Abstract: A vehicle remote control system includes an in-vehicle transmission unit which transmits an authentication-use inquiry signal and a presence-check inquiry signal; two or more mobile apparatuses, each comprising a reception unit which receives the presence-check inquiry signal and the authentication-use inquiry signal and a transmission unit which transmits to the in-vehicle apparatus a response signal to the presence-check inquiry signal and the authentication-use inquiry signal; an in-vehicle reception unit which receives the response signals transmitted from the transmission units of the two or more mobile apparatuses; and an in-vehicle operation control unit which controls an operation state of the in-vehicle apparatus when a response code in at least one of the response signals received by the in-vehicle apparatus has been compared.

Abstract: The transmission means of a mobile apparatus converts a response signal into binary data, modulates a carrier wave with a digital signal obtained through modulation by a plurality of pseudo-random codes corresponding to the binary data, and then transmits the response signal; the reception means of an in-vehicle apparatus evaluates the correlation of the received response signal by use of a plurality of correlators corresponding to the plurality of pseudo-random codes and demodulates the response signal, based on the outputs of the plurality of correlators; the transmission means of the in-vehicle apparatus retransmits an inquiry signal to the mobile apparatus when there has been outputs from the plurality of correlators within a predetermined time of the occurrence of the pseudo-random code.

Abstract: A communication system using a leakage transmission path, for sending and receiving signals lying within a passband, which the leakage transmission path essentially has as a conductive line, is provided with a signal generation unit for generating a signal to be transmitted by way of the leakage transmission path, and a relay unit disposed on a way of the leakage transmission path, for relaying the signal from the generation unit, and for converting the signal applied, via a cable, thereto into a signal lying within the passband, which the leakage transmission path essentially has, so as to send out it.

Abstract: An obstacle detection system includes a leaky transmission path, a leaky receiving path opposite to the leaky transmission path, a spread spectrum signal generator connected to an end of the leaky transmission path and generating a spread spectrum signal for radiation from the leaky transmission path to detect an obstacle. A correlator is connected to an end of the leaky receiving path to calculate a level of correlation between a reference spread spectrum signal and a spread spectrum signal received by the leaky receiving path. A detector detects an obstacle in accordance with a change in the level of correlation calculated by the correlator.

Abstract: An obstacle detection includes a transmission leakage transmission path, a receiving leakage transmission path opposite to the transmission leakage transmission path, a spread spectrum signal generation means connected to an end of the transmission leakage transmission path and generating a spread spectrum signal for detection of an obstacle for radiation from the transmission leakage transmission path. A correlation means is connected to an end of the receiving leakage transmission path so as to calculate a level of correlation between a reference spread spectrum signal and a spread spectrum signal received by the receiving leakage transmission path. A detecting means detects an obstacle in accordance with a change in the level of correlation calculated by the correlation means.

Abstract: A vehicle borne transmitter transmits a spread spectrum transmit signal which is pseudo (PN) encoded. The transmitted signal is reflected off of a reflector on known position which may be a highway guardrail, tunnel wall, or the like. The reflected signal is detected by a receiver in the vehicle and a pseudo noise code (PN code) is synchronized to the reflected signal to accomplish maximum correlation. The phase delay between the transmitted PN code and received PN code is thereby utilized to determine the distance between the vehicle and reflector to maintain the vehicle in the center of a roadway lane. Roadway transponders may be periodically located adjacent the roadway and will be responsive to the vehicle borne interrogation signal.

Abstract: In an automated roadway system having transponders or data-stations spaced at known positions along the roadway, a vehicle mounted system determines the position of a vehicle moving along the roadway. A vehicle borne transmitter transmits a spread spectrum transmit signal which is pseudo (PN) encoded. The transmitted signal is received by the transponder which emits a reply signal back to a vehicle borne receiver. The receiver also receives a second signal which may be a reply signal from the same transponder or a reply signal from an adjacent transponder. The system then measures a time difference between transmission of the vehicle originated interrogation signal and receipt of its corresponding reply signal to determine the distance between the vehicle and the transponder or reflector. Based on the determined distances, the positions of the transponders and the distance that the vehicle has traveled during its communications, the position of a vehicle is determined using triangulation methods.

Abstract: A combined diversity receiving apparatus comprises first mixers for mixing receiving signals from plural antennas with a signal from a feedback circuit, band-pass filters connected to outputs of the first mixers and having a band width to pass a random phase component due to fading and a main component of a modulation signal among received signals, second mixers for mixing output signals of the band-pass filters with the received signals, a coupler for combining outputs of the second mixers, and a feedback circuit for feeding back the output signal of the coupler to the first mixers.