A method (100, 200), by a base station of a wireless communication network, of allocating a first plurality of frequency resources among a second plurality of requesting mobile terminals, the allocation satisfying both an exclusivity constraint that each frequency resource is allocated to only one mobile terminal, and an adjacency constraint that all frequency resources allocated to any given mobile terminal are contiguous in a frequency domain, the method comprising: receiving channel conditions of the frequency resources as experienced by each mobile terminal; initially allocating frequency resources among the mobile terminals, based on the received channel conditions, to maximize spectral efficiency, the allocation satisfying the exclusivity constraint but made without regard to the adjacency constraint; for each mobile terminal allocated at least one frequency resource, clustering contiguous frequency resources allocated to the mobile terminal, to generate one or more virtual resources, VR; and iteratively reallocating the VRs according to one or more predetermined rules until the allocation satisfies the adjacency constraint, wherein the predetermined rules comprise a first predetermined rule that comprises the steps: identify a first VR and a second, non-adjacent VR allocated to the same mobile terminal; cluster all VRs lying between the first and second VR, inclusively, to form a new VR; and allocate the new VR to that mobile terminal, when there are no first VR and second, non-adjacent VR allocated to the same mobile terminal apply a second predetermined rule, wherein the predetermined rules comprise the second predetermined rule, that is to identify a VR allocated to a particular mobile terminal, cluster an adjacent VR with the identified VR to form a new VR, and allocate the new VR to that mobile terminal, and wherein the second predetermined rule further comprises any one of: ascertaining that no VR comprising lower frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next lower-frequency VR, if any, and ascertaining that no VR comprising higher frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next higher-frequency VR, if any. receiving channel conditions of the frequency resources as experienced by each mobile terminal; initially allocating frequency resources among the mobile terminals, based on the received channel conditions, to maximize spectral efficiency, the allocation satisfying the exclusivity constraint but made without regard to the adjacency constraint; for each mobile terminal allocated at least one frequency resource, clustering contiguous frequency resources allocated to the mobile terminal, to generate one or more virtual resources, VR; and iteratively reallocating the VRs according to one or more predetermined rules until the allocation satisfies the adjacency constraint, wherein the predetermined rules comprise a first predetermined rule that comprises the steps: identify a first VR and a second, non-adjacent VR allocated to the same mobile terminal; cluster all VRs lying between the first and second VR, inclusively, to form a new VR; and allocate the new VR to that mobile terminal, when there are no first VR and second, non-adjacent VR allocated to the same mobile terminal apply a second predetermined rule, wherein the predetermined rules comprise the second predetermined rule, that is to identify a VR allocated to a particular mobile terminal, cluster an adjacent VR with the identified VR to form a new VR, and allocate the new VR to that mobile terminal, and wherein the second predetermined rule further comprises any one of: ascertaining that no VR comprising lower frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next lower-frequency VR, if any, and ascertaining that no VR comprising higher frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next higher-frequency VR, if any. ascertaining that no VR comprising lower frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next lower-frequency VR, if any, and ascertaining that no VR comprising higher frequency resources is allocated to that mobile terminal, and wherein the adjacent VR clustered is the next higher-frequency VR, if any.