A method for allocating frequency resources to be used for multiple terminals in a Frequency Division Multiplexing, FDM, wireless communication system in which a base station communicates with the multiple terminals in a service frequency band, the method comprising: dividing, according to a node tree structure comprising several levels, a series of resource units formed of a set of consecutive sub-carriers in the service frequency band into blocks (332, 333, 342, 343, 352, 353) of consecutive resource units corresponding to respective nodes of the node tree structure at each level, wherein each node expresses logical frequency resources and frequency resources of nodes belonging to a lower level (342, 343) are included in frequency resources of a node belonging to their upper level, and allocating each of the terminals (331, 341, 351, 360) one of the nodes (301, 302, 303, 304) as a frequency resource without collisions between terminals, at a first transmission time; and hopping the blocks allocated as the frequency resources for each of the terminals so that the blocks each have a different frequency resource from frequency resources used at a first transmission time, wherein the hopping is performed hierarchically at each node corresponding to a first level, wherein a zero level corresponds to entire resources of the service frequency band, until levels to which each node corresponding to the first level belongs among the several levels, and wherein nodes in each level perform hopping within frequency resources belonging to the same upper node of each level, and allocating the hopped blocks as frequency resources for each of the terminals at a second transmission time, wherein the blocks in at least one of the levels are different from each other (760, 761) in a number of resource units included therein, wherein frequency bands allocated to individual terminals are different in size. dividing, according to a node tree structure comprising several levels, a series of resource units formed of a set of consecutive sub-carriers in the service frequency band into blocks (332, 333, 342, 343, 352, 353) of consecutive resource units corresponding to respective nodes of the node tree structure at each level, wherein each node expresses logical frequency resources and frequency resources of nodes belonging to a lower level (342, 343) are included in frequency resources of a node belonging to their upper level, and allocating each of the terminals (331, 341, 351, 360) one of the nodes (301, 302, 303, 304) as a frequency resource without collisions between terminals, at a first transmission time; and hopping the blocks allocated as the frequency resources for each of the terminals so that the blocks each have a different frequency resource from frequency resources used at a first transmission time, wherein the hopping is performed hierarchically at each node corresponding to a first level, wherein a zero level corresponds to entire resources of the service frequency band, until levels to which each node corresponding to the first level belongs among the several levels, and wherein nodes in each level perform hopping within frequency resources belonging to the same upper node of each level, and allocating the hopped blocks as frequency resources for each of the terminals at a second transmission time, wherein the blocks in at least one of the levels are different from each other (760, 761) in a number of resource units included therein, wherein frequency bands allocated to individual terminals are different in size.