JP2003047177A - Wireless communication system, mobile terminal, wireless base station, and wireless communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile terminal, which receives power supply using electromagnetic wave sent responding to a signal for demanding power, by sending the signal for demanding power according to lowering the battery voltage of the mobile terminal; a wireless base station which sends electromagnetic wave for power supply, and a wireless communication system using them, and a wireless communication method. SOLUTION: The wireless communication system, which charges a secondary battery 160 of the mobile terminal 100 using microwave for sending power sent from the wireless base station 200 to the mobile terminal 100, comprises the mobile terminal 100, which detects the battery voltage of the secondary battery 160 and sends a signal for demanding power supply and the one for demanding power supply stop to the wireless base station 200 based on the battery voltage; and the wireless base station 200, which sends a microwave for power transmission according to the signal for demanding power supply and the one for demanding power supply stop.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for supplying power using electromagnetic waves, a mobile terminal for charging by electromagnetic waves, a wireless base station for transmitting electromagnetic waves, and a wireless communication for supplying power using electromagnetic waves. It is about the method.

[0002]

2. Description of the Related Art In recent years in Japan, digital car telephone systems and PDC (Personal Digital Cel)
2. Description of the Related Art Mobile terminals in a wireless communication system such as a lural) and a PHS (Personal Handy-phone System) have become widespread. As the communication technology used in these wireless communication systems,
FDMA (Frequency Division Multiple Ac) that allocates information of each channel to different frequencies, multiplexes and transmits
cess) system and TDMA (Time Division Multiple Access) that multiplexes and transmits information of each channel in time division, and other next-generation digital wireless communication systems are also in practical use.

As another portable terminal, a portable information communication device PDA having a high performance by adding a communication function to an electronic notebook.
(Personal Digital Assistant) is available. This PDA
Is a mobile communication device using a portable modem, a mobile phone, a PHS or the like, which enables transmission and reception of e-mail.

As a power source in the above-mentioned portable terminal, a secondary battery using a lithium ion (Li ion) battery or the like has been conventionally used. Since this secondary battery has high volume energy density and weight energy density, it is extremely effective for driving the portable terminal for a long time and reducing the size and weight.

Normally, the portable terminal performs intermittent wireless communication with the wireless base station while the power is on. Intermittent wireless communication means that a mobile terminal transmits mobile terminal information such as a telephone number and position by a weak radio wave, the nearest wireless base station receives this, and the upper station always receives the mobile terminal via the wireless base station. It is to confirm the position of. Therefore, when there is a communication line connection request from a communication terminal of another network to the mobile terminal, the upper station calls the mobile terminal via the wireless base station and establishes a communication connection to perform another communication. Allows you to talk to the terminal.

[0006] The portable terminal consumes the power of the secondary battery when waiting for communication connection or making a call while the power is on. Further, the mobile terminal consumes the power of the secondary battery by displaying characters on the display unit, lighting a backlight, or operating a function such as a color liquid crystal display. Therefore, the user confirms whether or not the power of the secondary battery is present by looking at the number of bars in the graphic display in the shape of a battery showing the charge amount of the secondary battery while the power of the mobile terminal is on.

[0007] Here, for example, the user may take out the portable terminal to the place where he / she is out and the power of the secondary battery may be consumed while the user is using it. In such a case, there are measures such as using a spare secondary battery, charging with a battery pack using an AC charger, and using a battery holder using a commercially available alkaline battery.

However, when using the spare secondary battery, the user must always carry the spare secondary battery. Therefore, there is a risk of the spare secondary battery being lost or stolen, and a burden on the user such as an increase in weight. Also, AC
When charging with a battery pack using a charger, the user has to carry the AC charger with him, and also the user looks for the plug of the AC charger on the go. Further, when using a battery holder using a commercially available alkaline battery, the user carries the battery holder and uses four to six AA alkaline batteries or the like. The use of this alkaline battery is uneconomical. In addition, the user always uses the mobile terminal while paying attention to the remaining amount of the power source, which is mentally suppressed.

Therefore, as a method of charging a secondary battery for solving the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. 11-558.
There is an "electric vehicle power supply system" disclosed in Japanese Patent No. 78. This coping method is a method in which an electric vehicle receives a microwave transmitted from an artificial satellite via a ground station installed at a predetermined place, converts the microwave into electric power, and performs charging. In addition, as a method of charging a secondary battery, especially in a mobile terminal, there is a "mobile phone device" disclosed in, for example, Japanese Patent Laid-Open No. 8-149063. This is because the mobile terminal receives the microwaves transmitted from the communication satellite and converts the microwaves into electric power for charging, so that the electric power required for the call can be reached during the call as long as the radio waves from the communication satellite arrive. It is possible to replenish.

[0010]

However, in the charging method of the secondary battery such as the above "power supply system for electric vehicle", there is a problem that the electric vehicle cannot be charged unless it goes to a predetermined place. Further, in the charging method of the secondary battery in the mobile terminal such as the above-mentioned “mobile phone device”, when the mobile terminal is left without being connected to the communication line, it is not charged and power cannot be supplied. There's a problem. Further, while connected to the communication line, there is a problem that power is transmitted from the communication satellite regardless of whether or not the mobile terminal needs to transmit power.

The present invention has been made in view of the above-mentioned problems, and transmits a signal for requesting power in accordance with a decrease in battery voltage of a mobile terminal, and uses an electromagnetic wave transmitted in response to the signal for requesting power. An object of the present invention is to provide a portable terminal that receives power supply, a wireless base station that transmits an electromagnetic wave for power supply, a wireless communication system using these, and a wireless communication method.

[0012]

In order to achieve the above-mentioned object, a wireless communication system according to the present invention charges a secondary battery of a mobile terminal using an electromagnetic wave transmitted from a wireless base station to the mobile terminal. A wireless communication system for performing, detecting a battery voltage of the secondary battery, transmitting a request for transmission of the electromagnetic wave and a request to stop transmission of the electromagnetic wave to the wireless base station based on the battery voltage, and the transmission request and And a radio base station that transmits the electromagnetic wave in accordance with the transmission stop request.

With such a configuration, the portable terminal itself detects the battery voltage of the secondary battery and requests transmission of electromagnetic waves, and charges the secondary battery using the electromagnetic waves transmitted from the radio base station. This allows the user to use the mobile terminal without worrying about the amount of charge.

Also, in the wireless communication system according to the present invention, a database for registering charging information for the electromagnetic waves transmitted from the wireless base station to the mobile terminal for the charging is registered, and a request from the mobile terminal is provided. The billing information is accordingly transmitted to the mobile terminal.

According to such a configuration, the charging information for power transmission to the portable terminal is registered in the database, so that the user can extract and grasp the charging information for power transmission as desired.

Further, the portable terminal according to the present invention is a portable terminal equipped with a power converting means for converting an electromagnetic wave received from a radio base station into electric power, and charging the secondary battery with the electric power. It is characterized by comprising voltage detection means for detecting a battery voltage of a secondary battery, and control means for transmitting a transmission request and a transmission stop request for the electromagnetic wave to the radio base station based on the battery voltage. is there.

According to this structure, the portable terminal itself detects the battery voltage of the secondary battery and makes a transmission request and a transmission stop request for the electromagnetic wave, and the secondary battery is generated using the electromagnetic wave transmitted from the radio base station. By charging the mobile terminal, the mobile terminal can be charged with necessary power and can be prevented from being overcharged.

Further, the radio base station according to the present invention is provided with a power conversion means for converting the received electromagnetic wave into electric power and uses the electric power to charge the secondary battery. The electromagnetic wave is transmitted according to the transmission request and the transmission stop request of the electromagnetic wave.

According to this structure, the radio base station does not have to continuously transmit the electromagnetic wave by transmitting the electromagnetic wave in accordance with the transmission request and the transmission stop request.

A radio communication method according to the present invention is a radio communication method for charging a secondary battery of a mobile terminal using an electromagnetic wave transmitted from a radio base station to the mobile terminal, wherein the mobile terminal is The battery voltage of the secondary battery is detected, and the transmission request and the transmission stop request of the electromagnetic wave are transmitted to the wireless base station based on the battery voltage, and the wireless base station transmits the electromagnetic wave according to the transmission request and the transmission stop request. Is transmitted.

According to this structure, the portable terminal itself detects the battery voltage of the secondary battery and requests the transmission of the electromagnetic wave, and charges the secondary battery using the electromagnetic wave transmitted from the radio base station. This allows the user to use the mobile terminal without worrying about the amount of charge.

The above-mentioned power conversion means includes an antenna element for receiving an electromagnetic wave and converting it into a high frequency signal, a band limiting means for limiting the band of the high frequency signal, and a DC output for rectifying the output of the band limiting means. And a rectifying means for generating a voltage.

Further, the above-mentioned radio base station can transmit an electromagnetic wave at the timing of intermittent radio communication.

Further, the above-mentioned radio base station can transmit an electromagnetic wave during communication other than voice communication.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of the wireless communication system according to the present embodiment. As shown in FIG. 1, this wireless communication system
A mobile terminal 100, a radio base station 200 that communicates with the mobile terminal 100 in the radio zone, a network A300 that connects the radio base station 200 and a subscriber exchange described below, and a communication connection with another communication carrier are provided. Network B to enable
310, a voice storage device 230 that stores voice such as an answering machine message, a service control station 220 that manages information transmitted from the mobile terminal 100 by connecting the subscriber switching center 210 and the voice storage device 230, and a plurality of radios. Base station 2
Subscriber exchange 210 that manages 00 and subscriber exchange 2
The gateway switching center 240 which receives information from 10 and connects different networks. Here, the wireless zone indicates the range of the mobile terminal 100 that can communicate with each wireless base station 200.

Next, the operation of a normal wireless communication system will be described with reference to FIG. Here, network B
A case will be described in which a communication terminal existing in 310 makes a call to the mobile terminal 100. First, the mobile terminal 100
Becomes a standby state when the power is on. When there is a call from the communication terminal via the network B310, the gateway switching center 240 connects the network B310 to the subscriber switching center 210.

The subscriber switching center 210 calls the telephone number of the communication terminal or the portable terminal 1 of the other party by calling from the communication terminal.
The telephone number of 00 is recognized, and the recognized information is transmitted to the service control station 220. The service control station 220 confirms that the telephone numbers of the communication terminal and the mobile terminal 100 are registered, recognizes the position of the nearest wireless base station 200 where the mobile terminal 100 is present, and the recognized information. It transmits to the exchange 210. The subscriber switching center 210 receives the information from the wireless base station 20 via the network A300 according to the received information.
Connect to 0.

Next, the radio base station 200 is the mobile terminal 100.
Make a call to. When the mobile terminal 100 receives this call, it notifies the user of the incoming call by using a sound, blinking light, vibration of the vibrator, or the like. Here, when the user hooks the incoming call notification on the hook, the communication line is connected, and the call with the communication terminal existing in the network B310 becomes possible.

Next, the configurations of the radio base station 200, the subscriber switching center 210 and the service control station 220 will be described with reference to FIG. FIG. 2 is a diagram showing an example of configurations of a radio base station, a subscriber switching center, and a service control station according to the present embodiment. As shown in FIG. 2, the radio base station 200 includes a mobile communication transmitting / receiving antenna 201 and a power transmitting antenna 202. The subscriber switching center 210 is composed of a control device 211. Also, the service control station 2
20 comprises a mobile terminal information database 221 and an information management terminal device 222. In the present embodiment, the database is a mobile terminal information database (home memory function) 221 in which personal information of the user of the mobile terminal 100 is stored.

Next, the operations of the radio base station 200, the subscriber switching center 210 and the service control station 220 will be described with reference to FIG. The mobile communication transmitting / receiving antenna 201 in the radio base station 200 receives mobile terminal information transmitted as a weak radio wave from the mobile terminal 100 within the radio zone of the radio base station 200, and transmits the mobile terminal information to the subscriber exchange 210. Information from the subscriber exchange station 210 is transmitted to the mobile terminal 100 as a radio wave. The power transmission antenna 202 in the radio base station 200 is
A power supply control device (not shown) installed therein is provided and operates by turning on and off a power supply switch of the power supply control device according to an instruction from the subscriber switching center 210. When the power supply switch is ON, the microwave for power transmission is the mobile terminal 1.
00, and the power switch is OFF,
The transmission of microwaves for power transmission is stopped.

The control unit 21 in the subscriber switching center 210
1 uses the mobile terminal information received from the wireless base station 200 to perform relay, location management, subscriber connection, and the like.

The mobile terminal information database 221 in the service control station 220 writes the mobile terminal information received from the subscriber switching center 210. The mobile terminal information database 221 manages mobile terminal information of all mobile terminals, and the stored mobile terminal information includes a telephone number,
The location, contract information, usage status, billing information, presence / absence of message, e-mail address, etc. are included. For example, when the mobile terminal information database 221 receives an answering machine message from the subscriber exchange 210, the mobile terminal information database 221 transmits the message to the voice storage device 230. The service control station 2
The information management terminal device 222 of 20 is a device for an administrator of the service control station 220 to grasp mobile terminal information and provide a network service.

Next, the configuration of the portable terminal 100 is shown in FIG.
Will be explained. FIG. 3 is a diagram showing an example of the configuration of the mobile terminal according to the present embodiment. As shown in FIG. 3, the mobile terminal 100 includes a transmitting / receiving antenna 101 and a wireless unit 1.
02, the baseband signal processing unit 103, and the control unit 10
4, the input unit 105, the display unit 106, and the ringer 107.
, LED 108, vibrator 109, voice encoding unit 120, error detection unit 120a, and speaker 121.
, A microphone 122, a RAM 130, and a ROM 131
And a rectenna (Rectifying Antenna) device 140, an interface unit 150, and a secondary battery 160.

In the present embodiment, the power conversion means is the rectenna device 140, the voltage detection means is the interface section 150, and the control means is the control section 104.

Next, the operation of the mobile terminal 100 will be described. First, the operation during reception will be described. The transmitting / receiving antenna 101 receives a radio wave transmitted from the radio base station 200 and outputs it as a high frequency signal to the radio unit 102. The radio unit 102 frequency-converts the high-frequency signal into a baseband signal and outputs the baseband signal to the baseband signal processing unit 103. The baseband signal processing unit 103 demodulates the baseband signal and outputs the result to the control unit 104 as a demodulated digital audio signal.

The control unit 104 carries out the incoming call processing, and uses a preset method such as the display unit 106, the ringer 107, and the LE.
D (Light Emitting Diode) 108 and vibrator 10
9 is used to instruct the user to be notified of an incoming call. According to an instruction from the control unit 104, the display unit 106 displays, the ringer 107 emits a sound, the LED 108 blinks light, and the vibrator 109 notifies the user of an incoming call by vibration of the motor.

Further, the control section 104 outputs the demodulated digital voice signal to the voice encoding section 120. When the digital audio signal is decoded, the audio encoding unit 120 performs error correction of the digital audio signal based on the error correction code of the digital audio signal, and the error detection unit 120
Then, the encoded voice signal output from the error detection unit is expanded and digital-analog converted into an analog voice signal, which is output to the speaker 121. Speaker 121
Outputs an analog voice signal as voice to the outside.

Next, the operation during transmission will be described. The microphone 122 outputs the voice from the user to the voice encoding unit 120 as an analog voice signal. The voice coding unit 120 performs analog-digital conversion on the analog voice signal, performs voice coding processing of the digital voice signal, and error-correction-codes the coded voice signal in the error detection unit 120a and outputs the coded voice signal to the control unit 104.

The control section 104 outputs the digital audio signal to the baseband signal processing section 103. The baseband signal processing unit 103 modulates a digital audio signal,
The result is output to radio section 102 as a baseband signal. The wireless unit 102 frequency-converts the baseband signal into a high-frequency signal and outputs it to the transmitting / receiving antenna 101. The transmitting / receiving antenna 101 transmits a high frequency signal as a radio wave to the radio base station 200.

In addition to this, the control unit 104 is equipped with a clock, a timer, a timing control circuit (not shown), etc. for controlling transmission / reception, which is necessary for operating the function of the portable terminal.

A ROM (Read Only Memory) 131 stores an arithmetic processing program in the control unit 104 and a protocol for performing communication.

The input section 105 is a graphic representing a specific function,
It is provided with specific function keys for indicating outgoing and outgoing calls, and basic function keys such as numeric keys and character keys, and outputs character data and the like input by the user to the control unit 104.

When the user inputs memory dial data of a personal telephone directory, an e-mail address book, or the like to the input unit 105, the control unit 104 outputs the output of the input unit 105 to R.
Output to AM130. RAM130 (Random Access
Memory) records memory dial data of a personal telephone directory, an e-mail address book, and the like.

Under the control of the control unit 104, the display unit 106 displays a liquid crystal display (LCD: Liquid Crystal Displ) of input character data, contents of the RAM 130, communication data, and the like.
ay).

The rectenna device 140 converts the power transmission microwave received from the nearest radio base station 200 into a DC voltage and outputs it to the interface unit 150 under the control of the control unit 104.

When charging the secondary battery 160, the interface unit 150 uses the DC voltage to charge the secondary battery 160.
In addition to charging, the DC voltage supply state, the battery voltage of the secondary battery 160, and the power consumption of the secondary battery 160 are detected, and these are output to the control unit 104 as monitoring information.

On the other hand, when the power of the secondary battery 160 is consumed, the interface section 150 supplies the DC voltage charged in the secondary battery 160 to each electronic circuit in the portable terminal 100.

The control unit 104 includes an interface unit 15
According to the monitoring information from 0, control of the rectenna device 140, a power supply request for requesting the wireless base station 200 to start power supply, and a power supply stop request signal for requesting the wireless base station 200 to stop power supply. Control the transmission of. In the present embodiment, the transmission request is a power supply request, and the transmission stop request is a power supply stop request signal.

Further, the control unit 104 uses a preset notification method of charging or completion of charging of the secondary battery 160, such as the display unit 106, the ringer 107 or the LED (Ligh).
t Emitting Diode) 108 and vibrator 109 are used to instruct to notify the user. Control unit 1
According to the instruction of 04, the display unit 106 displays, the ringer 107 emits a sound, the LED 108 blinks light, and the vibrator 109 notifies the user of charging or completion of charging by rotational vibration of the motor.

Here, the rectenna device 140 will be described. FIG. 4 is a diagram illustrating an example of the configuration of the rectenna device. 4A is a block diagram showing an example of the configuration of the rectenna device, FIG. 4B is a circuit diagram showing an example of an equivalent circuit of a rectifying circuit in the rectenna device, and FIG. FIG. 4 is a diagram showing an example of a substrate that realizes a rectenna device. The rectenna device is a power conversion device that receives an electromagnetic wave transmitted from the wireless base station 200, for example, a microwave for power transmission in a microwave band of 3 GHz and converts the microwave into a DC voltage.

First, the structure of the rectenna device 140 will be described with reference to FIG. Here, each block is shown as a four-terminal circuit. As shown in FIG. 4A, the rectenna device 140 includes an antenna element 141.
An input filter 142 that is a band limiting unit, a rectifying circuit 143 that is a rectifying unit, an output circuit 144, and a switch 145. Here, the antenna element 14
1 may be a microwave receiving antenna. When the power efficiency of the antenna element 141 is improved, the antenna element 141 may be configured by a microstrip antenna, a microstrip line, a slot line, a coplanar line, or the like.

The antenna element 141 receives the microwave for power transmission transmitted from the nearest radio base station 200 and outputs it to the input filter 142 as a microwave signal. The input filter 142 removes unnecessary harmonic components while allowing the microwave signal to pass through without loss, and the rectifier circuit 14
Output to 3. Here, the input filter 142 is basically a low-pass filter, and is composed of a lumped constant, a distributed constant, and the like. Further, when unnecessary harmonics generated in the diode of the rectifier circuit 143 are re-radiated from the antenna element 141, other communication, broadcasting, etc. are affected, so that the input filter 142 is provided to block the re-radiation. Has been.

The rectifier circuit 143 rectifies the microwave signal by using a diode (non-linear circuit), smoothes the microwave signal by an output filter using a capacitor, and outputs the resulting DC voltage to the output circuit. To 144. Here, the output filter has a function of improving the RF (high frequency) / DC (direct current voltage) conversion efficiency as well as being a smoothing filter which is an original function. Further, the output filter is assumed to be composed of a line having a quarter wavelength of the frequency f and a capacitor.

For the construction of this output filter, see Reference (R. J. Gutmann et al., "Power Co").
mbining in an Array of Mi
crowave Power Rectifier
s ", IEEE Trans. Microwave T
hey and Technology, Vol. M
TT-27, No12, December 1979,
pp 958-968).

As shown in FIG. 4B, the equivalent circuit of the rectifier circuit 143 in the rectenna device 140 uses, for example, a half-wave rectifier circuit in which a diode 401 and a capacitor 402 are connected in parallel between the input terminals Ti1 and Ti2. And the rectified DC power is output terminals To1 and To2.
Is output to.

The output circuit 144 outputs a DC voltage to the interface section 150 via the switch 145. Here, the switch 145 switches between ON and OFF according to a control signal from the control unit 104. For example, when the charging of the secondary battery 160 is completed, the control unit 104 outputs a control signal for turning off the switch to the switch 145. The switch 145 is turned off,
As a result, no DC voltage is output to the interface unit 150.

Next, one embodiment of the rectenna device 140 will be described with reference to FIG. Here, the rectenna device 140 is formed on the dielectric substrate 410. The dielectric substrate 410 is composed of a pattern formation surface and a flat conductor formation surface opposite to the pattern formation surface.

A planar antenna, for example, is used as the antenna element 141. On the pattern formation surface, a receiving antenna 411 composed of a circular planar antenna, a pattern of an input filter 412 configured by using an open stub, a diode 413, and a pattern of a capacitor 414 configured by using an open stub, The output terminal 415 is formed. The anode of the diode 413 is connected to the plane conductor forming surface via the through hole.

Next, the secondary battery 16 by the portable terminal 100.
The charging process of 0 will be described with reference to FIG. Figure 5
6 is a flowchart showing an example of a charging process of a secondary battery in the mobile terminal according to the present embodiment.

First, the portable terminal 100 enters a standby state when the power is turned on in the wireless zone (S50).
1). In the standby state, the mobile terminal 100 performs intermittent wireless communication with the wireless base station 200.

In the standby state, the control unit 104 determines whether or not there is an incoming / outgoing call (S502). When there is an incoming / outgoing call (Y in S502), the control unit 104 performs the processing in the normal mode (S520), and returns to the processing S501.
Here, the normal mode is a process in which the mobile terminal 100 dials in to establish a communication connection with a communication partner, or the mobile terminal 100 receives an incoming radio wave from the wireless base station 200 to notify the incoming call. It is processing.

On the other hand, if there is no incoming or outgoing call (S502,
N), the control unit 104 continues to monitor the battery voltage of the secondary battery 160 according to the monitoring information from the interface unit 150 (S503).

FIG. 6 is a diagram showing a decrease in the battery voltage and charge amount of the secondary battery with time. The horizontal axis of FIG. 6 represents the usage time [minutes] of the mobile terminal 100, and the left vertical axis represents the secondary battery 160.
Battery voltage [V], and the right vertical axis shows a graphic display (picto display) showing the charge amount of the secondary battery 160. As shown in FIG. 6, the battery voltage and the charge amount decrease as the operating time elapses after the power is turned on. Also, when voice communication is performed, the slope of the downward-sloping curve becomes large.

The display unit 106 of the portable terminal 100 displays a pict according to the instruction of the control unit 104. Here, the charge amount of the secondary battery 160 is represented by three bars on the display unit 106 by a pictograph in the shape of a battery, and the number of bars is proportional to the charge amount of the secondary battery 160. Although the number of pictograph display bars is three here, any number may be used as long as it is three or more. The battery voltage of the secondary battery 160 may be displayed digitally.

The pictograph with one bar indicates a state called low battery, which is a caution / warning that the portable terminal 100 cannot be used. Therefore, the mobile terminal 100
Has a function of calling the user's attention by displaying a message indicating a warning and a warning sound.

The control unit 104 continues to monitor the battery voltage of the secondary battery 160 and determines whether or not there is only one pictograph bar (S504). When the number of pictograph display bars is not one (S504, N), the process returns to the process S501. on the other hand,
If there is only one pictograph bar (S504, Y),
The control unit 104 determines whether the battery voltage of the secondary battery 160 is less than or equal to a preset voltage value (S505).

Here, the set voltage value will be described. In the charging process of the present invention, it is important to determine in advance the time when charging is required. That is, the battery voltage value that does not function as a mobile terminal is not set as the set voltage value, but is set according to the power consumption for each operation such as voice call function, various setting functions, backlight lighting, and e-mail document creation. , The value of the battery voltage that requires charging is determined, and the set voltage value is determined.

Specifically, when the power consumption for each operation is arranged in ascending order, "intermittent wireless communication during standby <environment setting accompanied by lighting of backlight <e-mail document creation <transmission / reception during voice call]" is obtained. The power consumption of transmission / reception during a voice call is high mainly because transmission of a radio wave including a voice signal and modulation / demodulation processing of a digital signal are operated. Further, in recent years, the number of mobile terminals equipped with a color liquid crystal has increased, and the power consumption has increased as compared with the conventional monochrome (monochrome) liquid crystal display. Here, a method of predicting power consumption will be described by taking transmission and reception during a voice call as an example. For example, the history of the call time of the past 10 calls is stored in RAM
By recording in 130, most inclinations of power consumption during transmission and reception during a voice call can be predicted.

When the battery voltage of the secondary battery 160 is not lower than the set voltage value (S505, N), the process returns to S501.
On the other hand, when the battery voltage of the secondary battery 160 is less than or equal to the set voltage value (S505, Y), the control unit 104 causes the secondary battery 16 to operate.
When the battery voltage of 0 is low and it is determined that charging is required, automatic dial-in is performed, and a call setting signal with a power supply request added is transmitted to the nearest wireless base station 200. (S506).

Here, the automatic dial-in is not intended for making a call, but is for sending a radio wave to the service control station 220 for a request. Therefore, the called number is the telephone number with which the service function contract is signed. This service contract can be contracted at the time of purchasing a mobile terminal or by connecting to a telecommunications carrier and performing predetermined setting registration. The call setup signal includes a location registration request message and transfer capability information necessary for requesting another call connection. The location registration request message is a message type,
It consists of subscriber number and incoming service registration type.

Next, the information element of the incoming service registration type will be described. FIG. 7 is a diagram showing an example of information elements of the incoming service registration type. As shown in FIG. 7, the incoming service registration type consists of n octets, and one octet consists of 8 bits. The incoming service registration type is assigned a format type, a request type, a service type information length, a voice communication service, a packet communication service, and a spare information element. A power supply request, identification information for identifying the mobile device from among many mobile terminals existing in the wireless zone, and the like are added to the spare area.

Next, a method of adding a power supply request to the incoming service registration type will be described. In the incoming service registration type shown in FIG. 7, for example, the mobile terminal 10 is placed at the third bit position of the second octet of the spare information element.
The identification bit of the power supply request from 0 is added. Here, when the identification bit of the power supply request is 1, it indicates that the mobile terminal 100 requests the power supply. Mobile terminal 1
00 sets the identification bit of the power supply request to 1 when requesting the power supply, and transmits the call setting signal to which the power supply request is added to the nearest wireless base station 200.

Returning to FIG. 5, next, the control section 104 determines whether or not the power transmission microwave has been received from the radio base station 200 (S507). If the microwave for power transmission cannot be received (S507, N), the process returns to S506,
A call setup signal with a power supply request added is transmitted. Here, the service control station 220 that has received the call setup signal to which the power supply request has been added again via the radio base station 200 and the subscriber switching center 210, for example, transmits the microwave for power transmission first to the radio base station 200. Then, a correspondence such as transmission of a microwave for power transmission from another radio base station is determined.

On the other hand, when the power transmitting microwave is received (S507, Y), the rectenna device 140 converts the received power transmitting microwave into a DC voltage, and the interface unit 150 uses the DC voltage to recharge the secondary battery. 16 is charged (S508). While the secondary battery 160 is being charged,
The control unit 104 notifies the user that charging is in progress using a preset notification method (S509).

As a notification method during charging, for example, the display unit 10
Blinking of pictogram display in the shape of a battery in 6, display unit 1
Display by character movement in 06, display unit 1
Blinking multiple colors with 06 backlight, LED108
Blinking, a change in blinking pattern of the LED 108, color-coded notification by the LEDs 108 of a plurality of colors, ringing in the ringer 107, vibration by the vibrator 109, and the like. FIG. 8 is a diagram illustrating an example of a notification during charging. As shown in FIG. 8, the display unit 106 shows that the mobile terminal 100 receives the microwave for power transmission transmitted from the wireless base station 200, converts the received microwave for transmission into electric power, and performs charging. Shown.

Returning to FIG. 5, during charging, the control unit 10
4 determines whether charging of the secondary battery 160 has been completed (S510). Here, preset the required charge amount,
The charging may be stopped when the required charging amount is reached. When charging of the secondary battery 160 is not completed (S5
10, N), and the process returns to step S506.

On the other hand, when the charging of the secondary battery 160 is completed (S510, Y), the control unit 104 causes the rectenna device 1 to operate.
By turning off the switch 145 of 40, the DC voltage output from the rectenna device 140 is stopped, a power supply stop request signal is transmitted to the radio base station 200 (S511), and the user is notified by a preset notification method. A notification of the completion of charging is given to the terminal (S512), and this flow ends.

As a method of notifying the completion of charging, for example, the display unit 1
Blinking of a pictograph in the form of a battery in 06, display by the action of a character on the display unit 106, blinking of a plurality of colors by the backlight of the display unit 106, LED 10
8 blinking, a change in blinking pattern of the LED 108, color-coded notification by the LEDs 108 of a plurality of colors, ringing in the ringer 107, vibration by the vibrator 109, and the like.
FIG. 9 is a diagram illustrating an example of notification of completion of charging. As shown in FIG. 9, an image showing the completion of charging is displayed on the display unit 106.

At the time of completion of charging, the user can inquire billing information for power transmission. FIG. 10 is a diagram showing an example of display of charging information and charge amount. As shown in FIG. 10, the display unit 106 displays the charging information for the inquiry and the information indicating the charge amount. Information that the user can inquire is registered in the mobile terminal information database 221 of the service control station 220. Therefore, according to the user's request, the mobile terminal 100
The billing information is transmitted to.

Next, from the radio base station 200 to the portable terminal 10
The operation of supplying power to 0 will be described with reference to FIGS. 11 and 12. 11 and 12 are diagrams showing an example of a sequence for supplying power from the wireless base station to the mobile terminal.
This sequence is performed by the mobile terminal 100 and the wireless base station 200.
The content of communication between the service control station 220 and the service control station 220 is shown along the time axis. Here, as shown in FIGS. 1 and 2, communication between the radio base station 200 and the service control station 220 is performed via the subscriber switching center 210.

First, the portable terminal 100 enters a standby state when the power is turned on in the wireless zone. Mobile terminal 1
In the standby state of 00, the service control station 220
Confirms mobile terminal information such as the telephone number and position of the mobile terminal 100 via the wireless base station 200.

The mobile terminal 100 detects the detected secondary battery 16
When the battery voltage of 0 becomes equal to or lower than the set voltage value, the wireless base station 200 is requested to supply power. The mobile terminal 100 performs automatic dial-in and transmits a call setting signal added with a power supply request to the nearest wireless base station 200 (S60).
1).

Radio base station 200 that received the call setup signal
Transmits a call setting signal to the service control station 220 (S602), and also transmits a call setting acceptance signal indicating that the call setting signal has been accepted to the mobile terminal 100 (S60).
3).

Mobile terminal 100 receiving the call setting acceptance signal
Starts preparing to receive power. On the other hand, the service control station 220 performs response processing of the call setting signal, extracts a power supply request from the call setting signal, and registers a procedure for power transmission in the mobile terminal information database 221. Also, when the contract information registered in the mobile terminal information database 221 and the contract information such as flexible charging match the requested content, the service control station 200 starts power transmission to the corresponding wireless base station 200. The transmission instruction of the calling signal to be notified is transmitted (S604).

The radio base station 200 having received the call signal transmission instruction transmits a call signal to the portable terminal 100 (S6).
05). Normally, the mobile terminal 100 that receives the call signal is
Although the incoming call processing by the ring back tone (RBT) is performed, the calling signal here is not a call request.
The blinking of D108 is not performed.

Next, the radio base station 200 transmits a response signal confirming whether or not the power reception is ready to the mobile terminal 100 (S606). Mobile terminal 1 that received the response signal
00 transmits a response confirmation signal indicating completion of preparation to the radio base station 200 when the preparation for power reception is completed, and notifies that the preparation for power reception is completed (S607).

Radio base station 200 that has received the response confirmation signal
Transmits a response confirmation signal to the service control station 220 (S608). The service control station 220 confirms the response confirmation signal, and transmits a power transmission instruction for instructing the mobile terminal 100 to transmit the power transmission microwave to the wireless base station 200 (S609).

Radio base station 200 that has received the power transmission instruction
Transmits a call signal indicating the start of power transmission to mobile terminal 100 when the preparation for power transmission is completed (S610).
The mobile terminal 100 that has received the call signal starts the charging process. Next, the wireless base station 200 transmits the power transmission microwave to the mobile terminal 100 (S611). Here, the radio base station 200 transmits the microwave for power transmission, for example, at the timing of intermittent radio communication or during communication other than voice communication.

The mobile terminal 100 receiving the power transmitting microwave converts the power transmitting microwave into a DC voltage and charges the secondary battery 160. Mobile terminal 10 during charging process
0 detects the battery voltage of the secondary battery 160, and intermittently transmits a response confirmation signal including information on the charging status, operation of functions, etc. to the wireless base station 200 (S612). Upon receiving the response confirmation signal, the wireless base station 200 transmits the response confirmation signal to the service control station 220 (S613). The service control station 22 receives the response confirmation signal transmitted intermittently.
0 indicates the mobile terminal 100 continuously via the wireless base station 200.
Checks and understands information on the charging status and function operation of the.

The portable terminal 100 predicts the time of completion of charging from the amount of charge, and when the time of completion of charging approaches, it sends a power supply stop request preparation signal to the radio base station 200 (S614).

Upon receiving the power supply stop request preparation signal, the radio base station 200 notifies the service control station 220 of the power supply stop request preparation signal (S615). The service control station 220 prepares to write the power transmission status such as the usage status and billing information into the mobile terminal information database 221 and prepares the power transmission stop instruction in accordance with the power supply stop request preparation signal.

Next, when the portable terminal 100 confirms that the secondary battery 160 has been charged, it carries out charging stop processing. next,
When confirming that the charging stop process is completed, the mobile terminal 100 transmits a power supply stop request signal to the wireless base station 200 (S616).

Upon receiving the power supply stop request signal, the radio base station 200 notifies the service control station 220 of the power supply stop request signal (S617). Service control station 220
Registers the power transmission status such as the usage status and billing information in the mobile terminal information database 221 in accordance with the power supply stop request signal, and instructs the wireless base station 200 to stop the power transmission microwave transmission. Send (S6
18).

Radio base station 2 that has received the power transmission stop instruction
00 stops transmission of the microwave for electric power transmission with respect to the portable terminal 100 (S619). The mobile terminal 100 has already stopped the function of the charging process, and thereafter performs intermittent wireless communication with the wireless base station 200.

The service control station 220 sends a release signal indicating the release of control regarding this sequence to the radio base station 200.
To (S620). Upon receiving the release signal, the radio base station 200 is released from the control related to this sequence, transmits a release completion signal indicating that the release signal has been received to the service control station 220 (S621), and this sequence ends.

Radio base station 200 according to the present embodiment
Is not limited to a medium-scale or large-scale wireless base station, and a small-sized wireless base station used in PHS or a wireless base station used for wall mounting may be applied.

Further, in the present embodiment, the portable terminal 1
00 detects the battery voltage by itself and automatically makes a power supply request, but the user may make a power supply request when desired.

Further, in the present embodiment, the display unit 106 and the LED are used in the notification method during charging and the notification method of charging completion.
Although the 108, the ringer 107, the vibrator 109, and the like are used, the mobile terminal 100 may output a stimulus, a scent, or the like to the user to notify the user that charging is in progress or charging is completed. In addition, in the present embodiment, the mobile terminal 1
Although the incoming / outgoing call is not performed during charging of the secondary battery using the electromagnetic wave of 00, the outgoing / incoming call may be performed during charging of the secondary battery using the electromagnetic wave according to the user setting.

[0099]

As described in detail above, according to the present invention,
The mobile terminal itself detects the battery voltage of the secondary battery, requests power supply, and charges the secondary battery using the electromagnetic waves transmitted from the wireless base station, so that the user can determine the charge amount of the secondary battery. It can be used without worry, and since it is not necessary to carry an accessory for charging the mobile terminal when going out, an excellent effect that the agility as a mobile terminal can be enhanced is obtained. In addition, since the power is supplied using the existing wireless communication system, a large investment for configuring the power supply system is not necessary. Further, by registering the billing information for power transmission to the mobile terminal in the database, the user can extract and grasp the billing information for power transmission as desired.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a wireless communication system according to this embodiment.

FIG. 2 is a diagram showing an example of configurations of a radio base station, a subscriber switching center, and a service control station according to the present embodiment.

FIG. 3 is a diagram showing an example of a configuration of a mobile terminal according to the present embodiment.

FIG. 4 is a diagram showing an example of a configuration of a rectenna device.

FIG. 5 is a flowchart showing an example of a charging process of a secondary battery in the mobile terminal according to the present embodiment.

FIG. 6 is a diagram showing a decrease in battery voltage and charge amount of a secondary battery over time.

FIG. 7 is a diagram showing an example of an information element of an incoming service registration type.

FIG. 8 is a diagram illustrating an example of a notification during charging.

FIG. 9 is a diagram showing an example of notification of completion of charging.

FIG. 10 is a diagram showing an example of display of charging information and charge amount.

FIG. 11 is a diagram showing an example (1) of a sequence for supplying power from a wireless base station to a mobile terminal.

FIG. 12 is a diagram showing an example (2) of a sequence for supplying power from a wireless base station to a mobile terminal.

[Explanation of symbols]

100 mobile terminal, 101 transmitting / receiving antenna, 102
Radio unit 103 Baseband signal processing unit 104
Control unit, 105 input unit, 106 display unit, 107 ringer, 108 LED, 109 vibrator, 120
Speech coding unit, 120a error detection unit, 121 speaker, 122 microphone, 130 RAM, 131 RO
M, 140 rectenna device, 141 antenna element, 1
42 input filter, 143 rectifier circuit, 144 output circuit, 145 switch, 150 interface section,
160 secondary battery, 200 wireless base station, 201 mobile communication transmitting / receiving antenna, 202 power transmitting antenna,
210 subscriber exchange, 211 control device, 220 service control unit, 221 mobile terminal database (home memory function), 222 information management terminal device, 230
Voice storage device, 240 gateway exchange, 300 network A, 310 network B, 401 diode,
402 capacitor, 410 dielectric substrate, 411 receiving antenna, 412 input filter, 413 diode, 414 capacitor, 415 output terminal.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5K025 BB03 DD06                 5K067 AA21 BB04 EE02 EE10 EE16                       FF23 FF24 FF25 FF27 FF28                       KK06 KK15 LL01

Claims (5)

[Claims] 1. A wireless communication system for charging a secondary battery of a mobile terminal using an electromagnetic wave transmitted from a wireless base station to the mobile terminal, the battery voltage of the secondary battery being detected, and the battery voltage being detected. A mobile terminal for transmitting the electromagnetic wave transmission request and the transmission stop request to the wireless base station based on the above; and a wireless base station for transmitting the electromagnetic wave in accordance with the transmission request and the transmission stop request. Wireless communication system. 2. The wireless communication system according to claim 1, further comprising a database that registers charging information for the electromagnetic waves transmitted from the wireless base station to the mobile terminal for the charging, the mobile terminal A wireless communication system, wherein the charging information is transmitted to the mobile terminal in response to a request from the user. 3. A mobile terminal, comprising a power conversion means for converting an electromagnetic wave received from a wireless base station into electric power, for charging a secondary battery using the electric power, wherein the battery voltage of the secondary battery is detected. A mobile terminal, comprising: a voltage detection unit for controlling the transmission of the electromagnetic wave and a control unit for transmitting a transmission stop request for the electromagnetic wave to the wireless base station based on the battery voltage. 4. A request for transmission of the electromagnetic wave from the portable terminal and a request for stopping transmission of the electromagnetic wave to a portable terminal that includes a power conversion unit that converts the received electromagnetic wave into electric power and uses the electric power to charge the secondary battery. A radio base station which transmits the electromagnetic wave according to the above. 5. A wireless communication method for charging a secondary battery of a mobile terminal using an electromagnetic wave transmitted from a wireless base station to the mobile terminal, wherein the mobile terminal detects a battery voltage of the secondary battery. A transmission request and a transmission stop request of the electromagnetic wave are transmitted to the radio base station based on the battery voltage, and the radio base station transmits the electromagnetic wave in accordance with the transmission request and the transmission stop request. Wireless communication method.