FIG. 11(b) illustrates an example of transmitting an RI in addition to the example shown in FIG. 11(a). The RI may be signaled as a combination of a multiple of a WB CQI transmission period and an offset at the transmission period from a higher layer (e.g. RRC layer). The offset of the RI is signaled using a value relative to the offset of a CQI. For example, if the offset of the CQI is ‘1’ and the offset of the RI is ‘0’, the RI has the same offset as the CQI. The offset value of the RI is defined as 0 or a negative number. More specifically, it is assumed in FIG. 11(b) that, in an environment identical to that of FIG. 11(a), an RI transmission period is a multiple of 1 of the WB CQI transmission period and the RI offset is ‘?1’. Since the RS transmission period is a multiple of 1 of the WB CQI transmission period, the RS transmission period and the WB CQI transmission period are substantially the same. Since the offset of the RI is ‘?1’, the RI is transmitted based upon the value ‘?1’ (i.e. subframe index 0) relative to the offset ‘1’ of the CQI in FIG. 11(a). If the offset of the RI is ‘0’, the transmission subframes of the WB CQI and RI overlap. In this case, the WB CQI is dropped and the RI is transmitted.
