发明名称 |
Methods and systems for determining a range rate for a backscatter transponder |
摘要 |
Methods for determining a range rate of a backscatter transponder and readers implementing the methods are described. The reader transmits a continuous wave signal and receives a modulated reflected response signal from the transponder, mixes the modulated reflected response signal with the carrier frequency to produce a downconverted signal, bandpass filters the downconverted signal to pass a bandpass filtered signal containing at least the modulation frequency, applies a non-linear amplitude transfer function to produce a modulation-suppressed signal, and measures the frequency of the modulation-suppressed signal and determines the range rate from the measured frequency. |
申请公布号 |
US9599703(B2) |
申请公布日期 |
2017.03.21 |
申请号 |
US201414456589 |
申请日期 |
2014.08.11 |
申请人 |
Kapsch TrafficCom AG |
发明人 |
Vinski Lila;Kohli Japjeev;Malarky Alastair |
分类号 |
G01S13/58;G01S13/74;G01S13/75;G01S13/92;G01S13/82;G06K7/10;G08G1/052 |
主分类号 |
G01S13/58 |
代理机构 |
Fiala & Weaver P.L.L.C. |
代理人 |
Fiala & Weaver P.L.L.C. |
主权项 |
1. A method of determining a range rate of a vehicle-mounted backscatter transponder in a roadway using an automatic vehicle identification system, the system including an antenna defining a coverage area for communicating with the backscatter transponder, the range rate being a rate of change of a distance between the transponder and the antenna, the method comprising:
transmitting, via the antenna, a continuous wave signal having a carrier frequency; receiving a modulated reflected response signal from the transponder, wherein the modulation is at a modulation frequency; converting the modulated reflected response signal to a downconverted signal by mixing the modulated reflected response signal with the carrier frequency; bandpass filtering the downconverted signal to pass a bandpass filtered signal containing at least the modulation frequency; applying a non-linear amplitude transfer function to the bandpass filtered signal to remove modulation and produce a modulation-suppressed signal; measuring the frequency of the modulation-suppressed signal; and determining the range rate based upon a Doppler shift corresponding to the measured frequency of the modulation-suppressed signal. |
地址 |
Vienna AT |