Patent ID: 7504991
Filing Date: 2009-03-17
Classification: G01S

Abstract:
1. A distance measuring system: an Ultra Wide Band (UWB) transmitter including a UWB pulse sequence generator that sequentially generates UWB pulse sequences each having a plurality of UWB pulse signals of equal amplitudes arranged at equi-time intervals, and a transmitting unit that transmits the pulse sequence generated by the pulse sequence generator as a radio wave; and a UWB receiver including a receiving unit that receives the pulse sequence transmitted from the transmitter as a radio wave, and a distance calculating unit that acquires propagation times of the pulse signals in the pulse sequence received by the receiving unit to reach the receiving unit from the transmitting unit, and calculates a distance from the transmitter based on a propagation time for a selected pulse signal to reach the receiving unit from the transmitting unit, wherein the distance calculating unit selects said selected pulse signal by acquiring an average value of the amplitudes of the pulse signals in the pulse sequence received by the receiving unit, sequentially calculates an absolute value of the difference between the acquired average value of the amplitudes and the amplitudes of the pulse signals, specifies a pulse signal whose amplitude minimizes the calculated absolute value of differences, and calculates a distance from the transmitter based on a propagation time for the specified pulse signal to reach the receiving unit from the transmitting unit.