A method for receiving an uplink signal in a wireless communication system, and a device therefore. The method according to one embodiment includes transmitting a control channel signal including a resource allocation (RA) field; and receiving an uplink signal. A size of the RA field is represented by an expression including RASizeA and RASizeB. RASizeA is a first number of bits required for representing a resource indication value (RIV) corresponding to a starting resource block (RB) and a length of contiguously allocated RBs within a given uplink bandwidth. RASizeB is a second number of bits required for representing a combinatorial index r corresponding to 4 indexes used to indicate a start resource block group (RBG) index and an end RBG index of a first RB set and a start RBG index and an end RBG index of a second RB set within the given uplink bandwidth.