A doppler sensor includes a doppler signal generation unit and a determining unit. The doppler signal generation unit serves to transmit an electric wave to a detection range and receiving electric waves from a detection range, and generating a doppler signal based on a transmission signal used in transmitting the electric wave and a reception signal obtained from the received electric waves, and the determining unit serves to determine whether or not there exists a human body in the detection range through a spectrum analysis using a peak frequency, which is a frequency having the highest intensity in a difference spectrum obtained by subtracting a background spectrum from the spectrum of the doppler signal.

An information processing terminal defines a data transfer state for permitting a contactless data communication through an IC card and a data not transfer state for not permitting the contactless data communication so that the IC card manages the communication state of the information processing terminal. The IC card can transfer data to the terminal side depending on whether it is in any of the data transfer state and the data not transfer state without depending on the notification from the information processing terminal, synchronization can be easily established, a transfer speed can be increased, and a large amount of data can be transmitted.

It is possible to provide a tag communication device, a tag communication system, and a tag communication method which can secure an optimal communication region even when an antenna installation environment or a peripheral environment changes. A tag A is arranged in a preset communication region while a tag B is arranged outside the communication region. A reader/writer (3) repeatedly scans a radio beam M emitted from a scan antenna (4) and then controls the radio beam so that all the tags A can be read while no tag B can be read according to the ID which has been read.

A base station apparatus in a radio communications system is disclosed. The radio communications system has a mobile station apparatus and the base station apparatus in communication with the mobile station apparatus to which is applied a scheduling scheme which allocates a radio resource for each of constant periods.

The base station apparatus includes a first transmitting unit which conducts a first transmission of a first signal for each of the constant periods based on the scheduling scheme; and a second transmitting unit which conducts second and subsequent transmissions at predetermined timings when an error occurs in the first transmission.

A receiver includes a replica signal generating unit which generates a replica signal as a replica of a transmission signal based on a received signal; a time zone setting unit which sets a plurality of time zones to be extracted such that a part of a signal interval of the received signal is included in the plurality of time zones to be extracted; a signal extracting unit which extracts a signal in a predetermined time zone of the received signal based on the replica signal and a time zone which is set by the time zone setting unit; a combining unit which combines signals of the respective time zones extracted by the signal extracting unit; and a decoding processing unit which carries out decoding on the signal combined by the combining unit.

An information processing terminal defines a data transfer state for permitting a contactless data communication through an IC card and a data not transfer state for not permitting the contactless data communication so that the IC card manages the communication state of the information processing terminal. The IC card can transfer data to the terminal side depending on whether it is in any of the data transfer state and the data not transfer state without depending on the notification from the information processing terminal, synchronization can be easily established, a transfer speed can be increased, and a large amount of data can be transmitted.