A communication apparatus includes: a plurality of antennas; a pre-processing unit that, according to an instruction from a higher-level layer, performs processing on each zone generated by time-division of a transmission frame and generates a transmitting signal; and post-processing units that transmit the transmitting signal generated corresponding to each zone via one or more of the antennas. Each post-processing unit includes transmission of a preamble via each of the antennas. Thus, each post-processing unit transmits the preamble in a format that enables a receiving side to correctly determine AGC power control amount.