Abstract: The spectrum-efficient secondary users grouping method for two-tier cognitive radio groups femtocell base stations (FBSs) and macrocell secondary users (MSUs) into non-interfering groups based on their GPS location information, and then serves the FBSs/MSUs within each group using the same channel. A first approach for grouping the secondary users (SUs) is distance-based. A second approach utilizes profit maximization. Both approaches are extended to a co-channel deployment scenario where the FBSs can share part of the channels purchased for the MSUs to further reduce the number of channels to be purchased from the PU networks. The distance-based grouping method finds the minimum number of groups such that the desired quality of service (QoS) determined by an outage probability threshold is maintained. The profit maximization method tries to find the set of SUs that maximizes the expected total profit of the SU network.

Abstract: The spectrum-efficient secondary users grouping method for two-tier cognitive radio groups femtocell base stations (FBSs) and macrocell secondary users (MSUs) into non-interfering groups based on their GPS location information, and then serves the FBSs/MSUs within each group using the same channel. A first approach for grouping the secondary users (SUs) is distance-based. A second approach utilizes profit maximization. Both approaches are extended to a co-channel deployment scenario where the FBSs can share part of the channels purchased for the MSUs to further reduce the number of channels to be purchased from the PU networks. The distance-based grouping method finds the minimum number of groups such that the desired quality of service (QoS) determined by an outage probability threshold is maintained. The profit maximization method tries to find the set of SUs that maximizes the expected total profit of the SU network.

Abstract: A method of mitigating an interference and reducing costs resulting from a co-existence of a plurality of femtocells and a plurality of macrocells. The method groups the femtocells into groups of non-interferers based on the distances between a plurality of femtocell base stations and a cognitive radio network base station, wherein the distances are calculated based on the locations of a plurality of grouped femtocell base stations. The method accrues a revenue of the profit of the cognitive radio network base station from a plurality of K femto base stations and a plurality of I macro secondary user subscribers while paying only for a plurality of S non-interfering groups of the plurality of femto base stations plus the I macro secondary user subscriber channels.