Abstract: The object is simplification of a configuration in a pulse generator for UWB transmission, lower power consumption, and suppression of LO leakage by nonuse of the LO signal.

Abstract: In the conventional wireless location system that synchronizes base stations by wireless communication, waveforms of a signal used for synchronization and of a signal used for delay measurement are the same, and therefore if there is a reflected wave in an earlier-sent signal, it becomes difficult to distinguish two kinds of signals, and accordingly location accuracy suffers degradation. Moreover, when two different waveforms are allocated to the two signals, a matched filter that supports the two waveforms becomes necessary, which inevitably makes a circuit size large. The invention is characterized in that signals having the same waveform but having different polarities are allocated to the synchronizing signal and the signal for delay measurement, respectively. This enables the two kinds of signals to be detected with one matched filter and also to be distinguished by simple means using polarity difference.

Abstract: An ultra-wideband transmitter is provided which can reduce a leak of a local signal into a transmitted signal with a pulse train output from an antenna in UWB-IR communication. The transmitter comprises a pulse generator 0140 for generating a pulse signal having a pulse train of pulses produced intermittently according to data to be transmitted, an oscillator 0120 for producing a local signal, a frequency converter 0130 to which the pulse signal output from the pulse generator and the local signal output from the oscillator are input, and for frequency-converting the pulse signal to output a RF signal, an amplifier 0110 for amplifying the RF signal output from the frequency converter, and an antenna 0000 for emitting the RF signal output from the amplifier in the air. In a period corresponding to a pause period of the pulses produced intermittently, a leak of the local signal into the RF signal output from the antenna is reduced using a control signal 0300.

Abstract: A node position measuring system according to this invention includes a node, a reference station, base stations, a server that calculates a position of the node, and a network. The reference station includes a positioning signal reception module and a reference signal generation module that transmits a reference signal after the positioning signal reception module receives the positioning signal. Each of the base stations includes a signal reception module, a reception time measuring module that detects specific patterns from the positioning signal and the reference signal received by the signal reception module to measure a detection time, and a communication module that transmits time information, which is generated from the time measured by the reception time measuring module, to the server. The server includes a position calculation module that calculates the position of the node based on the time information transmitted from the base station.

Abstract: With the objective of enhancing receiving performance of a receiver with respect to pulse signals spread by spread codes, the receiver comprises an RF front-end section which performs amplification, an AD converter section which AD-converts signals outputted from the RF front-end section, a baseband section which inversely spreads the output of the AD converter section and performs signal detection and demodulation thereon, a reception environment measuring section which measures reception environment using the input signals of the baseband section, and a parameter setting section which sets parameters for respective parts on the basis of signals outputted from the reception environment measuring section. The parameter setting section sets the parameters for the respective parts to the optimum according to the environmental condition measured by the reception environment measuring section.

Abstract: A communications apparatus which ensures a predetermined communication quality even when an external environment changes dynamically, and enhances a throughput for overall system, thereby achieving favorable transmission efficiency. A communications apparatus having a receiver and a transmitter and carries out sending/receiving by use of a pulse train is provided with a communication environment measuring section to measure a communication status based on an output from the receiver. The transmitter is configured such that it transmits a transmission signal, in which the transmission rate of data to be transmitted and the pulse energy have been controlled in association with each other, according to a result of the measurement.