JP4995034B2 - UWB wireless communication system and contactless ID system using the same - Google Patents

Description

  The present invention relates to a UWB wireless communication system and a contactless ID system using the same.

  A non-contact ID system in which an interrogator (reader) reads a unique ID from a responder (non-contact ID tag) in a non-contact manner and locks / unlocks a room, controls lighting, and the like has been put into practical use. In such a non-contact ID system, as the communication area of the interrogator becomes wider, the user who possesses the transponder can, for example, perform authentication while keeping the transponder in the clothes pocket, and can enter and leave the room. Although responsiveness is increased and convenience is increased, for example, the system reacts only by passing through a corridor, resulting in increased malfunction. Therefore, in order to solve such a problem, when the interrogator measures the distance to the transponder and unlocks or turns on the light when it comes to a narrow area near the door, the malfunction will not occur. Therefore, more appropriate control can be performed.

  Therefore, in Patent Document 1, in a keyless entry system of an automobile in which a key module possessed by a user and a base station on the vehicle side automatically communicate with each other, the distance is obtained and the user is nearby. It has been proposed to prevent unauthorized unlocking only by unlocking.

Moreover, in patent document 2 by this applicant, the distance to the said measurement object is measured by transmitting the ultrashort pulse of UWB to a measurement object, and measuring the time taken until the reflected wave is received. In this regard, there has been proposed a distance measuring device that improves distance measuring accuracy by obtaining a distance from a time difference from when a receiving unit receives a transmission signal to when a reflected signal is received.
JP-T-2006-503273 JP 2007-86015 A

  Patent Document 2 is required to have a high accuracy in mm so as to determine the distance between the wall and the backside piping. Patent Document 1 can also distinguish whether the user is in the vehicle or outside the vehicle. And sending and receiving signals for ranging. On the other hand, when a magnetic field such as an LF band is used like a contact type automatic ticket gate, the attenuation with respect to the distance is large, so that authentication can be performed only at a very short distance, but authentication is performed at a certain distance. Is difficult and inconvenient. On the other hand, by using UWB, data communication can be performed at a certain distance (without contact), and the convenience as described above can be improved.

  An object of the present invention is to provide a UWB wireless communication system that does not require transmission / reception of a signal for distance measurement and a contactless ID system using the same.

In the UWB wireless communication system of the present invention, one wireless communication device continuously transmits an extremely short pulse at a predetermined cycle, and the other wireless communication device returns a pulse in response to each pulse. In the UWB wireless communication system in which the one wireless communication apparatus restores the data string so that data is transmitted from the other wireless communication apparatus to the one wireless communication apparatus, the one wireless communication apparatus has a pulse Based on a time difference from transmission to reception of a reply, it is provided with distance measuring means for performing distance measurement , and the one wireless communication apparatus can switch between a plurality of types of the cycle and circulates the cycle for each cycle. by Yuku switching, characterized Rukoto switching latency of the response signal from the other wireless communication device.

  According to the above configuration, when one wireless communication device continuously transmits an extremely short pulse at a predetermined cycle like a timing pulse, and a pulse responding to each pulse is returned from the other wireless communication device. 1 in the UWB wireless communication system in which data is transmitted from the other wireless communication device to the one wireless communication device by restoring the data string by setting the value to 0 if it does not come. The wireless communication apparatus is provided with distance measuring means, and there is a response to the pulse transmitted as the timing pulse. That is, in the case of 1 data, the time difference from the transmission to the reception of the reply is measured, and the distance is determined based on the time difference. Calculate

  Accordingly, it is possible to perform distance measurement without specially transmitting / receiving a signal for distance measurement by utilizing the characteristics of the impulse UWB wireless communication system.

In addition , when the distance between the two wireless communication devices is increased, it takes time until the response pulse is returned, and there is a possibility of collision with the next timing pulse. and whereas the data transmission rate is low, the cycle as possible plural kinds switched circulates for each slot (cyclically) by Yuku switching the cycle, i.e. transmitted from one wireless communication device By making the interval between the pulse waves to be a plurality of patterns, a high transmission rate can be obtained when the cycle is short and a short distance is targeted, and a transmission rate is low when the cycle is long. However, measurement and data transmission can be performed over long distances, and the dynamic range of the ranging area can be expanded.

Furthermore, the contactless ID system of the present invention, hand wireless communication apparatus becomes interrogator, a plurality of other side noncontact ID system the wireless communication device is responsive instrument, the one of the wireless communication device in advance Whether or not the other wireless communication device returns a pulse in response to each pulse by continuously transmitting an extremely short pulse at a predetermined cycle, and the one wireless communication device restores the data string, A UWB wireless communication system that performs data transmission from one wireless communication device to another wireless communication device, wherein the one wireless communication device performs distance measurement based on a time difference from transmission of a pulse to reception of a reply. comprising means, in said one wireless communication device, when the previously registered responder is authenticated, characterized by Rukoto with an electrical lock for performing unlocking of the room.

According to the above configuration, in the non-contact ID system in which the interrogator reads the unique ID from the responder in a non-contact manner and performs locking and unlocking , not only the identification of the ID but also the control for identifying the distance can be performed. .

  Therefore, a non-contact ID system capable of performing more appropriate control can be realized.

  In the non-contact ID system of the present invention, the interrogator transmits the extremely short pulse and receives a reply pulse in response thereto as a data reception period having a plurality of slots, and performs polling before that. It has a control slot, and the slot which should respond to each responder is determined in the control slot.

  According to the above configuration, when there are a plurality of responders, data will collide when responding all at once, so the data reception period is divided into a plurality of slots and polled in the control slot. The slot to respond to is determined in advance.

  Therefore, even if there are a plurality of responders, the TDMA can reliably receive data from each responder and perform distance measurement.

  Furthermore, in the non-contact ID system of the present invention, the slot determination is performed by slot designation from a responder.

  According to the above configuration, the responder performs slot designation together with the response to polling, thereby reducing the communication time required for authentication of the responder and slot designation.

  In the UWB wireless communication system of the present invention, as described above, one wireless communication device continuously transmits ultrashort pulses at a predetermined cycle like a timing pulse, and responds to each pulse from the other wireless communication device. The UWB is configured so that the data is transmitted from the other wireless communication device to the one wireless communication device by restoring the data string as 1 when the pulse is returned and 0 when the pulse is not received. In the wireless communication system, the one wireless communication device is provided with a distance measuring means, and when there is a response to the pulse transmitted as the timing pulse, that is, in the case of 1 data, the time difference from the transmission to the reception of the reply is measured. The distance is calculated based on the time difference.

  Therefore, it is possible to perform distance measurement using the characteristics of the impulse UWB wireless communication system without particularly transmitting / receiving a signal for distance measurement.

Also, the pre-Symbol period as possible plurality of types switching, since circulated for each slot Yuku by switching (cyclically) the period, if the period is intended for short-range short, obtain a high transmission rate When the period is increased, the transmission rate is lowered, but the measurement and data transmission can be performed over a long distance, and the dynamic range of the ranging area can be expanded.

Furthermore, the contactless ID system of the present invention, as described above, hand wireless communication apparatus becomes interrogator, a plurality of other side of the wireless communication device in the contactless ID system to be the responder, as described above After measuring the distance, unlock the electric lock .

Therefore, in the non-contact ID system in which the interrogator reads the unique ID from the responder in a non-contact manner and performs locking / unlocking , not only the identification of the ID but also the control for identifying the distance can be performed. Control can be performed.

  Further, as described above, the non-contact ID system of the present invention divides the data reception period into a plurality of slots, performs polling in the control slot, and determines in advance the slot to which each responder should respond.

  Therefore, even if there are a plurality of responders, the TDMA can reliably receive data from each responder and perform distance measurement.

  Furthermore, as described above, the contactless ID system of the present invention determines the slot by specifying a slot from a responder.

  Therefore, the responder performs the slot designation together with the response to the polling, so that the communication time required for the authentication of the responder and the slot designation can be suppressed.

[Embodiment 1]
FIG. 1 is a block diagram showing an electrical configuration of a contactless ID system using a UWB wireless communication system according to an embodiment of the present invention. This non-contact ID system includes one or a plurality of interrogators 1 (only one is shown in FIG. 1) installed near a door of a building or a commercial facility, and a number of users held by the user of the building or commercial facility. When the responder 2 (only one is shown in FIG. 1) and the responder registered in advance by the interrogator 1 (for the user permitted to enter the room) are authenticated, the ID is received. The host device 3 that manages the history of entry / exit and the control signal from the host device 3 unlocks the room when the pre-registered responder is authenticated, and locks it after a predetermined time. An electric lock 4 and an illumination control unit 5 that turns on the illumination when the entry of the pre-registered responder is detected and turns off the illumination when the exit is detected are configured.

  The interrogator 1 includes a data communication control unit 11 that performs control for communication with the host device 3, transmission / reception of data, and distance measurement, a transmission pulse wave generation unit 12 that generates an extremely short pulse wave, and shapes the waveform. The transmitting circuit 13 for amplifying the pulse wave, the antenna 14 for radiating the amplified pulse wave, the antenna 15 for receiving the pulse wave from the responder 2, and the amplifying circuit 16 for amplifying the received pulse wave. And a detector 17 that detects the amplified pulse wave, a demodulator 18 that demodulates the detected signal, and a time difference that measures the time difference between the transmission pulse and the reception pulse and calculates the distance as described later. And a unit 19.

  On the other hand, the responder 2 includes an antenna 21 that receives the pulse wave from the interrogator 1, an amplifier circuit 22 that amplifies the received pulse wave, and a detector 23 that detects the amplified pulse wave. A demodulator 24 for demodulating the detected signal, a response signal including its own ID according to the demodulated signal, a data communication controller 25 for controlling data transmission / reception, and the response signal A response pulse is generated and a transmission pulse wave generation unit 26 that shapes the waveform, a transmission circuit 27 that amplifies the response pulse, and an antenna 28 that radiates the amplified response pulse.

  In the non-contact ID system configured as described above, the interrogator 1 and the responder 2 periodically transmit and receive with a frame as shown in FIG. That is, the interrogator 1 polls each responder in the control slot at the beginning of the frame, transmits the number of slots in the subsequent data reception period, empty slot information, etc., and the responder 2 responds, The slot in which the responder 2 communicates with the interrogator 1 is determined. Thereafter, a data reception period starts, and ID communication is performed in the determined slot as described later.

  Therefore, when there are a plurality of responders 2, data will collide when responding all at once. In this way, the data reception period is divided into a plurality of slots and polled in the control slot. By determining in advance the slot to which the responder 2 should respond and communicating by TDMA, the interrogator 1 ensures that the data (ID) from each responder 2 is present even if there are a plurality of responders 2. Receive and can measure distance as described below.

  3 and 4 are diagrams for explaining a slot determination method. In the method shown in FIG. 3, the interrogator 1 transmits a polling signal and vacant slot information in the control slot of the slot determination frame, and when each responder 2 receives the polling signal, the interrogator 1 A desired slot is arbitrarily selected, and the ID number of the own machine is returned in the selected slot. When the interrogator 1 approves the request from the responder 2, the interrogator 1 returns an ACK signal in the slot. When the slot to be used is determined in this way, data communication and a distance measurement frame to be described later are obtained, communication is performed in the corresponding slot, and the selected slot is excluded from the empty slot information.

  On the other hand, in the method shown in FIG. 4, the interrogator 1 transmits only a polling signal in the control slot of the slot determination frame, and the responder 2 returns only the ID number of its own device when receiving it. The interrogator 1 then notifies the responder 2 of the slot number in the control slot of the next data communication and ranging frame (not necessarily the slot to which the responder 2 responded in the slot determination frame). The responder 2 communicates using the slot. In the slot determination method as described above, the method in which the responder 2 in FIG. 3 designates a slot has a simple procedure, and the communication time required for authentication of the responder 2 and slot designation can be suppressed. On the other hand, in the method in which the interrogator 1 in FIG. 4 designates a slot, the procedure is complicated, but since the interrogator 1 can manage the slot number, a slot with a lower number is assigned to the responder with a specific ID number. It becomes possible.

  FIG. 5 is a diagram for explaining a communication operation in the data reception period of the contactless ID system according to the embodiment of the present invention. FIG. 5 shows a case where slots 1 and 3 are used by the slot designation described above. In this way, the interrogator 1 continuously generates an extremely short pulse wave for each predetermined period T1 by the transmission pulse wave generation unit 12 in the slot to be used, and transmits the pulse wave from the transmission circuit 13 via the antenna 14. . On the other hand, the responder 2 receives the pulse wave transmitted from the antenna 21 by the amplifier circuit 22, and the data communication control unit 25 returns a reply including its own ID when it is a slot to respond to. The presence / absence of a pulse wave response is selected according to the data, and is given to the transmission pulse wave generator 26. The transmission pulse wave generation unit 26 has a reply at the timing detected by the detection unit 23, that is, in the case of 1 data, creates a pulse, transmits it from the transmission circuit 27 via the antenna 28, and does not reply That is, in the case of 0 data, no pulse is generated, and therefore no reply is made. The interrogator 1 receives the response pulse from the antenna 15 by the amplifier circuit 16 and then detects it by the detection unit 17, and the demodulation unit 18 sets it to 1 when a pulse responding to each pulse returns, and sets it to 0 if not. The data string is restored and given to the data communication control unit 11. In this way, data is transmitted from the responder 2 to the interrogator 1 by UWB wireless communication.

  When the data communication control unit 11 transmits the restored ID to the host device 3 and is authenticated that the ID is a pre-registered ID (for a user permitted to enter the room), the data communication control unit 11 As described above, the history of entry / exit is managed, and the electric lock 4 and the illumination control unit 5 are controlled. In this way, a non-contact ID system that manages entry / exit history is configured.

  It should be noted that in the present invention, as shown in FIG. 6, the distance measuring unit 19 measures a time difference τ from transmission of a pulse to reception of a reply, and calculates a distance D from the time difference τ according to the following equation: It is to transmit to the host device 3 via the data communication control unit 11. Specifically, the start pulse signal is output to the distance measurement unit 19 at the timing when the transmission pulse wave generation unit 12 transmits a pulse, and the distance measurement is performed at the timing when the detection unit 17 receives the pulse wave from the responder 2. A stop signal is output to the unit 19 and the time difference τ between them is measured.

D = C · (τ / 2)
However, C is the speed of light. Further, the time corresponding to the response delay on the transmission circuit 13, the amplifier circuit 16, the detection unit 17, and the responder 2 side may be subtracted from the time difference τ.

  With this configuration, it is possible to perform distance measurement using the characteristics of the impulse-type UWB wireless communication method without transmitting / receiving a signal for distance measurement. The reception area of the interrogator 1 is 3 m, for example. Even if the responder 2 is put in a pocket or the like, authentication can be performed reliably, and convenience can be improved. The entrance / exit management is performed when the distance obtained by the distance measuring unit 19 is within a range of 0.5 to 1 or less, for example, and it is possible to eliminate malfunctions that cause the door to be unlocked undesirably. it can.

  Note that the distance measuring unit 19 may obtain the distance from the average value of the time differences τ of not only one pulse but also a plurality of pulses. Since distance measurement cannot be performed, a dummy 1 may be inserted, that is, data with a response may be inserted.

[Embodiment 2]
FIG. 7 is a diagram for explaining a communication operation in the data reception period of a contactless ID system according to another embodiment of the present invention. The configuration of the non-contact ID system shown in FIG. 1 can be used in this embodiment, and only the pulse generation method by the transmission pulse generation unit 12 is different. Specifically, the period T1 of the pulse can be switched to a plurality of types (T1 and T1 ′ in the example of FIG. 7), and is cycled and switched every predetermined period (slot in the example of FIG. 7). It is to go.

  This is because when the responder 2 is far from the interrogator 1, it takes time until the response pulse is returned, and there is a possibility of colliding with the next timing pulse. This is because although the data transmission rate is lowered, collision can be avoided. With this configuration, when the cycle is short (T1) and a short distance is targeted, a high transmission rate can be obtained, and when the cycle is long (T1 ′), the transmission rate can be obtained. However, measurement and data transmission can be performed over long distances, and the dynamic range of the ranging area can be expanded.

  Here, in Patent Document 1, the transmission / reception unit transmits a pulse at a slightly different repetition frequency and measures the distance from the frequency difference, which is different from the present invention. Moreover, although the said patent document 2 measures distance, since it cannot authenticate with a reflective body, it cannot discriminate | determine whether a reflected signal is the object which wants to measure distance.

1 is a block diagram showing an electrical configuration of a contactless ID system using a UWB wireless communication system according to an embodiment of the present invention. It is a figure for demonstrating the communication frame which concerns on this Embodiment. It is a figure for demonstrating an example of the determination method of a slot. It is a figure for demonstrating the other example of the determination method of a slot. It is a figure for demonstrating the communication operation | movement in the data reception period of the non-contact ID system which concerns on one Embodiment of this invention. It is a figure for demonstrating the ranging method which concerns on this Embodiment. It is a figure for demonstrating the communication operation in the data reception period of the non-contact ID system which concerns on other forms of implementation of this invention.

DESCRIPTION OF SYMBOLS 1 Interrogator 2 Response machine 3 Host apparatus 4 Electric lock 5 Illumination control part 11, 25 Data communication control part 12, 26 Transmission pulse wave generation part 13, 27 Transmission circuit 14, 15, 21, 28 Antenna 16, 22 Amplifier circuit 17 , 23 Detection unit 18, 24 Demodulation unit 19 Distance measurement unit

Claims (5)

Whether one wireless communication device transmits a very short pulse continuously in a predetermined cycle and the other wireless communication device returns a pulse in response to each pulse, the one wireless communication device transmits a data string. In the UWB wireless communication system in which data is transmitted from the other wireless communication device to one wireless communication device by restoring
The one wireless communication device includes distance measuring means for measuring a distance based on a time difference from transmission of a pulse to reception of a reply ,
Furthermore said one wireless communication device, the period may be a plurality of types switching, by circulating for each slot Yuku by switching the cycle, Ru switching latency of the response signal from the other wireless communication device A UWB wireless communication system. A non-contact ID system using the UWB wireless communication system according to claim 1, wherein the one wireless communication device is an interrogator and the other wireless communication device is a responder. Hand wireless communication apparatus becomes interrogator, in the contactless ID system in which a plurality of other side of the wireless communication device is responder,
Whether one of the wireless communication devices transmits a very short pulse continuously in a predetermined cycle and the other wireless communication device returns a pulse in response to each pulse. By using the UWB wireless communication system that performs data transmission from the other wireless communication device to the other wireless communication device by restoring the column,
The one wireless communication device includes distance measuring means for measuring a distance based on a time difference from transmission of a pulse to reception of a reply,
In the one of the wireless communication device, pre-registration responses device is authenticated, the contactless ID system characterized Rukoto with an electrical lock for performing unlocking of the room. The interrogator has a data reception period including a plurality of slots as a period for transmitting the very short pulse and receiving a reply pulse in response thereto, and has a control slot for polling before that, in the control slot, 4. The contactless ID system according to claim 2 , wherein a slot to which each responder should respond is determined.   The contactless ID system according to claim 4, wherein the slot is determined by slot designation from a responder.

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