DEDICATED SHORT-RANGE COMMUNICATIONS APPARATUS AND FIXED STATION FOR THE DEDICATED SHORT-RANGE COMMUNICATIONS APPARATUS

摘要

PPROBLEM TO BE SOLVED: To provide small-sized and inexpensive dedicated short-range communications apparatus for performing stable road-to-vehicle communication at situations where fading occurs. PSOLUTION: A narrowcast communication apparatus includes a baseband section which generates a binary I-axis signal which changes between the intersection of an I axis and a Q axis substantially orthogonal with each other and a signal point on the I axis and a Q-axis signal of zero value based on an inputted digital data signal, in response to a select signal representing selection of ASK and generates I-axis binary signals and Q-axis binary signals based on an inputted digital data signal, in response to a select signal representing selection of QPSK; a radio transmission section having a modulator for modulating a carrier wave based on the I-axis signal and the Q-axis signal, while selectively switching to one of ASK and QPSK, in response to the select signal; a radio reception section for amplifying a received carrier wave using an AGC amplifier; and a transmitter/receiver antenna section for transmitting/receiving a carrier wave. In the narrowcast communication apparatus, the transmitter/receiver antenna section has two antennas. PCOPYRIGHT: (C)2006,JPO&NCIPI