Abstract: A radio receiver, configured to use an impulse UWB, includes: a reception antenna which receives the impulse UWB, a reception unit which amplifies the received impulse UWB and detects an envelope of the impulse UWB, maximum-peak and minimum-peak detection units which detect a maximum value and minimum value of the envelope, respectively, a comparator which acquires signal data from the envelope with an initial threshold value, a baseband unit which measures an error rate of the signal data, an MPU which calculates a correction value based on the error rate, and an arithmetic unit which calculates a corrected threshold value based on the maximum, minimum and correction values. The arithmetic unit transmits the corrected threshold value to the comparator. The comparator acquires the signal data from the envelope based on the corrected threshold value transmitted from the arithmetic unit.

Abstract: A radio receiver, configured to use an impulse UWB, includes: a reception antenna which receives the impulse UWB, a reception unit which amplifies the received impulse UWB and detects an envelope of the impulse UWB, maximum-peak and minimum-peak detection units which detect a maximum value and minimum value of the envelope, respectively, a comparator which acquires signal data from the envelope with an initial threshold value, a baseband unit which measures an error rate of the signal data, an MPU which calculates a correction value based on the error rate, and an arithmetic unit which calculates a corrected threshold value based on the maximum, minimum and correction values. The arithmetic unit transmits the corrected threshold value to the comparator. The comparator acquires the signal data from the envelope based on the corrected threshold value transmitted from the arithmetic unit.

Abstract: A high-precision distance measuring with a reduced error in a distance measuring system which calculates a distance from an arrival time of each pulse signal constituting a pulse sequence is provided. For an oscillator which generates pulse signals by counting the number of pulse signals constituting a received pulse sequence, a relative time difference between a transmitting device and a return device is acquired, a distance from the transmitting device to the return device is calculated, and the calculated distance is corrected based on the calculated relative time difference.

Abstract: A first communication apparatus sequentially generates a pulse sequence having pulse signals arranged based on the UWB communication system, performs a framing process to form a frame having at least a preamble and a data portion on the generated pulse sequence and inserts a preamble segment including a sequence of steady pulse signals in the data portion at a predetermined time interval, and transmits it as a radio wave. A second communication apparatus receives a pulse sequence as a radio wave transmitted from the first communication apparatus, and detects at least the preamble segment from the frame contained in the received pulse sequence through a detection window structured to have a predetermined time length, whereby a transmission timing for the pulse sequence to the first communication apparatus 2 controlled according to a state of detection of the preamble segment.

Abstract: A wireless communication system includes a coordinator (3) that broadcasts a beacon (21) having at least a preamble part (32) and a payload part (33), and a plurality of devices (2) each of which is synchronizable with at least the coordinator (3) by listening to the beacon (21) through a listen period set based on an own reference clock. The coordinator (3) fixes a position of the end of the beacon (21) with respect to a beacon slot constituting a superframe, and generates the beacon (21) where a start of a preamble part (32) is extended toward a start of the beacon slot over a time To. The devices (2) are synchronized with the coordinator (3) via an end time of the beacon slot detected from an end time of the preamble part (32) in the beacon frame.

Abstract: [Object] To achieve high-precision distance measuring with a reduced error in a distance measuring system which calculates a distance from an arrival time of each pulse signal constituting a pulse sequence. [Solving Means] For an oscillator which generates pulse signals by counting the number of pulse signals constituting a received pulse sequence, a relative time difference between a transmitting device 2 and a return device 3 is acquired, a distance from the transmitting device 2 to the return device 3 is calculated, and the calculated distance is corrected based on the calculated relative time difference.

Abstract: One communication apparatus 2 sequentially generates a pulse sequence having pulse signals arranged based on the UWB communication system, performs a framing process to form a frame having at least a preamble and a data portion on the generated pulse sequence and inserts a preamble segment comprised of a sequence of steady pulse signals in the data portion at a predetermined time interval, and transmits it as a radio wave, and another communication apparatus 2 receives a pulse sequence as a radio wave transmitted from the one communication apparatus 2, and detects at least the preamble segment from the frame contained in the received pulse sequence through a detection window structured to have a predetermined time length, whereby a transmission timing for the pulse sequence to the one communication apparatus 2 is controlled according to a state of detection of the preamble segment.

Abstract: Disclosed is a distance measuring system comprising a transmitter that sequentially generates pulse sequences each having a plurality of pulse signals of equal amplitudes arranged at equi-time intervals, and transmits the generated pulse sequence as a radio wave; and a receiver that receives the pulse sequence transmitted from the transmitter as a radio wave, and has a distance calculator that acquires propagation times of the pulse signals in the received pulse sequence, and calculates a distance from the transmitter by giving different weightings to the pulse signals for the propagation times acquired for the respective pulse signals. As the amplitudes of the pulse signals in the received pulse sequence become larger, the weightings are made larger.

Abstract: Disclosed is a distance measuring system comprising a transmitter that sequentially generates pulse sequences each having a plurality of pulse signals of equal amplitudes arranged at equi-time intervals, and transmits the generated pulse sequence as a radio wave; and a receiver that receives the pulse sequence transmitted from the transmitter as a radio wave, and has a distance calculator that acquires propagation times of the pulse signals in the received pulse sequence, and calculates a distance from the transmitter by giving different weightings to the pulse signals for the propagation times acquired for the respective pulse signals. As the amplitudes of the pulse signals in the received pulse sequence become larger, the weightings are made larger.