Patent ID: 7974654

Claim:
A communication apparatus, comprising: an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal; a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information; a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; and a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit, wherein the extraction unit extracts a derivative of a temporal waveform change shape of the received power as the reception key feature, the storage unit stores a threshold corresponding to the temporal waveform change shape of the transmission signal corresponding to the event information, and the determination unit compares the extracted derivative with the stored threshold with reference to signs and magnitudes, and determines that key features match, if a sign of the extracted derivative equals to a sign of the stored threshold match and a magnitude of the extracted derivative is larger than a magnitude of the stored threshold.