Process for the bidirectional transmission of data and system for the implementation thereof
First Claim
1. A process for the bidirectional transmission of data, in an access system, allowing access to an enclosed space, the process consisting in setting up a remote exchange of data between a recognition device installed in the enclosed space and an identifier intended to he carried by a user, access being authorized only when the recognition device has authenticated the identifier, which process consists in setting up an RF exchange of data at the same radio frequency between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of a response signal by the identifier to the recognition device by a predetermined duration (τ
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,which consists in transmitting, at the level of the recognition device, a pulsed oscillating signal, the carrier frequency of each pulse (I1) of which correspond, to said RF exchange, the duration of each pulse being very short with respect to the recurrence period of the pulses, in receiving, at the level of the identifier, said pulsed oscillating signal and in delaying its retransmission to the recognition device by said predetermined duration (τ
), which is greater than the duration of a pulse and less than said recurrence period, in retransmitting said delayed pulsed oscillating signal to the recognition device, and in receiving, at the level of the recognition device, said delayed pulsed oscillating signal retransmitted by the identifier, and which consists, at the level of the recognition device, in order to transmit said pulsed oscillating signal at the RF exchange;
in generating an oscillating signal at a reference radio frequency Fo substantially different from the RF exchange, in generating a continuous pulsed signal (V1), which defines a first control signal, having the same recurrence period and the same duration of the pulses (I1) as the aforesaid pulsed oscillating signal, in feeding a frequency divider by N (5) with said first control signal, in inputting into said divider said oscillating signal so as to output a pulsed oscillating signal having a frequency Fo/N, in mixing said pulsed oscillating signal at Fo/N with said oscillating signal at Fo, in filtering the outgoing mixed signal so as to center it on the frequency Fo+Fo/N, said central frequency corresponding to the RF exchange, and in transmitting said filtered mixed signal to the identifier.
1 Assignment
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Accused Products
Abstract
A process for the bidirectional transmission of data, in a hands-free vehicle access system, comprising the step of setting up a remote exchange of data between a recognition device installed in the vehicle and an identifier intended to be carried by a user, access being authorized only when the recognition device has authenticated the identifier, and the steps of setting up an exchange of data at the same radio frequency (RF) exchange between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of a response signal by the identifier to the recognition device by a predetermined duration with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at the RF exchange.
29 Citations
14 Claims
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1. A process for the bidirectional transmission of data, in an access system, allowing access to an enclosed space, the process consisting in setting up a remote exchange of data between a recognition device installed in the enclosed space and an identifier intended to he carried by a user, access being authorized only when the recognition device has authenticated the identifier, which process consists in setting up an RF exchange of data at the same radio frequency between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of a response signal by the identifier to the recognition device by a predetermined duration (τ
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
which consists in transmitting, at the level of the recognition device, a pulsed oscillating signal, the carrier frequency of each pulse (I1) of which correspond, to said RF exchange, the duration of each pulse being very short with respect to the recurrence period of the pulses, in receiving, at the level of the identifier, said pulsed oscillating signal and in delaying its retransmission to the recognition device by said predetermined duration (τ
), which is greater than the duration of a pulse and less than said recurrence period, in retransmitting said delayed pulsed oscillating signal to the recognition device, and in receiving, at the level of the recognition device, said delayed pulsed oscillating signal retransmitted by the identifier, andwhich consists, at the level of the recognition device, in order to transmit said pulsed oscillating signal at the RF exchange;
in generating an oscillating signal at a reference radio frequency Fo substantially different from the RF exchange, in generating a continuous pulsed signal (V1), which defines a first control signal, having the same recurrence period and the same duration of the pulses (I1) as the aforesaid pulsed oscillating signal, in feeding a frequency divider by N (5) with said first control signal, in inputting into said divider said oscillating signal so as to output a pulsed oscillating signal having a frequency Fo/N, in mixing said pulsed oscillating signal at Fo/N with said oscillating signal at Fo, in filtering the outgoing mixed signal so as to center it on the frequency Fo+Fo/N, said central frequency corresponding to the RF exchange, and in transmitting said filtered mixed signal to the identifier.- View Dependent Claims (2, 3, 4, 5, 6, 7)
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
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8. A system for the bidirectional transmission of data for implementing a process for the bidirectional transmission of data, in an access system, allowing access to an enclosed space, the process consisting in setting up a remote exchange of data between a recognition device installed in the enclosed space and an identifier intended to be carried by user, access being authorized only when the recognition device has authenticated the identifier, which process consists in setting up an RF exchange of data at the same radio frequency between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of a response signal by the identifier to the recognition device by a predetermined duration (τ
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
said system comprises a recognition device installed in the enclosed space, comprising a radio frequency transmission circuit (E), a radio frequency reception circuit (R) which are both linked to the same first antenna (2), by way of a two-way switch (7), an identifier intended to be carried by a user, comprising a radio frequency transmitter (29) and a radio frequency receiver (26), which are both linked to the same second antenna (21), by way of a second two-way switch (23), and a delayer means (27) interposed between the output of the receiver and the input of the transmitter of the identifier, so as to delay the retransmission of the signal by the identifier at the same RF exchange as the transmission of the signal by the recognition device, by a predetermined duration (τ
) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchangewherein the transmission circuit (E) of the recognition device comprises an oscillator (3) with reference frequency Fo which is intended to deliver an oscillating output signal at said reference frequency, said output signal being supplied in parallel to a frequency divider by N (5) and to a mixer (4), said divider being intended to he fed with a first continuous pulled control signal (V1) delivered by a central management unit (1), the output terminal of the divider (5) being linked to another input of the mixer (4), the mixer being linked at its output to a transmission amplifier (6) with power gain, whose output is linked to a first transmission terminal (7a) of the first switch (7) of the recognition device, and wherein the reception circuit (R) of the recognition device can comprise a low-gain preamplifier (10), linked at its input to a second reception terminal (7b) of the first switch (7), the output of the preamplifier being linked to a second mixer (11) which receives, on its second input, the oscillating signal at Fo delivered in parallel by the oscillator (3) of the transmission circuit (F), said second mixer being linked in series to a bandpass filter (12) centered on the frequency Fo/N, then to a gain amplifier (13), and to an envelope detector (14) which is connected to said central management unit (1). - View Dependent Claims (9, 10, 11, 12)
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
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13. A system for the bidirectional transmission of data for implementing a process for the bidirectional transmission of data, in an access system, allowing access to an enclosed space, the process consisting in setting up a remote exchange of data between a recognition device installed in the enclosed space and an identifier intended to be carried by a user, access being authorized only when the recognition device has authenticated the identifier, which process consists in setting up an RF exchange of data at the same radio frequency between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of a response signal by the identifier to the recognition device by a predetermined duration (τ
- ) with respect to the reception by the identifier of an interrogation signal transmitter by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
said system comprises a recognition device installed in the enclosed space, comprising a radio frequency transmission circuit (E), a radio frequency reception circuit (R) which are both linked to the same first antenna (2), by way of a two-way switch (7), an identifier intended to be carried by a user, comprising a radio frequency transmitter (29) and a radio frequency receiver (26), which are both linked to the same second antenna (21), by way of a second two-way switch (23) and a delayer means (27) interposed between the output of the receiver and the input of the transmitter of the identifier, so as to delay the retransmission of the signal by the identifier at the same RF exchange a the transmission of the signal by the recognition device, by a predetermined duration (τ
) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,wherein the delayer means (27) comprises a delay line, consisting of surface wave components.
- ) with respect to the reception by the identifier of an interrogation signal transmitter by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
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14. A process for the bidirectional transmission of data, in an access system, allowing access to an enclosed space, the process consisting in setting up a remote exchange of data between a recognition device installed in the enclosed space and an identifier intended to be carried by a user, access being authorized only when the recognition device has authenticated the identifier, which process consists in setting up an RF exchange of data at the same radio frequency between the recognition device and the identifier, and in delaying, in the course of this exchange, the transmission of response signal by the identifier to the recognition device by a predetermined duration (τ
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
which consists in transmitting, at the level of the recognition device, pulsed oscillating, signal, the carrier frequency of each pulse (I1) of which corresponds to said RF exchange, the duration of each pulse being very short with respect to the recurrence period of the pulses, in receiving, at the level of the identifier, said pulsed oscillating signal and in delaying its retransmission to the recognition device by said predetermined duration (τ
), which is greater than the duration of a pulse and less then said recurrence period, in retransmitting said delayed pulsed oscillating signal to the recognition device, and in receiving, at the level of the recognition device, said delayed pulsed oscillating signal retransmitted by the identifier, andwhich comprises, at the level of the identifier, the following steps which consist;
in amplifying the received signal, in delaying said amplified received signal by said predetermined duration (τ
), in detecting the end of each pulse (I1) of the amplified received signal, in deactivating the amplification of the receiver and in activating the amplification of the transmitter of the identifier after the detection of the end of each pulse, in amplifying the delayed signal so as to retransmit it to the recognition device, in deactivating the amplification of the transmitter and in activating the amplification of the receiver of the identifier, at the conclusion of a given timeout, counting from the detection of the end of each pulse, andwherein said radio frequency for said RF exchange is chosen from a group of frequencies consisting of 315 MHz, 434 MHz and 868 MHz, and wherein the duration of each pulse of said pulse oscillating signal is set to 0.5 μ
s and the recurrence period is set to 50 μ
s, and said predetermined duration (τ
) is set to 0.8 μ
s.
- ) with respect to the reception by the identifier of an interrogation signal transmitted by the recognition device, so that neither the recognition device nor the identifier operate simultaneously in transmission and in reception at said RF exchange,
Specification