A wireless communication apparatus having a plurality of antennas for
transmitting a known symbol by using a plurality of subcarriers to a
receiver, the known symbol including known information, the apparatus
includes each of the subcarriers which carries the known information
being classified into at least two groups, and a phase control unit
configure to control inversion/non-inversion of a phase of the known
information carried on two subcarriers which belong to the same group in
accordance with notification information to be notified to the receiver.