JP3875244B2 - Radio communication circuit, radio communication device, radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus capable of ensuring energy saving and long continuous communication time, and to provide a module to be built-in. <P>SOLUTION: The wireless communication apparatus comprises a transmission power amplifier 9 for amplifying a transmission signal transmitted from an antenna 1, a bypass route 22 for bypassing the signal route of the power amplifier 9, and each switch 23, 24 that is controlled, on the basis of the strength of a received signal so as to alternatively switch between the transmission power amplifier 9 and the bypass route 22. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention is connected to a personal computer, an ADSL (Asymmetric Digital Subscriber Line) modem, an information terminal device such as a wireless access point or a wireless router, or a consumer AV device such as a TV or a DVD, and uses a spread spectrum technology. The present invention relates to a wireless communication circuit suitable for a card-type wireless communication device having a wireless communication function using a DS (Direct Spread) system, a wireless communication device having the same, and a wireless communication system using the wireless communication circuit.

  First, spread spectrum radio will be described below. In general, in communication using spread spectrum technology, a modulated signal obtained by modulating an input baseband signal such as voice on the transmission side is spread spectrum using a spreading code, and then transmitted to a communication partner as a high frequency signal. Sent. On the receiving side, the spread spectrum signal received from the communication partner side is demodulated (despread) using the same spreading code as that on the transmitting side.

  Communication methods using spread spectrum technology include a direct spread method and a frequency hopping method. In the direct spreading method, spreading is performed while multiplying a narrowband modulated wave by a spreading code, and a certain continuous frequency band is uniformly used. On the other hand, the frequency hopping method is a spreading code that spreads a signal within a frequency band by randomly switching the frequency of a carrier wave when communicating with a communication partner. For example, Bluetooth (registered trademark) Etc.

  A conventional card type wireless communication device will be described below. FIG. 21 is a block circuit diagram showing a schematic configuration of a conventional card-type wireless communication apparatus. The conventional card type wireless communication device 50 of FIG. 21 has the following circuit configuration. The antenna 51 is connected to the receiving circuit unit 52 and the transmitting circuit unit 57, respectively.

  The reception circuit unit 52 includes an amplifier 53, a mixer circuit 54, and a demodulation circuit 55. The antenna 51 is connected to the baseband signal processing circuit unit 61 via the amplifier 53, the mixer circuit 54, and the demodulation circuit 55.

  The transmission circuit unit 57 includes a modulation circuit 60, a mixer circuit 59, and an amplifier 58. The baseband signal processing circuit unit 61 is connected to the antenna 51 through the modulation circuit 60, the mixer circuit 59, and the amplifier 58. Yes. A local oscillator 56 is connected to the mixer circuit 54 and the mixer circuit 59.

  The baseband signal processing circuit unit 61 is connected to the connector 65 via the interface circuit unit 62. Further, each of the reception circuit unit 52, the transmission circuit unit 57, and the baseband signal processing circuit unit 61 includes a circuit. A control unit 63 is connected. The power supply unit 64 is connected to the above-described circuits of the connector 65 and the card type wireless communication device 50.

  Next, the operation of the conventional card type wireless communication device 50 of FIG. 21 will be described. On the receiving side, the spread spectrum signal (for example, 2.4 GHz band) received from the communication partner side by the antenna 51 is amplified by the amplifier 53 and applied to the mixer circuit 54. The spread spectrum signal as a reception high-frequency signal is demodulated into a baseband signal by the mixer circuit 54 and the demodulation circuit 55, necessary signal processing is performed by the baseband signal processing circuit unit 61, and a connector is connected via the interface circuit unit 62. From 65, the data is output to an information terminal device such as a personal computer (not shown).

  On the transmission side, a data input signal input from an information terminal device such as a personal computer (not shown) through the connector 65 and the interface circuit unit 62 is subjected to necessary signal processing by the baseband signal processing circuit unit 61 and modulated. The signal is spread into a spread spectrum signal (for example, 2.4 GHz band) by the circuit 60 and the mixer circuit 59, then amplified by the amplifier 58, and transmitted from the antenna 51 to the communication partner side.

  The circuit control unit 63 controls the operations of the reception circuit unit 52, the transmission circuit unit 57, and the baseband signal processing circuit unit 61, and the power supply unit 64 is connected from an information terminal device such as a personal computer (not shown) to the connector. The power supplied through 65 is input, and the power + B is supplied to each circuit in the card type wireless communication device 50.

  The local oscillator 56 generates a frequency signal (for example, 2.4 GHz) necessary for each of the mixer circuits 54 and 59 to operate.

  Regarding the control of the RF signal of the radio unit, various communication devices modulate / demodulate signals having different frequencies and levels by frequency conversion, and therefore stable modulation / demodulation characteristics are required.

  At that time, one of the most important factors is called an input dynamic range. This is an index indicating how much a weak input signal to a strong input signal can be stably received and demodulated.

  This dynamic range is determined mainly by parameters such as a transmission (high frequency) power value, reception sensitivity, and distortion characteristics in a wireless communication apparatus including a transmission / reception circuit.

  As one method for widening the communicable area, conventionally, when the distance between the master unit and the slave unit is short, an attenuator circuit in the input stage of the receiver is used, or a GAIN such as a low noise amplifier or IF amplifier is used. By reducing (gain), the distortion characteristic for a strong input signal is not deteriorated (see Patent Document 1).

  FIG. 22 shows a block diagram of this conventional example. In FIG. 22, an attenuator circuit (RF ATT) 90 is provided between an input terminal 71 for a high frequency input signal and a high frequency amplifier 78, and is composed of PIN diodes 91, 92, 93 that can be used in a high frequency band.

  In this example, the diodes 91, 92, and 93 provided in the π-type are switched between switching to a high-frequency attenuator and switching to a through state by a switching signal from a terminal 77 that turns on / off according to the strength of the high-frequency input signal. ing.

In FIG. 22, a high frequency bandpass filter (RFBPF) 79, a mixer (MIXER) 80, a first voltage controlled oscillator (VCD1) 81, a first intermediate frequency amplifier (IFAMP) 82, an intermediate frequency bandpass. A filter 83, a second intermediate frequency amplifier 84, an FM detector (FMDET) 85, a second voltage controlled oscillator 86, and an output terminal 87 for outputting a detection signal are provided. Since these are conventionally known circuits, their description is omitted. Further, the attenuator circuit 90 shown in FIG. 22 may be arranged between the RF amplifier 78 and the RFBPF 79 or the mixer 80.
Japanese Utility Model Publication No. 4-116440 (publication date: October 19, 1992)

  However, in the prior art shown in FIG. 21, the power is supplied to the power supply unit 64 of the card-type wireless communication device 50 from an information terminal device such as a personal computer (not shown) via the connector 65. When the information terminal device such as is using a commercial power source, no particular problem occurs.

  However, when an information terminal device such as a personal computer is carried and used, the information terminal device such as a personal computer operates using a battery built in the main body as a power source, and the power supply unit 64 of the card-type wireless communication device 50. The power is supplied from the battery built in the main body of the information terminal device such as a personal computer through the connector 65.

  Accordingly, as the power consumed by the card-type wireless communication device 50 increases, the battery built in the main body of the information terminal device such as a personal computer is quickly consumed, and the information terminal device such as the personal computer can be carried and used. There was a problem of shortening the time.

  The present invention has been made in order to solve the above-described problems, and provides a wireless communication circuit capable of performing good communication with low power consumption both in itself and others, or for receiving received high-frequency signals. A card-type radio communication apparatus and a radio communication system using the card-type radio communication apparatus which achieve low power consumption by independently controlling on / off of the power supply of each circuit unit constituting the card-type radio communication apparatus according to the level The purpose is to provide.

(1) A wireless communication circuit according to a reference example of the present invention is a wireless communication circuit for an information transmission / reception terminal or a device-embedded module for solving the above-described problem, and is connected to an antenna and an antenna. an amplifier that includes a bypass route for bypassing the signal path of the amplifier, and a first switch for switching alternatively the signal path and the bypass route of the amplifier.

  Therefore, in the above configuration, when the bypass route is selected, the power consumption of an amplifier such as a normal “power amplifier” can be reduced as it is.

  For example, in a current wireless LAN card (wireless communication apparatus) compliant with the IEEE 802.11b standard, the power consumption of the power amplifier accounts for about one third of the power consumption of the entire card. Therefore, in an environment where the distance from the base unit is closer than the threshold value, the power consumption can be reduced to two-thirds of the conventional value. Therefore, the battery drive using the wireless communication device provided with the wireless communication circuit of the present invention is possible. It is possible to improve the duration of communication of portable transmission / reception terminals (notebook personal computers, PDAs, mobile phones, etc.), and to save energy.

Further, by using a wireless communication circuit having a control unit for the wireless communication device, the duration of communicable communication can be improved in the wireless communication device, and an energy saving design can be achieved.
(2) In the above wireless communication circuit, it is desirable that the control means controls the switching of the first switch based on the signal strength of the received signal.

Therefore, it is possible to accurately determine the distance between the wireless communication, can be accurately switched to the bypass route when the distance is short, to improve the duration of communicable, and while saving energy, Wireless communication can be ensured.
(3) In the wireless communication circuit, the control means includes a generation unit that generates a first control signal for controlling switching of the first switch from a received signal strength index value (RSSI) as a signal strength of the received signal. It is preferable.

Thereby, the circuit configuration can be simplified by using RSSI that is usually provided in a digital signal processing circuit such as a baseband signal processing circuit unit.
(4) The wireless communication circuit further includes a second switch for connecting / disconnecting power to the amplifier, and the control means generates a second control signal for controlling the second switch in cooperation with the first switch. It is desirable to have a control unit that does this.

As a result, when the bypass route is selected, the power supply to the amplifier can also be cut off by the second switch, so that the energy saving and communication duration can be improved.
(5) The wireless communication circuit may include a fixed attenuator in the bypass route. In the wireless communication circuit, a variable attenuator may be provided in the bypass route.

  As a result, “improvement of battery duration” and “energy-saving design” are applied as they are, and the route through which a signal passes through a fixed attenuator or a variable attenuator is close enough to the main unit. When selected, if the reception sensitivity deteriorates due to the distortion characteristics because the distance to the base unit is too close, the distortion characteristics are improved by the attenuation amount of the attenuator. As a result, the reach distance (range) on the closest distance side is reduced. Can be expanded. In addition, when a variable attenuator is provided, for example, when there is a possibility of communication while being carried, such as a PDA or a mobile phone, the distance to the parent device changes in real time, which is more effective.

In addition, even when a large number of wireless communication devices communicate simultaneously within a specific area, such as a wireless LAN, the communication partner can be brought into close range by providing a fixed or variable attenuator in the bypass route. In some cases, it is possible to reduce the output of each other's transmission signals and further occupy the communication band of another wireless communication device or cause a failure.
(6) In the wireless communication circuit, the amplifier may be a power amplifier that amplifies a transmission signal to be sent to the antenna. In the wireless communication circuit, the amplifier may be a low noise amplifier that amplifies a reception signal from the antenna. As a result, the effects of “improvement of battery duration” and “energy-saving design” can be exhibited. In particular, in the case of a power amplifier, the above-described effects can be exhibited remarkably and reliably.
(7) A circuit for wireless communication according to the present invention is a circuit for wireless communication having an amplifier for amplifying a signal in order to solve the above problem, and an amplification route through which the signal passes through the amplifier, Ru Tei provided alternatively selected route selection means either a bypass route for bypassing the amplifier.

  One of the objects of the present invention is to provide a wireless communication circuit capable of performing good communication with low power consumption both by itself and others, and according to the above configuration, it is better to amplify a signal. When transmission or reception is possible, the amplification route can be selected by route selection means.

In addition, if the signal is not amplified, distortion that occurs in the signal is not suppressed or other communication devices are not disturbed. A route can be selected. In this case, since no amplifier is used, the power consumption of the wireless communication circuit can be suppressed.
(8) It is preferable that the route selection means selects either the amplification route or the bypass route according to the strength of the signal received by the wireless communication circuit.

This makes it possible to switch between the amplification route and the bypass route according to the signal strength that changes every moment depending on the communication distance and communication environment. Therefore, the power consumption state of the wireless communication circuit can be changed according to the communication distance and communication environment.
(9) It is preferable that the route selection means selects a bypass route when the intensity of the received signal exceeds a preset threshold value or exceeds a threshold value.

As a result, when the intensity of the received signal exceeds or exceeds the preset threshold, it is not necessary to amplify the intensity of the received signal. Good communication can be performed.
(10) The route selection unit determines whether the communication state of the wireless communication circuit is good or not, and generates a first control signal for selecting either the amplification route or the bypass route based on the determination result. It is preferable to provide a control means.

According to the above configuration, since various factors are related to the quality of the communication state, it is possible to switch between the amplification route and the bypass route in consideration of the various factors. That is, the power consumption can be controlled finely in various forms.
(11) The route selection unit determines whether the communication state of the wireless communication circuit is good or not, and generates a first control signal for selecting either the amplification route or the bypass route based on the determination result. Provided with a control means, the control means, when it is determined that the communication state is good even when the strength of the signal received by the circuit for wireless communication is below a preset threshold value or below a threshold value, A first control signal for selecting a bypass route is generated.

According to said structure, when the intensity | strength of the signal received with the said circuit for radio | wireless communication is less than a preset threshold value or below a threshold value, since the received signal is weak, the case where it should be amplified is included. However, even if the received signal is weak, there is no problem as long as the communication state is good. Therefore, not only the strength of the received signal is determined, but also the effectiveness of the low power consumption control can be improved by determining whether the communication state is good or bad.
(12) The route selection means determines whether or not the communication state of the wireless communication circuit is good, and generates control signals for selecting either the amplification route or the bypass route based on the determination result. And when the signal strength received by the circuit for wireless communication exceeds a preset threshold or is equal to or greater than a threshold, the control means determines that the communication status is poor and A first control signal for selecting is generated.

According to said structure, when the intensity | strength of the signal received with the said circuit for radio | wireless communication exceeds the preset threshold value or more than a threshold value, the case where it is not necessary to amplify because the received signal is strong is included. Yes. However, even if the received signal is strong, good communication cannot be performed if the communication state is bad. Therefore, not only the strength of the received signal is determined, but also the reliability of communication can be improved while considering low power consumption by adding a pass / fail determination of the communication state.
(13) When the control means determines that the communication state is good,
(a) When the control means analyzes the contents of the information signal received from the other communication device and determines that it is ack (appropriate reception confirmation)
(b) When the control means detects the error level of the received data generated from the signal received by the wireless communication circuit, and the detected error level does not exceed the threshold value
(c) When the reception status of the received data generated from the signal received by the wireless communication circuit matches the content notified by the communication device of the communication partner prior to the reception of the signal
(d) The control means acquires time information for executing an application related to the received data from the received data generated from the signal received by the wireless communication circuit, and obtains the reception time of the signal and the time information. When comparing and determining that the received data of the above signal is in time for the time to execute the application
(e) When the error resilience tool provided in the application that uses the received data generated from the signal received by the wireless communication circuit does not work
(f) The case where the reception data generated from the signal received by the wireless communication circuit is streaming data, and the wireless communication circuit includes a reception buffer for temporarily storing the reception data, and the control Means receives information on the bit rate of the received data and the buffer size required to temporarily store the received data from the communication device transmitting the received data, and stores the received data in the receive buffer; Is obtained from the bit rate and the buffer size, and the buffering time t ′ required to actually store the received data in the receiving buffer is compared with the buffer full time t. As a result, t ′ ≦ t If the relationship is established
(g) A case where a communication device including the wireless communication circuit performs two-way communication with a communication device of a communication partner, and reception data generated from a signal received by the wireless communication circuit is continuously decoded. Various cases are included, such as the case where it is done.

  Therefore, if the application using the received data generated from the signal received by the wireless communication circuit is monitored from various viewpoints and the application is executed properly, the bypass route is set. The used low power consumption mode can be selected. Furthermore, the effectiveness of the low power consumption control can be improved by adding the strength determination of the received signal to the quality determination of the communication state.

  (h) Note that, when the reception buffer becomes empty during reception of the reception data, the control means may determine that the communication state is bad.

In this case, when the reception buffer becomes empty during reception of reception data, a failure occurs in reception of reception data. Therefore, as a measure that can be taken by the communication device on the receiving side, it is preferable to select an amplification route and attempt to amplify the received signal.
(14) Further, regarding the various cases (a) to (h), a threshold is set for the number of times that the control means determines that the communication state is not good, and the number of times falls below or below the threshold. In this case, the control means may determine that the communication state is good.

As a result, the threshold setting may be changed depending on how much communication reliability should be ensured, so that flexible low power consumption control considering the degree of communication reliability is possible.
(15) Further, a radio communication circuit of the present invention, the route selection means cooperates to selecting the bypass route, be provided with a power-off means for turning off the power supply to the amplifier Good .

According to the above configuration, the power selection unit turns off the power supply to the amplifier in cooperation with the route selection unit selecting the bypass route, thereby further reducing power consumption, for example, sustaining the built-in battery. You can extend the time. In addition, the effect of eliminating the risk of noise entering the bypass route from the amplification route can be obtained.
(16) A wireless communication circuit according to a reference example of the present invention, in order to solve the above problems, in a wireless communication circuit having an amplifier that amplifies a signal, a communication distance detection unit that detects a distance to a communication partner , provided on the basis of the distance detected by the communication distance detecting means, and amplifying route signal passes the amplifier, and a route selection means for signal for selecting one of the route of the bypass route for bypassing the amplifier It is .

  According to the above configuration, the signal received from the communication partner is strong if the distance to the communication partner is short, and the signal received from the communication partner tends to be weak if the distance to the communication partner is long. By switching the amplification route and the bypass route based on the distance, the power consumption can be controlled according to the reception state.

Note that the communication distance detection means includes, for example, a detection unit that detects the intensity of the received signal, a data storage unit that associates the intensity of the received signal with the communication distance, and the communication distance that corresponds to the detected intensity. And a determining unit that determines based on
(17) The route selection means may select the bypass route when the distance to the communication partner detected by the communication distance detection means is larger than a preset value.

As a result, the same effect as when the bypass route is selected can be obtained when the intensity of the received signal exceeds or exceeds a preset threshold value.
(18) In order to solve the above-described problems, a wireless communication apparatus according to the present invention includes any one of the above-described wireless communication circuits.

Therefore, it is possible to achieve “improvement of battery duration” and “energy saving design” in the wireless communication device.
(19) In order to solve the above-described problems, a wireless communication system of the present invention includes the above-described wireless communication device.

  Therefore, it is possible to achieve “improvement of battery duration” and “energy saving design” in the wireless communication system.

  As described above, the wireless communication circuit of the present invention includes route selection means for selectively selecting either an amplification route through which a signal passes through the amplifier or a bypass route through which a signal bypasses the amplifier. This is a configuration provided.

  Therefore, in the above configuration, when the bypass route is selected, the power consumption of an amplifier such as a normal “power amplifier” can be reduced as it is.

  For example, in a current wireless LAN card (wireless communication apparatus) compliant with the IEEE 802.11b standard, the power consumption of the power amplifier accounts for about one third of the power consumption of the entire card. Therefore, in an environment where the distance from the base unit is closer than the threshold value, the power consumption can be reduced to two-thirds of the conventional value. Therefore, the battery drive using the wireless communication device provided with the wireless communication circuit of the present invention is possible. It is possible to improve the duration of communication of portable transmission / reception terminals (notebook personal computers, PDAs, mobile phones, etc.), and to save energy.

  Further, by using a wireless communication circuit having a control unit for the wireless communication device, the duration of communicable communication can be improved in the wireless communication device, and an energy saving design can be achieved.

  The present invention will be described below with reference to the drawings.

  FIG. 2 is a block circuit diagram showing a schematic configuration of the card type wireless communication apparatus. The circuit configuration from the antenna end to the baseband processing LSI of the card type wireless communication apparatus is as follows.

  In the card-type wireless communication device, an antenna 1 is provided for radiating a transmission signal to the outside and for intercepting a reception signal from the outside. The antenna 1 includes a normal antenna and a diversity antenna, and a diversity circuit (SW) 1a and an RF bandpass filter (BPF) 2 for switching between the reception circuit unit (reception system) and the transmission circuit unit (transmission system) Are connected to each.

  In the reception circuit unit, an unnecessary frequency component of the reception signal input to the antenna 1 is attenuated by the RF bandpass filter (BPF) 2 and then received by the transmission / reception switching switch (TX / RXSW) 3. At a time when the side is selected, it is input to the low noise amplifier (LNA) 4 and amplified. Thereafter, the received signal is further attenuated by the low-pass filter 5 or the like, and then converted to an intermediate (IF) frequency (down-converted) by the receiving mixer 6 provided in the RF U / D converter. Band limiting is applied by the filter 7 and IQ demodulation is performed. Thereby, each of the I signal and the Q signal is transferred to the baseband processing circuit 8. Note that the RF frequency of the received signal may be directly downconverted to the baseband frequency instead of being downconverted to the IF frequency.

  The reproduction signal after the signal processing in the baseband processing circuit 8 is, for example, PCMCIA (16 BIT or 32 BIT card bus) for a PC card, USB 1.1 or USB 2.0 for a USB adapter, and SD card In the case of the SDIO or built-in type, the data is output to a personal computer, PDA, or other information transmitting / receiving terminal via a PCI bus or the like.

  On the other hand, the transmission circuit unit is based on a data input signal input from the above personal computer, PDA (Personal Digital Assistants), or other information terminal device via an interface circuit (PCMCIA, USB, SDIO, etc. described later). The signal is processed by the band processing circuit 8, further IQ-modulated, converted to an IF signal, up-converted (frequency conversion) by the transmission mixer 11 provided in the RF U / D converter, and then in the opposite direction to the reception direction. A transmission signal obtained by amplifying the modulated signal by the power amplifier 9 in the signal flow is transmitted from the antenna 1.

  In such a card-type wireless communication device, in normal communication operation, transmission and reception are alternately switched in a short time by a switch (TX / RXSW) 3 controlled by a controller (not shown).

  Further, in the IQ modulator / demodulator, a received signal whose band is limited by the IF filter 7 is detected by, for example, an envelope detection using a diode, and a received signal strength indicator value (RSSI) which is a DC voltage. Has been generated. The RSSI is input to the baseband processing circuit 8 to generate each control signal as will be described later.

  Note that power is supplied from the power supply 40 to the reception circuit unit and the transmission circuit unit.

(First basic form)
FIG. 1 is a block circuit diagram showing a high-frequency circuit unit of a radio communication apparatus according to the first basic form of the present invention. The main parts of this high-frequency circuit unit are a transmission power amplifier (amplifier) 9 and a bypass route 22. The transmission signal route switching switches 23 and 24 are configured.

  Therefore, the circuit for wireless communication according to the present invention is a circuit for wireless communication for an information transmitting / receiving terminal, and includes an antenna 1, a power amplifier 9 for transmission as an amplifier connected to the antenna 1, and a power amplifier 9 A bypass route 22 for bypassing (detouring) the signal path (amplification route) of the power amplifier 9, and route switching switches (first switches) 23, 24 for selectively switching the signal path of the power amplifier 9 and the bypass route 22. Yes.

  In the transmission circuit section, the detection diode 10 detects a transmission output signal with a Schottky diode, and a DC component thereof is usually formed by a TX DET circuit (an OP amplifier or the like) provided in the baseband processing circuit 8. In other words, the gain of the AGC amplifier is automatically varied by feedback, and as a result, the transmission power at the end of the antenna 1 becomes constant, which is a known circuit.

In the first basic embodiment, as shown in FIG. 2, the baseband processing circuit 8, based on the RSSI, and the low noise amplifier 4, the control means 18 is provided for controlling the operation of the power amplifier 9. The control means 18 controls the switching of the route switching switches 23 and 24 based on a signal indicating the distance to the communication partner, such as the signal strength of the received signal. For this reason, the control means 18 has a generation unit 18a that generates a control (ON / OFF) signal (first control signal) for controlling the switching of the route switching switches 23 and 24 based on the voltage value of RSSI. is doing.

  The control means 18 (including the generation unit 18a) and the route switching switches 23 and 24 include an amplification route through which the signal passes through the low noise amplifier 4 or the power amplifier 9, and a signal through the low noise amplifier 4 or the power amplifier 9 respectively. Route selection means for selectively selecting any one of the bypass route and the bypass route.

  Further, by acquiring data in which the intensity of the received signal and the communication distance are associated, the RSSI voltage value can be converted into the communication distance. In this case, for example, a detection unit that detects the strength of the received signal, a storage unit (lookup table or the like) that stores the received signal strength and the communication distance, and a communication distance that corresponds to the detected strength. A determining unit that determines based on the data may be provided in the control unit 18. Thereby, the control means 18 can be comprised as a communication distance detection means which detects the distance with a communicating party, and the above-mentioned route selection means.

Further, the first basic form further includes a second switch 41 for connecting / disconnecting power supply from the power supply 40 to the low noise amplifier 4 and the power amplifier 9. The control unit 18 includes a control unit 18b that generates a second control signal for controlling the second switch 41 in cooperation with the route switching switches 23 and 24 (hereinafter abbreviated as switches 23 and 24). Yes. The control means 18 and the second switch 41 are similarly used in the other embodiments described below.

  The control means 18 (including the control unit 18b) and the second switch 41 cooperate with the selection of the bypass route to turn off the power supply to the low noise amplifier 4 or the power amplifier 9. Is configured.

  The RSSI is generated as a DC voltage as shown in FIG. Therefore, the first control signal or the second control signal can be generated by setting a threshold value (for example, 1.5 V) for the RSSI voltage value and comparing the RSSI voltage value with the threshold value. For example, as shown in FIG. 20, when the RSSI voltage value is below the threshold value, the received signal strength is weak, so that the level of the second control signal is used to turn on the power amplifier 9 or the low noise amplifier 4. To high. When the RSSI voltage value is equal to or higher than the threshold value, the received signal strength is strong. Therefore, the level of the second control signal is used to turn off the power amplifier 9 or the low noise amplifier 4 and set the communication device in the power saving mode. Set to low.

Next, an operation procedure in the configuration of the basic form will be described. First, in this card-type wireless communication device, the received signal level input to the receiving circuit section changes in terms of radio waves depending on the distance from the base unit (device such as an access point or router, transmission box, etc.). Since it is wireless, there is no need to explain it, but the received signal level index value (RSSI) is used to display the strength of the input radio wave. For example, in the case of a mobile phone, the index value indicates that the radio wave is the strongest when the flag is 3 lines, and the radio wave is weak when the number is 1 or 0.

  As such an index value, the DC voltage of the terminal called RSSI provided in the baseband processing circuit 8 shown in FIG. 2 is monitored, a threshold value is determined, and digital display is performed, for example, in three stages as described above. What you are doing.

  In the case of the present invention, this RSSI voltage value (hereinafter referred to as RSSI value) is used to perform, for example, two-stage switching. The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the control means 18 monitors the direct current voltage at the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value, and when it detects the RSSI value, it determines whether or not the detected RSSI value is equal to or higher than a predetermined level (step (hereinafter, “step”). , Abbreviated as S) 1).

  When the RSSI value is equal to or higher than a predetermined level, the control means 18 recognizes that the parent device is close (S2), and switches the switches 23 and 24 from the baseband processing circuit (control system controller) 8 so as to select the bypass route 22. Control is performed by ON / OFF of a control (ON / OFF) signal (PA_CTRL). That is, the control unit 18 causes the generation unit 18a to generate the first control signal for controlling the switches 23 and 24 so as to switch the signal path of the power amplifier 9 to the bypass route 22 (S3).

  At this time, the power amplifier 9 is in a state where the supply of power is cut off by turning off the second switch 41 in accordance with the operation of the switches 23 and 24. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 41 (S4).

  On the other hand, if the detected RSSI value is less than the predetermined level in S1, the control means 18 recognizes that the master unit is far (S5), amplifies the signal by the power amplifier 9, and transmits the output to the switch 23. , 24 are controlled from the baseband processing circuit 8 by ON / OFF of a control (ON / OFF) signal (PA_CTRL). That is, the generator 18a generates a first control signal for controlling the switches 23 and 24 so as to switch the bypass route 22 to the signal path of the power amplifier 9 (S6).

  At this time, the power amplifier 9 is supplied with power when the second switch 41 is turned on in accordance with the operation of the switches 23 and 24 and can be amplified. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning on the second switch 41 (S7).

  Note that the user of the communication apparatus may be able to manually and manually switch ON / OFF of the switches 23 and 24 and the second switch 41 interlocked. Thereby, for example, in a situation where the user wants to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the bypass route 22 can be manually selected.

As described above, the first basic form can greatly reduce power consumption because the power amplifier 9 can be turned off when the communication distance to the communication partner (such as the master unit) is short during communication. It has the effect of “improving battery duration” and “energy-saving design”.

(Second basic form)
FIG. 3 is a block circuit diagram showing a high-frequency circuit unit of a wireless communication apparatus according to another basic embodiment of the present invention. The main part of the high-frequency circuit unit is composed of a transmission power amplifier 9, a fixed attenuator 22a in place of the bypass route 22 shown in FIG. 1, and switches 23 and 24 for switching the route of the transmission signal. The role of the detection diode 10 is as described above.

  Next, the operation procedure in this configuration will be described. This card-type wireless communication apparatus performs two-step switching using the RSSI value depending on the distance from the parent device (access point or device such as router, transmission box, etc.). The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the control means 18 monitors the DC voltage of the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value, and when detecting the RSSI value, it determines whether or not the detected RSSI value is equal to or higher than a predetermined level (S11).

  If the RSSI value is equal to or higher than a predetermined level, the control means 18 recognizes that the master unit is close (S12), and switches the switches 23 and 24 from the baseband processing circuit 8 to ON / OFF of PA_CTRL so as to select the fixed attenuator 22a. Control by OFF. That is, the control means 18 causes the generation unit 18a to generate the first control signal for controlling the switches 23 and 24 so as to switch the signal path of the power amplifier 9 to the signal path of the fixed attenuator 22a (S13).

  At this time, the power amplifier 9 is in a state where the supply of power is cut off by turning off the second switch 41 in accordance with the operation of the switches 23 and 24. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 41 (S14).

  On the other hand, if the detected RSSI value is less than the predetermined level in S1, the control means 18 recognizes that the master unit is far (S15), amplifies the signal by the power amplifier 9, and transmits the output to the switch 23. , 24 are controlled from the baseband processing circuit 8 by ON / OFF of PA_CTRL. That is, the generator 18a generates a first control signal for controlling the switches 23 and 24 so that the signal path of the fixed attenuator 22a is switched to the signal path of the power amplifier 9 (S16).

  At this time, the power amplifier 9 is supplied with power when the second switch 41 is turned on in accordance with the operation of the switches 23 and 24 and can be amplified. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning on the second switch 41 (S17).

  Note that the user of the communication apparatus may be able to manually and manually switch ON / OFF of the switches 23 and 24 and the second switch 41 interlocked. Thereby, for example, in a situation where the user wants to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the signal path of the fixed attenuator 22a can be manually selected.

The second basic form is a high-frequency amplification stage of a transmission circuit block, which is provided with a power amplifier 9 for transmission, a fixed attenuator 22a, and switches 23 and 24 for controlling it by connection and disconnection. For example, the switches 23 and 24 are switched according to the level of the high-frequency input signal to the reception block depending on the distance from the base unit (access point or device such as router, transmission box, etc.), and the power amplifier 9 and the fixed attenuator 22a. Is a wireless communication apparatus characterized in that is selectively incorporated into a circuit.

Therefore, the “improvement of battery duration” and “energy saving design”, which are the effects of the first basic form, are applied as they are, and the distance from the base unit is sufficiently close so that the signal is sent to the fixed attenuator 22a. When the route to be passed is automatically selected, interference with devices other than this communication device (the wireless communication device of the present invention and the device that becomes the parent device) using the same frequency band The level can be further reduced as compared to using the bypass route 22 in the first embodiment.

  Especially when applied to IEEE802.11b standard compliant wireless LAN, etc., the frequency used is 2.4 GHz, and it can be used quite freely for industrial, scientific and medical purposes, so Bluetooth, microwave oven, POS Various devices such as terminals and surveillance cameras emit radio waves, and it is an important function to suppress the radio wave radiation level using the fixed attenuator 22a as an etiquette.

  Further, when the RSSI value is larger than a predetermined level, that is, in the range where the communication distance is closer than the predetermined value, the fixed attenuator 22a is selected to reduce the current value of the transmission signal, and thus the fixed attenuator 22a is not used. Compared to this configuration, battery consumption can be further saved.

Further, as in the following third basic form, the variable attenuator 22b is used instead of the fixed attenuator 22a, and the current value of the transmission signal is reduced stepwise according to the communication distance. The following conditions are advantageous for battery saving. As shown in FIG. 19, the condition is that when the current value of the transmission signal is reduced to a predetermined value I ₀ at a certain communication distance, the current value I (fixed) when the fixed attenuator 22a is used is variably attenuated. The communication range (distances D1 to D2) that is lower than the current value I (variable) when using the device 22b is wider than the communication range (distances D2 to D3) that is the opposite.

(Third basic form)
FIG. 4 is a block circuit diagram showing a high-frequency circuit unit of a wireless communication apparatus according to still another basic form of the present invention. The main part of the high-frequency circuit section is composed of a transmission power amplifier 9, a variable attenuator 22b in place of the bypass route 22 shown in FIG. 1, and switches 23 and 24 for switching the route of the transmission signal. The role of the detection diode 10 is as described above.

  Next, the operation procedure in this configuration will be described. This card-type wireless communication apparatus performs fine switching using the RSSI value depending on the distance from the base unit (device such as an access point or router, transmission box, etc.). The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the control means 18 monitors the DC voltage at the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value. When the RSSI value is detected, the control means 18 determines whether the detected RSSI value is equal to or higher than a predetermined level 1 (S21).

  If the RSSI value is greater than or equal to the predetermined level 1, the control means 18 recognizes that the master unit is near (S22), and switches the switches 23 and 24 from the baseband processing circuit 8 to ON / OFF of PA_CTRL so as to select the variable attenuator 22b. Control by OFF. That is, the control unit 18 causes the generation unit 18a to generate the first control signal for controlling the switches 23 and 24 so as to switch the signal path of the power amplifier 9 to the signal path of the variable attenuator 22b (S23).

  At this time, the power amplifier 9 is in a state where the supply of power is cut off by turning off the second switch in accordance with the operation of the switches 23 and 24. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 41 (S24).

  Subsequently, according to the magnitude of the radio wave level associated with the distance from the base unit, the baseband processing circuit 8 responds, for example, to finely set the attenuation with the resolution degree from a 4-bit D / A converter (for example, If the amount of attenuation is 40 dB, in the case of 4 bits, the step is 2.5 dB).

  For example, the control means 18 determines whether or not the detected RSSI value is greater than or equal to a predetermined level 2 greater than the predetermined level 1 (S25). If the detected RSSI value is greater than or equal to the predetermined level 2, the control means 18 further determines whether or not the detected RSSI value is greater than or equal to the predetermined level 3 greater than the predetermined level 2 (S26). Here, assuming that the predetermined level 3 is the upper limit of the threshold value set in multiple stages, if the detected RSSI value is equal to or higher than the predetermined level 3, the variable attenuator is passed through the control means 18 and the D / A converter. The attenuation amount 22b is set to the attenuation level 3 (maximum attenuation amount) corresponding to the predetermined level 3 (S27).

  On the other hand, if the detected RSSI value is less than the predetermined level 2 in S25, the attenuation level of the variable attenuator 22b is set to the attenuation level 1 (minimum attenuation level) corresponding to the predetermined level 1 (S28). If the detected RSSI value is less than the predetermined level 3 in S26, the attenuation amount of the variable attenuator 22b is set to the attenuation level 2 corresponding to the predetermined level 2 (S29).

  The predetermined levels 1 to 3 to be compared with the RSSI value and the attenuation levels 1 to 3 associated with the predetermined levels 1 to 3 are stored in a memory such as a lookup table accessible by the control means 18.

  On the other hand, if the detected RSSI value is less than the predetermined level 1 in S21, the control means 18 recognizes that the master unit is far (S30), amplifies the signal by the power amplifier 9, and transmits the output to the switch 23. , 24 are controlled from the baseband processing circuit 8 by ON / OFF of PA_CTRL. That is, the generator 18a generates a first control signal for controlling the switches 23 and 24 so that the signal path of the variable attenuator 22b is switched to the signal path of the power amplifier 9 (S31).

  At this time, the power amplifier 9 is supplied with power when the second switch 41 is turned on in accordance with the operation of the switches 23 and 24 and can be amplified. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning on the second switch 41 (S32).

  Note that the user of the communication apparatus may be able to manually and manually switch ON / OFF of the switches 23 and 24 and the second switch 41 interlocked. Thereby, for example, in a situation where the user wants to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the signal path of the variable attenuator 22b can be manually selected.

The third basic form is a high-frequency amplification stage of a transmission circuit block, which is provided with a power amplifier 9, a variable attenuator 22b, and switches 23 and 24 for controlling the power amplifier 9, a device such as an access point or a router. The switches 23 and 24 are switched according to the level of the high frequency input signal (RSSI) to the reception block depending on the distance from the transmission box, etc., and the power amplifier 9 and the variable attenuator 22a are selectively incorporated in the circuit. This is a wireless communication apparatus characterized by the above.

Therefore, the “improvement of battery duration” and “energy saving design”, which are the effects of the first basic form, are applied as they are, and the signal passes through the variable attenuator 22b with a sufficiently close distance from the parent device. If the route to be automatically selected is selected, the interference level for devices using the same frequency band other than this communication device (the wireless communication device of the present invention and its parent device) Can be further reduced as compared with using the bypass route 22 in the first basic form.

Furthermore, in the second basic mode, since the fixed attenuator 22a is used, a large attenuation cannot be set because there is a possibility that the communication distance may be deteriorated. However, the variable attenuator 22b can communicate with the maximum attenuation. (while ensuring the communication distance, attenuation can be minimized interference given to external devices) it is possible to variably based on the level of constantly high frequency input signal (RSSI), the above second basic mode, The radio wave radiation level that interferes with external equipment can be suppressed.

  That is, if the intensity of the transmitted signal is greater than necessary, there is a risk of interference with electronic devices that use nearby frequencies, electronic devices that have close harmonic frequency bands and reception frequencies, etc. Get higher. Therefore, according to the RSSI level, the optimum attenuation rate for the communication state or communication distance at that time is selected via the variable attenuator 22b, so that the external device is not disturbed without degrading the communication state or communication distance. Can be suppressed to the optimal level at that time. As a result, it is possible to always minimize the possibility that the transmission signal will interfere with the electronic device.

(Fourth basic form)
FIG. 5 is a block circuit diagram showing a high-frequency circuit unit of a wireless communication apparatus according to still another basic form of the present invention. The main part of this high-frequency circuit unit is a low-noise amplifier 4 (LNA) for reception and a bypass. It comprises a route 32 and route switching switches 33 and 34 (first switches) for received signals.

Therefore, the wireless communication circuit is a wireless communication circuit for the information transmitting and receiving terminals, an antenna 1, a low noise amplifier 4 as an amplifier connected to the antenna 1, a signal path of the low-noise amplifier 4 A bypass route 32 for bypassing (detouring) and route switching switches (first switches) 33 and 34 for selectively switching the signal path of the low noise amplifier 4 and the bypass route 32 are provided. A second switch 42 is provided between the low-noise amplifier 4 and the power supply 40 that supplies power to the low-noise amplifier 4, and ON / OFF of the second switch 42 is generated by the control unit 18b. Controlled by a control signal.

  The route switching switches 33 and 34 (hereinafter abbreviated as switches 33 and 34) are controlled by a control (ON / OFF) signal from the control means 18 in the same manner as the switches 23 and 24 of the first embodiment. The low noise amplifier 4 is also connected to the power supply 40 by the second switch 42 that operates in cooperation with the operations of the route switching switches 33 and 34.

  Next, the operation procedure in this configuration will be described. This card-type wireless communication device performs two-step switching using an RSSI voltage depending on the distance from a base unit (device such as an access point or router, a transmission box, etc.). The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the switches 33 and 34 select the low noise amplifier 4 as an initial setting. This is because switching the normal mode of power supply to the power saving mode (selection of the bypass route 32) according to the communication state does not hinder the initial reception compared to the opposite case.

  Next, the control means 18 monitors the DC voltage at the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value. When the RSSI value is detected, the control means 18 determines whether the detected RSSI value is equal to or higher than a predetermined level (S41).

  When the above-mentioned RSSI value is equal to or higher than a predetermined level when the link with the parent device is established, the control means 18 recognizes that the parent device is near (S42), and selects the switch 33, so as to select the bypass route 32. 34 is controlled by ON / OFF of LNA_CTRL from the baseband processing circuit 8. That is, the control unit 18 causes the generation unit 18a to generate the first control signal for controlling the switches 33 and 34 so as to switch the signal path of the low noise amplifier 4 to the bypass route 32 (S43).

  At this time, the low noise amplifier 4 is in a state where the supply of power is cut off by turning off the second switch 42 in accordance with the operation of the switches 33 and 34. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 42 (S44).

  On the other hand, if the detected RSSI value is less than the predetermined level in S41, the control means 18 recognizes that the master unit is far (S45), and after the signal is amplified by the low noise amplifier 4, it is received by the receiving circuit in the next stage. The switches 33 and 34 are controlled by ON / OFF of LNA_CTRL from the baseband processing circuit 8 so that a passage signal is input to a certain LPF 5. That is, the generation unit 18a generates the first control signal for controlling the switches 33 and 34 so that the signal path of the bypass route 32 is switched to the signal path of the low noise amplifier 4 (S46).

  At this time, the low-noise amplifier 4 is supplied with power when the second switch 42 is turned on in accordance with the operation of the switches 33 and 34 and can perform an amplification operation. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning on the second switch 42 (S47).

  Note that the user of the communication apparatus may be able to manually and manually switch on and off the interlocked operation of the switches 33 and 34 and the second switch 42. Thereby, for example, in a situation where the user wishes to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the bypass route 32 can be manually selected.

The fourth basic form is a high-frequency amplification stage of a reception circuit block, which includes a low-noise amplifier 4 for reception, a bypass route 32, and switches 33 and 34 for controlling the low-noise amplifier 4 and a master unit (access point or router). The switches 33 and 34 are switched according to the level of the high-frequency input signal to the reception block according to the distance from the device, transmission box, etc.), and the low noise amplifier 4 and the bypass route 22 are selectively incorporated in the circuit. This is a wireless communication apparatus characterized by the above.

  Therefore, when the bypass route 32 is selected, the power consumption of the normal low noise amplifier 4 can be reduced as it is. For example, in a current wireless LAN card compliant with the IEEE802.11b standard, the power consumption of the low noise amplifier 4 accounts for about 1/20 of the power consumption of the entire card.

  Therefore, in an environment where the distance from the base unit is closer than the threshold, the power consumption can be reduced as compared with the prior art. Therefore, a battery-powered portable terminal using the wireless device (slave unit) of the present invention (notebook personal computer, PDA) , Mobile phones, etc.) can be improved in duration of communication, and can also be designed to save energy. The setting of the threshold will be described later.

(Fifth basic form)
FIG. 6 is a block circuit diagram showing a high-frequency circuit unit of a wireless communication apparatus according to still another basic form of the present invention. The main part of this high-frequency circuit section is composed of a low-noise amplifier 4 for reception, a fixed attenuator 32a in place of the bypass route 32 shown in FIG. 5, and switches 33 and 34 for switching the route of the received signal. A second switch 42 is provided between the low-noise amplifier 4 and the power supply 40 that supplies power to the low-noise amplifier 4, and ON / OFF of the second switch 42 is generated by the control unit 18b. Controlled by a control signal.

  Next, the operation procedure in this configuration will be described. This card-type wireless communication device performs two-step switching using an RSSI voltage depending on the distance from a base unit (device such as an access point or router, a transmission box, etc.). The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the switches 33 and 34 select the low noise amplifier 4 as an initial setting. Next, the control means 18 monitors the DC voltage at the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value. When the RSSI value is detected, the control means 18 determines whether the detected RSSI value is equal to or higher than a predetermined level (S51).

  When the above-mentioned RSSI value is equal to or higher than a predetermined level when the link with the parent device is established, the control means 18 recognizes that the parent device is close (S52) and switches 33 to select the fixed attenuator 32a. , 34 are controlled from the baseband processing circuit 8 by ON / OFF of LNA_CTRL. That is, the control unit 18 causes the generation unit 18a to generate the first control signal for controlling the switches 33 and 34 so as to switch the signal path of the low noise amplifier 4 to the signal path of the fixed attenuator 32a (S53).

  At this time, the low noise amplifier 4 is in a state where the supply of power is cut off by turning off the second switch 42 in accordance with the operation of the switches 33 and 34. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 42 (S54).

  On the other hand, if the detected RSSI value is less than the predetermined level in S51, the control means 18 recognizes that the master unit is far (S55), and amplifies the signal with the low noise amplifier 4 and then passes to the LPF 5 in the next stage. The switches 33 and 34 are controlled by the ON / OFF of the LNA_CTRL from the baseband processing circuit 8 so that the signal is input. That is, the generation unit 18a generates the first control signal for controlling the switches 33 and 34 so as to switch the signal path of the fixed attenuator 32a to the signal path of the low noise amplifier 4 (S56).

  At this time, the low-noise amplifier 4 is supplied with power when the second switch 42 is turned on in accordance with the operation of the switches 33 and 34 and can perform an amplification operation. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning on the second switch 42 (S57).

  Note that the user of the communication apparatus may be able to manually and manually switch on and off the interlocked operation of the switches 33 and 34 and the second switch 42. Thereby, for example, in a situation where the user wants to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the signal path of the fixed attenuator 32a can be manually selected.

The fifth basic form is a high-frequency amplification stage of a receiving circuit block, which includes a low-noise amplifier 4, a fixed attenuator 32a, and switches 33 and 34 for controlling the low-noise amplifier 4, and a master unit (access point or router, etc.). The switches 33 and 34 are switched according to the level of the high-frequency input signal to the reception block depending on the distance from the device, transmission box, etc.), and the low noise amplifier 4 and the fixed attenuator 32a are selectively incorporated in the circuit. This is a wireless communication apparatus characterized by the above.

Therefore, the “improvement of battery duration” and the “energy saving design”, which are the effects of the fourth basic form, are applied as they are, and the distance between the communication device and the base unit is sufficiently close so that the fixed attenuator 32a is installed. When the route through which the signal passes is automatically selected, since the distance from the base unit is too close, and the reception sensitivity deteriorates due to the distortion characteristic, the distortion characteristic is improved by the attenuation amount of the fixed attenuator 32a. As described above, the reachable distance (range) on the closest distance side can be expanded.

  Note that if the distance between the communication device and the base unit is too short, the reception sensitivity of the communication device deteriorates because of distortion of the switch (TX / RXSW) 3, the low noise amplifier 4, the U / D converter, etc. shown in FIG. This is because the rate deteriorates if the input signal strength is too high due to the characteristics of the transistors and diodes used in them.

(Sixth basic form)
FIG. 7 is a block circuit diagram showing a high-frequency circuit unit of a radio communication apparatus according to still another basic form of the present invention. The main part of this high-frequency circuit unit is composed of a low noise amplifier 4 and the bypass route shown in FIG. 32 includes a variable attenuator 32b instead of 32 and switches 33 and 34 for switching the route of the received signal. A second switch 42 is provided between the low-noise amplifier 4 and the power supply 40 that supplies power to the low-noise amplifier 4, and ON / OFF of the second switch 42 is generated by the control unit 18b. Controlled by a control signal.

  Next, the operation procedure in this configuration will be described. This card-type wireless communication apparatus performs fine switching using the RSSI voltage according to the distance from the parent device (device such as an access point or router, transmission box, etc.). The operation of the control means 18 at this time will be described below based on the flowchart of FIG.

  First, the control means 18 monitors the DC voltage at the RSSI terminal of the baseband processing circuit 8, that is, the RSSI value, and when detecting the RSSI value, it determines whether the detected RSSI value is equal to or higher than a predetermined level 1 (S61).

  If the RSSI value is greater than or equal to the predetermined level 1, the control means 18 recognizes that the parent device is close (S62), and switches the switches 33 and 34 from the baseband processing circuit 8 to turn on / off LNA_CTRL so as to select the variable attenuator 32b. Control by OFF. That is, the control unit 18 causes the generation unit 18a to generate the first control signal for controlling the switches 33 and 34 so as to switch the signal path of the low noise amplifier 4 to the signal path of the variable attenuator 32b (S63).

  At this time, the low-noise amplifier 4 is in a state where the supply of power is cut off by turning off the second switch in accordance with the operation of the switches 33 and 34. For this purpose, the control means 18 causes the control unit 18b to generate a second control signal for turning off the second switch 42 (S64).

  Subsequently, according to the magnitude of the radio wave level accompanying the distance from the base unit, the baseband processing circuit 8 responds to finely set the attenuation amount with the resolution degree from, for example, a 4-bit D / A converter (for example, 40 dB). If it is 4 bits, it becomes 2.5 dB steps).

  For example, the control means 18 determines whether or not the detected RSSI value is greater than or equal to a predetermined level 2 greater than the predetermined level 1 (S65). If the detected RSSI value is greater than or equal to the predetermined level 2, the control means 18 further determines whether or not the detected RSSI value is greater than or equal to the predetermined level 3 greater than the predetermined level 2 (S66). Here, assuming that the predetermined level 3 is the upper limit of the threshold value set in multiple stages, if the detected RSSI value is equal to or higher than the predetermined level 3, the variable attenuator is passed through the control means 18 and the D / A converter. The attenuation amount 32b is set to the attenuation level 3 (maximum attenuation amount) corresponding to the predetermined level 3 (S67).

  On the other hand, if the detected RSSI value is less than the predetermined level 2 in S65, the attenuation level of the variable attenuator 32b is set to the attenuation level 1 (minimum attenuation level) corresponding to the predetermined level 1 (S68). In S66, if the detected RSSI value is less than the predetermined level 3, the attenuation amount of the variable attenuator 32b is set to the attenuation level 2 corresponding to the predetermined level 2 (S69).

  The predetermined levels 1 to 3 to be compared with the RSSI value and the attenuation levels 1 to 3 associated with the predetermined levels 1 to 3 are stored in a memory such as a lookup table accessible by the control means 18.

  On the other hand, if the detected RSSI value is less than the predetermined level 1 in S61, the control means 18 recognizes that the master unit is far (S70), amplifies the signal by the low noise amplifier 4, and then receives the signal at the next receiving circuit. The switches 33 and 34 are controlled by ON / OFF of LNA_CTRL from the baseband processing circuit 8 so that a passage signal is input to a certain LPF 5. That is, the generator 18a generates the first control signal for controlling the switches 33 and 34 so that the signal path of the variable attenuator 32b is switched to the signal path of the low noise amplifier 4 (S71).

  At this time, the low-noise amplifier 4 is supplied with power when the second switch is turned on in accordance with the operation of the switches 33 and 34 and can perform an amplification operation. For this purpose, the control unit 18 causes the control unit 18b to generate a second control signal for turning on the second switch 42 (S72).

  Note that the user of the communication apparatus may be able to manually and manually switch on and off the interlocked operation of the switches 33 and 34 and the second switch 42. Thereby, for example, in a situation where the user wants to perform communication with reduced power consumption because the remaining battery level of the communication device has decreased, the signal path of the variable attenuator 32b can be manually selected.

The sixth basic form is a high-frequency amplification stage of a receiving circuit block, which includes a low-noise amplifier 4, a variable attenuator 32b, and switches 33 and 34 for controlling the low-noise amplifier 4, and a master unit (such as an access point or a router). The switches 33 and 34 are switched according to the level of the high frequency input signal (RSSI) to the receiving block depending on the distance from the device, transmission box, etc., and the low noise amplifier 4 and the variable attenuator 32b are selectively used as a circuit. A wireless communication apparatus characterized by being incorporated.

Therefore, the effect of the fourth basic form “improvement of battery duration” and “energy saving design” are applied as they are, and the signal passes through the variable attenuator 32b with a sufficiently close distance from the base unit. If the route to be automatically selected is too close to the base unit and the reception sensitivity deteriorates due to distortion characteristics, the amount of attenuation of the variable attenuator 32b depends on the level of the high frequency input signal (RSSI). Therefore, the reachable range (range) on the closest distance side can be expanded flexibly and conveniently compared to the fifth basic form or more.

  For example, by using the variable attenuator 32b, a more detailed mode selection (switching to a large attenuation / medium / small / none / low noise amplifier) rather than a 2-mode selection with attenuation (1) / without (0) Can do. Therefore, when a rapid level change occurs in the high-frequency input signal (RSSI), it is possible to make the reception sensitivity an optimum sensitivity according to the communication distance at that time as compared with the case of selecting the two modes.

  As an example, even if the optimum value of attenuation changes from 30 dB to 20 dB due to a rapid level change in the high-frequency input signal (RSSI) at a communication distance that originally requires an attenuation of 30 dB, is it 30 dB or 0? If the two modes are selected, the attenuation must be set to zero. As a result, the distance between the communication device and the parent device is too short, and the reception sensitivity is deteriorated due to distortion characteristics, and the frequency of occurrence of reception errors is increased.

  On the other hand, the use of the variable attenuator 32b makes it possible to set an optimum attenuation amount according to the communication state and communication distance at that time, thereby suppressing deterioration in reception sensitivity and increase in the frequency of occurrence of reception errors. be able to.

  In addition, by using the variable attenuator 32b, for example, when there is a possibility of communication while being carried, such as a PDA or a mobile phone, the distance to the parent device changes in real time, which is more effective.

The wireless communication apparatus includes an antenna, a receiving circuit unit that converts and demodulates a high-frequency signal received from the antenna, and outputs a baseband reception signal, and modulates and frequency-converts an input baseband transmission signal to the antenna. A transmission circuit unit that outputs a high-frequency signal; a baseband signal processing circuit unit that performs signal processing of the baseband transmission signal and the baseband reception signal; an interface circuit unit that has an interface function between the information terminal devices; In a card-type wireless communication device or a module for device incorporation connected to the information terminal device, the power supply unit for supplying power to the circuit unit and a connector connected to the information terminal device, in a high-frequency amplification stage of the transmission circuit block The transmission power amplifier and the bypass circuit are provided and the switching is controlled. The switching circuit is switched according to the level of the high-frequency input signal to the receiving block according to the distance from the base unit (access point or router device, transmission box, etc.), and the power amplifier and bypass circuit are It is characterized by being selectively incorporated into a circuit.

  In the above wireless communication apparatus, a transmission power amplifier and a fixed attenuation circuit are provided at the high frequency amplification stage of the transmission circuit block, and a switching circuit is provided to control the master unit (device such as an access point or router, transmission box, etc.) The switching circuit is switched according to the level of the high-frequency input signal to the receiving block, and the power amplifier and the fixed attenuation circuit may be selectively incorporated in the circuit.

  In the above-mentioned wireless communication device, a transmission power amplifier and a variable attenuation circuit are provided at the high frequency amplification stage of the transmission circuit block, and a switching circuit that controls the master circuit (device such as an access point or router, transmission box, etc.) ), The switching circuit may be switched according to the level of the high-frequency input signal to the receiving block, and the power amplifier and the variable attenuation circuit may be selectively incorporated in the circuit.

  In the above wireless communication apparatus, a reception low-noise amplifier and a bypass circuit are provided at the high-frequency amplification stage of the reception circuit block, and a switching circuit is provided to control the master unit (device such as access point or router, transmission box, etc.) Depending on the distance to the reception block, the switching circuit may be switched according to the level of the high frequency input signal to the reception block, and the low noise amplifier and the bypass circuit may be selectively incorporated in the circuit.

  In the above wireless communication device, a reception low-noise amplifier and a fixed attenuation circuit are provided at the high-frequency amplification stage of the reception circuit block, and a switching circuit is provided to control the master unit (access point or router or other device, transmission box) The switching circuit is switched according to the level of the high-frequency input signal to the receiving block, and the low noise amplifier and the fixed attenuation circuit may be selectively incorporated in the circuit.

  In the above wireless communication device, a reception low-noise amplifier and a variable attenuation circuit are provided at the high-frequency amplification stage of the reception circuit block, and a switching circuit is provided to control the master unit (device such as an access point or router, transmission box, etc.) ), The switching circuit is switched according to the level of the high-frequency input signal to the receiving block, and the low noise amplifier and the variable attenuation circuit may be selectively incorporated in the circuit.

In the following, taking the case of the first basic form as an example, how much the communication distance threshold correlated with the RSSI value is set will be described with reference to FIG. 8 showing simulation data. The simulation conditions related to the communication distance (reach distance) between the master unit and the slave unit are as follows.

  The calculation results assuming only the radio wave (direct wave) directly transmitted between the transmitting antenna and the receiving antenna at the visible distance (line-of-sight distance) in the simplest case of the radio wave path are shown below.

When using a virtual isotropic antenna, considering how much of the transmission power (Pt) is captured as reception power (Pr),
Only the distance (d) between the antennas and the wavelength (λ) of the used frequency are related, and the relationship between Pt and Pr is expressed by the following equation.

Pr = Pt × (λ / 4πd) ² = Pt / (4πd / λ) ² Equation 1
Pr = Pt × (λ / 4πd) ^2.5 = Pt / (4πd / λ) ^2.5 Equation 2
Pr = Pt × (λ / 4πd) ³ = Pt / (4πd / λ) ³ Equation 3
Here, (4πd / λ) ² or ^2.5 or ³ = Pt / Pr = Lp
Is called free space propagation loss.

  The square law of Equation 1 indicates an ideal free space. The 2.5 power law in Equation 2 is an index that is generally used from experience rules in a space (environment) such as a general home. The cubic law of Equation 3 indicates an index when assuming an office space (environment) in which desks, lockers, and people move frequently.

  In designing actual communication devices, one of the equations 1 to 3 is specified depending on whether the communication environment is closest to the square, 2.5, or 3 law. Good.

  Next, if the directivity gains (absolute gain (dBi)) of the transmitting and receiving antennas are Gt and Gr, respectively, they can be expressed by the following equations.

Pr = Pt · Gt · (1 / Lp) · Gr
Therefore, when this is displayed in decibels, the result is as follows.

Pr (dBm) = Pt (dBm) + Gt (dB) -10 logLp + Gr (dB)
The table of FIG. 8 was programmed so that the table calculation was performed by an equation obtained by transforming this with respect to the distance d.

  As is apparent from the results of this simulation, the generally used 2.5 power law has no problem when used in a general household as long as it is within the range of about 26 meters as shown in FIG. 8 (e). It is assumed that communication is possible. Therefore, when designing a communication device for a communication environment that conforms to the power law of 2.5, the threshold of the RSSI value is set to a value corresponding to a communication distance of 26 meters. Thereby, if the RSSI value is equal to or larger than the threshold value, the setting of the present invention for turning off the transmission power amplifier 9 is automatically selected.

  If the RSSI value is recognized as being farther than that, that is, if the RSSI value is less than the threshold value, the transmission power amplifier 9 is turned on, and a transmission signal flows using that route. As a result, as shown in FIG. 8B, communication is possible up to about 107 meters.

  In addition, even in the case of a rather complicated messy office environment, as is clear from FIG. 8 (f) showing the result of the cubic law simulation, if it is within a range of about 7 meters, It is assumed that communication can be performed without problems even when used. Therefore, when designing a communication device for a communication environment that conforms to the third power rule, the RSSI value threshold is set to a value corresponding to a communication distance of 7 meters. Thereby, if the RSSI value is equal to or larger than the threshold value, the setting of the present invention for turning off the transmission power amplifier 9 is automatically selected.

  If the RSSI value is recognized as being farther than that, the transmission power amplifier 9 is turned on and a signal flows using that route, and communication is possible up to about 22 meters as shown in FIG. 8C. I understand that

Further, in the case of the fourth basic form (on / off of the low-noise amplifier 4 on the receiving side), how much the threshold is set is as shown in FIG. 9 showing simulation data. Since the simulation conditions and the like are exactly the same as those in FIG.

( First embodiment)
Next, an example in which the quality of the communication state is determined using various signals generated by a communication protocol that defines a transmission / reception control method of the communication apparatus, and the power amplifier 9 or the low noise amplifier 4 is turned on / off using the determination result. Will be explained.

  FIG. 16 shows the configuration of a server and a client relating to a communication protocol for executing an application such as a voice call and video distribution between a server and a client by a wireless LAN (Local Area Network).

  Specific examples of such applications include streaming and VoIP (Voice over Internet Protocol). Both streaming and VoIP are applications that play while receiving multimedia data. However, an application that transmits multimedia data in one direction from the server to the client is called streaming, and is distinguished from VoIP for two-way communication. . In other words, VoIP is an application that communicates telephones, so-called two-way voice communication, and two-way communication of images and voices over an IP network.

  As shown in FIG. 16, the communication system using the wireless LAN is hierarchized into seven layers for both the server and the client.

  The first layer (RF: Radio Frequency) is a physical layer, and defines a communication standard such as IEEE802.11b for actually performing wireless communication via an access point (AP).

  The second layer (MAC / BB; Media Access Control / Back Baseband) is a data link layer, and defines a rule for transmitting and receiving data as a packet.

  The third layer (IP: Internet Protocol) is a network layer, and defines rules for sending data from computer to computer.

  The fourth layer (UDP / TCP; User Datagram Protocol / Transmission Control Protocol) is a transport layer that defines the rules for control procedures to improve communication quality so that all packets can be delivered to the other party without error. ing.

  The fifth layer (RTP: Real Time Protocol) is a presentation layer, and defines the rules regarding the packet format used when exchanging continuous data such as video data or audio data.

  The sixth layer (reception buffer) is a lower layer of the application layer, and defines a rule for temporarily storing packets to some extent according to various applications after receiving a packet formatted according to RTP.

  The seventh layer (video, audio, RTCP; Real Time Control Protocol) is an upper layer of the application layer, and includes interface processing for decoding video data or audio data encoded according to RTP, and between terminals. Establishes rules for control processing to define relationships.

  FIG. 17 shows various information inputted to the control means 18 for turning on / off the power supply of the low noise amplifier 4 and the power amplifier 9. The various types of information are obtained by data processing based on the various protocols described with reference to FIG. 16, and are information on the state of communication between the server and the client, as will be described in detail later. The control means 18 refers to the various types of information, causes the generation unit 18a to generate the first control signal corresponding to the communication state, and causes the control unit 18b to generate the second control signal. The first and second control signals are sent to the receiving circuit unit including the power amplifier 4 and the power amplifier 9 and the RF circuit unit 43 as the transmitting circuit unit.

  Thereby, switching between the amplification route through which the signal passes the low noise amplifier 4 or the power amplifier 9 and the bypass route 22 (32), and the low noise amplifier 4 or the power amplifier when the bypass route 22 (32) is selected. 9 is controlled in accordance with the result of the quality determination of the communication state in the control means 18.

  The various types of information include TCP information, UDP information, RTP information, RTCP information, A / V media information, and reception buffer information.

  The TCP information is generated by data processing according to the fourth layer TCP. TCP is a protocol capable of confirming whether transmitted data has been correctly received by the communication apparatus of the other party. When the other communication apparatus receives the data correctly, it transmits ack (acknowledgement) information to the communication apparatus on the transmission side. Accordingly, the communication device on the transmission side can confirm that the data is correctly received by the other communication device by receiving the ack information from the other communication device.

  Note that in TCP, when a communication device on the transmission side transmits information and fails to receive the ack information within a predetermined timeout period, the ACK information is received or a predetermined number of retransmissions are performed. Since it is a protocol that repeats data retransmission, it may be information indicating whether the communication state is good or not by a threshold of the number of retransmissions. Further, the threshold value may be set in multiple stages.

  The UDP information is information generated by data processing according to the UDP of the fourth layer and representing the error level of the received data. That is, the UDP information is generated by the UDP executing a process for determining the error level (so-called checksum). Note that UDP is a protocol that simplifies the communication procedure so that only information necessary for data exchange with the application layer is generated. In this embodiment, video data and audio data are sent to the receiving communication device in accordance with the following RTP and UDP.

  The UDP information may also be information indicating two states of whether there is an error in the received data, or may be information indicating whether the communication state is good or not by setting a threshold for the error level, The threshold value may be set in multiple stages.

  The RTP information is generated by data processing according to the RTP of the fifth layer, and the number of data packets to be transmitted from the transmitting communication device and the time (time stamp) expected to be received by the receiving communication device or This is information relating to the time to be played by the communication device on the receiving side. Since the RTP information is transmitted from the transmitting communication device to the receiving communication device by TCP, the receiving communication device can know in advance what data is to be received.

  However, the communication device on the receiving side may ignore lost packets or packets that are delivered late, and only reproduce the packets received at the time expected by the communication device on the receiving side. It is also possible to reproduce the packet as it is. Which form is adopted depends on the design of the application.

  The RTCP information relates to information regarding the communication status such as the degree of network congestion and the receiving speed of the transmission partner, and the number of data packets to be transmitted from the transmitting communication device and the time that the receiving communication device is expected to receive. Information (SR; sender report). Since RTP does not have a function for performing communication according to the situation, the transfer speed and transfer amount of multimedia data can be increased or decreased by using RTCP.

  The A / V media information is generated by the seventh layer application, and is an error resilience tool provided for information itself such as video data or audio data, time information to be reproduced, and video CODEC (COmpression and DECompression) or audio CODEC. Is information indicating whether or not has been operated. Note that when the error resilience tool finds errors such as missing data in the data, it performs interpolation or correction on the data.

  The reception buffer information is information relating to the time required to accumulate data received by the communication device on the reception side in the reception buffer, generated by the sixth layer. The reception buffer information will be described later in detail.

  Next, the control unit 18 determines that the communication state is good, and causes the generation unit 18a to generate a first control signal for bypassing the low noise amplifier 4 or the power amplifier 9 in the signal, and the low noise amplifier 4 or A case where the control unit 18b generates a second control signal for turning off the power of the power amplifier 9 will be described.

(1) Determination based on TCP information For the communication device on the reception side, when returning ack without returning “nack” (negative acknowledgement) in TCP to the communication device on the transmission side, the control means 18 on the reception side Based on such TCP information, it is determined that the communication state is good, and as a result, the power of the low noise amplifier 4 is turned off by the control unit 18b.

  On the other hand, for the communication device on the transmission side, when the ack is received from the communication device on the reception side without receiving the “nack” by TCP, the control unit 18 on the transmission side has a good communication state based on such TCP information. As a result, the control unit 18b turns off the power of the power amplifier 9.

(2) Judgment based on UDP information In the communication apparatus on the receiving side, if no error has occurred in the UDP checksum or the error level is below a threshold value, the receiving-side control means It is determined that the communication state is good, and the power source of the low noise amplifier 4 is turned off by the control unit 18b.

(3) Judgment based on RTP information and RTCP information In the communication apparatus on the receiving side, when the RTP information is compared with the SR of RTCP, and the actual reception status of the data matches the predicted content, the receiving side The control unit 18 determines that the communication state is good based on such RTP information and RTCP information, and as a result, the control unit 18b turns off the power supply of the low noise amplifier 4.

  The RTP information here is obtained by detecting how many packets the receiving side communication device has received, how many bytes of packets have been received, how many packets have been received in seconds, etc. Information.

(4) Judgment based on RTP information and A / V media information The packet arrival time detected by RTP is compared with the A / V media information (time information to be played (or decoded)) detected by the receiving application. When the relationship of packet arrival time <time information to be reproduced is established, the receiving-side control means 18 determines that the communication state is good based on such RTP information and A / V media information, and as a result, The power source of the low noise amplifier 4 is turned off by the control unit 18b. The fact that this relationship is established means that the communication device on the receiving side has received data with a margin with respect to the time to be reproduced.

  This point will be described more specifically. For example, as shown in FIG. 18A, in the case of a video signal, the video signal is sampled with 33 msec as a time unit to generate encoded data for one frame (33 msec). That is, the video signal is converted into encoded data v1, v2, v3, v4, etc. of a plurality of frames. The elapsed time from the sampling start time is written in the header of each frame.

  In FIG. 18A, the data lengths of the encoded data v1 and the like are depicted in various ways. This is because in the case of video data, the amount of data changes from moment to moment depending on the nature of the image, such as whether it is a still image or a moving image, or a moving image with a lot of motion or a moving image.

  The time (t, t + a, t + b, t + c) in which the encoded data v1 and the like are transmitted from the server to the client is continuous, whereas the time received by the client is discontinuous. That is, the time when the data v1 and the like are received by the client varies depending on the communication state between the server and the client.

  For this reason, as shown in FIG. 18A, for example, the data v1 is received by the client in time for the time T to be reproduced, but the reception of the data v3 is not in time for the time T + 2 to be reproduced. A phenomenon can occur.

  Note that the client reads time information from the header of each frame by RTP, and grasps the time at which each frame is to be reproduced.

  FIG. 18B shows the same thing for the audio signal. In the case of an audio signal, for example, in the AMR (adaptive multirate coder) system, the audio signal is sampled with 20 msec as a time unit, and encoded data for one frame (20 msec) is created. As in the case of the video signal, an elapsed time from the sampling start time is written in the header of each frame.

  In the case of an audio signal, the amount of data encoded for a fixed sampling time is basically the same. For this reason, as shown in FIG. 18B, the data lengths of the encoded data v′1, v′2, v′3, and v′4 of the audio signal are equal. The description of the transmission time and the time to be played back is similar to the description of the video signal.

(5) Determination based on A / V media information When the error resilience tool provided in the video CODEC or the audio CODEC does not operate in the communication apparatus on the reception side, the control means 18 on the reception side Based on the media information, it is determined that the communication state is good, and as a result, the power of the low noise amplifier 4 is turned off by the control unit 18b.

  Next, in the opposite case, that is, an example in which the control unit 18 determines that the communication state is bad and as a result, the control unit 18b turns on the power supply of the low noise amplifier 4 or the power amplifier 9. Is as follows.

(1) Judgment based on TCP information For the communication device on the reception side, when the “nack” is continuously returned n times by TCP to the communication device on the transmission side, the control means 18 on the reception side makes such TCP Based on the information, it is determined that the communication state is bad, and as a result, the power of the low noise amplifier 4 is turned on by the control unit 18b.

  On the other hand, for the communication device on the transmission side, if the control unit 18 on the transmission side has a bad communication state based on such TCP information, when the nack is continuously received n times by TCP from the communication device on the reception side. As a result, the power of the power amplifier 9 may be turned on by the control unit 18b.

  The above example is merely an example, and the number of occurrences of nack per unit time may be used as a criterion for determination instead of the number of consecutive nacks. Alternatively, the number of consecutive “nack” s or the number of occurrences of “nack” as a criterion may be determined in consideration of the relationship with the data length of the packet (for example, the number of times is increased when the data length is long).

(2) Judgment based on UDP information When an error occurs in the UDP checksum in the receiving side communication device or the error level exceeds a threshold value, the receiving side control means 18 determines whether or not the receiving side control means 18 is based on such UDP information. It is determined that the communication state is bad, and as a result, the power source of the low noise amplifier 4 is turned on by the control unit 18b. Note that the threshold value may be determined in consideration of the relationship with the data length of the packet.

(3) Judgment based on RTP information and RTCP information In the communication apparatus on the receiving side, the RTP information is compared with the SR of the RTCP, and if the actual reception status of the data does not match the announced content, the control on the receiving side The means 18 determines that the communication state is poor based on such RTP information and RTCP information, and as a result, the power of the low noise amplifier 4 is turned on by the control unit 18b.

(4) Judgment based on RTP information and A / V media information The packet arrival time detected by RTP is compared with the A / V media information (time information to be played (or decoded)) detected by the receiving application. If the relationship of packet arrival time ≧ time information to be reproduced is established, the receiving-side control means 18 determines that the communication state is poor based on such RTP information and A / V media information, and as a result, The power source of the low noise amplifier 4 is turned on by the control unit 18b.

(5) Judgment based on A / V media information When the error resilience tool provided in the video CODEC or audio CODEC operates in the communication apparatus on the reception side, the control means 18 on the reception side makes such A / V Based on the media information, it is determined that the communication state is bad, and as a result, the power of the low noise amplifier 4 is turned on by the control unit 18b.

  For example, in a video signal compression encoding system defined by MPEG-4, encoded data is generated from a video signal according to a certain rule. Whether or not there is an error in the encoded data can be determined based on whether or not the error tolerance tool has correctly detected the error detection data according to a certain rule when decoding the encoded data. As a result of the determination, the error resilience tool executes error correction when it detects an error from the encoded data.

  It is to be noted that the result of the determination of the quality of the communication state in the communication device on the reception side is reported to the communication device on the transmission side, and the power of the power amplifier 9 in the communication device on the transmission side is turned on / off based on the determination of the quality of the communication device on the reception side You may control to do.

  For example, when the communication device on the transmission side cannot detect a communication state failure (that is, the power amplifier 9 is turned off), but the communication device on the reception side detects a communication state failure, the low noise amplifier 4 on the reception side. In addition to turning on the power, the control for turning on the power amplifier 9 on the transmission side is performed in each communication device. As a result, in some cases, the communication state is synergistically improved.

  On the contrary, since the RSSI is small in the communication device on the transmission side, in the situation where the power amplifier 9 is turned on, the communication device on the reception side has detected a good communication state. By reporting to the communication device, not only the power of the low noise amplifier 4 is turned off on the receiving side, but also the control of turning off the power amplifier 9 on the transmitting side can be performed in each communication device. As a result, there is a synergistic effect that the power consumption of both communication devices can be suppressed.

(6) Determination Specific to Streaming and VoIP Next, on / off control specific to each application of streaming and VoIP will be described. The reason for the power on / off control process is different depending on the application because the usage of the reception buffer is different.

  First, in streaming, since data is sent in one direction from the server to the client, it is a feature that even if data is accumulated to some extent in the reception buffer of the client, the user does not recognize the retention of data. This is because, regardless of whether data is stored in the reception buffer, the user only views the data sent out from the reception buffer and reproduced. Rather, since the communication speed changes from time to time depending on the state of the network, the user can enjoy natural reproduction when data is accumulated in the reception buffer to some extent and then transferred to the application for reproduction.

  The client receives information on the bit rate (T) of the data transmitted from the server and the necessary buffer size (B) from the server. As a result, the client can obtain the time (buffer full time t) required to accumulate the data in the reception buffer by the equation t = B / T (sec).

  The quality of the communication state is determined by the buffer full time t obtained by this calculation and the buffering time t ′ required to store the actually received data in the reception buffer (t and t ′ correspond to the reception buffer information). Is determined by the control means 18 comparing. That is, in the client buffering process, if the relationship of t ′ ≦ t is established, the control unit 18 determines that the communication state is good, and as a result, the control unit 18b turns off the power supply of the low noise amplifier 4. .

  On the other hand, if the relationship t ′> t is established in the buffering process of the client, the control unit 18 determines that the communication state has deteriorated, and as a result, the control unit 18b turns on the power source of the low noise amplifier 4. turn on. Also, in streaming, when the reception buffer becomes empty during data reception, data reception is delayed, so the control means 18 determines that the communication state has deteriorated, and as a result, The power source of the low noise amplifier 4 is turned on by the control unit 18b.

  Note that the buffer size (B) requested by the server to the client varies depending on the content and is not constant. In addition, the bit rate (T) also changes depending on how busy the communication line is. In the client, when the amount of data scheduled in the reception buffer is accumulated, the data is sent from the reception buffer to the application, and reproduction starts.

  Since the memory capacity of the reception buffer is larger than the buffer size (B), the received data is stored in the reception buffer even when the amount of data input to the reception buffer exceeds the amount of data output from the reception buffer. I can keep it. The server can also know the size of the client reception buffer and the amount of data that can be transmitted.

  Next, VoIP has a feature that it basically does not allow a delay in receiving voice data because a conversation is established by performing two-way voice communication between a server and a client or between communication devices. . For this reason, unlike streaming, VoIP does not perform buffering processing.

  Therefore, in VoIP, if voice data can be continuously decoded during a call in the communication device on the receiving side, the state is input to the control means 18 as A / V media information. As a result, the control unit 18 determines that the communication state is good, and as a result, the control unit 18b turns off the power supply of the low noise amplifier 4.

  On the other hand, when decoding of audio data is interrupted during a call, the state is input to the control means 18 as A / V media information. Thereby, the control means 18 judges that the communication state has deteriorated, and as a result, the control section 18b turns on the power supply of the low noise amplifier 4.

  When the conversation is interrupted, it is detected that there is no voice input by the voice CODEC, and silence information is generated and sent to the other party, so that the decoding of the voice data is not interrupted.

  As described above, the processing in which the control unit 18 determines the quality of the communication state using various signals generated by the communication protocol has been described in six categories as (1) to (6). In the following, the order in which the determinations in (1) to (6) are performed and the conditions incidental to the determinations in (1) to (6) in order to determine the power on / off of the low noise amplifier 4 will be described.

  The order of determining (1) to (6) is the same as the order of the numbers (1) to (6). This order is the same as the order in which the determination is made earlier according to the communication protocol. Therefore, the control means 18 performs the quality determination of the communication state in the order of (1) to (6).

  As an incidental condition, in the first method for turning on the power supply of the low noise amplifier 4, if any one of (1) to (6) indicates that the communication state is poor even once. The control means 18 determines that the communication state is bad, and turns on the power supply of the low noise amplifier 4 by the control unit 18b.

  As an incidental condition, in the second method of turning on the power supply of the low noise amplifier 4, with respect to (1) to (4), when an event indicating that the communication state is bad occurs once, the control means 18 It is determined that the communication state is bad, and the power source of the low noise amplifier 4 is turned on by the control unit 18b. Furthermore, for (5) and (6), an event indicating that the communication state is bad is allowed to occur n times of the threshold value, and when it occurs n times, the control means 18 determines that the communication state is bad, and the control unit 18 The power supply of the low noise amplifier 4 is turned on by 18b.

  In the second method, the number of occurrences of an event indicating that the communication state is poor in (1) to (4) is not limited to one. That is, regarding the number of occurrences of an event indicating that the communication state is bad, threshold values that are allowable from the viewpoint of communication reliability may be independently set in (1) to (6).

  Further, regarding the threshold value n times, it may be a further incidental condition that an event indicating that the communication state is bad occurs continuously or occurs within a predetermined time interval.

  Furthermore, as an incidental condition, in the first method for turning off the power supply of the low noise amplifier 4, if no event indicating that the communication state is bad occurs in all of (1) to (6), the control means 18 determines that the communication state is good, and turns off the power supply of the low noise amplifier 4 by the control unit 18b.

  Further, as an incidental condition, in the second method of turning off the power supply of the low noise amplifier 4, if no event indicating that the communication state is bad occurs in (1) to (4), the control means 18 It is determined that the communication state is good, and the power source of the low noise amplifier 4 is temporarily turned off by the control unit 18b. For (5) and (6), the control means 18 counts the number of occurrences of an event indicating that the communication state is bad, and when any one of the occurrence times reaches a threshold, the control means 18 Is determined to have deteriorated, and the power of the low-noise amplifier 4 is turned on by the control unit 18b.

  Further, as an incidental condition, in the third method for turning off the power supply of the low noise amplifier 4, the number of occurrences of an event indicating that the communication state is bad is related to the reliability of communication in each of (1) to (6). A threshold that is acceptable from the viewpoint is set independently, and the control means 18 determines that the communication state is good until the number of occurrences exceeds the threshold in any one of (1) to (6). The power supply of the low noise amplifier 4 is turned off.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  When the wireless communication circuit is used in a plurality of wireless communication devices included in a wireless communication system such as a wireless LAN, the amplifier for transmission or the reception is used depending on the distance between the wireless communication devices that are communicating with each other. The amplifier can be made unnecessary, the power consumption can be reduced, the energy can be saved, and the communication duration at the portable transmission / reception terminal such as battery drive can be improved.

It is a block diagram which shows the specific example of the switching system of the transmission power amplifier and bypass circuit of the card-type radio | wireless communication apparatus concerning one basic form of this invention. It is a block circuit diagram which shows the schematic structure of the said card-type radio | wireless communication apparatus. It is a block diagram which shows the specific example of the switching system of transmission power amplifier and a fixed attenuator based on the other basic form of this invention. It is a block diagram which shows the specific example of the switching system of transmission power amplifier and a variable attenuator based on the further another basic form of this invention. It is a block diagram which shows the specific example of the switching system of a receiving low noise amplifier and a bypass circuit based on the further another basic form of this invention. It is a block diagram which shows the specific example of the switching system of a receiving low noise amplifier and a fixed attenuator based on the further another basic form of this invention. It is a block diagram which shows the specific example of the switching system of a reception low noise amplifier and a variable attenuator based on the further another basic form of this invention. It is a table | surface which shows the simulation result of the relationship between the presence or absence of a transmission power amplifier, and an arrival distance. It is a table | surface which shows the simulation result of the relationship between the presence or absence of a reception low noise amplifier, and reachable distance. It is a flowchart which shows the procedure which controls switching of a power amplifier and a bypass route, and the electric power supply to a power amplifier according to an RSSI value in a transmission system. It is a flowchart which shows the procedure which controls switching of a power amplifier and a fixed attenuator, and the electric power supply to a power amplifier according to an RSSI value in a transmission system. It is a flowchart which shows the procedure which controls switching of a power amplifier and a variable attenuator, switching of the attenuation amount of a variable attenuator, and electric power supply to a power amplifier according to an RSSI value in a transmission system. It is a flowchart which shows the procedure which controls switching of a low noise amplifier and a bypass route, and the electric power supply to a low noise amplifier in a receiving system according to an RSSI value. It is a flowchart which shows the procedure which controls switching of a low noise amplifier and a fixed attenuator, and the electric power supply to a low noise amplifier in a receiving system according to an RSSI value. It is a flowchart which shows the procedure which controls the switching of a low noise amplifier and a variable attenuator, the switching of the attenuation amount of a variable attenuator, and the electric power supply to a low noise amplifier in a receiving system according to an RSSI value. It is explanatory drawing which shows the structure of the server regarding the communication protocol of wireless LAN, and a client. It is explanatory drawing which shows the various information input into the control means which turns on and off the power supply of a low noise amplifier and a power amplifier. (A) is explanatory drawing which shows the transmission / reception timing of the encoding data of a video signal, (b) is explanatory drawing which shows the transmission / reception timing of the encoding data of an audio | voice signal. It is explanatory drawing which shows the relationship between the state which attenuate | damped the transmission signal with the fixed attenuator or the variable attenuator, and communication distance. It is a graph which shows the production | generation of the 1st control signal or 2nd control signal based on an RSSI value. It is a block diagram of schematic structure of the conventional card-type radio | wireless communication apparatus. It is a block diagram of the radio | wireless module which employ | adopted the conventional RFAGC circuit.

Explanation of symbols

1: Antenna 4: Low noise amplifier (amplifier)
9: Power amplifier (amplifier)
18: Control means (communication distance detection means)
18a: generation unit (route selection means)
18b: Control unit (power-off means)
22: Bypass route 22a: Fixed attenuator (attenuator)
22b: Variable attenuator (attenuator)
23: Route switching switch (first switch, route selection means)
24: Switch for route switching (first switch, route selection means)
32a: Fixed attenuator (attenuator)
32b: Variable attenuator (attenuator)
40: Power supply 41: Second switch (power-off means)
42: Second switch (power-off means)

Claims (19)

A wireless communication circuit having an amplifier for amplifying a signal ,
An amplification route through which the signal passes through the amplifier;
Route selection means for selectively selecting either one of the bypass route for the signal to bypass the amplifier is provided,
The route selecting means determines whether or not the communication state of the wireless communication circuit is good and, based on the determination result, controls means for generating a first control signal for selecting either the amplification route or the bypass route. Prepared,
The control means, if the reception status of the reception data generated from the signal received by the wireless communication circuit matches the content notified by the communication device of the communication partner prior to the reception of the signal, A circuit for wireless communication, characterized in that it is determined that A wireless communication circuit having an amplifier for amplifying a signal,
An amplification route through which the signal passes through the amplifier;
Route selection means for selectively selecting either one of the bypass route for the signal to bypass the amplifier is provided,
The route selecting means determines whether or not the communication state of the wireless communication circuit is good and, based on the determination result, controls means for generating a first control signal for selecting either the amplification route or the bypass route. Prepared ,
The control means selects the bypass route when it is determined that the communication state is good even when the intensity of the signal received by the wireless communication circuit is lower than or lower than a preset threshold value. In generating the first control signal, the reception status of the reception data generated from the signal received by the circuit for wireless communication matches the content notified from the communication device of the communication partner prior to the reception of the signal. A circuit for wireless communication , wherein the communication state is determined to be good . A wireless communication circuit having an amplifier for amplifying a signal,
An amplification route through which the signal passes through the amplifier;
Route selection means for selectively selecting either one of the bypass route for the signal to bypass the amplifier is provided,
The route selecting means determines whether or not the communication state of the wireless communication circuit is good and, based on the determination result, controls means for generating a first control signal for selecting either the amplification route or the bypass route. Prepared,
The control means selects an amplification route when it is determined that the communication state is poor even when the intensity of the signal received by the wireless communication circuit exceeds or exceeds a preset threshold. In generating the first control signal, the reception status of the reception data generated from the signal received by the circuit for wireless communication matches the content notified from the communication device of the communication partner prior to the reception of the signal. If the communication state is good, it is determined that the communication state is good . It said control means, from the other communication device which has transmitted the information signal, when not receiving the retransmission request for the information signals, any one thing determines that the communication state is good claim 1, wherein 3 A circuit for wireless communication according to 1. It said control means detects an error of the received data generated from the signal received by the wireless communication circuit, when the detected error level does not exceed the threshold value, and wherein the determining the communication state is good The circuit for radio | wireless communication of any one of Claim 1 to 4 . The control means acquires time information for executing an application related to the received data from the received data generated from the signal received by the wireless communication circuit, compares the reception time of the signal with the time information, receiving data of the signal, if it is determined that time for the time to execute the application, wireless communication circuit according to claim 1, any one of 5, characterized in that determines the communication state is good . The control means determines that the communication state is good when an error resilience tool provided in an application that uses received data generated from a signal received by the circuit for wireless communication does not operate. 7. The wireless communication circuit according to any one of 1 to 6 . When the reception data generated from the signal received by the circuit for wireless communication is streaming data, a reception buffer for temporarily storing the reception data is provided,
The control means receives information on the bit rate of the received data and the buffer size required to temporarily store the received data from the communication device that transmits the received data, and stores the received data in the receive buffer. The buffer full time t required for accumulation is obtained from the bit rate and the buffer size, the buffering time t ′ required for actually storing the received data in the reception buffer is compared with the buffer full time t, and t ′ ≦ If the relation of t is established, the wireless communication circuit according to any one of claims 1 to 7, characterized in that determines the communication state is good. 9. The wireless communication circuit according to claim 8, wherein when the reception buffer becomes empty during reception of the reception data, the control means determines that the communication state is bad . When a communication device including the wireless communication circuit performs two-way communication with a communication partner communication device, if reception data generated from a signal received by the wireless communication circuit is continuously decoded, control means, the wireless communication circuit according to any one of claims 1 to 9, characterized in that determines the communication state is good. A threshold is set for the number of times that the control means determines that the communication state is not good, and the control means determines that the communication state is good when the number of times is less than or less than the threshold. The circuit for wireless communication according to any one of claims 1 to 10 . The power supply off means which turns off the power supply to the said amplifier in cooperation with having selected the bypass route by the said route selection means is provided in any one of Claim 1 to 11 characterized by the above-mentioned. The circuit for wireless communication as described. The wireless communication circuit according to any one of claims 1 to 12 , wherein the bypass route is provided with an attenuator for attenuating the signal . The bypass route, wireless communication circuit according to claim 1, any one of 12, characterized in that the variable attenuator the attenuation rate is variable is provided. The amplifier, the wireless communication circuit according to any one of claims 1 to 4, characterized in that a power amplifier for amplifying a signal to be transmitted. 16. The wireless communication circuit according to claim 1, wherein the amplifier is a low noise amplifier that amplifies a received signal . A wireless communication apparatus comprising the wireless communication circuit according to claim 1. A wireless communication system comprising the wireless communication device according to claim 17. The route selection means includes power-off means for turning off the power supply to the amplifier in cooperation with the selection of the bypass route.
The power-off means reports the result of the quality determination of the communication state in the reception-side wireless communication device to the transmission-side wireless communication device, and based on the determination of the reception-side wireless communication device, the transmission-side wireless communication device 19. The wireless communication system according to claim 18, wherein the power source of the amplifier is turned on / off.

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