Patent ID: 7983692

Claim:
A wireless communication apparatus comprising: a radio unit which performs communication using a frame that includes at least a data period for transferring data and a beacon period for transmitting a beacon; and a distance measuring unit which measures the distance from said wireless communication apparatus to a target object whose distance is to be measured, by transmitting a measuring signal to the target object, wherein said distance measuring unit determines the distance from said wireless communication apparatus to the target object by measuring time from transmission of the beacon as the measuring signal from said radio unit to receipt of the beacon by said radio unit owing to reflection by the target object, and wherein said distance measuring unit transmits the measuring signal during the beacon period and does not transmit the measuring signal during the data period, and said distance measuring unit calculates distance that is based upon the beacon that has been reflected from the target object; wherein said distance measuring unit determines the distance to another wireless communication apparatus, which is a target object whose distance is to be measured, based upon time response behavior of the beacon as the measuring signal transmitted from the other wireless communication apparatus; and wherein said distance measuring unit acquires the time response behavior by applying an inverse Fourier transform to a frequency response characteristic obtained by applying a Fourier transform to an OFDM-scheme beacon transmitted from the other wireless communication apparatus.