JP2007135142A - Radio communication system and radio communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform ad hoc data communication between communication stations mounted with reflectors without spoiling merits such as excellent communication speed and low power consumption by reflection wave transmission. <P>SOLUTION: A carrier transmitting station for supplying a nonmodulated carrier to each communication station is provided in a system. Each communication station performs data transmission by performing modulation processing with respect to a reflected wave of the nonmodulated carrier from the carrier transmitting station, and performs data reception by reading data from modulated reflection wave signals from other communication stations. High-speed direct communication using the reflection wave transmission between communication stations is obtained, and authorization work such as conformity certification is unnecessary since the communication stations do not correspond to objects of radio stations in the radio law. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication system and a wireless communication apparatus that perform communication between a plurality of communication stations, and more particularly to an ad hoc wireless communication system and a wireless communication apparatus in which communication stations perform ad hoc data communication on an equal basis. .

  More particularly, the present invention relates to a radio communication system and a radio communication apparatus in which communication stations perform ad hoc data communication by a reflected wave transmission method, and in particular, perform ad hoc data communication between communication stations equipped with reflectors. The present invention relates to a wireless communication system and a wireless communication apparatus.

  As an example of wireless communication means that can be applied only locally, an RFID system is widely known. RFID was originally developed as a device including identification information and a readable / writable storage area. That is, the wireless tag has an operating characteristic of transmitting a radio wave corresponding to identification information or stored information in response to reception of a radio wave of a specific frequency, and the tag reader is configured to approach or close the information of the radio tag. It can be read from the distance in a non-contact manner, and the article to which the wireless tag is attached can be specified (for example, refer to Patent Document 1).

  Recently, since the communication method can be realized with low power consumption, it is considered to replace the wireless data communication with the RFID system such as the reflected wave communication from the conventional wireless LAN or Bluetooth communication.

  Examples of the communication method of the RFID system include an electrostatic coupling method, an electromagnetic induction method, and a radio wave communication method. Among them, the radio wave communication type RFID system includes a reflector that transmits data by a reflected wave obtained by modulating a received unmodulated carrier, and a reflected wave reader that reads data from a modulated reflected wave signal from the reflector. It is configured (see, for example, Patent Document 2), and performs reflected wave transmission, which is also called a “back scatter method”. When a non-modulated carrier is sent from the reflected wave reader, the reflector modulates the reflected wave and superimposes data based on an antenna load impedance switching operation or the like. Since no carrier generation source is required on the reflector side, the data transmission operation can be driven with low consumption. An antenna switch for changing the load impedance of the antenna is generally composed of a gallium arsenide IC, and its power consumption is several tens of μW or less. Therefore, in reflected wave transmission, data transmission is possible at several tens of μW, which is an overwhelming performance difference compared to the average power consumption of a general wireless LAN (see, for example, Patent Document 3). This is particularly effective in a communication mode in which the transmission ratio in one direction from a device equipped with a reflector to a device equipped with a reflected wave reader occupies most of the communication. In addition, since a terminal equipped with a reflector only performs an operation of reflecting a received carrier, it is not regarded as a radio station, and is treated as a target not subject to legal regulations imposed on radio wave communication.

  For example, a battery-driven mobile device such as a digital still camera, a digital video camera, or a mobile phone is used as a data transmitter, and a host device such as a personal computer that displays, reproduces, prints out, stores, or manages data is used as a data receiver. Consider a data communication system. In this case, a reflector is mounted on the mobile device side, and a non-modulated carrier is sent from the reflected wave reader connected to the host device, so that still images, videos, and music data are not burdened on the mobile device battery. It is possible to read (upload) a relatively large amount of data.

  The reflected wave transmission system is basically a one-way communication from the reflector to the reflected wave reader. In order to perform bidirectional communication, it is necessary to provide another communication path from the reflected wave reader to the reflector. is there. As one of the means for solving this problem, a radio communication system that employs a relatively low bit rate ASK modulation method for transmission from the reflected wave reader to the reflector has been proposed due to the ease of the transmission / reception circuit (for example, (See Patent Document 3). In this case, a predetermined frame period is divided into a transmission section from the reflector and a transmission section from the reflected wave reader, and bidirectional data communication by the time division multiplexing (TDD) method is performed.

  For example, when performing relatively large-scale data communication such as image data from a reflector to a reflected wave reader, the reflector side divides transmission data into packets and transmits the packet, and the reflected wave reader determines whether or not the data packet has arrived. Can be performed in two-way packet communication in which a control packet such as Ack (Acknowledgement) or NACK (Negative Acknowledgment) is used.

  In consideration of the diversity of applications of the reflected wave transmission system, the present inventors need to realize bidirectional communication with improved convenience in addition to reading data from the reflector by the reflected wave reader. Think.

  For example, in a conventional wireless network, a method of constructing a network under the overall control of an access point is generally used. However, when performing asynchronous communication between a communication device on a transmission side and a reception side, an access point must be set. Wireless communication is required, so that the efficiency of use of the transmission path is halved. Therefore, recently, “ad-hoc communication” in which communication stations autonomously distribute and communicate with each other without using a specific access point has been attracting attention.

  When considering the application of applying the reflected wave transmission method to ad hoc data communication, not only data reading from a communication station equipped with a reflector by a communication station equipped with a reflected wave reader, but also communication stations Data communication must be possible. However, a reflector is installed because the basic operation is one-way communication in which the reflector receives an unmodulated carrier and sends the modulated reflected wave signal that is modulated according to the transmission data to the reflected wave. Two-way data communication cannot be performed between the communication stations.

  In order to perform data communication between communication stations equipped with reflectors, as shown in FIG. 6, the reflected wave reader reads the transmission data from one reflector and transfers it to the other reflector. A communication procedure for relaying the wave reader is also conceivable. However, as with a conventional wireless network with an access point, the overhead of relaying the reflected wave reader occurs, so the efficiency of the transmission line is halved and the communication speed advantage of reflected wave transmission Can not enjoy.

  In addition, since the ASK modulation method is used for data communication from the reflected wave reader to the reflector (described above), the transmission speed is sufficient for the transmission of control packets such as Ack and Nack. Is slow. For this reason, data that is reflected wave-transmitted at 10 to 20 Mbps from one reflector is relayed through a low bit rate transmission line called ASK modulation, which becomes a bottleneck for communication between reflectors.

  A solution is also conceivable in which a communication terminal equipped with a reflector generates a carrier by itself and performs data transmission with phase modulation such as BPSK or QPSK. However, since the power consumption also increases on the terminal side where the reflector is mounted, the above-mentioned reflected wave that “the data transmission operation can be driven with low consumption because a carrier generation source is unnecessary on the reflector side”. The merit of transmission is impaired. Further, in this case, a terminal equipped with a reflector may be treated as a radio station, which is subject to laws and regulations imposed on radio wave communication, and it is necessary to receive conformity certification, resulting in an increase in development cost.

JP-A-6-123773 Japanese Patent Laid-Open No. 01-182784 JP 2005-64822 A

  An object of the present invention is to provide an excellent radio communication system and radio communication apparatus capable of performing ad hoc data communication between communication stations using a reflected wave transmission method.

  A further object of the present invention is to provide an excellent wireless communication system and wireless communication capable of performing ad hoc data communication between communication stations equipped with reflectors without impairing merits such as communication speed and low power consumption in reflected wave transmission. It is to provide a communication device.

  A further object of the present invention is that it is possible to perform ad hoc data communication between communication stations equipped with reflectors without incurring an increase in development cost due to a design change or conformity certification for legal regulations associated therewith. Another object of the present invention is to provide a wireless communication system and a wireless communication apparatus.

  The present invention has been made in view of the above problems, and is a wireless communication system that performs bidirectional data communication between communication stations, in which a reflected wave with respect to a received carrier is subjected to modulation processing according to transmission data. Accommodates two or more communication stations equipped with a transmission unit that transmits a modulated reflected wave signal and a reception unit that reads data from the modulated reflected wave signal, and a carrier transmission station that supplies carriers to each communication station is provided. The communication station that performs data transmission is a wireless communication system that transmits data using a modulated reflected wave signal using an unmodulated carrier from the carrier transmission station.

  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 (hereinafter the same).

  Reflected wave transmission is used for radio wave communication type RFID and the like, but can also be applied to data communication having advantages such as communication speed and low power consumption. When considering an application of applying the reflected wave transmission method to ad hoc data communication, it is necessary to realize bidirectional communication.

  However, since the reflector itself does not generate a carrier, two-way data communication cannot be performed between communication stations equipped with the reflector. Although a communication procedure of relaying between two reflectors with a reflected wave reader is also conceivable, a time overhead occurs when the reflected wave reader relays, so that it is not possible to enjoy the communication speed advantage of reflected wave transmission. . In addition, while data transmission from the reflector to the reflected wave reader is high-speed communication, the transmission path from the reflected wave reader to the reflector has a low bit rate to which ASK modulation is applied, and is a communication bottleneck. It becomes. Although there is a solution that the reflector itself generates a carrier, it causes problems such as increased power consumption and subject to legal regulations concerning radio wave communication.

  In the wireless communication system according to the present invention, each communication station is equipped with a transmitting unit that transmits data using a modulated reflected wave signal using a received carrier and a receiving unit that can read data from the modulated reflected wave signal. ing. Further, a carrier transmission station that supplies unmodulated carriers to each communication station is provided in the system. In such a case, a communication station that performs data transmission can transmit data using a modulated reflected wave signal using an unmodulated carrier from the carrier transmission station, and the communication station that is one of the transmission destinations is at the receiving unit. Transmission data can be read from the modulated reflected wave signal. That is, high-speed bidirectional data communication using reflected wave transmission can be realized between communication stations, and there is no need to relay a reflected wave reader or other devices.

  Each communication station that performs bidirectional communication does not need to generate a carrier by itself, so that it can keep its power consumption low while enjoying the merit of communication speed by reflected wave transmission. In addition, as long as no carrier is generated, it is considered that the communication station is not treated as a radio station and is not subject to legal regulations regarding radio wave communication.

A second aspect of the present invention is a wireless communication device that performs data communication on a reflected wave transmission line,
A reflection transmitter that receives an unmodulated carrier, performs modulation processing according to transmission data on the reflected wave, and transmits a modulated reflected wave signal;
A reflected wave receiving unit that demodulates a modulated reflected wave signal received from another communication station and reads data;
A communication control unit for controlling a communication operation on a reflected wave transmission path in the reflected transmission unit and the reflected wave receiving unit;
A signal processing unit for processing data signals transmitted and received in the reflected transmission unit and the reflected wave receiving unit;
In the wireless communication system according to the first aspect of the present invention, an unmodulated carrier supplied from a carrier transmission terminal is used to communicate with another communication station. Direct communication by reflected wave transmission can be performed between them.

A third aspect of the present invention is a wireless communication apparatus that operates in the wireless communication system according to the first aspect of the present invention,
A carrier transmitter for transmitting an unmodulated carrier;
A communication control unit for controlling a communication operation in the carrier transmission unit;
A signal processing unit for processing a signal to be transmitted in the carrier transmission unit;
In the wireless communication system according to the first aspect of the present invention, the wireless communication apparatus can operate as a carrier transmission terminal. That is,

  The carrier transmitting terminal further includes a modulated wave transmission unit that performs modulation processing according to transmission data and transmits a modulated wave signal, and a reflected wave that demodulates a modulated reflected wave signal received from another communication station and reads data. By including the receiving unit, direct communication can be performed between a non-modulated carrier supplied by the own station and a communication station within a communication range where the reflected wave reaches. That is, the wireless communication apparatus receives a modulated reflected wave data signal reflected from a communication station and demodulates data, in addition to spatially radiating an unmodulated carrier for other communication stations to perform reflected wave transmission. The modulated wave data signal is transmitted to the communication station. The carrier transmitting terminal in this case can operate as one autonomous communication station under the ad hoc mode, or can operate as a control station or a terminal station under the infrastructure mode.

  ADVANTAGE OF THE INVENTION According to this invention, the outstanding radio | wireless communications system and radio | wireless communication apparatus which can perform ad hoc data communication between communication stations by a reflected wave transmission system can be provided.

  Further, according to the present invention, an excellent wireless communication system capable of performing ad hoc data communication between communication stations equipped with reflectors without impairing merits such as communication speed and low power consumption in reflected wave transmission, and A wireless communication device can be provided.

  Further, according to the present invention, it is possible to perform ad hoc data communication between communication stations equipped with reflectors without incurring an increase in cost due to a design change or conformity certification for legal regulations accompanying this. A wireless communication system and a wireless communication device can be provided.

  In the wireless communication system according to the present invention, direct communication using reflected wave transmission between communication stations in a communication range in which a plurality of communication stations are supplied from a carrier transmitting station and each other's reflected wave signals reach each other. Can be realized. That is, the communication station uses the unmodulated carrier from the carrier transmitting station to transmit data using the modulated reflected wave signal, while reading data from the modulated reflected wave signal from other communication stations and receives data. Is possible. Therefore, bidirectional communication between communication stations is possible on a reflected wave transmission line that is low cost and low power consumption and high speed. Furthermore, since communication stations do not fall under the category of radio stations in the Radio Law, certification work such as conformity certification is unnecessary.

  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 relates to a radio communication system to which a reflected wave transmission system is applied. Reflected wave transmission is a communication method that transmits data using a modulated reflected wave signal in which data is superimposed on the reflected wave of an unmodulated carrier. Since no reflector is required on the reflector side, data is transmitted with extremely low power consumption. Transmission can be performed, and there is an overwhelming performance difference compared to a general wireless LAN.

  Recently, ad hoc communication has attracted attention as a communication method for improving the utilization efficiency of a transmission line when performing asynchronous communication between communication stations. Here, reflected wave transmission uses position-direction communication from a reflector to a reflected wave reader as a basic data transmission procedure. However, when an application of applying the reflected wave transmission method to ad hoc data communication is considered, it is relayed. It is necessary to realize bidirectional communication that is equal to each other between communication stations that exchange data without intervening stations.

  However, since the reflector itself does not generate a carrier, two-way data communication cannot be performed between communication stations equipped with the reflector. Although there is a solution that a communication station equipped with a reflector also generates a carrier, it causes a problem that the power consumption of the communication station increases and is subject to laws and regulations related to radio wave communication.

  Therefore, in the present invention, the communication station is equipped with a transmission unit that transmits data using a modulated reflected wave signal using the received carrier and a reception unit that can read data from the modulated reflected wave signal. The receiving unit here has a function of reading data from the modulated reflected wave signal, but does not generate a carrier (unmodulated carrier) for obtaining a reflected wave from the counterpart station, so a so-called reflected wave reader and Is different. Instead, a carrier transmission station that supplies an unmodulated carrier to each communication station is provided in the system.

  FIG. 1 schematically shows a configuration example of a wireless communication system according to an embodiment of the present invention. The system shown in FIG. 2 includes a carrier transmission station 200 and two communication stations 100-A and 100-B that perform wireless data communication by reflected wave transmission.

  The communication stations 100-A and 100-B are accommodated in a communication range in which the unmodulated carrier supplied from the carrier transmission station 200 and the reflected wave signals of each other reach each other.

  The communication station 100-A performs data transmission by performing modulation processing on the reflected wave of the unmodulated carrier from the carrier transmitting station 200, while transmitting data from the modulated reflected wave signal from the other communication station 100-B. Data can be received by reading.

  Therefore, bidirectional communication between communication stations is possible on a reflected wave transmission line that is low cost and low power consumption and high speed. Furthermore, since communication stations do not fall under the category of radio stations in the Radio Law, certification work such as conformity certification is unnecessary.

  FIG. 2 shows a configuration example of the communication station 100 that operates in the wireless communication system shown in FIG. As illustrated, the communication station 100 includes an antenna 102, a reflection transmission function unit 106 that transmits data using a modulated reflected wave signal using the received unmodulated carrier, and a reflected wave reception function that reads data from the modulated reflected wave signal. A communication function unit 103 including a unit 107, a communication control unit 104 that controls data transmission / reception operations in the communication function unit 103, and a signal processing function unit 105 that performs signal processing of transmission / reception data.

  The reflection transmission function unit 106 includes a microstrip line that reflects a received radio wave with a phase delay of λ / 4 wavelength and an antenna switch SW. When receiving data from the communication control unit 104, the reflection transmission function unit 106 receives the data series. In response to this, the antenna switch SW connected to the antenna 102 is turned on / off. For example, when data 1 is turned on, the received radio wave from the antenna is reflected at the end of the microstrip line for λ / 4 wavelengths. When the data is 0, the antenna 102 is turned off and the antenna 102 is opened, and the incoming radio wave is reflected in the opposite phase to that of the data 1. Data transmission using the reflected wave signal from the carrier transmitting station 200 to the unmodulated carrier is performed by such a change in the phase of the reflected wave due to the on / off operation of the antenna switch SW. This reflected wave signal is equivalent to a BPSK modulated wave. The reflection transmission function unit 107 may have a QPSK modulation function as described in, for example, Japanese Patent Application Laid-Open No. 2005-136944 already assigned to the present applicant.

  The reflected wave reception function unit 107 performs processing for reading data from the modulated reflected wave signal from another communication station. FIG. 3 shows an internal configuration of the reflected wave reception function unit 107. The reflected wave reception function unit 107 shown in the figure includes a carrier recovery circuit 109, a quadrature detection unit 108, and a data demodulation unit 110. When a modulated reflected wave signal is received from another communication station, the quadrature detection unit 108 extracts signals of IQ axes by synchronous detection, and the data demodulation unit 110 extracts demodulated data from transmission signal points mapped to the IQ signal space. Take out. Thereafter, the demodulated data is passed to the signal processing function unit 106 via the communication control unit 104. In the illustrated example, a synchronous detection circuit using the carrier recovery circuit 109 is shown, but a delay detection circuit may be used. In FIG. 2, the reflected wave reception function unit 107 shares the reflection transmission function unit 106 and the antenna 102 and is configured to switch transmission and reception by a switch. For example, each transmission and reception may include a dedicated antenna. Good.

  The communication control unit 104 controls the reflection / transmission function unit 106 according to the transmission timing to perform a data transmission operation, and also performs control related to a radio communication function such as reception frequency setting of the reflected wave reception function unit 107. The signal processing function unit 105 performs, for example, error correction and protocol processing in reflected wave transmission, takes out desired data, and passes it to a higher-level application (not shown).

  FIG. 4 schematically shows an internal configuration of a carrier transmission station 200 that supplies an unmodulated carrier for reflected wave transmission to each communication station 100 in the wireless communication system shown in FIG. The illustrated carrier transmission station 200 includes an antenna 201, a carrier transmission function unit 202, a communication control unit 203, and a signal processing function unit 204.

  The carrier transmission function unit 202 includes, for example, a phase comparator, a loop filter, and a PLL (Phase Locked Loop) circuit formed of a VCO (Voltage Controlled Oscillator), for example, a PA (Power Amp), and an arbitrary carrier wave. A frequency is radiated from the antenna 201 to space with an arbitrary power.

  The communication control unit 203 performs carrier generation by the carrier transmission function unit 202, control of the start and stop timing of the operation of spatially radiating the carrier, and control of the carrier frequency and transmission power.

  The carrier transmitting station 200 may always transmit an unmodulated carrier in order to enable data transmission between communication stations. However, in order to avoid wasting power, for example, the carrier transmitting station 200 may transmit an unmodulated carrier at an arbitrary time interval. You may stop. For example, a switch (not shown) may be provided in the carrier transmission function unit 202 so that the user can arbitrarily turn on / off the transmission operation. Alternatively, the carrier transmission operation may be turned on / off using an instruction unit such as an infrared remote controller. In the latter case, communication stations can arbitrarily communicate with each other.

  The carrier transmitting station 200 shown in FIG. 4 is configured to perform only the operation of supplying an unmodulated carrier for reflected wave transmission to the communication station 100 within a predetermined communication range. 200 also has a data transmission / reception function by reflected wave transmission, and can be configured to perform bidirectional data communication with other communication stations 100. In this case, the carrier transmitting station 200 can also perform ad hoc data communication with other communication stations 100.

  FIG. 5 shows an internal configuration of the carrier transmission station 200 having a data transmission function by reflected wave transmission. The illustrated carrier transmission station 200 includes an antenna 201, a carrier and modulated wave transmission function unit 205, a reflected wave reception function unit 206, a communication control unit 203, and a signal processing function unit 204.

  The carrier and modulated wave transmission function unit 205 includes a baseband signal generation unit 208 that performs serial / parallel conversion and encoding of data, and an orthogonal modulation unit 207. Then, under the control from the communication control unit 203, the IQ modulation signals generated by the baseband signal generation unit 208 are converted into IQ signals by the orthogonal modulation unit 207 using the signals from the frequency synthesizer 211 that oscillates at the carrier frequency. A modulated wave equivalent to the reflected wave is generated by mapping to the signal space and performing QPSK (or BPSK) modulation. As a result, data transmission from the carrier transmission station 200 to the communication station 100 within the communication range becomes possible.

  The reflected wave reception function unit 206 includes a quadrature detection unit 209 and a data demodulation unit 210. The signal demodulation unit 210 extracts a signal of each IQ axis by performing synchronous detection using a signal from the frequency synthesizer 211, and the data demodulation unit 210 performs IQ detection. Demodulated data is extracted from transmission signal points mapped in the signal space. Thereafter, the demodulated data is passed to the signal processing function unit 204 via the communication control unit 203. Thereby, reflected wave data can be transmitted from the neighboring communication station 100 to the carrier transmission station 200.

  As described above, two-way communication is possible between all the communication stations constituting the communication system shown in FIG.

  For example, an application is conceivable in which a communication station function as shown in FIG. 2 is incorporated in a portable terminal such as a mobile phone or a digital camera, and a large-capacity storage unit such as a hard disk is provided in a carrier transmission station. In this case, it is possible to construct a backup system on the desk, such as a photographed digital photograph or an address stored in the mobile phone. In addition, when the communication station function according to the present invention is incorporated in a portable terminal, the portable terminal is not a target for a radio station in the Radio Law, and therefore, certification work such as conformity certification is unnecessary, which is beneficial in development cost.

  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 in which the present invention is applied to ad hoc communication using reflected wave transmission has been mainly described, but the gist of the present invention is not limited to this. Of course, the present invention can be similarly applied to other communication modes when direct communication is performed between communication stations that have reflectors and do not have a carrier generation source. For example, by setting one of the communication stations equipped with a reflector and having no carrier generation source as a control station and installing a carrier transmission terminal separately from this, a wireless network corresponding to the infrastructure mode can be established. Can be built.

  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 should be taken into consideration.

FIG. 1 is a diagram schematically illustrating a configuration example of a wireless communication system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration example of the communication station 100 that operates in the wireless communication system illustrated in FIG. 1. FIG. 3 is a diagram showing an internal configuration of the reflected wave reception function unit 107 in the communication station 100. FIG. 4 is a diagram schematically showing an internal configuration of a carrier transmission station 200 that supplies an unmodulated carrier for reflected wave transmission to each communication station 100 in the wireless communication system shown in FIG. FIG. 5 is a diagram illustrating an internal configuration of the carrier transmission station 200 having a data transmission function by reflected wave transmission. FIG. 6 is a diagram showing a configuration in which data communication is performed between reflectors by relaying a reflected wave reader.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Communication station 102 ... Antenna 103 ... Communication function part 104 ... Communication control part 105 ... Signal processing function part 106 ... Reflection transmission function part 107 ... Reflection wave reception function part 108 ... Quadrature detection part 109 ... Carrier reproduction circuit 110 ... Data demodulation 200: Carrier transmitting station 201 ... Antenna 202 ... Carrier transmission function unit 203 ... Communication control unit 204 ... Signal processing function unit 205 ... Carrier and modulated wave transmission function unit 206 ... 207 ... Orthogonal modulation unit 208 ... Baseband signal generation unit 209 ... Quadrature detector 210 ... Data demodulator 211 ... Frequency synthesizer

Claims (5)

A wireless communication system for performing bidirectional data communication between communication stations,
Accommodates two or more communication stations including a transmitter that sends a modulated reflected wave signal by performing modulation processing according to transmission data on the reflected wave for the received carrier, and a receiver that reads data from the modulated reflected wave signal. , Providing a carrier transmitting station for supplying a carrier to each communication station,
Within the communication range where the unmodulated carrier radiated from the carrier transmitting station and its reflected wave reach, the communication station that performs data transmission transmits data using the modulated reflected wave signal using the unmodulated carrier from the carrier transmitting station. To
A wireless communication system. The carrier transmitting station has a function of transmitting a modulated wave signal carrying data together with a transmission function of an unmodulated carrier, and a function of reading data from a modulated reflected wave signal from a communication station,
Within the communication range, the communication stations communicate directly with each other and between the carrier transmission station and the communication stations.
The wireless communication system according to claim 1. A wireless communication device that performs data communication on a reflected wave transmission line,
A reflection transmitter that receives an unmodulated carrier, performs modulation processing according to transmission data on the reflected wave, and transmits a modulated reflected wave signal;
A reflected wave receiving unit that demodulates a modulated reflected wave signal received from another communication station and reads data;
A communication control unit for controlling a communication operation on a reflected wave transmission path in the reflected transmission unit and the reflected wave receiving unit;
A signal processing unit for processing data signals transmitted and received in the reflected transmission unit and the reflected wave receiving unit;
A wireless communication apparatus comprising: A wireless communication device that operates within the wireless communication system according to claim 1,
A carrier transmitter for transmitting an unmodulated carrier;
A communication control unit for controlling a communication operation in the carrier transmission unit;
A signal processing unit for processing a signal to be transmitted in the carrier transmission unit;
A wireless communication apparatus comprising: A modulated wave transmission unit that performs modulation processing according to transmission data and transmits a modulated wave signal;
Further comprising a reflected wave receiving unit that demodulates a modulated reflected wave signal received from another communication station and reads data;
The communication control unit also controls communication operations in the modulated wave transmission unit and the reflected wave reception unit,
The signal processing unit also processes a data signal transmitted and received in the modulated wave transmitting unit and the reflected wave receiving unit.
The wireless communication apparatus according to claim 4.

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