Patent ID: 7187716
Filing Date: 2007-03-06
Classification: B60C

Abstract:
1. A vehicle mounted DSRC apparatus which uses a dedicated short range communications system of an intelligent transport system including ground devices, and which outputs an ASK modulated signal or a QPSK modulated signal in response to transmission data from one of said ground devices, said vehicle mounted DSRC apparatus comprising: an antenna for receiving transmission data from said ground devices, and for transmitting said ASK modulated signal and said QPSK modulated signal to said ground devices; an ASK data generation part in an ASK modulation part for generating ASK data in response to said transmission data; a QPSK data generation part in a QPSK modulation part for generating QPSK data containing I data and Q data in response to said transmission data; a first band limiting filter in said QPSK modulation part for band limiting one of said I data and said Q data in said QPSK data and said ASK data; a second band limiting filter for band limiting the other of said I data and said Q data in said QPSK data; an ASK low pass filter for removing harmonic components from said ASK data which has passed through said first band limiting filter; a first low pass filter in said QPSK modulation part for removing harmonic components from said QPSK data which has passed through said first band limiting filter; a second low pass filter for removing harmonic components from said QPSK data which has passed through said second band limiting filter; an ASK modulator for ASK modulating said ASK data from said ASK low pass filter; a QPSK modulator for QPSK modulating said QPSK data from said first and second low pass filters; a power supply for supplying electric power to said ASK modulator and said QPSK modulator; and a power amplifier for amplifying output data from said ASK modulator or said QPSK modulator to a desired level thereby to output it to said antenna as said ASK modulated signal and said QPSK modulated signal.