Abstract: An occupant detection system includes a transmitter provided adjacent to a first side face of a vehicle before a predetermined seat and successively transmitting a radio wave over a range covering a seat door located on a second side face of the vehicle and in a same row as the predetermined seat, a receiver provided adjacent to the second side face behind the predetermined seat and receiving the radio wave transmitted from the transmitter, and an occupant detection device including a reception intensity acquirer, an occupant detector, an opening and closing detector. The reception intensity acquirer successively acquires a reception intensity of a radio wave successively received by the receiver. The occupant detector detects an occupant in the vehicle according to the reception intensity of the radio wave received by the receiver while the opening and closing detector detects that the seat door is open.

Abstract: A detection apparatus includes: a transmitter transmitting an electric wave toward an inside of a vehicle; a receiver receiving the transmitted electric wave each time the transmitter transmits the electric wave, and performing output in accordance with reception strength of the received electric wave; and a determination portion, based on the reception strength of the electric wave received by the receiver, comparing a change mode of the electric wave received by the receiver changing over time to a predetermined reference mode and determining whether a person is present between the receiver and the transmitter.

Abstract: An object detection apparatus includes: a transmitter transmitting a radio wave with a predetermined intensity at the radio wave transmission end; a receiver receiving the radio wave, which is to be transmitted when the radio wave is transmitted from the transmitter, at the radio wave reception end; a setter setting a transmission scheme of the transmitter to a plurality of different transmission characteristics; a transmission controller controlling the transmitter to transmit the radio wave with the transmission scheme, which is to be set when the setter sets the transmission scheme; and a detector detecting a presence of the object at a position inside the vehicle, based on a detected reception intensity indicating a respective radio wave reception intensity received by the receiver, the object blocking the radio wave transmitted from the transmitter to the receiver at the position inside the vehicle.

Abstract: An occupant detection system includes a transmitter provided adjacent to a first side face of a vehicle before a predetermined seat and successively transmitting a radio wave over a range covering a seat door located on a second side face of the vehicle and in a same row as the predetermined seat, a receiver provided adjacent to the second side face behind the predetermined seat and receiving the radio wave transmitted from the transmitter, and an occupant detection device including a reception intensity acquirer, an occupant detector, an opening and closing detector. The reception intensity acquirer successively acquires a reception intensity of a radio wave successively received by the receiver. The occupant detector detects an occupant in the vehicle according to the reception intensity of the radio wave received by the receiver while the opening and closing detector detects that the seat door is open.

Abstract: A detection apparatus includes: a transmitter transmitting an electric wave toward an inside of a vehicle; a receiver receiving the transmitted electric wave each time the transmitter transmits the electric wave, and performing output in accordance with reception strength of the received electric wave; and a determination portion, based on the reception strength of the electric wave received by the receiver, comparing a change mode of the electric wave received by the receiver changing over time to a predetermined reference mode and determining whether a person is present between the receiver and the transmitter.

Abstract: An object detection apparatus includes: a transmitter transmitting a radio wave with a predetermined intensity at the radio wave transmission end; a receiver receiving the radio wave, which is to be transmitted when the radio wave is transmitted from the transmitter, at the radio wave reception end; a setter setting a transmission scheme of the transmitter to a plurality of different transmission characteristics; a transmission controller controlling the transmitter to transmit the radio wave with the transmission scheme, which is to be set when the setter sets the transmission scheme; and a detector detecting a presence of the object at a position inside the vehicle, based on a detected reception intensity indicating a respective radio wave reception intensity received by the receiver, the object blocking the radio wave transmitted from the transmitter to the receiver at the position inside the vehicle.

Abstract: A spread spectrum communication system comprising a transmitter including an angle modulator, a frequency divider, a spread code generator, and a spread spectrum modulator, and a receiver including a despreading circuit, an angle demodulator, a sync detection circuit, and a clock signal generating circuit. In the transmitter, the spread code generator produces a spread code having correlation with the angle-modulated signal outputted from the angle modulator. In the receiver the despreading circuit despreads the spread spectrum modulation signal sent from the transmitter by a demodulation spread code. The angle demodulator generates a demodulation output by means of a phase-locked loop circuit contained therein. The sync detection circuit detects sync condition on the basis of noise level of a phase detector provided in the phase-locked loop circuit, and generates a sync detection signal when sync condition is established.

Abstract: A demodulation system for spread spectrum communication includes a first low pass filter for processing an input spread spectrum signal including a product of an information signal and a first spread code. A second spread code is generated which is equivalent to the first spread code. A second low pass filter processes the second spread code and has a transfer function substantially equal to a transfer function of the first low pass filter. An absolute value circuit derives an absolute value of an output signal from the second low pass filter. A division circuit derives a reciprocal of an output signal from the absolute value circuit. A delay circuit delays the second spread code by a predetermined time. A first multiplier multiplies an output signal from the division circuit and an output signal from the delay circuit, and generates a third spread code in response to the output signals from the division circuit and the delay circuit.