JP2009164924A - Communication device and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device equipped with an RFID function and a function to participate a power line communication system via electromagnetic induction communications with a predetermined coupler. <P>SOLUTION: The communication device performs two types of communications, one by a power line and the other by electromagnetic induction type RFID, and uses one and the same coil for both communications. The communication device is designed appropriate in terms of space and cost, and deterioration in performance by interference between coils can be eliminated. For a mobile phone, the mobile phone is usually used as a RFID device and therefore is controlled in such a manner that the coil is usually connected to the RFID communication section side and is connected to the power line communication modem side when so instructed by the user. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile communication device and a communication system that operate without using a commercial AC power source such as a PDA or a mobile phone, and more particularly, to a communication device having an RFID function for using an electronic money service or the like, and The present invention relates to a communication system.

  More particularly, the present invention relates to a communication apparatus and a communication system having an RFID function and a function of participating in a power line communication system through electromagnetic induction communication with a predetermined coupling device, and in particular, two electromagnetic induction methods. The present invention relates to a communication apparatus and a communication system for realizing the communication function of the above in a space-saving and low cost.

  2. Description of the Related Art A non-contact communication system called RFID (Radio Frequency IDentification) is known as a communication system in which a communication terminal that does not itself generate radio waves transmits data to a device that is a communication partner wirelessly. For example, an electromagnetic induction type RFID system includes a primary coil on the reader / writer side and a secondary coil on the card (or transponder) side, and data communication is performed via the coil by magnetic coupling of these two coils. . Specifically, the reader / writer transmits data by amplitude-modulating the magnetic field generated by the primary coil, and this is detected on the transponder side. The transponder can transmit data to the reader / writer by performing modulation processing such as amplitude modulation by load switching (LS) of the secondary coil.

  The communication method "NFC (Near Field Communication)" used in Sony's "FeliCa" and Phillips's "Mifare", which are widely used as contactless IC cards, uses 13.56MHz radio waves and is about 10cm. Two-way communication is possible at a very short distance.

  Currently, many mobile devices such as mobile phones are equipped with RFID functions, and various services are provided to make it possible to use mobile devices in place of wallets, such as prepaid electronic money, electronic coupons, and credit card functions. Has been. In stores and the like that support this type of service, a dedicated reader is prepared at the store, and by simply holding the portable device, procedures such as payment can be easily performed without handling cash. For example, proposals have been made for mobile phones equipped with electronic wallet application programs, PHS phones (PHS: Personal Handyphone System), PDA devices (PDA: Personal Digital Assistant), and notebook personal computer devices (for example, patents). (Ref. 1).

  FIG. 7 schematically shows a configuration of an electronic money system using the mobile phone 10 equipped with the RFID function. The cellular phone 10 includes a coil 11 for performing 13.56 MHz electromagnetic induction communication with the reader. When the mobile phone 10 is placed on the dedicated reader / writer 12, it receives various services.

  On the other hand, as a means for easily constructing a LAN (Local Area Network) in a building such as a home, a device having a communication function that receives power supply via a power line superimposes a communication signal on the power line, Power line communication (PLC: Power Line Communication) for performing communication with a device having a function via a power line has been put into practical use. According to the PLC, a “ubiquitous environment is realized in which the ability of a computer having the same performance can be used regardless of where the user moves. For example, in the home, various home appliances and the like are used in the home. Give the device power line communication function, and monitor and control the home devices from the parent device composed of PC, etc., and access the parent device from the outside via the public communication network, Proposals have been made on systems that monitor and control devices (see, for example, Patent Document 2).

  The PLC is basically used by a device having an AC plug that can be plugged into an AC outlet using a commercial AC power source as a main driving power source such as a desktop PC. In other words, a mobile device such as a mobile phone cannot perform power line communication in a battery-driven state that does not use commercial AC power. On the other hand, Japanese Patent Application No. 2007-308300 already assigned to the present applicant proposes a communication system in which a mobile device that operates without using a commercial AC power source can perform power line communication. Yes. In this communication system, a coupling device including a filter for attenuating an AC component of a power line and a coil for electromagnetic coupling with a coil on the mobile device side after the filter is connected to the power line. The mobile device is equipped with a power line communication modem and a coil for exchanging a power line communication signal with the outside by electromagnetic coupling, and intervenes proximity communication by electromagnetic coupling with a coil on the coupling device side. By this, you can join a friend of power line communication.

  FIG. 8 schematically shows a configuration example of a power line communication system to which the mobile phone 10 is added. Reference numeral 100 in the figure is a power line laid in the home, reference numbers 101, 106, and 200 are home outlets, reference numbers 102, 107, and 201 are AC plugs, and reference numbers 103 and 108 are shown. Is a PLC modem (where the PLC modem 103 is a master), reference numeral 109 is a host such as a personal computer (PC), reference numeral 104 is an optical line terminator, and reference numeral 105 is the Internet. Reference numeral 104 may be an ADSL (Asymmetric Digital Subscriber Line) modem.

  The PLC modem 103 and the PLC modem 108 communicate with each other via the power line 100, whereby the PC 109 can be connected to the Internet 105 via the optical line terminator 104. Since the transmission line is a power line in the PLC, the network configuration is a bus type in the existing wiring, and all communication devices in the home connected to the power line by the PLC share the bandwidth in a time-sharing manner.

  Since the mobile phone 10 is not a device that operates with a commercial AC power supply, it cannot participate in the PLC network in such a manner that an AC plug is inserted into an AC outlet. For this reason, the cellular phone 10 has a built-in coil 205 for transmitting and receiving a signal by electromagnetic coupling with a power line communication modem, and participates in the PLC network through electromagnetic coupling with the electromagnetic coupling sheet 202. Yes. The electromagnetic coupling sheet 202 includes a filter for attenuating the AC component of the power line and an electromagnetic coupling coil connected to the subsequent stage of the filter. When the coil 205 in the mobile phone 10 comes close to the electromagnetic coupling sheet 202, the electromagnetic coupling action between the coils is achieved. Occurring, the mobile phone 10 can send and receive PLC signals. Since the band used in power line communication is, for example, 2 to 30 MHz, broadband electromagnetic coupling that covers this frequency band is necessary.

  The electromagnetic coupling sheet 202 is a coil 204 for performing electromagnetic induction between a high-pass filter (HPF) 203 that cuts (or attenuates) an AC component (50 Hz to 60 Hz) from an AC line and a coil on the mobile device side. Consists of. In the above description, the coupling is based on the magnetic field between the mobile device and the electromagnetic coupling sheet. However, it is considered that the electric field is not limited.

  Accordingly, the mobile phone 10 which is a mobile device can communicate with the PLC signal via the electromagnetic coupling sheet 202, the power line 100, the PLC modem 103, and the PLC modem 108, and further, the Internet 105 via the optical line termination device 104. Or communicate with a personal computer 109 participating in the PLC network.

  As shown in FIG. 8, the mobile phone 10 is used while being placed on the electromagnetic coupling sheet 202, but the number of mobile devices placed on the electromagnetic coupling sheet 202 is not limited to one, depending on the size of the electromagnetic coupling sheet 202. A plurality of mobile devices can be placed and each can communicate with other PLC modems. In addition, as shown in FIG. 9, a plurality of mobile devices can communicate with each other via the electromagnetic coupling sheet 202.

  As described above, in order to participate in a power line communication system using a mobile device such as a mobile phone, it is necessary to equip a short-wave electromagnetic induction coil as in the case of RFID for using an electronic money service. However, it is difficult for mobile devices such as mobile phones to arrange the coils individually in order to realize these two types of electromagnetic induction type communication functions. Because of the problem of influence, it seems to be undesirable.

JP 2006-48270 A JP 2005-143026 A

  An object of the present invention is to operate without using a commercial AC power source such as a PDA or a mobile phone, and to perform power line communication through an RFID function for using an electronic money service or the like and electromagnetic induction type communication between a predetermined coupling device. An object of the present invention is to provide an excellent communication apparatus and communication system having both functions of participating in a system.

  It is a further object of the present invention to provide an excellent communication apparatus and communication system that can realize two types of electromagnetic induction communication functions at a reduced space and at a low cost.

The present invention has been made in consideration of the above problems,
A coil for electromagnetic induction;
An RFID communication unit that performs load modulation of the coil in accordance with transmission data and performs communication control by demodulating a reception signal from the coil;
A power line communication modem for exchanging power line communication signals with the outside by electromagnetic coupling using the coil;
A switching unit for switching the connection of the coil to the RFID communication unit or the power line communication modem;
Processing means for processing transmission / reception data via the RFID communication unit and the power line communication modem;
A communication device comprising:

  Currently, a mobile device such as a mobile phone often has a built-in RFID coil in order to use an electronic money service.

  On the other hand, a battery-powered mobile device that does not use a commercial AC power supply includes a modem for power line communication and a coil for transmitting and receiving a power line communication signal to and from the outside by electromagnetic coupling. By interposing proximity communication by electromagnetic coupling, it is possible to join a power line communication companion.

  However, it is disadvantageous in terms of space and cost that a mobile device incorporates a separate coil for each electromagnetic induction type communication, and there is a concern about the influence of the coils.

  On the other hand, the communication device according to the present invention has a coil for transmitting and receiving power line communication signals with an external device by electromagnetic coupling, and a coil for performing electromagnetic induction type RFID communication in common. Since one communication is performed, a design that is appropriate in terms of space and cost can be realized, and performance deterioration due to mutual influence can be eliminated by using one coil.

  The power line communication modem is connected to the power line, and electromagnetic coupling is generated between the coils when it is brought close to a coupling device including a filter for attenuating an AC component of the power line and a second coil provided at the subsequent stage of the filter. It can participate in power line communication through proximity communication by action. Specifically, in a state where the switching unit connects the coil to the power line communication modem, the power line communication modem is close to the coupling device due to the electromagnetic coupling action generated between the coils when the coil is brought close to the coupling device. Communication becomes possible, and it participates in power line communication through this.

  An example of a communication device is a mobile phone that supports electronic money services, and it is assumed that it is often used as an RFID at all times. For this reason, the switching unit is controlled to be connected to the RFID communication unit side. When the user instructs to perform power line communication, the switching unit controls to connect to the power line communication modem side. Alternatively, the switching of both communication functions may be performed by polling signals from both communication partners at certain time intervals.

  According to the present invention, power line communication is performed through an RFID function that operates without using a commercial AC power source such as a PDA or a mobile phone and uses an electronic money service and the like, and electromagnetic induction communication between a predetermined coupling device. It is possible to provide an excellent communication apparatus and communication system having both functions of participating in the system.

  In addition, according to the present invention, by using one electromagnetic induction coil for both electronic money service and power line communication, two types of electromagnetic induction communication functions can be realized in a space-saving and low-cost manner. A communication apparatus and a communication system can be provided. When coils are individually provided for each electromagnetic induction communication function, mutual influences are exerted. However, the performance deterioration can be eliminated by using one coil.

  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.

  FIG. 1 schematically shows the configuration of a mobile phone 10 with a built-in RFID. The cellular phone 10 includes an RFID unit 305 including a coil 11 for performing electromagnetic induction type RFID communication, an RFID control unit 300 for demodulating load modulation and signals from the reader / writer 12, and performing communication control, and a cellular phone unit. 301, a battery unit 302, a display unit 303, and an operation unit 304.

  When the mobile phone 10 is held over the reader / writer 12, an electromotive force is generated in the coil 11 by electromagnetic induction. When the RFID controller 300 detects this, communication by RFID starts. Since the RFID system itself is a well-known technology, detailed description thereof is omitted in this specification.

  FIG. 2 schematically shows the configuration of the mobile phone 10 that performs power line communication. As shown in FIG. 8, the cellular phone 10 can participate in the power line communication system through the coupling device 202. An OFDM (Orthogonal Frequency Division Multiplex) scheme is used as a PLC modulation scheme. As a communication standard using PLC, for example, HD-PLC (High Definition Power Line Communication) adopting the Wavelet-OFDM method is known, but the gist of the present invention is not limited to a specific communication method. .

  In FIG. 2, reference numeral 400 corresponds to the PLC modem unit, reference numeral 205 is a coil that performs electromagnetic coupling with the coil 204 of the electromagnetic coupling sheet 202, and reference numeral 301 is a mobile phone unit. The interface unit 408 between the PLC modem unit 400 and the mobile phone unit 301 is configured by serial connection or bus connection. In addition, it includes a battery unit 302, a display unit 303, and an operation unit 304.

  The PLC modem unit 400 includes a reception unit 402 and a transmission unit 403, and one coil 205 is shared for transmission and reception via the coupler 401.

  The PLC signal received by the coil 205 is amplified by the receiving unit 402 via the coupler 401 and passed to the baseband processing unit 407. In the baseband processing unit 407, the received signal is AD-converted and further subjected to OFDM demodulation to be converted into digital data.

  Also, the transmission data from the mobile phone unit 301 enters the baseband processing unit 407 via the interface unit 408, performs OFDM modulation here, performs DA conversion, and then becomes a PLC signal, which is passed to the transmission unit 403. The PLC signal amplified by the transmission unit is sent as an electromagnetic wave from the coil 205 to the coil 204 of the electromagnetic coupling sheet 202 via the coupler 401.

  The baseband processing unit 407 also performs MAC (Machine Access Control) processing such as framing, deframing, error detection, and retransmission.

  The main feature of the mobile phone 10 according to the present embodiment is that the electromagnetic induction coil portion is shared in two independent systems of RFID and power line communication.

  FIG. 3 shows a configuration of the mobile phone 10 that uses one coil for both electronic money service and power line communication. The illustrated mobile phone 10 is basically a combination of the configurations shown in FIG. 1 and FIG. 2, and the functions of the respective parts are the same. The main difference from FIG. 1 and FIG. 2 is that a switching unit 502 for switching between the case of using as an RFID and the case of using as a PLC communication is newly provided in order to use the coil 501 in common.

  It is assumed that the mobile phone 10 is often used as an RFID at all times. For this reason, the switching unit 502 is controlled by the mobile phone unit 301 so as to be connected to the RFID control unit 300 side. When the operation unit 304 instructs the user to perform PLC communication, the mobile phone unit 301 controls the switching unit 502 to be connected to the coupler 401 (that is, the PLC modem).

  Switching between the two communication functions may be performed by a user instruction or a method of polling signals from both communication partners at regular intervals.

  In this way, it is possible to use a common coil for communication by electromagnetic induction in both RFID and PLC.

  FIG. 4 shows the internal configuration of the electromagnetic coupling sheet 202. Reference numeral 203 is a high-pass filter, and reference numeral 204 is a coil. The high-pass filter 203 includes a transformer 600 and two capacitors 601, 602, and forms a balanced high-pass filter with input and output. The tips of the capacitors 601 and 602 are connected to the power line 100.

  Reference numeral 603 in the figure is the waveform of the PLC signal sent from the power line 100 side. An OFDM signal is superimposed on the AC signal. When this signal passes through the high-pass filter 203, the AC component of 50 to 60 Hz is removed and a single OFDM signal as indicated by reference numeral 604 is obtained. Further, the OFDM signal from the electromagnetic coupling sheet 602 (that is, the transmission signal from the PDA 20) passes through the high-pass filter 203 on the reverse path, is superimposed on the AC signal, and is transmitted to the PLC modem on the other side. .

  In the OFDM modulation scheme, the frequency of each carrier is set so that the subcarriers are orthogonal to each other within a symbol interval. When subcarriers are “orthogonal” to each other, the peak point of the spectrum of an arbitrary subcarrier always coincides with the zero point of the spectrum of another subcarrier, and crosstalk occurs even if adjacent subcarrier bands overlap each other. Means no. Therefore, since transmission data is distributed and transmitted to a plurality of carriers whose frequencies are orthogonal to each other, the band of each carrier becomes narrow and the frequency utilization efficiency is very high.

  FIG. 5 shows an internal configuration of the PLC modem 700. The PLC modem 103 and the PLC modem 108 in FIG. 1 correspond to this. Reference numeral 701 is an AC plug, reference numeral 402 is a power supply unit that performs rectification conversion from an AC power source to a DC power source, reference numeral 703 is a high-pass filter, reference numeral 704 is a coupling unit that combines a transmission wave and a reception wave, and reference numeral 705 is A receiving unit, reference numeral 706 is a transmitting unit, and reference numeral 707 is a baseband processing unit that performs OFDM modulation / demodulation processing and communication control. Reference numeral 708 denotes an interface unit, which performs, for example, Ethernet (registered trademark) interface processing.

  The PLC signal received by the AC plug 701 is cut from an AC power component of 50 Hz to 60 Hz by the high pass filter 703, amplified by the receiving unit 705 via the coupler 704, and passed to the baseband processing unit 707. In the baseband processing unit 707, after AD conversion, OFDM is demodulated and converted into digital data.

  Data from the Ethernet (registered trademark) side enters the baseband processing unit 707 via the interface unit 708, performs OFDM modulation here, and after DA conversion, becomes a PLC signal and is passed to the transmission unit 706. . The PLC signal amplified by the transmission unit 706 is superimposed on the AC power signal via the coupler 704 and the high-pass filter 703 and is transmitted to the power line 100 from the AC plug 701.

  The baseband processing unit 707 also performs MAC processing such as framing, deframing, error detection, and retransmission.

  Further, the PLC modem 700 requires a relationship between the master and the slave, and the user can manually switch the master / slave by a switching unit indicated by reference numeral 710. The PLC modem serving as the master station intermittently transmits a beacon signal. On the other hand, a PLC modem serving as a slave station can obtain communication availability and various types of information by looking at a beacon signal. However, the master station is useful when QoS (Quality of Service) is required, and the relationship between the master and slave is particularly meaningful when multiple PLC modems are interconnected in an autonomous and distributed manner. Absent.

  FIG. 6 shows a PLC communication procedure. In the illustrated communication procedure, a master-slave relationship is set between PLCs. PLC 1 is a master, PLC 2 is a slave, and PLC 3 is a slave.

  PLC1 transmits the beacon signal 800 intermittently. Although not shown in the figure, the beacon signal continues to be transmitted even during subsequent communication.

  When the PLC 2 receives the beacon signal, the PLC 2 transmits the entry signal 801 to the PLC 1 and receives the permission signal 802 from the PLC 1. The PLC 3 also executes the same sequence as the PLC 2 as a slave as indicated by reference numerals 803 and 804.

  When these are completed, communication can be performed at any time without connection. In other words, PLC1, PLC2, and PLC3 can communicate with each other by CSMA / CA (Carrier Sense Multiple Access with Collision Avidance) 805.

  However, the slave PLCs 2 and 3 must always receive the beacon signal of the master PLC 1.

  In the communication procedure shown in FIG. 6, the best-effort data is used. However, in an application that requires QoS such as streaming, the data communication section is controlled by the centralized control of the master PLC 1.

  As a communication standard using PLC, for example, HD-PLC (High Definition Power Line Communication) adopting the Wavelet-OFDM method is known, but the gist of the present invention is not limited to a specific communication method. .

  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 applied to a mobile device such as a mobile phone has been mainly described, but the gist of the present invention is not necessarily limited thereto. The present invention is similarly applied to various electronic devices having both an RFID function for using an electronic money service and the like and a function of participating in a power line communication system through electromagnetic induction communication with a predetermined coupling device. can do.

  Further, in the present specification, the embodiment has been described as the coupling by the magnetic field between the mobile device and the electromagnetic coupling sheet. However, since it is considered that the electric field is acting not a little, the gist of the present invention is not necessarily limited to the electromagnetic coupling. Is not to be done.

  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 showing the configuration of a mobile phone 10 with a built-in RFID. FIG. 2 is a diagram schematically showing the configuration of the mobile phone 10 that performs power line communication. FIG. 3 is a diagram showing a configuration of the mobile phone 10 that uses one coil for both electronic money service and power line communication. FIG. 4 is a diagram illustrating an internal configuration of the electromagnetic coupling sheet 202. FIG. 5 is a diagram showing an internal configuration of the PLC modem 700. FIG. 6 is a diagram showing a PLC communication procedure. FIG. 7 is a diagram schematically showing a configuration of an electronic money system using the mobile phone 10 equipped with the RFID function. FIG. 8 is a diagram schematically illustrating a configuration example of a power line communication system to which the mobile phone 10 is added. FIG. 9 is a diagram showing a state in which a plurality of mobile devices communicate with each other via the electromagnetic coupling sheet 202.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mobile phone 12 ... Reader / writer 205 ... Coil 300 ... RFID control part 301 ... Mobile phone part 302 ... Battery part 303 ... Display part 304 ... Operation part 400 ... PLC modem part 401 ... Coupler 402 ... Reception part 403 ... Transmission part 407 ... Baseband processing unit 408 ... Interface unit 501 ... Coil 502 ... Switching unit

Claims (10)

A coil for electromagnetic induction;
An RFID communication unit that performs load modulation of the coil in accordance with transmission data and performs communication control by demodulating a reception signal from the coil;
A power line communication modem for exchanging power line communication signals with the outside by electromagnetic coupling using the coil;
A switching unit for switching the connection of the coil to the RFID communication unit or the power line communication modem;
Processing means for processing transmission / reception data via the RFID communication unit and the power line communication modem;
A communication apparatus comprising: The switching unit performs connection switching of the coil to the RFID communication unit or the power line communication modem according to an instruction from a user.
The communication apparatus according to claim 1. The switching unit connects the coil to the RFID communication unit or the power line communication modem based on a result of polling a signal from each communication partner of the RFID communication unit and the power line communication modem every predetermined time. Switch,
The communication apparatus according to claim 1. In the state where the switching unit is connected the coil to the power line communication modem,
The power line communication modem is connected to the power line, and electromagnetic waves generated between the coils when approaching a coupling device including a filter for attenuating an AC component of the power line and a second coil provided at a subsequent stage of the filter. Join power line communication through proximity communication by coupling action,
The communication apparatus according to claim 1. One or more power line communication devices interconnected via a general power line supplying commercial AC power;
A first coil, an RFID communication unit that performs load modulation of the coil in accordance with transmission data and demodulates a received signal from the first coil and performs communication control; and an external device using the first coil A power line communication modem for transmitting and receiving a power line communication signal by electromagnetic coupling; a communication terminal including a switching unit for switching the connection of the first coil to the RFID communication unit or the power line communication modem;
A filter that is connected to the power line and attenuates an alternating current component of the power line; and a coupling device that includes a second coil provided in a subsequent stage of the filter;
Comprising
The communication terminal has an electromagnetic coupling action generated between the first and second coils when the switching unit is brought close to the coupling device in a state where the first coil is connected to the power line communication modem. Communicate with each other through proximity communication by
A communication system characterized by the above. The switching unit switches the connection of the first coil to the RFID communication unit or the power line communication modem according to an instruction from a user.
The communication system according to claim 5. The switching unit is configured to connect the first coil to the RFID communication unit or the power line communication based on a result of polling a signal from each communication partner of the RFID communication unit and the power line communication modem every predetermined time. Switch connection to modem
The communication system according to claim 5. The coupling device comprises:
Means for connecting to the power line;
A filter that attenuates the AC component of the power line;
A coil provided downstream of the filter;
Comprising
The communication system according to claim 5. The filter is a high-pass filter that cuts AC components of 50 Hz to 60 Hz.
The communication system according to claim 8. The filter is a high-pass filter composed of a transformer having one end connected to the coil and the other end connected to a power line through a pair of capacitors.
The communication system according to claim 8.