time. We show that the use of mobility information in opportunistic scheduling increases channel capacity. We also provide analytical bounds on the performance of the approximate algorithm using the fundamental inequality of Dyer et al., (1986) for linear programs. Simulation results on high data rate (HDR) illustrate the usefulness of the proposed schemes for elastic traffic and macrocell structures

This paper considers the problem of scheduling of multiple users in the downlink of a time-slotted cellular data network. It introduces optimal and approximate opportunistic scheduling algorithms, which combine channel variations and user mobility information in the decision rule. The proposed algorithms modify opportunistic scheduling algorithm of Liu et al. with dynamic fairness constraints that adapt according to the user mobility. The optimum algorithm is an offline algorithm because it pre-computes constraint values for all mobility states according to a known mobility model. The approximate algorithm is an on-line algorithm, and it relies on the future prediction of user mobility locations in time. These predicted values are used in computing constraint values. Simulation results illustrate the usefulness of the proposed schemes for elastic traffic and restrictive constraints. The use of mobility information in opportunistic scheduling also increases channel capacity.

The paper presents an online opportunistic scheduling algorithm for downlink transmission in a time-slotted shared wireless network that combines channel fluctuation and user mobility information in the decision rule. The algorithm is a general scheduling scheme and adapts well with any utility function for elastic traffic. For finite workload service demands, the scheme uses less completion time than the max-rate scheduling scheme. Under moderate load conditions, it gives time savings of up to 10%. For infinite backlog service demands, the proposed algorithm performs better than the proportional fair algorithm. Simulation results illustrate the usefulness of the proposed scheme for elastic traffic and moderate load conditions.