A method is presented for a communication apparatus to transmit an uplink signal in a wireless communication system. The communication apparatus receives a control channel signal including resource allocation information indicating a plurality of non-consecutive resource sets, each of the resource sets including a single resource block group (RBG) or at least two consecutive RBGs. The communication apparatus transmits the uplink signal using the RBGs of the plurality of non-consecutive resource sets indicated by the resource allocation information of the control channel signal. The resource allocation information uses a combinatorial index corresponding to at least four different indices, s0, s1, s2 and s3, to indicate the two or more non-consecutive resource sets, whereby s0 and s1−1 indicate a starting RBG and an ending RBG, respectively, of a first resource set, or s2 and s3−1 indicate a starting RBG and an ending RBG, respectively, of a second resource set.