JP2006050243A - Radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio communication equipment automatically reducing power consumption by transferring a state to a power saving state even under a condition not necessarily requiring a wide band and low latency. <P>SOLUTION: A power saving determination section 109 involves: reading the present brightness from a photosensor 108 measuring surrounding brightness at a place installing the radio communication equipment 100; and outputting a power saving transfer signal when the brightness is below a specified value, for example, m10(lx) or below. Furthermore, a power saving suspension signal is outputted to an MAC (Media Access Control) processing section 104 and an RF (Radio Frequency) amplifier 107 when illuminance from the photosensor section 108 is higher than a specified value, for example, higher than 10 (lx) while generating the power saving transfer signal. The power saving state is then released. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication device, and more particularly to a wireless communication device that performs power saving control.

  Normally, wireless devices are designed so that communication quality such as communication speed is kept constant even when the usage environment changes. Therefore, for example, the power used by the wireless device is always almost constant.

  On the other hand, for wireless devices used in environments where power consumption is strict, reduce power consumption by reducing or stopping the normal mode that operates at the normal usage speed and the operating speed of each block that makes up the wireless device. Some have a power saving mode (see Patent Document 1). Since the operation of each block is delayed when the power saving mode is entered, there are side effects that the usable bandwidth is narrowed and the response frequency (latency) to various requests / commands is increased.

As a method for switching between the normal mode and the power saving mode, there are a method of manually setting the mode and a method of switching to the normal mode when the traffic amount increases and the power saving mode when the traffic amount decreases.
JP-A-10-51400

  However, when actually using a wireless communication device, especially when using a battery-powered device, the person who operates the device operates the device in real time and requires a wide bandwidth and low latency. The person who operates the device operates in the same normal power mode, especially in a situation where the device is not operated and does not necessarily require broadband / low latency, and consumes power wastefully. There was a problem.

  Also, when saving power when traffic is reduced, the person who starts the batch process and operates the device no longer needs to operate the device, and cannot enter the power saving state even when a wide bandwidth is no longer needed. There was also a problem.

  The present invention has been proposed in view of such circumstances, and an object of the present invention is to provide a wireless communication apparatus capable of shifting to a power saving state in a situation where broadband and low latency are not required.

  The wireless communication apparatus according to the present invention has the following features in order to achieve the above-described object.

  A wireless communication device according to the present invention is a wireless communication device having a normal power consumption state and a power saving state, a sensor unit that measures brightness around the wireless communication device, and a measurement measured by the sensor unit It is determined whether or not the value is smaller than a predetermined value, and when it is determined that the brightness of the periphery of the wireless communication device is dark, a signal for shifting the wireless data communication device to a power saving state is output. And a power determination unit.

  The wireless communication device according to the present invention includes a sensor unit that senses whether a user is present around the wireless communication device in a wireless communication device having a normal power consumption state and a power saving state, and the sensor unit. A power saving determination unit that captures user presence information and outputs a signal for shifting the wireless data communication device to a power saving state when it is determined that there is no user around the wireless communication device; It is provided with.

  In the wireless communication device according to the present invention, the sensor unit captures an image around the own wireless communication device, and sends out information for determining whether a user exists around the own wireless communication device. It is a part.

  In the wireless communication apparatus according to the present invention, the sensor unit captures a change in propagation state of radio waves between the own wireless communication apparatus and a specific partner communication apparatus, and determines whether a user exists around the own wireless communication apparatus. It is a sensor unit that transmits information for determination.

  In the frequency of the GHz band used for data communication, even an obstacle such as an operator generates a multipath. Since the state of the multipath changes depending on the position and posture of the operator, it is possible to determine whether the operator exists in the vicinity without using the optical sensor unit, CCD, or the like by monitoring the propagation state.

  The wireless communication apparatus according to the present invention includes a data transmission rate variable unit between wireless communication transmission and reception, and when the power consumption determination unit determines to shift to a power saving state, the data transmission rate variable unit performs predetermined data transmission It is characterized by being set below the speed.

  The wireless communication device according to the present invention includes a bandwidth control unit that performs bandwidth control in a logical connection between the transmission and reception devices, and when the power consumption determination unit determines to shift to a power saving state, the bandwidth control unit includes the logical connection It is characterized by reducing the bandwidth of the.

  Since the wireless communication apparatus according to the present invention has the above-described configuration, the following effects can be obtained.

  According to the wireless communication apparatus of the present invention, when the periphery of the apparatus becomes darker than the predetermined brightness, it is determined that there is no user operating the apparatus, and an efficient operation for automatically reducing power consumption is performed. Is possible.

  In addition, according to the wireless communication device of the present invention, when there is no user around the device, the wireless communication device automatically operates to have the lowest possible power consumption and can be operated efficiently. .

  Embodiments of a wireless communication apparatus according to the present invention will be described below with reference to the accompanying drawings. The same components as those described above are denoted by the same reference numerals and description thereof is omitted.

<First Embodiment>
FIG. 1 is a block configuration diagram showing a first embodiment of a wireless communication apparatus according to the present invention.

  In FIG. 1, a wireless communication device 100 (a wireless device according to the present invention is, for example, a PC equipped with a wireless LAN) and an antenna 101 for transmitting and receiving radio waves and a connection destination of the antenna 101 at the time of transmission and Switch 102 that switches at the time of reception, received data processing unit 103 that demodulates the received radio wave and extracts it as data, and sends it to the MAC processing unit 104 described below, packetization of transmission data, extraction of payload from received data packet , A data transmission speed variable unit (hereinafter referred to as a MAC (Media Access Control) processing unit) 104 that arbitrates transmission / reception and actually controls a change in data rate of packet transmission / reception, a MAC processing unit 106, and a host computer A host I / F 105 for performing an interface for data transmission Yes. Furthermore, the transmission data processing unit 106 that converts the transmission data sequence created by the MAC processing unit 104 into a transmission signal, and the strength necessary for emitting the transmission signal created by the transmission data processing unit 106 from the antenna 101 RF amplifier 107 that amplifies the signal, sensor unit (hereinafter referred to as the optical sensor unit in this embodiment) 108 that measures ambient brightness, and information from the optical sensor unit 108 determines whether to enter the power saving mode. In addition, a power saving determination unit 109 that outputs a power saving signal to the RF amplifier 107 and the MAC processing unit 104 when it is determined that the surrounding brightness is a brightness that should enter the power saving mode is provided.

  Next, the operation of radio communication apparatus 100 configured as described above will be described.

  The wireless communication device 100 connects to a communication partner and exchanges data according to instructions from the host. Since this connection process is not directly related to the present invention, description of the connection process and the data transmission procedure is omitted here.

  Note that various methods can be applied to the transmission procedure, such as the IEEE 802.11 procedure. IEEE802.11 is a transmission procedure that uses a connectionless protocol to transmit data when transmission is possible without establishing a connection in advance before data transmission / reception.

  The power saving determination unit 109 reads the current brightness from the optical sensor unit 108 that measures the brightness of the surroundings where the wireless communication device 100 is installed, and saves it when it is less than a certain value, for example, 10 (lx) or less. Output power transfer signal. In this case, the power saving transition signal is not output immediately even when the value is below a certain value, and if the ambient brightness is below a certain value after waiting for a certain time, for example, 3 seconds, the power saving transition signal is output. Is output. When this power saving transition signal is generated, the wireless communication device 100 shifts to a power saving state.

Thus, by providing the delay time, a reliable power saving transition signal can be generated so as not to follow a rapid change in brightness (illuminance).
Note that the optical sensor unit may be a single element sensor such as an LED or a two-dimensional sensor such as a CCD.

  When the illuminance from the optical sensor unit 108 becomes larger than a certain value, for example, 10 (lx) while the power saving transition signal is generated, the power saving stop signal is sent to the MAC processing unit 104 and the RF amplifier 107. Output and cancel the power saving state.

  The MAC processing unit 104 operates at a full transmission / reception data rate when a power saving stop signal is output from the power saving determining unit 109. On the other hand, when a power saving transition signal is output, the transmission / reception data rate is lowered. When operating at a lower transmission data rate, the operation clock of the MAC processing unit 104 is also lowered, and the power consumption of the MAC processing unit 104 is reduced.

  Similarly, when the power saving determination unit 109 outputs a power saving stop signal, the RF amplifier 107 also transmits with the transmission power being full. When the power saving transition signal is output, the transmission power is lowered and transmitted. When the transmission power decreases, the power consumption of the RF amplifier 107 decreases.

  In this way, the power consumption of the entire apparatus can be automatically reduced by operating each block according to the flow described above.

<Second Embodiment>
FIG. 2 is a block configuration diagram showing a wireless communication apparatus according to the second embodiment of the present invention.

  Among the components shown in FIG. 1 for explaining the first embodiment described above, some of the components shown below are changed and added.

A sensor unit 208 including a lens and a CCD sensor that captures an image around the wireless communication apparatus 200 (hereinafter, referred to as an image sensor unit) 208, and image information from the image sensor unit 208 is captured, and this wireless It is determined whether there is a user or the like who handles the communication device 200, and when it is determined that there is no user who is operating and the power saving mode should be entered, the RF amplifier 107, the MAC processing unit 204, the bandwidth A power saving determination unit 209 that outputs a power saving signal to the control unit 210; a band control unit 210 that controls a band of a connection established by an instruction from the host via the host I / F according to the power saving signal; It has.
The image sensor unit 208 here may be a so-called small surveillance camera. Furthermore, as a determination algorithm for determining whether or not a user or the like is present, detection of movement used in general image processing, eye gaze detection, and the like can be given.

  Next, the power consumption control operation of the wireless communication apparatus 200 configured as described above will be described in detail.

  The wireless communication apparatus 200 connects to and establishes a connection with an access point according to an instruction from the host, and exchanges data with a communication partner via the access point. Since this connection process is not directly related to the present invention, a description of the connection process and the data exchange procedure is omitted. As this connection process, various methods can be applied. For example, a HiSWAN procedure can be applied. This HiSWAN procedure is a procedure in which a connection is established in advance prior to data transmission / reception in accordance with a protocol that uses a connection for communication, and data is transmitted / received using the connection.

  The power saving determination unit 209 reads the image information output from the image sensor unit 208, and operates this wireless communication device when determining that there is no user continuously for a certain period of time, for example, for 3 seconds or more. The power saving transition signal is output to the MAC processing unit 204, the RF amplifier 107, and the band control unit 210.

  When it is determined that there is an operator who operates for a certain period of time or longer, for example, for 3 seconds or longer, a power saving stop signal is output to the MAC processing unit 204, the RF amplifier 107, and the band control unit 210.

  When receiving the power saving transition signal, the MAC processing unit 204 operates by reducing the transmission data rate. As described in the first embodiment, when the transmission data rate is lowered and the operation is performed, the operation clock of the MAC processing unit 204 is also lowered, and the power consumption of the MAC processing unit 204 is reduced.

  In addition, when the RF amplifier 107 receives a power saving stop signal from the power saving determination unit 209, the RF amplifier 107 operates with a reduced transmission power. When the transmission power is reduced, the power consumption of the RF amplifier 107 is reduced.

  On the other hand, when a power saving stop signal is output from the power saving determining unit 209, the MAC processing unit 204 operates at full speed. The MAC processing unit 204 also operates at full power.

  In this case, the wireless communication device operates in a normal power consumption mode.

  When a power saving stop signal is output from the power saving determination unit 209, the bandwidth control unit 210 displays the permitted maximum bandwidth value via the MAC processing unit 204 on the other party's receiving side (hereinafter called the other party's reception). Request). When a power saving transition signal is output from the power saving determining unit 209, a value obtained by narrowing the band by a certain amount, for example, a half value of the permitted band is passed through the MAC processing unit 204 to the access point. To request. When the bandwidth of the connection is reduced, the data rate used for reception is reduced, so that the power consumption of the reception data processing unit 103 is reduced.

  Thus, the power consumption of the entire wireless communication apparatus can be automatically reduced by the operation of each block according to the flow described above.

<Third Embodiment>
FIG. 3 is a block diagram showing a wireless communication apparatus according to the third embodiment of the present invention.

  Among the components shown in FIG. 2 for explaining the second embodiment described above, some of the components shown below are changed.

  A reception data processing unit 303 that outputs a correlation value output signal, and a sensor unit that determines whether or not there is a user around the wireless communication device 300 based on the correlation value output signal from the reception data processing unit 303 (in this embodiment) (Hereinafter referred to as correlation sensor unit) 308 and whether or not to enter the power saving mode by determining whether to enter the power saving mode based on the information from the correlation sensor unit 308, the RF amplifier 107 and the MAC processing unit 104 And a power saving determination unit 109 that outputs a power saving signal.

  Hereinafter, the operation of the wireless communication apparatus configured as described above will be described in detail.

  This wireless device establishes a connection with an access point in accordance with an instruction from the host, and exchanges data with the communication partner via the access point. Since this connection process is not directly related to the present invention, the description of the connection process and the data exchange procedure will be omitted. As described in the first and second embodiments, various methods can be applied as the connection process.

  FIG. 4 is a schematic block diagram of the reception data processing unit 308 provided with a correlator.

  The received data processing unit 303 includes an A / D converter 401 that converts an input analog received wave into digital data, a filter 402 that removes unnecessary signals from the digital signal output from the A / D converter 401, and a filter 402 Correlator 403 for examining the value of the cross-correlation between the signal output from the signal and the preamble pattern, the demodulator 404 for extracting the data block from the output from the correlator and the output of the synchronization controller 405, and the correlation output from the correlator 403 Only the correlation value of the preamble part of the signal received from the access point using the output of the correlator 403 and the output of the demodulator 404 using the value to instruct the timing to extract data to the demodulator 404. A selection unit 406 for selecting is provided.

  FIG. 5 is a diagram illustrating an example of a data structure of a packet data signal handled by the correlator.

  Reference numeral 501 denotes a synchronization preamble arranged at the head of the signal, and 502 denotes a data part including data used for actual communication arranged immediately after the preamble 501.

  A preamble 501 having a small autocorrelation peak within a code period is used. As a result, when multipath occurs, the reception side can know the state of delay of the multipath wave. This is shown in FIG. Reference numeral 601 denotes a waveform indicating an example of an autocorrelation characteristic of a code used for the preamble. Reference numeral 602 denotes a waveform indicating an example of a signal that directly reaches the wireless communication apparatus, and reference numeral 603 denotes a waveform that indicates an example of a signal that arrives after being delayed by multipath.

  Reference numeral 604 denotes a waveform indicating an example of the output from the correlator 404 of the terminal that has received the direct wave 602 and the delayed wave 603.

  Correlation sensor section 308 determines whether or not there is a user around using the correlator output output from received data processing section 303, and outputs a signal to power saving determination section 109.

  As the determination method, for example, a change in the propagation state is determined by looking at a temporal change in the time interval at which the three outputs having the largest correlator outputs are recorded during reception of the preamble 501. Since the access point normally does not move and beacons are sent periodically, if there is a change in the correlation value of the signal received from the access point, it can be determined that the propagation situation has changed around the user, and the user can do some activity. It can be determined that

  FIG. 7 is a diagram showing an example of how the correlation value fluctuates.

Reference numeral 701 is a graph showing a change in the correlation value received at a certain time, and reference numeral 702 is a graph showing a change in the correlation value received after further elapse of time. The times when the three largest outputs are recorded are T1, T2, T3, T1 ′, T2 ′, and T3 ′. In this case, for example, since the time between T1 and T2 and the time between T1 ′ and T2 ′ have changed, it can be determined that the propagation situation has changed, and it is determined that there is a user around.
Further, in determining whether there are users in the surrounding area, it is assumed that measures are taken to reduce the probability of erroneous detection such that the user is not present.

  The power saving determination unit 209 reads a signal indicating whether or not there is a user in the vicinity from the correlation sensor unit 308, and determines that the user has not been continuous for a certain period of time, for example, 10 seconds or more. Then, it is determined that there is no person who operates this wireless communication device, and a power saving transition signal is output to the MAC processing unit 104 and the RF amplifier 107.

  On the other hand, if it is determined that there is a person who operates for a certain period of time or longer, for example, 10 seconds or longer, a power saving stop signal is output to the MAC processing unit 104 and the RF amplifier 107.

  The MAC processing unit 104 operates at the full speed when the power saving stop signal is output from the power saving determination unit 109, and decreases the transmission data rate when the power saving shift signal is output. When operating at a lower transmission data rate, the operation clock of the MAC processing unit 104 is also lowered, and the power consumption of the MAC processing unit 104 is reduced.

  The RF amplifier 107 operates at full power when a power saving stop signal is output from the power saving determination unit 109 and lowers transmission power when a power saving shift signal is output. When the transmission power is reduced, the power consumption of the RF amplifier 107 is reduced.

  In this way, the power consumption can be automatically reduced by operating each block according to the above flow.

  Note that the wireless communication apparatus of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a block block diagram which shows the radio | wireless communication apparatus which concerns on the 1st Embodiment of this invention. It is a block block diagram which shows the radio | wireless communication apparatus which concerns on the 2nd Embodiment of this invention. It is a block block diagram which shows the radio | wireless communication apparatus which concerns on the 3rd Embodiment of this invention. It is a schematic block which shows one structural example of the received data processing part 303 provided with the correlator. It is a figure which shows an example of the data structure of the packet signal handled with a correlator. It is a wave form diagram which shows an example of the multipath generate | occur | produced in a propagation path. It is a wave form diagram which shows an example of a correlator output.

Explanation of symbols

100, 200, 300 Wireless communication device 101 Antenna 102 Transmission / reception switch 103, 303 Reception data processing unit 104, 204 MAC processing unit 105, 205 Host I / F
106 Transmission data processing unit 107 RF amplifier 108 Optical sensor unit 109, 209 Power saving determination unit 208 Image sensor unit 210 Band control unit 308 Correlation sensor unit 401 A / D
402 Filter 403 Correlator 404 Demodulation 405 Synchronization 406 Selection 501 Synchronization preamble 502 Data part

Claims (7)

In a wireless communication device having a normal power consumption state and a power saving state,
A sensor unit for measuring brightness around the wireless communication device;
It is determined whether or not the measurement value measured by the sensor unit is smaller than a predetermined value, and when it is determined that the brightness around the wireless communication device is dark, the wireless data communication device is shifted to a power saving state. A power saving determination unit that outputs a signal for
A wireless communication apparatus comprising: In a wireless communication device having a normal power consumption state and a power saving state,
A sensor unit for sensing whether a user is present around the wireless communication device;
Power saving that captures user presence information from the sensor unit and outputs a signal for shifting the wireless data communication device to a power saving state when it is determined that there is no user around the wireless communication device A determination unit;
A wireless communication apparatus comprising:   The sensor unit is a sensor unit that captures an image around a local wireless communication device and transmits information for determining whether a user exists around the local wireless communication device. Item 3. The wireless communication device according to Item 2.   A sensor for transmitting information for determining whether a user exists in the vicinity of the own wireless communication device by detecting a change in propagation state of radio waves between the own wireless communication device and a specific counterpart communication device. The wireless communication apparatus according to claim 2, wherein the wireless communication apparatus is a unit. It has an RF amplifier that transmits radio waves,
5. The RF amplifier according to claim 1, wherein, when the power consumption determination unit determines to shift to a power saving state, the RF amplifier transmits by reducing transmission power to reduce power consumption. The wireless communication device according to item. It has a data transmission speed variable part between wireless communication transmission and reception,
The data transmission rate variable unit sets the data transmission rate variable unit to be equal to or lower than a predetermined data transmission rate when the power consumption determination unit determines to shift to a power saving state. A wireless communication device according to 1. A bandwidth control unit that performs bandwidth control in a logical connection between transmission and reception devices,
5. The radio according to claim 1, wherein when the power consumption determination unit determines to shift to a power saving state, the bandwidth control unit reduces the bandwidth of the logical connection. 6. Communication device.

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