Provided are a radio transmission apparatus and a radio transmission method whereby the increase of number of signaling bits can be suppressed and further the flexibility of frequency scheduling can be improved. A notified RBG calculating unit (203) that adds a predetermined offset value of “1” or “−1” to one of the start RBG number and the end RBG number of allocated RBG number information (b′i) output by a scheduling unit (201), thereby calculating notified RBG number information (bi). An RBG total number setting unit (204) calculates the total number of RBGs, which is to be notified, by adding “1” to the total number of allocated RBGs. A notified information generating unit (205) applies the notified RBG number information (bi) and the notified total number of RBGs (Nrb′) to a predetermined formula, thereby generating and transmitting, to terminals, notified information (r).