JP2006005553A - System, device and method for radio communication, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clarify the receiving status of a reflected wave in a reflected wave reader side to a user who operates a reflector. <P>SOLUTION: The reflected wave reader transmits a beacon for informing a reception signal strength for every predetermined time, and transmits a carrier wave subsequently to the beacon. The reflector uses the reflected wave of a received carrier wave to transmit the notification request of the reception signal strength. In response to this, the reflected wave reader notifies the reception signal strength by beacon in response to the notification request. On the reflector side, the reception signal strength of the notified reflected wave is displayed and outputted, thereby presenting the user about the communication status. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program that realize a communication operation with low power consumption between devices at relatively short distances. Back-scatter wireless communication system, wireless communication apparatus, wireless communication method, and computer for performing data communication using modulation carrier transmission and reflected wave modulation based on antenna load impedance switching operation on reflector side, etc.・ Regarding the program.

  More specifically, the present invention relates to a wireless communication system, a wireless communication apparatus and a wireless communication method, and a computer program that make clear to the user the communication status by reflected wave transmission between reflectors or reflected wave readers. Radio communication system, radio communication apparatus, and radio for clarifying reception status of reflected wave on reflected wave reader side for user operating reflector when performing reflected wave transmission using reflector and reflected wave reader The present invention relates to a communication method and a computer program.

  By connecting a plurality of devices to the network, it is possible to achieve efficient command and data transmission, sharing information resources, and sharing hardware resources. More recently, wireless networks have attracted attention as systems that release users from wired wiring.

  Examples of standard standards relating to wireless networks include IEEE (The Institute of Electrical and Engineering Engineers) 802.11, HiperLAN / 2 (, IEEE 802.15.3, Bluetooth communication, etc. In recent years, wireless LAN systems can be cited. Coupled with the fact that it has become inexpensive and has been built into PCs as a standard, wireless LAN has become very popular.

  A relatively small wireless communication system is used for data transmission between a host device and a terminal device in a home or the like. Examples of the host device mentioned here include stationary home appliances such as a television, a monitor, a printer, a PC, a VTR, and a DVD player. Examples of terminal devices include mobile devices such as digital cameras, video cameras, mobile phones, personal digital assistants, and portable music players that want to minimize power consumption. An application of this type of system is uploading image data taken with a mobile phone with a camera or a digital camera to a PC via a wireless LAN.

  However, the wireless LAN is originally designed and developed on the assumption that it is used in a computer, and its power consumption becomes a problem when mounted on a mobile device. Many of the IEEE802.11b wireless LAN cards currently on the market have a power consumption of 800 mW or more when transmitting and 600 mW or more when receiving. This power consumption is a heavy burden for battery-powered portable devices.

  Even if the wireless LAN function is operated in a limited range and the transmission power is reduced, the power consumption can be reduced by only about 80%. In particular, since transmission from an image input device such as a digital camera to the image display device is in a communication form in which the transmission ratio occupies the entire communication, wireless transmission means with low power consumption is still required.

  As for Bluetooth communication, the maximum transmission speed is as low as 720 kbps, and it is time-consuming and inconvenient for the recent high-quality image transmission.

  On the other hand, wireless transmission using reflected waves based on the back scatter method used in RFID realizes low power consumption in a communication mode in which the transmission ratio occupies most of the communication between devices, for example. be able to.

  A back-scatter wireless communication system includes a reflector that transmits data using a modulated reflected wave, and a reflected wave reader that reads data from the reflected wave from the reflector. During data transmission, the reflected wave reader transmits an unmodulated carrier. On the other hand, the reflector transmits data by performing a modulation process corresponding to the transmission data on the unmodulated carrier by using a load impedance operation such as on / off of the end of the antenna, for example. The reflected wave reader side can receive the reflected wave, demodulate and decode it, and acquire transmission data.

  In a reflected wave transmission system, an antenna switch for performing back scattering is generally composed of an IC of gallium arsenide, and its power consumption is several tens of μW or less. As an average power when data transmission is performed, In the case of the delivery confirmation method, data transmission is possible at 10 mW or less, and in the unidirectional transmission, data transmission is several tens of μW. This is an overwhelming performance difference compared to the average power consumption of a general wireless LAN (for example, see Non-Patent Document 1).

  For example, a reflector is incorporated in a mobile terminal device such as a digital camera, a video camera, a mobile phone, a personal digital assistant, a portable music player, etc. to minimize power consumption, and a TV, monitor, printer, PC, A reflected wave reader is incorporated in a host device such as a VTR, DVD player, or other stationary home appliances. For example, image data taken with a camera-equipped mobile phone or digital camera can be uploaded to a PC via a reflected wave transmission path, and image data can be stored, displayed, and printed out.

  FIG. 4 shows a configuration example of the reflected wave transmission system.

  The host 1 includes an RF function unit 11, a host communication control function unit 12, and a host function unit 13. The RF function unit 11 operates as a reflected wave reader in the reflected wave transmission system.

  Data transmitted from the host function unit 13 is modulated by the modulation function unit 121 of the host communication control function unit 12 via the control interface 14. The modulated signal 15 is transmitted to the terminal 2 on the unmodulated carrier 31 generated by the carrier generation source 111 of the RF function unit 11. The RF function unit 21 of the terminal 2 receives the unmodulated carrier 31 and obtains the demodulated signal 25. The demodulated signal 25 is demodulated by the demodulation function unit 223 and is received by the terminal function unit 23 via the control interface 24.

  On the other hand, the terminal 2 includes an RF function unit 21, a terminal communication function control function unit 22, and a terminal function unit 23. The RF function unit 21 operates as a reflector in the reflected wave transmission system.

  Data transmitted by the terminal function unit 23 of the terminal 2 is modulated by the modulation function unit 222 of the communication control function unit 22. The modulated signal 26 is placed on the reflected wave 32 obtained by detecting the unmodulated carrier 31 in the RF function unit 26 and transmitted to the host 1. The RF function unit 11 of the host 1 receives the reflected wave 32 and obtains the demodulated signal 16. The demodulated signal 16 is demodulated by the demodulation function unit 123 and received by the host function unit 13 via the control interface 14.

  Further, in addition to the data transmission / reception function described above, the host 1 and the terminal 2 can be provided by providing the protocol function units (121, 221) that mutually function in the host 1 and the terminal 2 in the respective communication control function units (12, 22). Protocol control such as connection and disconnection is realized.

  In the reflected wave transmission system, since no carrier generation source is required for the RF function unit 21 of the terminal 2, the system can be driven with low consumption. Also, by performing multi-level modulation on the terminal side, high-speed communication can be realized from the terminal to the host direction. Note that ASK is used for the modulation in the host in consideration of the ease of detection on the terminal side. This results in a low data rate.

  The terminal 1 is, for example, a digital still camera or a digital video camera, and the host 2 is, for example, a television or a printer. It is assumed that a still image or a moving image is uploaded from the terminal 1 to the host 2 and displayed or printed out.

  By the way, in the wired system, it is clearly known whether or not devices can communicate with each other depending on whether or not a cable is connected. On the other hand, in the wireless communication system, there is a problem that the communication status between devices is not clear to the user.

  In the reflected wave transmission system, since the wireless transmission distance is limited to a short distance of several meters, at least one of the reflector and the reflected wave reader has directivity to the antenna, and a large antenna in a specific direction. In many cases, a device such as extending the wireless communication distance is obtained by obtaining a gain.

  FIG. 5 shows a directional antenna in which both the reflector and the reflected wave reader use an omnidirectional antenna, and in which both the reflector and the reflected wave reader can obtain a large gain in one direction. It shows the difference in communication status when using. In the figure, the reflector 21 and the reflected wave reader 22 use omnidirectional antennas. The reflected wave arrival distance of the reflector 21 is a slanted line 23 and the unmodulated carrier reachable distance of the reflected wave reader 22 is a slanted line. 24.

  On the other hand, the reflector 25 and the reflected wave reader 26 use directional antennas. The reflected wave arrival distance of the reflector 25 is represented by a hatched line 27, and the unmodulated carrier reachable distance of the reflected wave reader 26 is represented by a hatched line 28. ing. However, the distance between the reflector 21 and the reflected wave reader 22 and the distance between the reflector 25 and the reflected wave reader 26 are the same.

  In the example shown in FIG. 5, when an omnidirectional antenna is used, the unmodulated carrier 24 of the reflected wave reader 22 does not reach the reflector 21, and therefore the reflector 21 may generate the reflected wave 23. There is no communication. On the other hand, when a directional antenna is used, communication is established because both the unmodulated carrier 28 of the reflected wave reader 26 and the reflected wave 27 of the reflector 25 reach the other party.

  Particularly in the former case, even if the reflector can receive the unmodulated carrier from the reflected wave reader with sufficient reception intensity, the reflected wave reader cannot receive the reflected wave with sufficient reception intensity. In some cases, it is not possible to accurately determine the communication status on the reflector side alone.

  For example, in a general wireless device, the received signal electric field strength (RSSI) is measured and reflected on the user interface display as a good or bad communication state (see, for example, Patent Document 1). The mobile phone antenna type user interface display is the most common example. In recent years, antenna-type display, percentage conversion display, and the like have also been made in devices equipped with a wireless LAN or Bluetooth.

  In these conventional wireless communication systems, each other's devices (such as a mobile phone and a base station, an access point mobile station in a wireless LAN) are individually provided with a carrier generation source. For this reason, if the received signal field strength (RSSI) of the radio wave received from the communication partner by the device itself is a good value, it can be estimated that the RSSI of the radio wave received from the communication partner is also good. . Therefore, when viewing the user interface display, it is safe to assume that the communication status of the system system is good regardless of reception or transmission.

  On the other hand, in the reflected wave transmission system, the unmodulated carrier is attenuated while reaching the reflector from the reflected wave reader, and the reflected wave is further attenuated while reaching the reflected wave reader from the reflector. For this reason, even if the reflector can receive the unmodulated carrier from the reflected wave reader with sufficient reception intensity, the reflected wave reader may not be able to receive the reflected wave with sufficient reception intensity. In such a case, the received signal strength on the reflector side does not reflect the communication status of the system system.

Japanese Patent Laid-Open No. 05-014221 Japanese Patent Application No. 2003-291809 Specification

  An object of the present invention is to suitably perform data communication using transmission of an unmodulated carrier from the reflected wave reader side and modulation of the reflected wave based on an antenna load impedance switching operation on the reflector side. Another object of the present invention is to provide a wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program that are excellent in backscattering.

  A further object of the present invention is to provide an excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program capable of clarifying to the user the communication status by reflected wave transmission between reflectors or reflected wave readers. Is to provide.

  A further object of the present invention is to clarify the reception status of the reflected wave on the side of the reflected wave reader for the user operating the reflector when performing reflected wave transmission using the reflector and the reflected wave reader. An excellent wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program are provided.

  The present invention has been made in consideration of the above-mentioned problems, and is a radio that performs reflected wave transmission by transmitting an unmodulated carrier from the reflected wave reader side and modulating the reflected wave according to transmission data on the reflector side. In the communication system, the reflected wave reader side measures a received signal intensity of a reflected wave with respect to an unmodulated carrier from the reflector and notifies the reflector of the received signal strength.

  However, “system” here refers to a logical collection of a plurality of devices (or functional modules that realize specific functions), and each device or functional module is in a single housing. It does not matter whether or not.

  The wireless transmission system according to the present invention is intended to realize low power consumption in a communication mode in which a transmission ratio occupies most of communication between devices that are relatively limited to a short distance, Wireless transmission is performed using modulation of reflected waves based on the back scatter method used in RFID. The RFID system itself is widely known in the art as an example of a wireless communication means that can be applied only at an extremely short distance.

  Here, in the wireless communication system, there is a problem that it is not clear whether devices are within the communication range. In particular, in a reflected wave transmission system, unmodulated carriers are attenuated while reaching the reflector from the reflected wave reader, and further, the reflected wave is attenuated while reaching the reflected wave reader from the reflector. For this reason, even if the reflector can receive the unmodulated carrier from the reflected wave reader with sufficient reception intensity, the reflected wave reader side may not be able to receive the reflected wave with sufficient reception intensity. The communication status cannot be accurately determined only by the reflector side.

  On the other hand, in the wireless communication system according to the present invention, the reflected wave reader measures the received signal intensity of the reflected wave with respect to the unmodulated carrier from the reflector and notifies the reflector. By displaying and outputting the received signal intensity of the reflected wave, the communication status can be presented to the user.

  In a wireless communication system using reflected wave transmission, it can be said that the reception environment in the reflected wave reader represents the communication status of the system. According to the present invention, the received signal measured on the reflected wave reader side is notified to the reflector and displayed and output by the reflector, so that the communication status of the system system is reflected in the same manner as the conventional wireless communication system. A user interface display can be provided to the user. Therefore, the user can adjust the communication status by guiding the device to a communicable range based on the display of the communication quality measurement result.

  In addition, in order to secure the user interface function for presenting the communication status to the user, the reflector uses the reflected wave of the unmodulated carrier to transmit a received signal strength notification request, and the reflected wave reader A protocol for notifying the received signal strength may be prepared.

  For example, the reflected wave reader may transmit a beacon notifying the received signal strength at every predetermined time interval. Then, following the beacon, an unmodulated carrier is transmitted, and the reflector can transmit a received signal strength notification request using the received reflected wave of the unmodulated carrier. On the other hand, the reflected wave reader notifies the received signal strength by a beacon in response to the communication request.

  Also, in a communication environment where there are a plurality of communication terminals equipped with reflectors, when each communication terminal has unique terminal identification information, the reflected wave reader receives received signal strength for each terminal identification information. A beacon that describes Then, the communication terminal transmits a notification request to which the terminal identification information of the local station is added, and the reflected wave reader notifies the strength of the received signal corresponding to the terminal identification information requested to be notified by a beacon. .

  According to the present invention, an excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program capable of clarifying to a user a communication state by reflected wave transmission between a reflector or a reflected wave reader are provided. Can be provided.

  According to the present invention, when reflected wave transmission is performed using a reflector and a reflected wave reader, the reflected wave reception status on the reflected wave reader side is clarified to the user operating the reflector. An excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program can be provided. The user can adjust the communication status by guiding the device to a communicable range based on the display of the communication quality measurement result.

  Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The present invention is a communication mode in which the transmission ratio occupies most of the communication between devices that are relatively limited to a short distance. The purpose is to realize transmission and mutual communication, and wireless transmission is performed using a reflected wave based on the back scatter method used in RFID.

  The RFID system itself is widely known in the art as an example of wireless communication means that can be applied only locally. Examples of the communication method between the tag and the reader / writer include an electromagnetic coupling method, an electromagnetic induction method, and a radio wave communication method. The present invention relates to a radio wave communication system using a microwave such as a 2.4 GHz band.

  The basic operation of the reflected wave transmission system that performs back-scatter data transmission is as described with reference to FIG.

  FIG. 1 shows a configuration example of a reflected wave transmission system according to an embodiment of the present invention.

  As illustrated, the host 1 includes an RF function unit 11, a communication control function unit 12, a host function unit 13, and a control interface 14. The RF function unit 11 operates as a reflected wave reader in the reflected wave transmission system.

  The host function unit 13 is configured by a host device that processes or reproduces and outputs received data, such as a stationary home appliance such as a television, a monitor, a printer, a PC, a VTR, and a DVD player.

  Data transmitted from the host function unit 13 is modulated by the modulation function unit 121 of the host communication control function unit 12 via the control interface 14. Then, the modulated signal 15 is placed on the unmodulated carrier 31 generated by the carrier generation source 111 of the RF function unit 11 and transmitted to the terminal. In general, ASK is used for the downlink from the host 1 to the terminal 2 in consideration of the ease of detection on the terminal side. The RF function unit 21 of the terminal 2 receives the unmodulated carrier 31 and obtains the demodulated signal 25. The demodulated signal 25 is demodulated by the demodulation function unit 223 and is received by the terminal function unit 23 via the control interface 24.

  On the other hand, the terminal 2 includes an RF function unit 21, a terminal communication function control function unit 22, and a terminal function unit 23. The RF function unit 21 operates as a reflector in the reflected wave transmission system.

  The terminal function unit 23 includes a mobile terminal device that is a transmission data supply source, such as a digital camera, a video camera, a mobile phone, a portable information terminal, and a portable music player.

  Data transmitted by the terminal function unit 23 of the terminal 2 is modulated by the modulation function unit 222 of the communication control function unit 22. The modulated signal 26 is placed on the reflected wave 32 obtained by detecting the unmodulated carrier 31 in the RF function unit 26 and transmitted to the host 1. The RF function unit 11 of the host 1 receives the reflected wave 32 and obtains the demodulated signal 16. The demodulated signal 16 is demodulated by the demodulation function unit 123 and received by the host function unit 13 via the control interface 14.

  In the reflected wave transmission system, a low bit rate modulation method such as ASK or BPSK is generally employed for the uplink from the reflector to the reflected wave reader. However, the gist of the present invention is not limited to this. It is not something. When modulating the reflected wave, in addition to the operation of load impedance such as antenna termination, a phase difference is given on the signal path along which the reflected wave reciprocates, so that a higher bit rate modulation method such as QPSK or 8-phase PSK modulation can be used. Can be realized. For example, Japanese Patent Application No. 2003-352223 already assigned to the present applicant discloses a back scatter type communication system incorporating QPSK modulation processing.

  Further, in addition to the data transmission / reception function described above, the protocol function units (121, 221) that mutually function in the host 1 and the terminal 2 are provided in the respective communication control function units (12, 22), so that the host 1 and the terminal 2 Protocol control such as connection and disconnection is realized.

  In the present embodiment, an RSSI measurement function unit 112 is added to the RF function unit 11 of the host 1 in addition to the original function as a reflected wave reader in the reflected wave transmission system.

  The RSSI measurement function unit 112 receives the reflected wave 32, measures the received signal strength RSSI (Received Signal Strength Indicator), and notifies the protocol control unit 121 of the RSSI value. Regarding the notification, a voltage corresponding to the RSSI value is generally output as a level. For measurement of RSSI, for example, a well-known technique such as a detection diode that rectifies an AC oscillating electric field applied to its surroundings and outputs it as a DC signal can be used.

  The RSSI value measured by the RSSI measurement function unit 112 on the host 1 side is communicated from the host 1 to the terminal 2 via the protocol control unit (121, 221). The RSSI value acquired by the protocol control unit 211 of the terminal 2 is passed to the control interface 24 and displayed and output by the user interface display unit 231 of the terminal function unit 23. The user can grasp the communication quality of the entire system more accurately based on this display. Also, the user can adjust the communication status by guiding the device to a communicable range based on the display of the communication quality measurement result.

  In the reflected wave transmission method according to the present embodiment, the image transmission device or the like built in the digital camera is the terminal 2, but it does not have a carrier generation source and sends data on the reflected wave with respect to the received radio wave. The back scatter method is adopted. For this reason, the unmodulated carrier necessary for generating the reflected wave must always be transmitted from the host 1, but the transmission operation of the unmodulated carrier when waiting for reception is not only a waste of power consumption, It also becomes an interference wave to other wireless communication systems. In particular, in the reflected wave transmission system using the 2.4 GHz band, there is a concern about the influence on the proximity system because it overlaps the normal frequency band used for wireless LAN.

  Therefore, in this embodiment, the host 1 adopts a protocol in which a beacon signal including a modulated identification code and an unmodulated signal is intermittently transmitted, and an unmodulated carrier is added immediately after the beacon. On the terminal 2 side, for example, after the identification code included in the received beacon signal is collated, data can be transmitted as a reflected wave by modulating the non-modulated carrier.

  FIG. 2 shows an operation example of the protocol control method when the RSSI value is notified from the host to the terminal.

  The host 1 periodically transmits a beacon frame 100 to the terminal 2 and then transmits an unmodulated carrier 101. The terminal receives an unmodulated carrier as an unmodulated carrier, modulates predetermined data, and transmits a control frame on a reflected wave.

  Here, the beacon frame 100 is ASK-modulated and carries various information. The preamble 102 is a synchronization pattern for clock synchronization. A unique word (UW) 103 is a synchronization pattern for frame synchronization. The header 104 includes information such as the type of frame, the ID information of the host 1 that is the beacon transmission source, or the information length of the subsequent additional information 105. The additional information 105 includes information notified from the host 1 to the terminal 2. A CRC (Cyclic Redundancy Code) 106, which is error correction data for valid data in the frame, is added to the end of the frame.

  The control frame 200 includes a preamble 202, a unique word 203, header information 204, additional information 205, and a CRC 206.

  In this embodiment, the control frame 200 is used to request an RSSI value from the terminal 2 to the host 1. In this case, the header 204 is provided with identification information 207 indicating that the frame is an RSSI request frame. Further, the additional information 205 is given a terminal ID 206 for identifying the terminal 1 that is the request source.

  On the other hand, a beacon frame 100 is used as a frame for reporting RSSI from the host 1 to the terminal 2. In this case, the RSSI value 107 measured for the reflected wave received by the host 1 from the terminal 2 and the terminal ID 108 of the terminal 2 are given in the additional information 105.

  The terminal 2 transmits a control frame 200 given as an RSSI request frame as a reflected wave with respect to the unmodulated carrier 101 during a period of the unmodulated carrier 101 following the beacon frame 100.

  The host 1 receives the control frame 200 and measures the RSSI of the reflected wave that gives the control frame 200. Then, the host 1 notifies the terminal 2 of the terminal ID and RSSI value to be measured by the beacon frame 100 after the next.

  Since the beacon frame is used as broadcast information for a plurality of terminals, it is conceivable that information of RSSI values regarding a plurality of terminals is included in one beacon frame. In this case, however, the terminal ID and RSSI are included. Listed as a set with values.

  FIG. 3 shows an operation example of another protocol control method when the RSSI value is notified from the host to the terminal.

  In the illustrated protocol control system, control frames are exchanged between the terminal 2 and the host 1. That is, RSSI is notified by transmitting a control frame (response) 201 giving an RSSI response from the host 1 to the terminal 2 in response to a control frame (request) 200 giving an RSSI request from the terminal 2 to the host 1.

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention.

  In the present specification, the embodiment of the present invention has been described by taking as an example the transmission of an unmodulated carrier from the reading device side and the reflected wave transmission system that modulates the reflected wave with the transmission data on the transmission device side. The gist of the present invention is not limited to this. Even in other wireless communication systems that use media other than reflected wave transmission, when the communication status at the communication partner is not clear, the communication quality of the entire system can be displayed more accurately by applying the present invention. Can do. Also, the user can adjust the communication status by guiding the device to a communicable range based on the display of the communication quality measurement result.

  In short, the present invention has been disclosed in the form of exemplification, and the description of the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims section described at the beginning should be considered.

FIG. 1 is a diagram showing a configuration example of a reflected wave transmission system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an operation example of the protocol control method when the RSSI value is notified from the host to the terminal. FIG. 3 is a diagram illustrating an operation example of another protocol control method when the RSSI value is notified from the host to the terminal. FIG. 4 is a diagram illustrating a configuration example of the reflected wave transmission system. FIG. 5 shows a case where a reflector and a reflected wave reader both use omnidirectional antennas, and a directional antenna in which both the reflector and the reflected wave reader can obtain a large gain in one direction. It is the figure which showed the difference in the communication condition in the case of using.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Host 11 ... RF function part 111 ... Carrier generation source 112 ... RSSI measurement function part 12 ... Communication control function part 121 ... Modulation function part 122 ... Modulation function part 123 ... Demodulator function part 13 ... Host apparatus 14 ... Control interface 2 ... Terminal 21 ... RF function part 22 ... Communication control function part 221 ... Protocol function part 222 ... Modulation function part 223 ... Demodulation function part 23 ... Terminal function part 221 ... User interface display part

Claims (23)

A wireless communication system that performs reflected wave transmission by transmitting an unmodulated carrier from the reflected wave reader side and modulating the reflected wave according to transmission data on the reflector side,
On the reflected wave reader side, the received signal intensity of the reflected wave with respect to the unmodulated carrier from the reflector is measured and notified to the reflector.
A wireless communication system. The reflector displays and outputs the received signal strength of the notified reflected wave.
The wireless communication system according to claim 1. The reflector transmits a received signal strength notification request using a received reflected wave of an unmodulated carrier,
The reflected wave reader notifies the received signal strength in response to the notification request.
The wireless communication system according to claim 1. The reflected wave reader transmits a beacon notifying the received signal strength every predetermined time interval, and subsequently transmits an unmodulated carrier,
The reflector transmits a received signal strength notification request using a received reflected wave of an unmodulated carrier,
The reflected wave reader notifies a received signal strength using a beacon in response to the communication request.
The wireless communication system according to claim 1. In a communication environment where a plurality of communication terminals including reflectors exist, each communication terminal includes unique terminal identification information,
The reflected wave reader broadcasts a beacon that describes the received signal strength for each terminal identification information,
The communication terminal sends a notification request with its own terminal identification information added,
The reflected wave reader notifies the strength of the received signal corresponding to the terminal identification information requested for notification by a beacon.
The wireless communication system according to claim 4. A wireless communication device that performs reflected wave communication using modulation of a reflected wave with respect to an unmodulated carrier,
A transmission means for transmitting an unmodulated carrier;
Receiving means for receiving data on a reflected wave from a communication partner for an unmodulated carrier transmitted by the transmitting means;
Measuring means for measuring the intensity of the received signal with respect to the reflected wave;
A notification means for notifying a communication partner of the measured received signal strength;
A wireless communication apparatus comprising: In response to receiving the notification request of the received signal strength from the communication partner, the notification means notifies the communication partner of the received signal strength.
The wireless communication apparatus according to claim 6. It further comprises a beacon transmitting means for generating and transmitting a beacon for notifying the received signal strength every predetermined time interval,
The transmission means transmits an unmodulated carrier following transmission of a beacon,
In response to receiving a request for notification of received signal strength as a reflected wave for an unmodulated carrier from a communication partner, the notification means notifies the communication partner of the received signal strength using a beacon.
The wireless communication apparatus according to claim 6. In a communication environment where a plurality of communication terminals including reflectors exist, each communication terminal includes unique terminal identification information,
The beacon transmitting means broadcasts a beacon describing received signal strength for each terminal identification information,
In response to receiving a request for notification of received signal strength as a reflected wave with respect to an unmodulated carrier from a communication partner, the notification means notifies the received signal strength together with the terminal identification information of the communication partner using a beacon.
The wireless communication apparatus according to claim 8. A wireless communication device that performs reflected wave communication using modulation of a reflected wave with respect to a received unmodulated carrier,
A transmission means for receiving an unmodulated carrier from a communication partner and transmitting a reflected wave modulated according to transmission data;
Receiving means for receiving a modulated carrier from a communication partner and processing transmission data;
In response to receiving the intensity of the received signal at the communication partner receiving the reflected wave from the transmitting means, display means for displaying and outputting the intensity of the received signal;
A wireless communication apparatus comprising: A notification request means for requesting the communication partner to notify the received reflected wave signal intensity;
The wireless communication apparatus according to claim 10. From the communication partner, a beacon notifying the received signal strength is transmitted every predetermined time interval, followed by an unmodulated carrier,
The notification request means transmits a notification request for received signal strength using the received unmodulated carrier;
The wireless communication apparatus according to claim 10. In a communication environment where there are a plurality of communication terminals that transmit reflected waves with respect to an unmodulated carrier, each communication terminal includes unique terminal identification information,
The communication partner broadcasts a beacon that describes the received signal strength for each terminal identification information,
The notification request means adds a terminal identification information of itself and transmits a reception signal strength notification request.
The wireless communication apparatus according to claim 12. A wireless communication method for performing reflected wave communication using modulation of a reflected wave with respect to an unmodulated carrier,
A transmission step of transmitting an unmodulated carrier;
A receiving step of receiving data on a reflected wave from a communication partner for an unmodulated carrier transmitted by the transmitting means;
A measurement step for measuring the intensity of the received signal with respect to the reflected wave;
A notification step of notifying a communication partner of the measured received signal strength;
A wireless communication method comprising: In the notification step, in response to receiving a request for notification of received signal strength from a communication partner, the received signal strength is notified to the communication partner.
The wireless communication method according to claim 14. Further comprising a beacon transmission step of generating and transmitting a beacon notifying the received signal strength at predetermined time intervals,
In the transmission step, following the transmission of the beacon, an unmodulated carrier is transmitted,
In the notification step, in response to receiving a request for notification of received signal strength as a reflected wave with respect to an unmodulated carrier from a communication partner, the received signal strength is notified to the communication partner using a beacon.
The wireless communication method according to claim 14. In a communication environment where a plurality of communication terminals including reflectors exist, each communication terminal includes unique terminal identification information,
In the beacon transmission step, a beacon that describes the received signal strength for each terminal identification information is notified,
In the notification step, in response to receiving a request for notification of received signal strength as a reflected wave with respect to an unmodulated carrier from a communication partner, the received signal strength is notified using a beacon together with the terminal information of the communication partner.
The wireless communication method according to claim 16. A wireless communication method for performing reflected wave communication using modulation of a reflected wave with respect to a received unmodulated carrier,
A transmission step of receiving an unmodulated carrier from a communication partner and transmitting a reflected wave modulated according to transmission data;
A receiving step of receiving a modulated carrier from a communication partner and processing transmission data;
A display step for displaying and outputting the intensity of the received signal in response to receiving the intensity of the received signal in the communication partner receiving the reflected wave transmitted in the transmitting step;
A wireless communication method comprising: A notification request step for requesting the communication partner to notify the received reflected wave signal intensity;
The wireless communication method according to claim 18. From the communication partner, a beacon notifying the received signal strength is transmitted every predetermined time interval, followed by an unmodulated carrier,
In the notification request step, a received signal strength notification request is transmitted using the received unmodulated carrier.
The wireless communication method according to claim 18. In a communication environment where there are a plurality of communication terminals that transmit reflected waves with respect to an unmodulated carrier, each communication terminal includes unique terminal identification information,
The communication partner broadcasts a beacon that describes the received signal strength for each terminal identification information,
In the notification request step, a notification request for reception signal strength is transmitted by adding own terminal identification information,
21. The wireless communication method according to claim 20, wherein: A computer program written in a computer-readable format for executing on a computer system a process for performing reflected wave communication using modulation of a reflected wave with respect to an unmodulated carrier,
A transmission step of transmitting an unmodulated carrier;
A receiving step of receiving data on a reflected wave from a communication partner for an unmodulated carrier transmitted by the transmitting means;
A measurement step for measuring the intensity of the received signal with respect to the reflected wave;
A notification step of notifying a communication partner of the measured received signal strength;
A computer program comprising: A computer program written in a computer-readable format to execute processing on a computer system for performing reflected wave communication using reflected wave modulation on a received unmodulated carrier,
A transmission step of receiving an unmodulated carrier from a communication partner and transmitting a reflected wave modulated according to transmission data;
A receiving step of receiving a modulated carrier from a communication partner and processing transmission data;
A display step for displaying and outputting the intensity of the received signal in response to receiving the intensity of the received signal in the communication partner receiving the reflected wave transmitted in the transmitting step;
A computer program comprising:

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