JP2005303822A - Radio communication device and starting control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication device that reduces power consumption in a radio communication device outside a range for enabling radio communication, and can be started by automatically recognizing a movement into the range for enabling the radio communication. <P>SOLUTION: The radio communication device comprises a radio wave detection section 12 for detecting that radio waves near a frequency band in a specified radio communication system are received; a signal type determination section 13 for identifying whether the received waves have the format of the radio communication system; and a digital signal processing section 14 for processing the received waves having the format of the radio communication system. Outside the range, a radio wave detection section 12 regularly repeats activation and stop, and the signal type determination section 13 and the digital signal processing section 14 stop. When the radio wave detection section 12 detects radio waves near the frequency band in the radio communication system, the signal type determination section 13 is started. When the signal type determination section 13 identifies that the received waves have the format of the radio communication system, the digital signal processing section 14 is started. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication apparatus and an activation control method.

  In a conventional wireless communication system, when a wireless LAN terminal moves out of the wireless LAN usage range, the wireless LAN terminal starts searching for a usable base station. If not found, turn off the power. Then, when the wireless LAN terminal moves into the wireless LAN usage range, if the user turns on the wireless LAN terminal, communication is started. By repeating such a series of operations, the power consumption of the wireless LAN terminal is reduced.

  Some wireless LAN terminals continue to search for available base stations when moving outside the wireless LAN service area, but this type of wireless LAN terminal cannot reduce power consumption unless the user turns off the power. .

Also, in the conventional wireless communication system, when only the reception level detection comparison block is activated at the wireless LAN access point to detect the reception level, and when the reception level detection comparison block detects reception power of a predetermined level or higher A technique for reducing power consumption by supplying power to blocks other than the reception level detection comparison block of the wireless LAN access point so that the entire wireless LAN access point operates is known (for example, Patent Document 1).
JP 2001-156788 A

  In a conventional wireless communication system, when a wireless LAN terminal moves out of the wireless LAN service area, if it cannot be found even after searching for a base station that can be used for a predetermined period, the power is turned off, and then the wireless LAN service area In a wireless LAN terminal of a type in which the user turns on the power and starts communication when moving to the wireless LAN terminal, the user cannot be automatically notified that the wireless LAN is in use, and the user turns on the power. There is a problem that communication cannot be started unless it is inserted.

  Further, in a conventional wireless communication system, a wireless LAN terminal of a type that continues to search for a usable base station when moving outside the wireless LAN service area has a problem of wasteful power consumption unless the user turns off the power. is there.

  In the conventional wireless communication system, the wireless LAN access point reduces power consumption by activating only the reception level detection / comparison block. Is detected, regardless of the type of received radio wave, power is supplied to the wireless LAN access point. For example, the wireless LAN access point is activated due to factors other than the wireless LAN radio wave such as noise and radar. There is a problem that power is wasted.

  The present invention has been made in consideration of the above circumstances, and can reduce the power consumption of the wireless communication device outside the wireless communicable area and can automatically recognize that it has moved into the wireless communicable area and can be activated. It is an object of the present invention to provide a wireless communication device and an activation control method.

  The present invention provides a wireless communication apparatus for performing wireless communication in accordance with a specific wireless communication system, a receiving unit that receives a radio wave, and a radio wave received by the receiving unit is a radio wave having a format used in the wireless communication system. A judging means for judging whether or not there is a processing means for processing the received radio wave when the judging means judges that the received radio wave is a radio wave having the format; Recognizing means for recognizing that the wireless communication apparatus has moved out of a wireless communication range according to the wireless communication method based on a processing result, and the wireless communication apparatus has moved out of the range in the recognition means Stop means for controlling the processing means to be in a stopped state when it is recognized that the processing means is stopped. After being in the state, when the received radio wave is determined to be a radio wave having said format, and performs control to restart the processing means.

The present invention relating to the apparatus is also established as an invention relating to a method, and the present invention relating to a method is also established as an invention relating to an apparatus.
Further, the present invention relating to an apparatus or a method has a function for causing a computer to execute a procedure corresponding to the invention (or for causing a computer to function as a means corresponding to the invention, or for a computer to have a function corresponding to the invention It can also be realized as a program (for realizing the program), and can also be realized as a computer-readable recording medium on which the program is recorded.

  According to the present invention, it is possible to reduce the power consumption of the wireless communication device outside the wireless communicable area, and to automatically recognize that the wireless communication apparatus has moved into the wireless communicable area and start it up.

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

(First embodiment)
In the first embodiment, IEEE 802.11, which is one of the communication methods based on the wireless LAN system, will be described as an example. However, the present embodiment is not limited to the wireless LAN communication method based on IEEE 802.11. The present invention can be applied to all communication methods (this is the same in other embodiments in this respect).

  FIG. 1 shows a configuration example of a wireless LAN module 11 provided in a wireless communication device including a wireless LAN communication system based on IEEE 802.11 according to the present embodiment.

  FIG. 2 is a flowchart showing an operation example of the wireless communication device when the wireless communication device of the present embodiment moves from outside the wireless LAN usage area to the usage area.

  FIG. 3 illustrates a change in the activation cycle of the radio wave detection unit 12 of the wireless LAN module 11 of the wireless communication device outside the wireless LAN usage range.

  As shown in FIG. 1, the wireless LAN module 11 detects the reception of radio waves in the frequency band used in the wireless LAN communication system according to IEEE802.11 by receiving an antenna 15 for receiving radio waves, and converts it into a digital signal. A radio wave detection unit 12, a signal type determination unit 13 that analyzes whether the converted digital signal is an IEEE802.11 frame, and a digital signal processing unit 14 that performs digital control processing necessary for normal data transmission / reception. Yes. The radio wave detection unit 12 includes a radio wave detection unit internal control unit 121, and the signal type determination unit 13 includes a signal type determination unit internal control unit 131. In FIG. 1, it is assumed that the radio wave detection unit 12 is composed of one semiconductor chip, and the signal type determination unit 13 and the digital signal processing unit 14 are composed of another single semiconductor chip.

  The digital control processing necessary for performing the normal data transmission / reception includes encoding / decoding of digital signals, modulation / demodulation, MAC (Media Access Control) processing, and the like.

  When the wireless communication device according to the present embodiment moves outside the wireless LAN communication system using IEEE 802.11 (S2) while operating in the wireless LAN using area (S1), the digital signal processing unit 14 uses the IEEE 802.11. The digital signal processing unit 14 searches for a communicable radio base station or radio terminal station (S3).

  As a result, when a communicable wireless base station or terminal station is found, it is determined that the wireless LAN is in the service area (S1).

  On the other hand, if the digital signal processing unit 14 cannot find a communicable radio base station or radio terminal station (in the present embodiment, for example, it continues to search for an available base station in the prior art). ) The signal type determination unit 13 and the digital signal processing unit 14 (self) in the wireless LAN module 11 are completely stopped (S4), and the radio wave detection unit control unit 121 is instructed to cause the radio wave detection unit 12 to periodically Start (S5) (here, it is assumed that the control unit 121 in the radio wave detection unit is always started). Thus, it is detected whether radio waves in the frequency band used in the wireless LAN communication system based on IEEE802.11 are received while reducing the power consumption of the wireless LAN module 11.

  When the radio wave detection unit 12 is periodically activated (S5) and a radio wave in the frequency band used in the wireless LAN communication system according to IEEE 802.11 is received (S6), the radio wave detection unit internal control unit 121 Activates the signal type determination unit internal control unit 131, issues an activation signal to the signal type determination unit internal control unit 131 to activate the signal type determination unit 13 (S7), and further sets a timer for a predetermined time (S8). Then, in a state where the radio wave detection unit 12 and the signal type determination unit 13 are activated in order to continuously receive radio waves (S9), radio waves in the frequency band used in the wireless LAN communication system based on IEEE 802.11 are waited for. Here, the timer is assumed to be in the radio wave detection unit 12, but may be in the signal type determination unit 13, for example. The timer control is performed by the radio wave detection unit internal control unit 121, but may be performed by the signal type determination unit internal control unit 131, for example.

  In the above description, the radio wave detection unit internal control unit 121 activates the signal type determination unit internal control unit 131. However, the signal type determination unit internal control unit 131 may be activated all the time.

  When the radio wave detection unit 12 and the signal type determination unit 13 are activated (S9), when the radio wave of the frequency band used in the wireless LAN communication system according to IEEE 802.11 is received (S10), the radio wave detection unit 12 The received radio wave is converted into a digital signal, and the signal type determination unit 13 analyzes whether the digital signal is an IEEE 802.11 frame (S11). The radio wave detection unit 12 may activate the signal type determination unit 13 in response to noise or interference other than radio waves that can actually be communicated. However, the signal type determination unit 13 generates a communicable IEEE 802.11 frame. Since it is possible to determine whether or not it is received, it is possible to prevent wasteful power consumption by activating the digital signal processing unit 14 outside the use range of the wireless LAN communication system.

  As a method of analyzing whether the digital signal is an IEEE 802.11 frame in the signal type determination unit 13 (S11), for example, a method of analyzing whether the digital signal is an IEEE 802.11 frame using an OFDM preamble. Alternatively, a method of analyzing using header information of a digital signal may be used.

  If the signal type determining unit 13 determines that the frame is an IEEE802.11 frame, it is determined that the frame has been moved to the area where the wireless LAN communication system can be used, so the signal type determining unit internal control unit 131 sends a start signal to the digital signal processing unit 14. Is activated (S12), the entire wireless LAN module 11 is activated, and normal transmission / reception processing is started. That is, the state returns to the wireless LAN service area (S1).

  On the other hand, when a radio wave other than the IEEE 802.11 frame is received, the radio wave detection unit 12 and the signal type determination unit 13 are returned to the activated state (S9) and are continuously used in the wireless LAN communication system based on IEEE 802.11. Stands for radio waves in the frequency band.

  While the radio wave detection unit 12 and the signal type determination unit 13 are activated (S9), the timer set in S8 expires while waiting for radio waves in the frequency band used in the wireless LAN communication system based on IEEE 802.11 (S13). ), The radio wave detection unit internal control unit 121 outputs a signal to the signal type determination unit internal control unit 131 to stop the signal type determination unit 13 (S14) and periodically start the radio wave detection unit 12 (S5). ) To reduce the power consumption of the wireless LAN module 11.

  By the way, the activation time and activation timing of the radio wave detection unit 12 may be dynamically changed by using statistical information such as the radio wave reception status and the out-of-service movement time without periodicity.

  In the example shown in FIG. 3, for example, the activation cycle of the radio wave detection unit 12 is set to a second when moving outside the service area, and the activation cycle increases as “the number of times the radio wave detection unit 12 is activated but no radio wave is detected” increases. If the radio wave is not detected even when the activation period reaches b seconds, the activation period of the radio wave detection unit 12 may be fixed to b seconds.

  If the radio wave detection unit 12 is fixed at b seconds and no radio wave is detected even after the radio wave detection unit 12 is activated t times, the activation cycle of the radio wave detection unit 12 is set to the initial value. Returning to a seconds, the process of extending the activation cycle may be repeated according to the number of times the radio wave detection unit 12 is activated but no radio wave is detected, or the maximum activation cycle may be operated.

  In addition, instead of using the number of activations of the radio wave detection unit 12, “time elapsed after moving out of the service area” is used, and if the remaining time has not elapsed since moving out of the service area, the activation cycle of the radio wave detection unit 12 (A seconds) is shortened, and the activation cycle of the radio wave detection unit 12 is lengthened as the time outside the service area increases. When the predetermined activation cycle (b seconds) is reached, the activation cycle is further increased. You may make it not.

  In addition, when a predetermined time (t seconds) has elapsed in the maximum activation cycle (b seconds), the activation cycle is returned to the initial value (a seconds), and the activation cycle is determined according to the time elapsed after moving out of the service area. It is also possible to repeat the process of lengthening or to operate with the maximum starting cycle.

  Further, “a time during which the radio wave detection unit 12 is activated and waiting for radio waves” may be used instead of the time that has elapsed since moving out of the service area.

  In addition to the above, various methods are possible.

  As described above, according to the present embodiment, the power consumption of the wireless LAN terminal outside the wireless LAN usage area is reduced, and the movement to the wireless LAN usage area is automatically recognized to shift to the normal transmission / reception state. Can do.

  Note that when the method of the present embodiment is applied to a system including a plurality of carrier frequencies, the method of the present embodiment may be repeatedly used for a plurality of channels. As a result, a similar effect can be obtained even in a system composed of a plurality of carrier frequencies.

(Second Embodiment)
Since the second embodiment is basically the same as the first embodiment except that the radio wave detection unit of the first embodiment is modified, the following points will focus on differences from the first embodiment. explain.

  FIG. 4 shows a configuration example of a radio wave detection unit in a wireless LAN module provided in a wireless communication device provided with a wireless LAN communication system based on IEEE 802.11 according to the present embodiment.

  FIG. 5 is a flowchart showing an operation example of the wireless communication device when the wireless communication device of the present embodiment moves from outside the wireless LAN usage area to the usage area.

  In the example of FIG. 5, the steps corresponding to S7, S8, S13, and S14 of FIG. 2 are omitted as compared with the example of FIG. 2, but they may not be omitted (they may be omitted). If not, for example, a procedure corresponding to S7 and S8 may be inserted after S27 in FIG. 5, and a procedure corresponding to S13 and S14 may be inserted between S28 and before S5).

  In the present embodiment, as shown in FIG. 4, an amplifier 22 that adjusts the output of an analog signal received from an antenna, and an A / A that converts the analog signal adjusted by the amplifier 22 into a digital signal are included in the radio wave detection unit 21. The D converter 23, the output detection unit 24 that detects the digital signal output from the A / D converter, and the radio wave detection unit 21 that performs power management of the amplifier 22, the A / D converter 23, and the output detection unit 24. It includes a power supply control unit 25 that manages internal operations. However, the power supply control unit 25 has an interface with the outside of the radio wave detection unit 21, and controls the inside of the radio wave detection unit 21 from the outside via the power supply control unit 25 or outputs a control signal from the power supply control unit 25 to the outside. It is possible to make it.

  When the wireless communication device of the present embodiment moves outside the wireless LAN usage area while operating within the wireless LAN usage area, a wireless base station or a wireless terminal station that can communicate outside the wireless LAN usage area cannot be found. In the case (S21 to S23), the digital signal processing unit 14 stops (S24) the signal type determination unit 13 and the digital signal processing unit 14 (self), and causes the power control unit 25 in the radio wave detection unit 21 to do so. In response to this, the power supply control unit 25 maximizes the gain of the amplifier 22 so that reception of radio waves can be detected even with weak radio waves (S25).

  The A / D converter 23 converts the analog signal into a digital signal during normal transmission / reception processing by changing the gain of the amplifier 22 according to the power value of the received radio wave to convert it into a normal digital signal. However, weak radio wave reception can be detected by maximizing the gain of the amplifier 22 in this way (S25). Here, it is assumed that the gain of the amplifier 22 is maximized, but it is needless to say that the gain of the amplifier 22 is not limited to the maximum, as long as it is larger than the reference.

  Next, the power supply control unit 25 activates the amplifier 22, the A / D converter 23, and the output detection unit 24 in the same manner as the procedure for activating the radio wave detection unit 12 in the first embodiment (S26), and IEEE802. .11 of radio waves in the frequency band used in the wireless LAN communication system.

  When the amplifier 22, the A / D converter 23, and the output detection unit 24 are activated (S26), an output is made when determining the presence or absence of radio waves in the frequency band used in the wireless LAN communication system according to IEEE 802.11. The radio wave reception can be detected only by observing the maximum 1 bit of the digital signal output from the A / D converter 23 by the detection unit 24. Note that the number of bits observed by the output detection unit 24 is not limited to the maximum one bit. For example, a method of observing the second bit, the minimum bit, a bit near the middle, or the like may be used. An observation method may be used.

  When the output detection unit 24 detects the output of the digital signal (S27), it is determined that the radio wave of the frequency band used in the wireless LAN communication system according to IEEE 802.11 is received, and the output detection unit 24 controls the power supply. The power supply control unit 25 activates the signal type determination unit 13 in the same manner as the signal type determination unit 13 is activated from the radio wave detection unit 12 in the first embodiment (S28). The process proceeds to processing for determining whether the frame is an IEEE802.11 frame (S29).

  If it is determined in S29 that a radio wave other than the IEEE802.11 frame has been received, the process returns to the activated state of the amplifier 22, the A / D converter 23, and the output detection unit 24 (S26), and the IEEE802.11 continues. It stands by for radio waves in the frequency band used in the wireless LAN communication system.

  When receiving a radio wave other than the IEEE 802.11 frame reaches a predetermined number of times (S30), the power supply control unit 25 sets the gain of the amplifier 22 (for example, a predetermined value) as shown in FIG. Alternatively, the amplifier 22, the A / D converter 23, and the output detection unit 24 may be activated (S 26) by lowering (by an amount corresponding to the level or reduction rate) (S 31). For example, the gain of the amplifier 22 may be lowered every time a radio wave other than the IEEE 802.11 frame is received five times, and the gain may be kept constant when the gain becomes half, or the gain is lowered, for example. May be continued for several seconds and then returned to the maximum value to repeat the same operation.

  If it is determined in S29 that the radio wave of the IEEE802.11 frame has been received, it is determined that the wireless LAN communication system has been used, so an activation signal is sent from the power supply control unit 25 to the digital signal processing unit 14. Start (S32), start all wireless LAN modules, and start normal transmission / reception processing. That is, the state returns to the wireless LAN usage range (S21).

  As described above, according to the present embodiment, as in the first embodiment, the power consumption of the wireless LAN terminal outside the wireless LAN usage area is reduced, and the movement to the wireless LAN usage area is automatically recognized. It is possible to shift to a normal transmission / reception state.

  Even when the method of the present embodiment is applied to a system composed of a plurality of carrier frequencies, the method of the present embodiment may be used repeatedly for a plurality of channels. As a result, a similar effect can be obtained even in a system composed of a plurality of carrier frequencies.

(Third embodiment)
The third embodiment is basically the same as the first or second embodiment except that the wireless LAN module includes a power supply control unit. Therefore, the third embodiment is different from the first or second embodiment below. The explanation will focus on the points to be performed.

  FIG. 6 shows a configuration example of the wireless LAN module 31 provided in the wireless communication device according to the present embodiment.

  FIG. 7 is a flowchart showing an operation example of the wireless communication device when the wireless communication device of the present embodiment moves from outside the wireless LAN usage area to the usage area.

  As shown in FIG. 6, the wireless LAN module 31 includes an antenna 35 that receives radio waves, a radio wave detection unit 32, a signal type determination unit 33, a digital signal processing unit 34, a radio wave detection unit 32, a signal type determination unit 33, and a digital signal. A power control unit 36 capable of managing power management and operation of the signal processing unit 34 is provided. The radio wave detection unit 32 may take the same form as that of the first embodiment, or may take the same form as that of the second embodiment. In the former case, the power supply control unit 36 uses the first embodiment. It is possible to perform power management and operation management inside the radio wave detection unit 32 via a control unit corresponding to the control unit 121 in the radio wave detection unit of the embodiment. In the latter case, the power control unit 36 is the second embodiment. Power management and operation management inside the radio wave detection unit 32 can be performed via a control unit corresponding to the power control unit 25. In FIG. 6, the radio wave detection unit 32 is composed of one semiconductor chip, the signal type determination unit 33 and the digital signal processing unit 34 are composed of another semiconductor chip, and the power supply control unit 36 is still another semiconductor. The case where it consists of a chip is assumed.

  In the present embodiment, when the wireless communication device cannot communicate with the wireless base station or the wireless terminal station while operating in the wireless LAN usage range (S41) (S42), the digital signal processing unit 34 can communicate with the wireless base station or the wireless terminal station. A base station or a wireless terminal station is searched (S43).

  If, as a result of this search (S43), a communicable wireless base station or terminal station is found (S44), it is determined that the wireless LAN is within the service area (S41).

  On the other hand, if the digital signal processing unit 34 cannot find this as a result of searching for a communicable wireless base station or wireless terminal station, it is determined that the digital signal processing unit 34 has moved out of the wireless LAN service area, The digital signal processing unit 34 notifies the power supply control unit 36 of the movement (S45).

  Here, since the signal type determination unit 33 and the digital signal processing unit 34 do not need to be activated, the power supply control unit 36 completely stops the power supply of the signal type determination unit 33 and the digital signal processing unit 34. (S46), to reduce power consumption.

  Then, the radio wave detection unit 32 is operated using a predetermined method (for example, the method of the first embodiment or the method of the second embodiment) (S47), and is used in the wireless LAN communication system according to IEEE 802.11. The presence / absence of radio waves in a certain frequency band is determined by a predetermined method (for example, the method of the first embodiment or the method of the second embodiment).

  When operating the radio wave detection unit 32 (S47), if a radio wave in the frequency band used in the wireless LAN communication system according to IEEE 802.11 is detected, the radio wave detection unit 32 detects the radio wave in the power supply control unit 36. Is notified (S48).

  Thereafter, the power supply control unit 36 performs a procedure for starting the signal type determination unit 33 and the digital signal processing unit 34 step by step (S49).

  Here, it is assumed that the power control unit 36 manages the same operation as that of the first embodiment. Specifically, after the power supply control unit 36 receives the detection notification signals from the radio wave detection unit 32 and the signal type determination unit 33, the operation management of the radio wave detection unit 32, the signal type determination unit 33, and the digital signal processing unit 34 is performed. Do. When the activation time and the activation timing are controlled using the statistical information described in the first embodiment, the power management unit 36 also performs the operation management.

  When the signal type determination unit 33 and the digital signal processing unit 34 are configured by a system LSI including a CPU, when only the signal type determination unit 33 is operated, the clock frequency supplied to the CPU is set as the signal type determination unit. Only 33 is provided with an operable low clock, and the clock frequency supply and power supply to the digital signal processing unit 34 unnecessary for operating the signal type determination unit 33 are stopped, thereby reducing power consumption. be able to.

  As described above, according to the present embodiment, as in the first and second embodiments, the power consumption of the wireless LAN terminal outside the wireless LAN usage area is reduced and the mobile LAN usage area is moved. It can be automatically recognized and shifted to a normal transmission / reception state.

  Even when the method of the present embodiment is applied to a system composed of a plurality of carrier frequencies, the method of the present embodiment may be used repeatedly for a plurality of channels. As a result, a similar effect can be obtained even in a system composed of a plurality of carrier frequencies.

(Fourth embodiment)
The fourth embodiment is basically the same as the third embodiment and the first embodiment except that a signal type determination unit is included in the radio wave detection unit of the wireless LAN module and the wireless LAN module includes a power supply control unit. Or since it is the same as that of 2nd Embodiment, it demonstrates focusing on the point which is different from those embodiment below.

  FIG. 8 shows a configuration example of the wireless LAN module 41 of the wireless communication device provided with the wireless LAN communication system based on IEEE 802.11 according to the present embodiment.

  As shown in FIG. 8, the wireless LAN module 41 includes an antenna 45 that receives radio waves, a radio wave detection unit 42 that includes a signal type determination unit 43 therein, a digital signal processing unit 44, a radio wave detection unit 42, and a signal type determination unit. 43. A power control unit 46 capable of managing the power management and operation of the digital signal processing unit 44 is provided. In FIG. 8, the radio wave detection unit 42 including the signal type determination unit 43 is formed of one semiconductor chip, the digital signal processing unit 44 is formed of another semiconductor chip, and the power supply control unit 46 is further replaced with another type. The case where it consists of one semiconductor chip is assumed.

  The signal type determination unit 43 in the radio wave detection unit 42 is necessary for analyzing whether it is an IEEE 802.11 frame used in a wireless LAN communication system based on IEEE 802.11 as in the first embodiment. It is not necessary to include all functions necessary for demodulation of received radio waves and functions necessary for data transmission / reception that are contained in the signal type determination unit inside the digital signal processing unit. In the present embodiment, the function included in the signal type determination unit inside the radio wave detection unit 42 may be included in the digital signal processing unit 44, and the function of the signal type determination unit may be included in the digital signal processing unit 44. All the functions of the signal type determination unit may be included in the radio wave detection unit 42 without being inserted.

  In the present embodiment, as in the third embodiment, when the digital signal processing unit 44 detects that the wireless communication device has moved out of the wireless LAN service area, the digital signal processing unit 44 notifies the power control unit 46. Is done. In the power supply control unit 46, the power supply of the digital signal processing unit 44 is completely stopped to reduce the power consumption, and the radio wave including the signal type determination unit 43 inside using the method of the first or second embodiment. The detection unit 42 is operated. At this time, when performing operation management using statistical information such as detection statuses in the radio wave detection unit 42 and the signal type determination unit 43 described in the first embodiment, this is also performed by the power supply control unit 46.

  The radio wave detection unit 42 including the signal type determination unit 43 determines the presence or absence of radio waves in the frequency band used in the wireless LAN communication system according to IEEE 802.11 using the method of the first or second embodiment. When a radio wave in the frequency band used in the wireless LAN communication system according to IEEE 802.11 is detected, the signal type determination unit 43 in the radio wave detection unit 42 uses the same method as that of the first embodiment. It is determined whether a communicable IEEE 802.11 frame is received, and when it is determined that the IEEE 802.11 frame is received, the signal type determination unit 43 in the radio wave detection unit 42 receives the IEEE 802.11 frame from the power control unit 46. To be notified.

  Next, by starting the digital signal processing unit 44 from the power supply control unit 46 and shifting to the normal data transmission / reception state, it is possible to reduce power consumption.

  As described above, according to this embodiment, as in the first to third embodiments, the power consumption of the wireless LAN terminal outside the wireless LAN usage area is reduced, and the movement to the wireless LAN usage area is automatically detected. It can be recognized and shifted to a normal transmission / reception state.

  Even when the method of the present embodiment is applied to a system composed of a plurality of carrier frequencies, the method of the present embodiment may be used repeatedly for a plurality of channels. As a result, a similar effect can be obtained even in a system composed of a plurality of carrier frequencies.

(Fifth embodiment)
The fifth embodiment is the same as the previous embodiments except that the wireless LAN module includes a power control unit and each of the four units is independent. The following points are different from those embodiments. The explanation is centered.

  FIG. 9 shows a configuration example of a wireless LAN module 81 of a wireless communication device provided with a wireless LAN communication system based on IEEE 802.11 according to the present embodiment.

  As shown in FIG. 9, the wireless LAN module 81 includes an antenna 85 for receiving radio waves, a radio wave detection unit 82, a signal type determination unit 83, a digital signal processing unit 84, a radio wave detection unit 82, a signal type determination unit 83, and digital. A power control unit 86 capable of managing power management and operation of the signal processing unit 84 is provided. In FIG. 9, it is assumed that the radio wave detection unit 82, the signal type determination unit 83, the digital signal processing unit 84, and the power supply control unit 86 are made of different semiconductor chips.

  The third embodiment is different from the third embodiment in that the radio wave detection unit 82, the signal type determination unit 83, and the digital signal processing unit 84 are independent of each other and are independently controlled by the power management unit 86. Different.

  The operation method using the radio wave detection unit 82, the signal type determination unit 83, the digital signal processing unit 84, and the power management unit 86 is basically the same as that of the third embodiment. Although the radio wave detection unit 82, the signal type determination unit 83, and the digital signal processing unit 84 are independent of each other, low power consumption can be achieved by performing power control similar to that of the third embodiment.

  As described above, according to the present embodiment, as in the first to fourth embodiments, the power consumption of the wireless LAN terminal outside the wireless LAN usage area is reduced, and the movement to the wireless LAN usage area is automatically detected. It can be recognized and shifted to a normal transmission / reception state.

  Even when the method of the present embodiment is applied to a system composed of a plurality of carrier frequencies, the method of the present embodiment may be used repeatedly for a plurality of channels. As a result, a similar effect can be obtained even in a system composed of a plurality of carrier frequencies.

Each of the above functions can be realized even if it is described as software and processed by a computer having an appropriate mechanism.
The present embodiment can also be implemented as a program for causing a computer to execute a predetermined procedure, causing a computer to function as a predetermined means, or causing a computer to realize a predetermined function. In addition, the present invention can be implemented as a computer-readable recording medium that records the program.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the structural example of the radio | wireless communication apparatus used for the radio | wireless communications system which concerns on the 1st Embodiment of this invention. A flowchart showing an operation example of a wireless communication apparatus used in the wireless communication system according to the embodiment The figure for demonstrating the mode of a change of the starting period of the electromagnetic wave detection part of the radio | wireless communication apparatus outside a wireless LAN use area The figure which shows the structural example of the radio | wireless communication apparatus used for the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. A flowchart showing an operation example of a wireless communication apparatus used in the wireless communication system according to the embodiment The figure which shows the structural example of the radio | wireless communication apparatus used for the radio | wireless communications system which concerns on the 3rd Embodiment of this invention. A flowchart showing an operation example of a wireless communication apparatus used in the wireless communication system according to the embodiment The figure which shows the structural example of the radio | wireless communication apparatus used for the radio | wireless communications system which concerns on the 4th Embodiment of this invention. The figure which shows the structural example of the radio | wireless communication apparatus used for the radio | wireless communications system which concerns on the 5th Embodiment of this invention.

Explanation of symbols

  11, 31, 41, 81 ... wireless LAN module, 12, 21, 32, 42, 82 ... radio wave detection unit, 13, 33, 43, 83 ... signal type determination unit, 14, 34, 44, 84 ... digital signal processing 15, 35, 45, 85 ... antenna, 22 ... amplifier, 23 ... A / D converter, 24 ... output detection unit, 25, 36, 46, 86 ... power supply control unit, 121 ... control unit in radio wave detection unit, 131... Signal type determination unit internal control unit

Claims (9)

In a wireless communication device for performing wireless communication according to a specific wireless communication method,
A receiving means for receiving radio waves;
Determining means for determining whether the radio wave received by the receiving means is a radio wave having a format used in the wireless communication method;
Processing means for processing the received radio wave when it is determined in the determining means that the received radio wave is a radio wave having the format;
Recognizing means for recognizing that the wireless communication apparatus has moved out of a wireless communication range in accordance with the wireless communication method based on a processing result by the processing means;
Stop means for performing control for bringing the processing means to a stop state when the recognition means recognizes that the wireless communication device has moved out of the range;
The determination means performs control for restarting the processing means when it is determined that the received radio wave is a radio wave having the format after the processing means is put into a stopped state. A wireless communication device. The determination means includes
First determination means for determining whether or not radio waves in a frequency band used in the wireless communication method are received by the reception means;
Second determination means for determining whether or not the received radio wave is a radio wave having the format when the first determination means determines that the radio wave of the frequency band has been received. The wireless communication apparatus according to claim 1. The second determination unit is in a stopped state when the recognition unit recognizes that the wireless communication device has moved out of the range,
The first determination unit restarts the second determination unit when it is determined that the radio wave of the frequency band is received by the reception unit after the second determination unit is in a stopped state. Control to do
The second determination unit performs control for restarting the processing unit when it is determined that the received radio wave is a radio wave having the format after being restarted. The wireless communication apparatus according to claim 2.   The said 1st judgment means repeats a stop and restart until it is restarted after the said process means is made into the stop state, The Claim 2 or 3 characterized by the above-mentioned. Wireless communication device.   The first determination means is at least one of a usage situation after the recognition means recognizes that the wireless communication device has moved out of the range or a judgment situation by the first or second judgment means. The wireless communication apparatus according to claim 4, wherein the timing for repeating the stop and restart is dynamically changed based on statistical information related to the communication. The first determination means includes a conversion means for converting the analog signal output from the reception means into a digital signal, and the analog signal so that the power of the analog signal is optimal as an input to the conversion means. Amplifying means for amplifying the signal, third judging means for judging whether or not radio waves in the frequency band have been received by the receiving means based on a digital signal output from the converting means, and these amplifying means and converting means And control means for controlling power supply to the third judging means,
The control means sets the gain of the amplifying means to a maximum or a reference value when the recognizing means recognizes that the wireless communication apparatus has moved out of the range. Item 3. The wireless communication device according to Item 2.   It is determined in the first determining means that the radio wave in the frequency band is received by the receiving means, and the radio wave in the frequency band received by the receiving means in the second determining means is not a radio wave having the format. The wireless communication apparatus according to claim 6, wherein when the determined number reaches a predetermined number, the control unit decreases the gain of the amplification unit. In a startup control method in a wireless communication device for performing wireless communication according to a specific wireless communication method,
Processing the received radio wave having the format used in the wireless communication method by the processing means;
Control for setting the processing means to a stop state when it is recognized that the wireless communication apparatus has moved out of the wireless communication range in accordance with the wireless communication method based on the processing result by the processing means. The steps of
Determining whether the received radio wave is a radio wave having the format after the processing means is brought into a stopped state;
And a step of performing control for restarting the processing means when it is determined that the received radio wave is a radio wave having the format. In a startup control method in a wireless communication device for performing wireless communication according to a specific wireless communication method,
Processing the received radio wave having the format used in the wireless communication method by the processing means;
Control for setting the processing means to a stop state when it is recognized that the wireless communication apparatus has moved out of the wireless communication range in accordance with the wireless communication method based on the processing result by the processing means. And performing control for stopping the determination means for determining whether or not the received radio wave is a radio wave having the format, and
Determining whether or not a radio wave of a frequency band used in the wireless communication method has been received after the processing means is in a stopped state;
Performing a control for restarting the determination means when it is determined that radio waves of the frequency band have been received;
Determining by the restarted determination means whether the received radio wave is a radio wave having the format;
And a step of performing control for restarting the processing means when it is determined that the received radio wave is a radio wave having the format.

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