JP4177836B2 - RECEIVING DEVICE, SEMICONDUCTOR INTEGRATED CIRCUIT, TRANSMITTING / RECEIVING DEVICE, TRANSPORTING DEVICE, PORTABLE TRANSMITTING / TRANSMITTING DEVICE, COMMUNICATION DEVICE, AND RECEIVING METHOD - Google Patents

Description

  The present invention relates to a receiving apparatus used for small area communication represented by narrow area communication, wireless LAN, and the like, a transmission / reception apparatus including the receiving apparatus, a transportation apparatus, and a communication apparatus.

  FIG. 23 is a block diagram showing a configuration of a vehicle-mounted communication device used for conventional narrow-area communication and the like. The in-vehicle communication device shown in the figure includes a control unit 171 having a CPU 172 and a signal processing circuit 173, a transmitter 174, a circulator 175 connected to an antenna 176, a receiver 177, and an oscillator 178. . In addition, a power supply circuit 179 that supplies a power supply voltage is connected to the signal processing circuit 173, the CPU 172, the receiver 177, and the oscillator 178. A power supply voltage is supplied to the transmitter 174 via a switch circuit (SW circuit) 180 (see, for example, Patent Document 1).

  Next, the operation of the conventional in-vehicle communication device will be further described.

  FIG. 24 is a diagram illustrating the operation of a conventional in-vehicle communication device. In an ETC (Electric Toll Collection) or the like, when a vehicle equipped with a vehicle-mounted communication device is outside the communication area of the antenna of the base station (roadside wireless device), the timer function of the CPU 172 operates and a predetermined value set in this timer When the time elapses, the vehicle-mounted communication device enters the sleep mode. In this sleep mode, the CPU 172 and the oscillator 178 are stopped by the control of the signal processing circuit 173, the switch circuit 180 is turned off, and the power supply to the transmitter 174 is stopped.

  In this state, the vehicle equipped with the vehicle-mounted communication device approaches the communication area of the antenna of the base station (roadside wireless device), and the antenna 176 of the vehicle-mounted communication device is called a call data signal from the base station (roadside wireless device). In response to the reception of the data signal, the signal processing circuit 173 operates the oscillator 178 and the CPU 172, turns on the switch circuit 180, and supplies power to the transmitter 174. As a result, the vehicle-mounted communication device is in the active mode, and transmission to the base station is possible.

  When the transmission to the base station is completed, the vehicle-mounted communication device is in the halt mode. In this halt mode, only the CPU 172 and the transmitter 174 are stopped while the oscillator 178 remains in the operating state. When the vehicle-mounted communication device resumes operation, since the oscillator 178 is operating, there is no waiting time required to start the operation of the oscillator 178, and the active mode can be quickly returned from the halt mode.

In the above conventional example, the halt mode is set between the sleep mode and the active mode. As a result, power consumption during non-communication can be suppressed and the active mode can be quickly returned to the reconnection request, so that the response speed to the reconnection request can be increased.
JP 2000-278201 A JP 2002-260034 A

  Communication devices are expected to become more sophisticated in the future, and reduction of power consumption is strongly demanded. In particular, it may be possible to make a receiving apparatus that receives a signal transmitted from a base station portable, and in that case, reduction of power consumption becomes more important than ever. However, in the conventional technology for reducing power consumption in the vehicle-mounted communication device described in Patent Document 1, one threshold is provided for the received electric field strength, and the circuit can be stopped during non-communication based on the threshold. Is a transmitter, an oscillator, a CPU, etc., and other circuits such as a receiver must always be turned on to determine whether they are in the communication area of the antenna of the base station. It could not be reduced.

  The present invention solves the above-described conventional problems, and can reduce power consumption during non-communication without lowering the reception speed for a signal transmitted from a base station, and uses the same. The purpose is to provide a communication method.

  In order to solve the above-described problems, the present invention provides a receiving device included in a communication device (mobile station) that is 2 times higher than a received electric field strength of a radio wave transmitted from a base station (roadside wireless communication device) and received by the receiving device. It is characterized by providing two or more threshold values.

  As a result, by using only the comparison result of the received electric field strength based on the threshold value, the position information of the receiving device, the moving speed of the receiving device, etc., in order to start up only the circuits necessary for communication in order, It is possible to stop power supply to unnecessary circuits and reduce power consumption.

That is, the receiving device of the present invention is a receiving device that receives a signal transmitted from a base station, and that receives a received electric field strength of a signal received via an antenna as a received electric field strength signal, and a receiving circuit. the level of the reception electric field intensity signal output from, indicates that the receiving device is a communication area, at a lower value than the first threshold and the first threshold is a communication start level for communication with the base station A comparison circuit that uses the second threshold value indicating the electric field strength measurement level at which the continuous operation of the reception circuit is started, and outputs a comparison result, and a period for intermittently operating the reception circuit An intermittent reception control circuit that outputs a signal, and an operation control circuit that controls the operation of the reception circuit based on the comparison result of the comparison circuit, and the operation control circuit determines the level of the received electric field strength signal as a result of the comparison by the comparison circuit But Lower than second threshold, the reception circuit on the basis of the periodic signal is intermittent operation, when the level of reception electric field intensity signal is equal to or higher than the second threshold value, thereby continuously operating the receiver circuit.

  Thus, when the electric field strength of the received signal is weak, the receiving circuit is operated intermittently. Thereby, power consumption can be reduced as compared with the case where the receiving circuit is operated continuously. Further, when the level of the received electric field strength signal becomes equal to or higher than the second threshold value, it is possible to prevent a delay in the receiving operation by operating the receiving circuit.

  In the present invention, the receiving circuit further has a function of amplifying and outputting the received signal, and further includes a demodulating circuit that demodulates the signal amplified by the receiving circuit and outputs the demodulated signal. Thus, in the configuration including the demodulation circuit, the operation control circuit preferably controls the operation of the demodulation circuit. In such a case, the operation of the demodulation circuit can be stopped as appropriate, so that power consumption in the power supply of the demodulation circuit can be reduced.

  In the present invention described above, the operation control circuit preferably operates the demodulation circuit when the level of the received electric field strength signal exceeds the first threshold as a result of the comparison in the comparison circuit. Thereby, the demodulation of the received signal can be performed without delay.

  Furthermore, it is preferable that the operation control circuit supplies the first clock signal to the demodulation circuit when the level of the received electric field strength signal exceeds the first threshold as a result of the comparison in the comparison circuit. As described above, the operation control circuit can supply the clock signal to the demodulation circuit, which is effective when the demodulation circuit is a digital circuit.

  In the present invention described above, it is preferable to further include a signal processing circuit that processes the demodulated signal output from the demodulation circuit, and an arithmetic processing device that performs arithmetic processing on the demodulated signal processed by the signal processing circuit. In such a configuration, the operation control circuit supplies the second clock signal to the signal processing circuit and the arithmetic processing unit when the level of the received electric field strength signal is lower than the second threshold as a result of the comparison in the comparison circuit, And it is preferable to control. Therefore, the operation of the signal processing circuit and the arithmetic processing unit can be controlled by appropriately controlling the second clock signal by the operation control circuit. For example, when the level of the received electric field strength signal is equal to or lower than the second threshold, the operation of the signal processing circuit and the arithmetic processing device is stopped by stopping the supply of the second clock signal, and the power consumption of each circuit Can also be reduced.

  Moreover, it is preferable that the 2nd threshold value in this invention mentioned above consists of a 1st boundary value smaller than a 2nd threshold value, and a 2nd boundary value larger than a 2nd threshold value. In such a case, when the received electric field strength signal increases and exceeds the second boundary value, the receiving circuit can shift from the intermittent operation to the continuous operation. On the other hand, when the received electric field strength decreases and reaches the first boundary value, the receiving circuit can shift from continuous operation to intermittent operation. That is, the first boundary value can be defined as the power-off determination level of the receiving circuit, and the second boundary value can be defined as the power-on determination level of the receiving circuit. As described above, by providing each boundary value corresponding to the upper limit and the lower limit of the second threshold, it is possible to remove the influence of noise included in the electric field strength of the reception signal on the operation of the reception circuit. Therefore, even when the received electric field strength signal varies up and down due to noise, it is possible to prevent malfunction of the receiving circuit and to provide stable operation of the receiving circuit.

  The above-described receiving apparatus according to the present invention is characterized in that it further includes speed detecting means for detecting the moving speed of the receiving apparatus (or communication apparatus) and outputting the detected speed as a speed signal. Further, it is preferable that the comparison circuit varies the second threshold value in accordance with the speed signal output from the speed detection means. Therefore, it is possible to flexibly cope with a change in the moving speed of the receiving device (communication device) so that the operation of the receiving circuit is not delayed. In such a configuration, when the moving speed of the receiving device (communication device) increases, the comparison circuit preferably varies the second threshold so that the difference between the first threshold and the second threshold is widened. . When the moving speed of the receiving device (communication device) is fast, the receiving device approaches the base station earlier, so the receiving circuit is shifted from intermittent operation to continuous operation at an earlier time point by lowering the second threshold. Can do. Accordingly, since the communication standby state is entered at an early point, communication with the base station can be started without delay. On the other hand, when the moving speed of the receiving device (communication device) is slow, it takes time for the receiving device to approach the base station. Therefore, by increasing the second threshold value, the cycle of the intermittent operation of the receiving circuit is relatively set. Can be long. Thereby, when the moving speed of the receiving device (communication device) is slow, the power consumption of the receiving circuit can be reduced by increasing the second threshold value.

In the above-described receiving apparatus of the present invention, it is preferable that the intermittent reception control circuit varies the period of the periodic signal in accordance with the received electric field strength signal. In such a configuration, when the level of the received electric field strength signal becomes high, the intermittent control circuit can shorten the cycle of the intermittent operation. Therefore, since the receiving circuit is operated in a short cycle, it is possible to cope with a change in the received electric field strength signal more quickly. For this reason, it is possible to determine the time when the received electric field intensity exceeds the second threshold value while reducing the degree of error, and thus it is possible to prevent a delay in the operation of the receiving circuit.

In addition, the present invention preferably further includes speed detection means for detecting the moving speed of the receiving device (communication device) and outputting the detected speed as a speed signal. Further, in such a configuration, it is preferable that the intermittent reception control circuit varies the period of the periodic signal in accordance with the speed signal. Thereby, since the intermittent period of the receiving circuit can be changed according to the change in the moving speed of the receiving device (communication device), the delay of the operation of the receiving circuit can be prevented. For example, in the above configuration, when the moving speed of the receiving device (communication device) increases, the distance between the receiving device and the base station decreases rapidly, so that the intermittent operation cycle can be shortened. Therefore, when the moving speed of the receiving apparatus is high, the receiving circuit is operated in a short cycle, so that the transition from the intermittent operation to the continuous operation of the receiving circuit can be effectively performed without delay.

The present invention is further characterized by further comprising storage means for storing position information of the base station and position detection means for detecting the position of the receiving apparatus. In this configuration, it is preferable that the intermittent reception control circuit varies the period of the periodic signal in accordance with a comparison result between the position of the base station stored in the storage unit and the detection result of the position detection unit. As a result, the distance between the base station and the receiving apparatus can be appropriately grasped and the period of the intermittent operation can be changed, so that the delay of the transition to the continuous operation of the receiving circuit can be prevented.

  For example, when the distance between the base station and the receiving device decreases, it is preferable that the intermittent control circuit shortens the cycle of the intermittent operation of the receiving device. Thereby, since the receiving circuit can measure the received electric field intensity in a short period, the transition from the intermittent operation to the continuous operation of the receiving circuit can be effectively performed without delay.

  Further, in the above configuration, when the receiving apparatus passes through a new base station, it is preferable that the position of the new base station is written in the storage means. Accordingly, by newly storing the position information of the base station not stored in the storage unit in the storage unit, when the base station passes through the base station from the second time, the base station can be handled as a known base station. Will be able to. Therefore, a delay in the operation of the receiving circuit can be prevented.

  The present invention is further characterized by further comprising a reception control circuit for controlling a reception time for the reception circuit to receive a signal via the antenna. In this configuration, in addition to the first threshold value and the second threshold value, the comparison circuit compares the level of the received electric field strength signal using a third threshold value that is lower than the second threshold value and indicates the presence or absence of the received signal. It is preferable. At this time, the reception control circuit receives the reception time when the level of the received electric field strength signal exceeds the third threshold as a result of the comparison in the comparison circuit than when the level of the received electric field strength signal is equal to or lower than the third threshold. It is preferable to lengthen the length. Thereby, for example, even when there are a plurality of communication frequencies of the received signal, the influence of other frequency signals can be removed.

  Further, the intermittent reception control circuit preferably lengthens the period in the intermittent operation of the reception circuit when the level of the received electric field strength signal is equal to or lower than the third threshold value.

  In the receiving apparatus of the present invention, when the received signal includes a plurality of frequency signals, the comparison circuit may compare each of the plurality of frequency signals with a threshold value. At this time, if the level of the received electric field strength signal for any one of the plurality of frequency signals is higher than the third threshold as a result of the comparison by the comparison circuit, the reception control circuit receives the received electric field strength. It is preferable that the operation time in the intermittent operation of the receiving circuit is made longer than when the signal level is equal to or lower than the third threshold value. As a result, it is possible to receive the signal having the strongest frequency over a period of time that can remove the influence of other frequency signals. Therefore, it is possible to reliably receive a signal having a frequency used by the base station.

  The receiving apparatus of the present invention may further include a reception control circuit that controls the reception time of the received signal, and the received signal may include a plurality of frequency signals. In this case, the comparison circuit compares each of the plurality of frequency signals, and the reception control circuit determines that the level of the received electric field strength signal for any one of the plurality of frequency signals is the result of the comparison by the comparison circuit. When larger than the third threshold, it is preferable to increase the reception time of the receiving circuit for other frequency signals as compared to the case where all of the plurality of frequency signals are equal to or smaller than the third threshold. As a result, the influence of other frequency signals can be removed, and a signal having a frequency generated by the base station can be reliably received.

  In the present invention, it is preferable that a reception control circuit for measuring the rate of change of the received electric field strength is further provided, and the reception control circuit varies the reception time for receiving the signal according to the rate of change. Thereby, reception of a received signal can be made more reliable.

  In the present invention, when the received signal includes a plurality of frequency signals, it is preferable that the comparison circuit compares each of the plurality of frequency signals with a threshold value. Further, when the rate of change in the received electric field strength for any one of the plurality of frequency signals increases, the reception control circuit increases the operation time in the intermittent operation of the reception circuit for the frequency signal. The frequency signal emitted from the base station can be reliably received.

  The receiving apparatus of the present invention also includes a receiving control circuit for controlling a receiving time for the receiving circuit to receive a signal via an antenna, and a storage means for storing the position of the base station and the frequency information of the signal transmitted by the base station And a position detecting means for detecting the position of the receiving device. In this configuration, it is preferable that the reception control circuit varies the reception time according to a comparison result between the position of the base station stored in the storage unit and the detection result of the position detection unit. As a result, it is possible to keep the delay time for starting reception small without being affected by noise and obstacles.

  In the present invention, when the distance between the base station and the receiving apparatus decreases, it is preferable to increase the reception time for a signal transmitted from the base station. As a result, the delay in starting reception can be reduced.

  In the present invention, it is preferable to further include a channel selection means for selecting one frequency signal received by the receiving circuit from a plurality of frequency signals based on the output of the reception control circuit. In this configuration, the channel selection means selects a frequency signal in which the level of the received electric field strength signal exceeds the second threshold value from among the plurality of frequency signals as a result of comparison in the comparison circuit, and the reception circuit selects the selected frequency signal. Can be received.

  In addition, the above-described receiving apparatus, an antenna that receives a signal transmitted from the base station, and a signal input (received) via the antenna are processed and output (transmitted) to the base station via the antenna again. It is preferable to configure a communication device that can transmit and receive signals.

  Moreover, it is preferable that the communication device according to the present invention described above is integrated on a semiconductor substrate to constitute a semiconductor integrated circuit. As described above, a transmission / reception IC including a reception device and a transmission device, a control unit including a signal processing circuit and a CPU, and an antenna can be mounted on one chip.

  Moreover, it is preferable to provide the above-described receiving device in a transportation device such as a car. In such a case, the communication device can obtain power from a drive motor or the like that the transport device has, and can transmit and receive information to and from a fixed base station without delay when the transport device is moving. Become.

  Further, the above-described receiving device can be used for a portable wireless communication device, other communication devices, and the like.

  The receiving apparatus according to the present invention further includes a notification unit that notifies that the level of the received electric field strength signal exceeds the second threshold as a result of comparison by the comparison circuit. For example, in the ETC system, it is possible to prevent the user from forgetting to insert an external component such as a fee payment card by notifying that the second threshold has been exceeded when approaching a toll gate that is a base station. . Therefore, the exchange of information at the toll gate (base station) can be performed reliably.

The receiving method of the present invention is a receiving method using a receiving device that receives a signal transmitted from a base station, and includes a first step of receiving the signal received via an antenna by a receiving circuit; second and steps, the level of the output the received field strength signal, indicates that the receiving device is a communication region for outputting a reception electric field intensity of the signal from the receiving circuit as the reception field strength signal A first threshold value that is a communication start level of communication with the base station, and a second value that is lower than the first threshold value and indicates a field strength measurement level at which continuous operation of the receiving circuit is started A third step of comparing using a threshold value, a fourth step of intermittently operating the receiving circuit when the level of the received electric field strength signal is lower than the second threshold value as a result of the comparison, and the comparison As a result of the reception Level of the field strength signal and a fifth step of continuously operating the receiver circuit in the case of more than the second threshold value.

  Thus, according to the method of the present invention, the reception circuit is intermittently operated when the electric field strength of the reception signal is weak. As a result, power consumption can be reduced as compared with the case where the receiving circuit is always operated. Further, when the level of the received electric field strength signal becomes equal to or higher than the second threshold value, it is possible to prevent a delay in the receiving operation by operating the receiving circuit.

  The reception method of the present invention further includes a sixth step of operating a demodulation circuit that demodulates the signal received by the reception circuit when the level of the received electric field strength signal is equal to or higher than the first threshold as a result of the comparison. Yes.

  As a result, when the receiving apparatus enters the communication area, signal reception can be started without delay. Further, the operation of the demodulation circuit can be stopped when the level of the received electric field strength signal is lower than the first threshold, and in this case, the power consumption in the power supply of the demodulation circuit can be reduced.

  In the present invention, it is preferable that the sixth step supplies a demodulation operation clock signal to the demodulation circuit. Thus, supplying the clock signal to the demodulation circuit is effective when the demodulation circuit is a digital circuit.

  In the receiving method of the present invention, the fourth and fifth steps include a step of supplying a clock signal to a signal processing circuit that processes a signal output from the receiving circuit and an arithmetic processing device that performs arithmetic processing on the signal processed signal. It is preferable.

  In the third step, the second threshold value is compared with the level of the received electric field strength signal by hysteresis control using a first boundary value lower than the second threshold value and a second boundary value higher than the second threshold value. It is preferable to include a process. In such a case, the reception circuit can shift from the intermittent operation to the continuous operation when the received electric field strength signal increases and exceeds the second boundary value level. On the other hand, when the received electric field strength signal decreases and reaches the first boundary value level, the receiving circuit can shift from continuous operation to intermittent operation. That is, the first boundary value can be defined as the power-off determination level of the receiving circuit, and the second boundary value can be defined as the power-on determination level of the receiving circuit. As described above, by providing each boundary value corresponding to the upper limit and the lower limit of the second threshold, it is possible to remove the influence of noise included in the electric field strength of the reception signal on the operation of the reception circuit. Therefore, even when the received electric field strength signal varies up and down due to noise, it is possible to prevent malfunction of the receiving circuit and to provide stable operation of the receiving circuit.

  The receiving method of the present invention includes a seventh step of detecting the moving speed of the receiving device and outputting the detected moving speed as a speed signal before the third step, and a second step according to the speed signal. It is preferable to further include an eighth step of changing the threshold value. Thereby, it is possible to flexibly cope with a change in the moving speed of the receiving device (communication device) so that the operation of the receiving circuit is not delayed.

  In the present invention, it is preferable that the eighth step fluctuates the second threshold value so that the difference between the first threshold value and the second threshold value increases when the moving speed increases. Therefore, it is possible to flexibly cope with a change in the moving speed of the receiving device (communication device) so that the operation of the receiving circuit is not delayed.

  In the reception method of the present invention, it is preferable that the fourth step includes a ninth step of changing the period of the intermittent operation according to the received electric field strength signal. In this reception method, in the ninth step, the period of the intermittent operation can be shortened when the level of the received electric field strength signal is high. Therefore, since the receiving circuit is operated in a short cycle, it is possible to cope with a change in the received electric field strength signal more quickly. For this reason, it is possible to determine the time when the received electric field intensity exceeds the second threshold value while reducing the degree of error, and thus it is possible to prevent a delay in the operation of the receiving circuit.

  The receiving method of the present invention includes a tenth step of detecting a moving speed of the receiving device and outputting the detected moving speed as a speed signal, and an eleventh step of changing the cycle of the intermittent operation according to the speed signal. It is preferable to further include a step. As a result, the intermittent cycle of the receiving circuit can be changed in accordance with a change in the moving speed of the receiving device (communication device), so that it is possible to prevent a delay in starting the operation of the receiving circuit.

  In the reception method of the present invention, in the eleventh step, it is preferable to shorten the cycle of the intermittent operation when the moving speed increases. Therefore, when the moving speed of the receiving apparatus is high, the receiving circuit is operated in a short cycle, so that the transition from the intermittent operation to the continuous operation of the receiving circuit can be effectively performed without delay.

  The receiving method of the present invention further includes a step of detecting a position of the receiving device, and a step of calculating a distance between the position of the base station stored in the receiving device and the detected position of the receiving device. It is characterized by being. In this case, it is preferable that the fourth step further includes a twelfth step of changing the cycle of the intermittent operation according to the calculated distance. As a result, the distance between the base station and the receiving apparatus can be appropriately grasped and the period of the intermittent operation can be changed, so that the delay of the transition to the continuous operation of the receiving circuit can be prevented.

  In the reception method of the present invention described above, in the twelfth step, when the distance between the base station and the reception apparatus decreases, it is preferable to shorten the cycle of the intermittent operation.

  In the reception method of the present invention, the third step further includes a step of indicating presence / absence of a signal to be received and comparing a third threshold value lower than the second threshold value with the level of the received electric field strength signal. In this case, in the fourth step, as a result of the comparison, when the level of the received electric field strength signal exceeds the third threshold, the operation of the receiving circuit is performed more than when the level of the received electric field strength signal is equal to or lower than the third threshold. It is preferable to include a step of increasing the time. Thereby, for example, even when there are a plurality of communication frequencies of the received signal, the influence of other frequency signals can be removed.

  In the reception method of the present invention, it is preferable that the fourth step includes a step of changing a reception time in which the reception circuit receives a signal in accordance with a change rate of the received electric field strength. Thereby, reception of a received signal can be made more reliable.

  The reception method of the present invention described above further includes a step of detecting the position of the reception device and a step of calculating a distance between the position of the base station stored in the reception device and the detected reception device. You may do it. In this case, it is preferable that the fourth step includes a step of changing a reception time in which the reception circuit receives a signal according to the calculated distance. As a result, it is possible to keep the delay time for starting reception small without being affected by noise and obstacles.

  It is preferable that the reception method of the present invention includes a step of selecting, after the third step, a signal whose received electric field strength signal level is equal to or higher than the second threshold among the plurality of reception signals.

  In the receiving method of the present invention, it is preferable that the fifth step includes a step of notifying that the level of the received electric field strength signal is equal to or higher than the second threshold value. For example, in the ETC system, it is possible to prevent the user from forgetting to insert an external component such as a fee payment card by notifying that the second threshold has been exceeded when approaching a toll gate that is a base station. . Therefore, the exchange of information at the toll gate (base station) can be performed reliably.

  As described above, according to the receiving device or the communication device and the communication method using the same according to the present invention, the operation of each circuit of the receiving device and the communication device is controlled by the reception state, position information, moving speed, etc. of the receiving device. By doing so, it is possible to reduce power consumption and to prevent delay in starting communication with the base station.

  Hereinafter, embodiments of a receiving apparatus according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing an example of a configuration of a receiving apparatus according to the first embodiment of the present invention. As shown in the figure, the receiving apparatus of this embodiment receives a signal transmitted from a base station (not shown) via an antenna 7, and outputs the received signal strength of the received signal as a received signal strength signal. And a demodulation circuit 2 that demodulates and outputs the reception signal processed by the reception circuit 1. In addition, the receiving apparatus of the present embodiment intermittently connects the receiving circuit 1 and the comparing circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with the first threshold value and the second threshold value. An intermittent reception control circuit 5 that outputs a signal for operation is provided. Here, in other words, the intermittent reception control circuit 5 outputs an intermittent periodic signal for causing the reception circuit 1 to intermittently receive the received electric field strength signal. Furthermore, the receiving apparatus of this embodiment controls the output of the operation control circuit 4 according to the comparison result by the operation control circuit 4 which controls supply of the power supply voltage to the receiving circuit 1 and the demodulation circuit 2, and the comparison circuit 3. The determination circuit 8 includes a signal processing circuit 9 for processing the demodulated signal output from the demodulation circuit 2 and a CPU (arithmetic processing unit) 10. The determination circuit 8 is configured by a logic circuit or the like.

  In the above-described receiving device, the operation control circuit 4 determines whether the level of the received electric field strength signal is equal to or lower than the second threshold value in the comparison circuit 3 according to the output from the intermittent reception control circuit 5. Supply power intermittently. The second threshold will be described later.

  When the comparison circuit 3 determines that the level of the received electric field strength signal exceeds the second threshold value, the operation control circuit 4 continuously supplies power to the reception circuit 1 regardless of the output of the intermittent reception control circuit 5. Control to supply. At this time, the determination circuit 8 determines whether the reception circuit 1 performs intermittent reception or continuous reception based on the determination result of the comparison circuit 3 and the intermittent periodic signal of the intermittent reception control circuit 5, and the result is obtained. This is output to the operation control circuit 4.

  As described above, the receiving apparatus according to the present embodiment is characterized in that the intermittent operation control circuit 5 is provided to effectively incorporate the intermittent operation of the receiving circuit 1. Here, the first threshold indicates a communication start level (reception start level) with the base station, and the second threshold indicates a continuous electric field strength measurement start level (reception circuit operation start level).

  The receiving apparatus in the present invention receives a signal including information transmitted from a base station, such as an ETC system (Electronic Toll Collection System) or a DRSC (Dedicated Short Range Communications) system, or processes the received signal, The signal is used in a mobile station communication device that transmits the received signal to a base station. This mobile station is installed or carried on a moving object such as a car or a person, and can communicate within a distance of approximately 20 m or less between the base station and the mobile station.

  Next, the operation of this receiving apparatus will be described with reference to FIGS. FIG. 2 is a diagram illustrating a control method of the receiving apparatus illustrated in FIG. The horizontal axis in FIG. 2 indicates the moving distance (hereinafter referred to as time t) when it is assumed that the communication apparatus is moving at a constant speed, and the vertical axis indicates the received electric field strength at time t. Note that “s1” shown in the figure represents a demodulated signal output from the demodulating circuit 2 shown in FIG. “S2” represents a signal (power supply voltage) that the operation control circuit 4 supplies to the reception circuit 1. “S3” represents a signal (power supply voltage) supplied from the operation control circuit 4 to the demodulation circuit 2. “S4” represents the received electric field strength signal 25 output from the reception circuit 1 to the comparison circuit 3. For the sake of simplicity, FIG. 2 shows the received electric field strength signal 25 when the receiving apparatus (mobile station) according to the present invention approaches the base station, and the received electric field strength signal is proportional to the time. The present embodiment will be described below in the case where 25 becomes large. In practice, however, the received electric field strength signal is not linear and vibrates up and down. Needless to say, the present embodiment is merely an example, and can be applied to reception electric field strength signals of other shapes.

  Further, as shown in FIG. 2, in the demodulated signal s1, the signal section 20 is a part including information for the own station (target receiving apparatus), and the signal section 21 is a demodulated signal and does not include information for the own station. Part. However, it goes without saying that it is not limited to the signal sections 20 and 21 shown in the figure.

  In the present embodiment, first, when the receiving apparatus is far from the base station (before time t1), that is, the comparison circuit 3 determines that the received electric field strength v is smaller than the second threshold 27 (continuous electric field strength measurement start level v2). In this case, as in the signal section (intermittent reception section) 22 shown in FIG. Here, the comparison circuit 3 measures the reception electric field strength v of the communication frequency while the power supply of the reception circuit 1 is ON (intermittent reception section). That is, in the signal section 22, the received electric field strength v is measured intermittently. Note that the power supply to the demodulation circuit 2 is stopped during the signal section 22, and the operations of the CPU 10 and the signal processing circuit 9 are also stopped or operated at a low speed by a clock.

  Further, when the receiving apparatus approaches the base station, the received electric field strength v increases with time (distance). Eventually, when the second threshold value 27 (continuous electric field strength measurement start level v2) is exceeded at time t1, the comparison circuit 3 determines that the communication area is approaching, and reception is performed as in the reception circuit power ON section 23. Continue supplying power to circuit 1. As described above, the reception circuit 1 changes from the intermittent reception state (intermittent reception section; signal section 22) to the continuous reception state (continuous reception section; reception circuit power ON section 23), and continuously measures the received electric field strength v. Here, the power supply to the demodulation circuit 2 has not been started yet, and the signal processing circuit 9 for processing the demodulated signal is not operating. On the other hand, the CPU 10 operates or operates at a low speed.

  Subsequently, when the receiving device further approaches the base station and the received electric field strength v exceeds the first threshold value 26 (reception start level v1) at time t2, the comparison circuit 3 determines that the receiving device has entered the communication area. To do. As a result, the power of the demodulating circuit 2 and the signal processing circuit 9 is turned on by the operation control circuit 4, and the CPU 10 enters an operating state. At this time t2, the demodulator circuit 2 enters the demodulator circuit power ON section 24. As a result, the reception signal input from the antenna 7 through the reception circuit 1 to the demodulation circuit 2 is output as the demodulation signal s1. The demodulated signal s1 in the signal section 20 is processed by the signal processing circuit 9.

  In the present embodiment, the first threshold value 26 is larger than the second threshold value 27, and both the first threshold value 26 and the second threshold value 27 are held in the comparison circuit 3.

  According to the receiving apparatus of this embodiment, when the receiving apparatus (mobile station) is located away from the base station, the receiving circuit 1 performs intermittent reception and the power of the demodulating circuit 2 is turned off. , 24, the power consumption in the receiving circuit 1 and the demodulating circuit 2 can be reduced. That is, it is possible to reduce the power consumption in the reception standby state outside the communication area with the base station. Therefore, the receiving apparatus according to the present embodiment is preferably used for a portable type transmission / reception apparatus that requires reduction of power consumption, in addition to a narrow-range communication or a wireless LAN in-vehicle communication device.

  In particular, in-vehicle transmission / reception devices such as ETC have been conventionally powered directly from the vehicle body (battery), so that they can always supply power and there is no need for low power consumption. However, the temperature inside the vehicle may be higher than room temperature, and if the power source of the transmission / reception device is always in an ON state in such an environment, the transmission / reception device may be heated. However, as described above, according to the present invention, as the power consumption is reduced, the heat generation of the transmission / reception device can be reduced, and the heat resistance reliability of the transmission / reception device can be further improved. Yes.

  In addition, the threshold for turning on the power of the receiving circuit 1 (second threshold 27) is set separately from the threshold for turning on the power of the demodulating circuit 2 (first threshold 26). Therefore, the power supply of the receiving circuit 1 can be turned on before the demodulating circuit 2, and the receiving device can be quickly started up and communicated with the base station when approaching the communication area. For this reason, for example, when the receiving device of this embodiment is used in a transmitting / receiving device for ETC, the receiving device is operated without delay before the toll gate. It is possible to prevent accidents such as the car colliding with the opening / closing bar of the toll gate due to the delay of the start.

  When the receiving circuit 1 or the demodulating circuit 2 uses a digital circuit, the same effect can be obtained even if the clock signal is controlled instead of controlling the power supply, and the current consumption can be reduced. In this case, an operation control circuit for controlling the clock supply to the receiving circuit 1, the demodulating circuit 2, the signal processing circuit 9, and the CPU 10 may be provided instead of the operation control circuit 4.

  Note that the receiving device of this embodiment or a transport device (such as a vehicle equipped with an ETC system) equipped with the receiving device warns that the received electric field strength v exceeds the second threshold value 27 by sound or color. You may have a notice part to do. For example, in the case of warning by sound, a device that emits a sound such as music or buzzer, and in the case of warning by color, any device having a display function such as a light emitting diode or a lamp may be used. Thereby, it is possible to prevent forgetting to attach external parts necessary for communication operation with the base station, such as an ETC card, before entering the toll gate.

  Note that even if a CPU is used instead of the determination circuit 8, the same function as that of the receiving apparatus shown in FIG. 1 can be realized.

  Here, the setting criteria for the first threshold value and the second threshold value described above will be described below.

First threshold level:
The standard sensitivity of the ETC (ASK) receiver specified in ARIB STD-T75 3.4.3.2 reception sensitivity is set to -60 dBm. Must receive.

  Similarly, the no-response input standard has a rule that it should not respond to base station radio waves of −70.5 dBme.ir.p. Therefore, assuming an antenna of about 0 dBi, the lower limit of the first threshold level allowed is about −70 dBm at the input level.

  Therefore, a first threshold level is set between the no-response input standard and the standard reception sensitivity. Here, for example, the range is −70 dBm or more and −60 dBm or less.

Second threshold level:
The second threshold level is set to a range equal to or lower than the upper limit (−70 dBm) of the no-response input level defined in the above-mentioned standard and the level of natural noise at the receiver antenna terminal is about −100 dBm or higher. It is preferable.

  For example, in the case of a receiver with a noise figure of 10 dB, a level that is 10 dB higher than natural noise is the noise level at the time of no input, and in this case, it is preferable to set the second threshold value between -90 dBm and -70 dBm. Also in the present embodiment, the second threshold level is in a range of −90 dBm or more and −70 dBm or less.

  The setting of the first threshold value and the second threshold value described above is the same for the other embodiments described later.

(Second Embodiment)
As a second embodiment of the present invention, hysteresis control used in the receiving apparatus according to each embodiment of the present invention will be described.

  FIG. 3 is a diagram illustrating a method of determining the reception start level v2 (second threshold 27) in the receiving apparatus of this embodiment. As shown in the figure, the signal received by the receiving circuit 1 includes noise and the received electric field strength v varies depending on the measurement time. Therefore, in the receiving apparatus shown in FIG. 1, if the comparison circuit 3 determines the level of the received electric field strength signal 25 based on the second threshold value having a single value, the operation of the receiving circuit 1 may not be performed accurately. is there. That is, due to the influence of noise, the received electric field strength v rises and falls with the threshold as a boundary, and the power of the receiving circuit 1 may be repeatedly turned on and off unintentionally.

  Therefore, as shown in FIG. 3, the receiving circuit power ON determination level (second boundary value 27A) higher than the second threshold 27 and the receiving circuit power OFF determination level (first boundary) lower than the second threshold. The value 27B) is held in the comparison circuit 3, and these are regarded as the second threshold value 27 for determination. That is, when the level of the received electric field strength signal 25 exceeds the second boundary value 27A, the power supply of the receiving circuit 1 is turned on, and when the level of the received electric field strength signal 25 becomes equal to or lower than the first boundary value 27B. Power supply to the receiving circuit 1 (clock supply in the case of a digital circuit) is stopped.

  If the difference between the second boundary value 27A and the first boundary value 27B is appropriately set according to the amplitude of the received signal, an error in determination can be prevented by the above method. Similarly to this, the demodulation circuit 2 can be started without error by setting the demodulation circuit power ON determination level and the demodulation circuit power OFF determination level for the first threshold 26 as well.

  As described above, in the control method of the present embodiment, in order to prevent malfunction of the receiving circuit, etc., the influence of noise included in the electric field strength signal of the received signal using the first boundary value and the second boundary value. Remove. The second boundary value is larger than the first boundary value, and can be the same value as the second threshold value. Further, it is desirable that the first boundary value is equal to or less than the lower limit value of the noise signal of the received electric field intensity due to the movement of the receiving device. For example, it is desirable that the value be 6 dB or less from the second threshold. However, the first boundary value is a value that can be determined to be greater than natural noise when the noise signal level when there is no reception signal of the receiving apparatus is −90 dBm. For example, the first boundary value is desirably set between a value 6 dB lower than the second threshold and −90 dBm.

(Third embodiment)
Hereinafter, a receiving apparatus according to the third embodiment will be described with reference to FIG. However, detailed description of the same contents as in the first embodiment and the same components as in FIG. 1 will be omitted.

  FIG. 4 is a block diagram showing a configuration of a receiving apparatus according to the third embodiment of the present invention. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs a reception signal received via the antenna 7 as a reception electric field strength signal, and the reception signal processed by the reception circuit 1. The demodulating circuit 2 that outputs the signal, the comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with the first threshold value and the second threshold value, and intermittently measures the received electric field strength signal. An intermittent reception control circuit 5 that outputs a signal (intermittent periodic signal) for this purpose, and an operation control circuit 4 that controls the supply of power supply voltage to the reception circuit 1 and the demodulation circuit 2. In addition, the receiving apparatus according to the present embodiment includes a determination circuit 8 that determines a control method of the operation control circuit 4 according to the determination result of the comparison circuit 3, and a signal processing circuit 9 that processes a demodulated signal output from the demodulation circuit 2. And a CPU 10 and speed detecting means 31 for detecting the moving speed of the receiving device and outputting the detection result to the comparison circuit 3. As described above, the receiving apparatus according to the present embodiment has a configuration in which the receiving apparatus according to the first embodiment further includes speed detecting means 31 that detects the moving speed of the receiving apparatus that is a mobile station.

  The operation of this receiving apparatus will be described with reference to FIGS. FIG. 5 is a diagram illustrating a control method of the receiving apparatus illustrated in FIG. In the demodulated signal output shown in the figure, the signal interval 20 is a portion including information for the own station, and the signal interval 21 is a portion not including information for the own station. In the figure, “s1” represents a demodulated signal output from the demodulating circuit 2 shown in FIG. 1, “s2” represents a signal (power supply voltage) supplied to the receiving circuit 1 by the operation control circuit 4, “S3” represents a signal (power supply voltage) supplied from the operation control circuit 4 to the demodulation circuit 2. “S4” represents the received electric field strength signal 25 output from the reception circuit 1 to the comparison circuit 3.

  The feature of the receiving apparatus of the present embodiment is that the second threshold 27 shown in the first embodiment is changed according to the moving speed of the receiving apparatus detected by the speed detecting unit 31, as will be described below. . FIG. 5 shows an example in which the second threshold value 43 when the moving speed of the receiving device is slow and the second threshold value 44 when the moving speed of the receiving device is fast are set. Here, the second threshold value 43 (second threshold level v2) is higher than the second threshold value 44 (second threshold level v3).

  First, when the receiving apparatus approaches the base station from outside the communication area with the base station, the intermittent reception control circuit 5 periodically receives the reception circuit 1 as in the intermittent reception section (signal section 22) shown in FIG. An intermittent cycle signal for turning on / off the power of the receiver is output, and the operation control circuit 4 controls the receiving circuit 1. At this time, the comparison circuit 3 measures the reception electric field strength v of the communication frequency while the power supply of the reception circuit 1 is ON. Further, as the receiving apparatus approaches the base station, the received electric field strength v increases and changes, for example, like a received electric field strength signal 25 shown in FIG.

  Here, the speed detection means 31 measures the moving speed of the receiving device, and if the measured moving speed is equal to or higher than a certain speed, the second threshold value 27 held by the comparison circuit 3 is lowered according to the measurement result, and the first A threshold 44 of 2 is assumed. If the measured moving speed is lower than a certain speed, the second threshold value 27 of the comparison circuit 3 is increased to be the second threshold value 43.

  Here, the certain speed mentioned above refers to a speed that can be traveled safely and safely below the court speed limit outside the communication area. For example, in the case of a highway, the speed is set to 80 km / h or less.

  Therefore, when the moving speed is high, when the received electric field strength v exceeds the second threshold level v3 at time t3 earlier than time t1, the receiving circuit 1 starts from the intermittent reception state (intermittent reception section; signal section 22). The reception circuit power ON section (continuous reception section) 42 in a continuous reception state is obtained.

  On the other hand, when the moving speed is low, when the received electric field strength v exceeds the second threshold level v2 at time t1, the receiving circuit 1 is in a continuous reception state from the intermittent reception state (intermittent reception interval; signal interval 22). The receiver circuit power ON section (continuous reception section) 41 is entered, and the received electric field strength v is continuously measured. Here, power supply to the demodulation circuit 2 is not started, and the signal processing circuit 9 and the CPU (arithmetic processing unit) 10 for processing the demodulated signal s1 are not operating.

  Subsequently, when the received electric field strength v exceeds the first threshold level v1 at time t2, the determination circuit 8 determines that the receiving device has entered the communication area based on the output of the determination result of the comparison circuit 3. Based on the determination result of the determination circuit 8, the operation control circuit 4 starts supplying the power supply voltage to the demodulation circuit 2, and enters the demodulation circuit power supply ON section 24. As a result, the reception signal input from the antenna 7 through the reception circuit 1 to the demodulation circuit 2 is output as the demodulation signal s1. The demodulated signal s1 is processed by the signal processing circuit 9 and the CPU 10.

  In the conventional receiving apparatus, if the moving speed of the receiving apparatus is fast, the receiving apparatus may move a long distance during the sleep mode, and reception start may be delayed. On the other hand, in the receiving apparatus of the present embodiment, when the moving speed of the receiving apparatus increases, the power-on timing of the receiving circuit 1 is advanced, so that the intermittent receiving section 22 to the continuous receiving section (receiving circuit power ON section 42) stably. ) Can be switched to. Therefore, it is possible to prevent a delay in the operation start of the receiving circuit 1. Further, the intermittent reception of the receiving circuit 1 can realize reduction of current consumption in a reception standby state outside the communication area.

  When a digital circuit is used for the receiving circuit 1 or the demodulating circuit 2, the same effect can be obtained by controlling the clock signal instead of controlling the power supply, and the reduction of power consumption can be realized.

  In the present embodiment, the case where the first threshold value is larger than the second threshold value has been described. However, it is only necessary that the received electric field strength v changes according to the time point of the receiving device, and the moving speed of the receiving device is fast. In such a case, the difference between the first threshold value and the second threshold value may be increased.

  As described above, according to the receiving device of the present embodiment, by changing the electric field strength measurement start level (second threshold value) according to the moving speed of the receiving device, the receiving circuit can be set at an appropriate time without delay. The power can be turned on.

  In the present embodiment, the determination as to whether the moving speed of the receiving device is fast or slow may be made by, for example, increasing or decreasing the acceleration of the receiving device. In other words, assuming a case where the vehicle is traveling at a certain speed, the threshold value is lowered when it is known that the vehicle has been accelerated from there, and the threshold value is raised if the vehicle is decelerated. According to this method, the moving speed of the receiving device can be obtained by using the acceleration sensor without attaching a device for measuring the moving speed of the receiving device to the axle or the like. Therefore, wiring is not necessary and the speed of a ship or the like that does not have an axle can be measured.

(Fourth embodiment)
FIG. 6 is a block diagram showing a configuration of a receiving apparatus according to the fourth embodiment of the present invention. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs a reception signal received via the antenna 7 as a reception electric field strength signal, and the reception signal processed by the reception circuit 1. A demodulating circuit 2 that outputs the signal and a comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with a first threshold value and a second threshold value are provided. In addition, the receiving apparatus of the present embodiment outputs a signal for intermittently measuring the received electric field strength signal, and changes the measurement cycle according to the strength of the received electric field strength signal, and the receiving circuit. 1 and the operation control circuit 4 that controls the supply of the power supply voltage to the demodulation circuit 2, the determination circuit 8 that changes the control of the operation control circuit 4 according to the determination result of the comparison circuit 3, and the demodulation circuit 2 A signal processing circuit 9 for processing the demodulated signal and a CPU 10 are provided.

  Unlike the receiving apparatus according to the first embodiment, the receiving apparatus of the present embodiment is characterized in that the intermittent period in the intermittent period signal output from the intermittent reception control circuit 5 can be set according to the received electric field strength signal. And

  The operation of the receiving apparatus of this embodiment will be described with reference to FIGS. FIG. 7 is a diagram illustrating a control method of the receiving apparatus illustrated in FIG. However, the description of the same components as those in FIG. 2 and the same contents as those in the first embodiment will be omitted.

  In the receiving apparatus of this embodiment, when the received electric field strength signal 25 is outside the communication area and is equal to or smaller than the second threshold value 27, the intermittent reception control circuit 5 determines the level of the received electric field strength signal 25 output from the receiving circuit 1. Accordingly, the power ON / OFF cycle of the receiving circuit 1 is changed. Specifically, the intermittent reception control circuit 5, for example, at the time point t3, the level of the reception electric field strength signal 25 increases to some extent, and as the second threshold level v2 is approached, the power ON / OFF cycle of the reception circuit 1 is increased. A signal s2 is outputted. Therefore, when the received electric field strength signal 25 becomes high, it is determined that the receiving device is approaching the base station, and the reception electric field strength measurement is started (by turning on the power of the receiving circuit 1) by shortening the intermittent reception period of the electric field strength. (Start) delay can be prevented.

  Here, for determining whether the level of the received electric field strength signal 25 is high or low, for example, an electric field strength determination circuit is provided, and the electric field strength level lower than the second threshold 27 is set as a desired level in the determination circuit. Then, it is determined whether or not the received electric field strength signal s4 output from the receiving circuit 1 exceeds the desired level. In addition, it is possible to make the comparison circuit 3 hold a desired level in addition to the first threshold level and the second threshold level without providing another electric field strength determination circuit.

  Here, for example, as in the first embodiment, when the second threshold level v2 is set to −90 dBm or more and −70 dBm or less, the desired level is set to a value smaller than v2 by 6 dB or more, and the thermal noise level of the receiving apparatus is set. It is good to provide in the range.

  The subsequent operation of the receiving apparatus is the same as that of the first embodiment. That is, when the receiving apparatus approaches the communication area and exceeds the second threshold value 27 (continuous electric field strength measurement start level v2) at time t1, the comparison circuit 3 determines that the communication area is approaching, and the receiving apparatus Becomes the receiving circuit power ON section 23 in the continuous receiving state from the intermittent receiving state (intermittent receiving section 61), and the power supply voltage is supplied to the receiving circuit 1 to continuously measure the received electric field strength v. Here, power supply to the demodulation circuit 2 is not started, and the signal processing circuit 9 and the CPU 10 for processing the demodulated signal s1 are not operating.

  Subsequently, when the received electric field strength signal 25 exceeds the first threshold value (communication start level v1) 26 at time t2, the comparison circuit 3 determines that a receiving device has entered the communication area, and the power supply of the demodulation circuit 2 is turned on. Thus, the demodulator circuit power ON section 24 is obtained. As a result, the reception signal input from the antenna 7 through the reception circuit 1 to the demodulation circuit 2 is output as the demodulation signal s1. The demodulated signal s1 is processed by the signal processing circuit 9 and then output to the CPU 10. In this method, the first threshold value 26 is larger than the second threshold value 27, and both the first threshold value 26 and the second threshold value 27 are held in the comparison circuit 3.

  As described above, according to the receiving apparatus of the present embodiment, it is possible to reduce the delay of the reception start by making the intermittent reception period variable in the receiving circuit 1 according to the level of the received electric field strength v, and communication. It is possible to reduce current consumption in a reception standby state outside the area.

(Fifth embodiment)
FIG. 8 is a block diagram showing a configuration of a receiving apparatus according to the fifth embodiment of the present invention. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs the reception signal received via the antenna 7 as the reception electric field strength signal s4, and the reception signal processed by the reception circuit 1. And a demodulating circuit 2 for outputting. In addition, the receiving apparatus according to the present embodiment includes a comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with the first threshold value and the second threshold value, and intermittently receives the received electric field strength signal. And an intermittent reception control circuit 5 for outputting a signal for measurement. Furthermore, the receiving apparatus of this embodiment changes the control of the operation control circuit 4 according to the determination result of the operation control circuit 4 that controls the supply of the power supply voltage to the receiving circuit 1 and the demodulation circuit 2 and the comparison circuit 3. And a determination circuit 8. The receiving apparatus according to the present embodiment detects the moving speed of the signal processing circuit 9 and the CPU 10 that process the demodulated signal s1 output from the demodulation circuit 2 and the receiving apparatus, and outputs the detection result to the intermittent reception control circuit 5. Speed detecting means 31 for performing the above operation.

  Unlike the receiving apparatus according to the fourth embodiment, the receiving apparatus according to the present embodiment can set the intermittent period in the intermittent period signal output by the intermittent reception control circuit 5 according to the moving speed of the receiving apparatus. Features.

  Next, the operation of the receiving apparatus of this embodiment will be described with reference to FIGS. FIG. 9 is a diagram illustrating a control method of the receiving apparatus illustrated in FIG. However, the description of the same components as those in FIG. 7 and the same contents as those in the fourth embodiment will be omitted.

  As shown in FIG. 9, when the receiving device is outside the communication area and the received electric field strength signal 25 is equal to or lower than the second threshold level v2, the intermittent reception control circuit 5 is intermittently turned on. An intermittent periodic signal is output so as to repeat OFF and OFF. Here, the intermittent reception control circuit 5 changes the ON / OFF cycle of the reception circuit 1 in accordance with the level of the speed signal output from the speed detection means 31.

  Specifically, when the detected moving speed of the receiving device is slow (for example, before time t3), the operation control circuit 4 outputs a signal s2 that makes the power ON / OFF cycle of the receiving circuit 1 longer. When the detected moving speed of the receiving device is fast, the operation control circuit 4 outputs a signal s2 that shortens the power ON / OFF cycle of the receiving circuit 1. Since the subsequent operations are the same as those in the first embodiment, description thereof will be omitted.

  Here, for example, when it is determined that the moving speed at the time point t3 is higher than the moving speed of the receiving device set in advance, the intermittent reception control circuit 5 outputs the signal s2 having a short intermittent period. The preset moving speed is, for example, a legally limited speed.

  As described above, according to the receiving device in the present embodiment, when the moving speed of the receiving device is slow, it is possible to reduce power consumption by the receiving circuit by increasing the intermittent reception cycle of the receiving circuit. When the moving speed of the receiving device is fast, the intermittent reception cycle of the receiving circuit can be shortened to reduce the delay in starting reception (powering on state of the receiving circuit).

  In the receiving method of the third embodiment, the second threshold value is lowered at the time t3 when the moving speed is increased, and the continuous receiving state is entered. However, in the receiving method of the present embodiment, the receiving method of the third embodiment is used. Unlike the above, the intermittent cycle in the intermittent reception state is shortened at time t3 when the moving speed is increased.

(Sixth embodiment)
FIG. 10 is a block diagram showing a configuration of a receiving apparatus according to the sixth embodiment of the present invention. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs a reception signal received via the antenna 7 as a reception electric field strength signal, and the reception signal processed by the reception circuit 1. A demodulating circuit 2 that outputs the signal and a comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with a first threshold value and a second threshold value are provided. In addition, the receiving apparatus according to the present embodiment controls the intermittent reception control circuit 5 that outputs a signal for intermittently measuring the received electric field strength signal, and the operation for controlling the supply of the power supply voltage to the receiving circuit 1 and the demodulating circuit 2. A control circuit 4; a determination circuit 8 that changes control of the operation control circuit 4 according to a determination result of the comparison circuit 3; a signal processing circuit 9 that processes a demodulated signal output from the demodulation circuit 2; Yes. Furthermore, the receiving apparatus of the present embodiment is stored in the position detecting means 91 for measuring the position of the receiving apparatus, the storage means 92 for storing the position of the base station, the measurement result of the position detecting means 91 and the storing means 92. Position comparison means 99 is provided for comparing the position of the base station and determining the distance of the receiving device from the base station. The determination result of the position comparison means 99 is output to the intermittent reception control circuit 5.

  Unlike the fifth embodiment, the present embodiment is characterized in that the intermittent reception control circuit 5 outputs an intermittent period of intermittent reception of the reception apparatus according to the position of the reception apparatus with respect to the base station.

  Here, the position detecting means 91 includes, for example, car navigation using a GPS (Global Positioning System) system, and examples of the storage means 92 include car navigation, RAM (Random Access Memory), and a hard disk. .

  Next, the operation of the receiving apparatus of this embodiment will be described with reference to FIGS. FIG. 11 is a diagram illustrating a reception method using the reception apparatus illustrated in FIG.

  As shown in FIG. 11, when the receiving device is outside the communication area and the received electric field strength signal 25 is equal to or smaller than the second threshold value 27, the receiving circuit 1 measures the received electric field strength v by intermittent reception. At this time, using the determination result of the position comparison means 99, the intermittent reception cycle is changed depending on whether the distance between the base station and the receiving apparatus is larger than a certain set value or less than the set value. Specifically, as shown in FIG. 11, when the distance to the base station is long (before time t4), that is, when the distance between the base station and the receiving apparatus is larger than a certain set value, intermittent reception is performed. The intermittent period is set to be relatively long as the section 101. On the other hand, when the distance to the base station is short (from time t4 to time t1), that is, when the distance between the base station and the receiving device is smaller than a certain set value, the intermittent reception period 102 is the intermittent reception cycle. To shorten.

  Subsequently, when the receiving device is further closer to the base station and the received electric field strength signal 25 exceeds the second threshold level v2, it is determined by the comparison circuit 3 that the receiving device is close to the communication area, and the operation control is performed. The circuit 4 turns on the power supply of the receiving circuit 1. The subsequent operations are the same as those in the first embodiment.

  As described above, the receiving apparatus according to the present embodiment includes the storage unit 92 that stores the position of a known base station in advance, so that the distance between the receiving apparatus and the base station can be accurately determined. Thus, the power supply to the receiving circuit can be started more efficiently and without delay. Furthermore, as in the previous embodiments, it is possible to reduce power consumption in a reception standby state outside the communication area.

  In the present embodiment, the intermittent reception control is performed based on the position information of the base station stored in advance in the storage unit 92. However, for a new base station not stored in the storage unit 92, When the new base station is found, the position of the new base station is measured by the position detecting means 91 such as GPS, and stored in the storage means 92, so that the next time the base station is passed The position information can be used.

(Seventh embodiment)
FIG. 12 is a block diagram showing a configuration of a receiving apparatus according to the seventh embodiment of the present invention. Unlike the first embodiment, this embodiment further includes a reception control circuit 111, a storage unit 112, and a channel selection unit 113, and is particularly effective when there are a plurality of communication frequencies received from the base station. It is a device. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs the reception signal received via the antenna 7 as the reception electric field strength signal s4, and the reception signal processed by the reception circuit 1. And a comparison circuit 3 that compares and determines the level of the received electric field strength signal s4 output from the reception circuit 1 with the first threshold value, the second threshold value, and the third threshold value. . In addition, the receiving apparatus of the present embodiment controls the intermittent reception control circuit 5 that outputs a signal for intermittently measuring the received electric field strength signal s4, and the supply of the power supply voltage to the receiving circuit 1 and the demodulating circuit 2. And an operation control circuit 4. Furthermore, the receiving apparatus of this embodiment includes a channel selection unit 113 that selects a communication frequency received by the reception circuit 1 while the power of the reception circuit 1 is ON, and a plurality of communication using the channel selection unit 113. A reception control circuit 111 that selects frequencies in order and causes the comparison circuit 3 to measure the received electric field strength of each communication frequency is provided. Further, the receiving device outputs from the storage means 112 that stores the determination result by the comparison circuit 3, the determination circuit 8 that changes the control of the operation control circuit 4 according to the determination result of the comparison circuit 3, and the demodulation circuit 2. A signal processing circuit 9 and a CPU 10 for processing the demodulated signal s1 are provided.

  Next, the operation of the receiving apparatus of this embodiment will be described with reference to FIGS. FIG. 13 is a diagram illustrating a control method of the receiving apparatus illustrated in FIG.

  The receiving apparatus of this embodiment is used when there are a plurality of communication frequencies transmitted from the base station. In this case, the signal section 20 is a portion including information to the own station in the demodulated signal s1 of the selected communication frequency, and the signal section 21 does not include information to the own station in the demodulated signal s1 of the selected communication frequency. Part. Further, each of the received electric field strength signals 25 and 121 shown in FIG. 13 represents the transition of the received electric field strength v over time for two communication frequencies over time. Here, the received electric field strength signal at the first communication frequency is referred to as a received electric field strength signal 25, and the received electric field strength signal at the second communication frequency is referred to as a received electric field strength signal 121. In FIG. 13, in the diagram showing the signal s2, the upper stage shows an output signal to the receiving circuit 1 for receiving the first communication frequency, and the lower stage shows an output to the receiving circuit 1 for receiving the second communication frequency. Signals are shown.

  When the receiving device approaches the base station from outside the communication area of the base station, the intermittent reception control circuit 5 supplies power to the receiving circuit 1 if the received electric field strength v at each communication frequency is equal to or less than the second threshold value 27. Are turned ON and OFF periodically. While the receiving circuit 1 is powered on, the channel selection means 113 sequentially selects a plurality of communication frequencies, and the comparison circuit 3 measures the received electric field strength v at each communication frequency based on the selection of the channel selection means 113. To do. Here, as the receiving apparatus approaches the base station, the received electric field strength of the first communication frequency increases with time, for example, as in the received electric field strength signal 25, and the received electric field strength of the second communication frequency is In this case, the comparison circuit 3 determines whether or not the received field strength signal for the communication frequency with the larger received field strength v has reached the third threshold value 122. If the received electric field strength signal for the higher communication frequency is equal to or smaller than the third threshold value 122, the received electric field strength signals 25 and 121 of the first communication frequency and the second communication frequency are measured at the same intermittent period and at the same time. To do.

  For example, when the comparison circuit 3 determines that the received electric field strength signal 25 of the first communication frequency exceeds the third threshold level v3 at time t5, the reception control circuit 111 stores the determination result in the storage unit 112. To do. According to the comparison result in the comparison circuit 3 stored in the storage unit 112, for the first communication frequency exceeding the third threshold 122, the time for measuring the received electric field strength signal 25 is determined by the influence of the signal of the second communication frequency. Sampling is performed at a time sufficient to remove the signal, and the same sampling is performed at the second communication frequency as at the first communication frequency. The fluctuation of the measurement time of each communication frequency in the intermittent reception sections 123 and 124 is caused by the reception control circuit 111 outputting a control signal to the intermittent reception control circuit 5.

  Next, when the received electric field strength signal 25 of the first communication frequency exceeds the second threshold level v2 at time t1, the comparison circuit 3 determines that the communication area is approaching, and the comparison result is determined by the determination circuit 8 and Output to the reception control circuit 111.

  In response to this, the reception control circuit 111 causes the channel selection unit 113 to select the first communication frequency based on the comparison result of the comparison circuit 3. The receiving apparatus enters the receiving circuit power ON section 23 from the intermittent receiving state and continuously measures the received electric field strength signal 25.

  Thereafter, when the received electric field strength signal 25 of the first communication frequency exceeds the first threshold level v1 at time t2, the comparison circuit 3 determines that the receiving device has entered the communication area, and outputs the comparison result to the determination circuit 8. To do. Then, regardless of the output of the intermittent reception control circuit 5, the power supply voltage is supplied to the demodulation circuit 2 by the operation control circuit 4, and the demodulation circuit power supply ON section 24 is obtained. As a result, the received signal input from the antenna 7 to the demodulating circuit 2 via the receiving circuit 1 is output to the signal processing circuit 9 as the demodulated signal s1.

According to the receiving apparatus of this embodiment, in small area communication such as narrow area communication and wireless LAN,
Even when there are a plurality of communication frequencies, the best communication frequency can be selected. And while reducing the power consumption in the reception standby state outside the communication area, etc., when it is determined that the desired communication frequency, it is possible to perform a highly accurate measurement over time and turn on the receiving circuit power Therefore, when entering the communication area, communication with a desired communication frequency can be started without delay. Further, since the received electric field strength signal measurement at a frequency other than the desired communication frequency is performed in a short time, the power can be effectively reduced.

  When the receiving circuit 1 or the demodulating circuit 2 uses a digital circuit, the same effect can be obtained by controlling the clock signal instead of controlling the power supply, and the current consumption during standby can be reduced.

  When the received electric field strength signal 25 of the first communication frequency exceeds the third threshold level v3 at time t5, it is only necessary to determine the presence or absence of the received signal for the second communication frequency. The measurement may be performed in a time shorter than the frequency measurement time (reception time). In this case, power consumption can be reduced by an amount corresponding to a reduction in the measurement time of the second communication frequency.

  FIG. 14 is a diagram illustrating another example of the control method of the receiving apparatus of this embodiment.

  In the example shown in the figure, when the received electric field strength signal 25 of the first communication frequency exceeds the third threshold level v3 and is equal to or lower than the second threshold level v2, the first communication exceeding the third threshold level v3. The period for measuring only the reception field strength signal 25 of the frequency and the period for measuring the reception field strength signals of all the communication frequencies (the first communication frequency and the second communication frequency) are alternately and periodically repeated. That is, in this example, measurement is performed by thinning out the measurement for the communication frequency (second communication frequency) equal to or lower than the third threshold level v3.

  This method can also shorten the overall measurement time and reduce power consumption.

(Eighth embodiment)
FIG. 15 is a block diagram showing a configuration of a receiving apparatus according to the eighth embodiment of the present invention. In the present embodiment, unlike the seventh embodiment, the reception control circuit 111 measures the rate of change of the received electric field strength, and varies the intermittent reception time (reception time) of the received electric field strength according to the rate of change. It is characterized by. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs a reception signal received via the antenna 7 as a reception electric field strength signal, and the reception signal processed by the reception circuit 1. A demodulating circuit 2 that outputs the signal and a comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with a first threshold value and a second threshold value are provided. In addition, the receiving apparatus according to the present embodiment controls the intermittent reception control circuit 5 that outputs a signal for intermittently measuring the received electric field strength signal, and the operation for controlling the supply of the power supply voltage to the receiving circuit 1 and the demodulating circuit 2. And a control circuit 4. Furthermore, the receiving apparatus of the present embodiment includes a channel selection unit 113 that selects a communication frequency while the power of the reception circuit 1 is ON, and outputs the selection result to the reception circuit 1; A reception control circuit 111 that sequentially selects a plurality of communication frequencies and measures a rate of change in received electric field strength at each communication frequency, and a storage unit 112 that stores a measurement result in the reception control circuit 111 are provided. The receiving apparatus includes a determination circuit 8 that changes the control of the operation control circuit 4 according to the determination result of the comparison circuit 3, a signal processing circuit 9 that processes the demodulated signal output from the demodulation circuit 2, and a CPU 10. I have.

  Next, the operation of the receiving apparatus according to this embodiment will be described with reference to FIGS. 15 and 16. FIG. 16 is a diagram illustrating a control method of the reception apparatus illustrated in FIG.

  The receiving apparatus of this embodiment is used when there are a plurality of communication frequencies transmitted from the base station. In this case, the signal interval 20 is a portion including information to the own station in the demodulated signal of the selected communication frequency, and the signal interval 21 is a portion not including information to the own station in the demodulated signal of the selected communication frequency. is there. Also, the received electric field strength signals 25 and 151 shown in FIG. 16 represent changes in the received electric field strength v for two communication frequencies over time. Here, the received electric field strength signal at the first communication frequency is referred to as a received electric field strength signal 25, and the received electric field strength signal at the second communication frequency is referred to as a received electric field strength signal 151.

  When the receiving device approaches the base station from outside the communication area of the base station, if the received electric field strength signal 25 of the first communication frequency is equal to or lower than the second threshold level v2, the intermittent reception control circuit 5 1 is periodically turned on and off. While the receiving circuit 1 is powered on, the channel selection unit 113 sequentially selects a plurality of communication frequencies, and the reception control circuit 111 determines the received electric field strength v of each communication frequency based on the selection of the channel selection unit 113. The time change rate (difference in unit time) is measured. When the received electric field strength at any communication frequency does not tend to increase, the received electric field strength measurements at the first communication frequency and the second communication frequency are performed over the same period and the same time (intermittent reception section 123 in FIG. 16). .

  When the rate of change of the received electric field strength signal 25 at the first communication frequency changes to a positive value at time t5 and the rate of change of the received electric field strength signal 151 for other communication frequencies is negative or zero, reception control is performed. The circuit 111 stores in the storage means 112 that the received electric field strength signal 25 of the first communication frequency tends to increase. At this time, weighting is performed according to the rate of change of the received electric field strength signal 25 to determine whether precise measurement or coarse measurement is performed, and this is also stored in the storage unit 112. Further, the frequency to be measured is changed using the channel selection means 113, and the measurement of the necessary communication frequency is continued. For example, it is assumed that precise measurement is performed on the first communication frequency and the second communication frequency is continuously measured. During this period, according to the change rate determination result (difference determination result) stored in the storage unit 112, the second time for measuring the received electric field strength v is set to the second time for the first communication frequency in which the received electric field strength v tends to increase. Sampling is performed at a time that can sufficiently remove the influence of the signal of the communication frequency, and other communication frequencies (such as the second communication frequency) are sufficient to determine whether there is a received radio wave and the first. Measurement is performed in a time shorter than the measurement time of the communication frequency.

  Next, when the second threshold value 27 is exceeded at time t1, the comparison circuit 3 determines that the communication area is approaching, and outputs the determination result to the determination circuit 8 and the reception control circuit 111.

  In response to this, the reception control circuit 111 selects the communication frequency by the channel selection means 113 based on the determination result of the comparison circuit 3. In addition, the receiving device enters the receiving circuit power ON section 23 from the intermittent receiving state and enters a continuous receiving state, and continuously measures the received electric field strength.

  Thereafter, when the received electric field strength of the first communication frequency exceeds the first threshold value 26 at time t2, the comparison circuit 3 determines that the receiving device has entered the communication area, and outputs the determination result to the determination circuit 8. Then, regardless of the output of the intermittent reception control circuit 5, the power supply voltage is supplied to the demodulation circuit 2 by the operation control circuit 4, and the demodulation circuit power supply ON section 24 is obtained. As a result, the received signal input from the antenna 7 through the receiving circuit 1 to the demodulating circuit 2 is output as a demodulated signal to a signal processing circuit (not shown). Although the case where there are two communication frequencies has been described here, reception and measurement can be similarly performed even when there are three or more communication frequencies.

  According to the receiving apparatus of this embodiment, in a small area communication such as narrow area communication or wireless LAN, it is possible to control only a necessary part of the power supply of the receiving circuit and the demodulating circuit, and even when there are a plurality of communication frequencies, It is possible to select the best communication frequency. Then, it is possible to perform highly accurate measurement over time when it is determined as the communication frequency while reducing the power consumption in the reception standby state outside the communication area. In addition, since signal measurement at frequencies other than the communication frequency is performed in a short time, the entire measurement time can be shortened, and power consumption can be effectively reduced.

  Note that when the receiving circuit or the demodulating circuit uses a digital circuit, the same effect can be obtained by controlling the clock signal instead of controlling the power supply, and the current consumption can be reduced. In addition, when the received electric field intensity at any communication frequency starts to increase, the electric field measurement period of another communication frequency may be lengthened instead of shortening the measurement time of the other communication frequency.

(Ninth embodiment)
FIG. 17 is a block diagram showing a configuration of a receiving apparatus according to the ninth embodiment of the present invention. As shown in the figure, the receiving apparatus according to the present embodiment demodulates the reception circuit 1 that outputs a reception signal received via the antenna 7 as a reception electric field strength signal, and the reception signal processed by the reception circuit 1. And a demodulation circuit 2 for outputting. In addition, the receiving apparatus according to the present embodiment includes a comparison circuit 3 that compares and determines the level of the received electric field strength signal output from the receiving circuit 1 with the first threshold value and the second threshold value, and intermittently receives the received electric field strength signal. And an intermittent reception control circuit 5 for outputting a signal for measurement. Further, the receiving apparatus includes an operation control circuit 4 that controls the supply of power supply voltage to the receiving circuit 1 and the demodulation circuit 2, and a channel selection unit that selects a communication frequency while the power of the receiving circuit 1 is ON. 113 and position detecting means 161 for measuring the position of the receiving apparatus. In addition, the receiving apparatus of the present embodiment includes a storage unit 112 that stores the position and communication frequency of the base station, and a reception control circuit 111 that causes the channel selection unit 113 to select the communication frequency of the base station stored in the storage unit 112. And. This receiving apparatus compares the output of the position detection means 161 and the position information from the storage means 112 to determine the distance from the base station, and operates according to the determination result of the comparison circuit 3. A determination circuit 8 that changes the control of the control circuit 4, a signal processing circuit 9 that processes a demodulated signal output from the demodulation circuit 2, and a CPU 10 are provided. The position detection means 161 is, for example, a car navigation system equipped with a GPS system, and is the same as the position detection means 91 of the sixth embodiment.

  Next, the operation of the receiving apparatus of this embodiment will be described with reference to FIGS. FIG. 18 is a diagram illustrating a control method of the reception device illustrated in FIG.

  The receiving apparatus of this embodiment is used when there are a plurality of communication frequencies. In this case, the position comparison means 120 measures the position of the receiving device by the position detection means 161, and compares this measurement result with the output of the storage means 112 that previously stores the position of the base station and the communication frequency. Determine the distance. The determination result is input to the reception control circuit 111. Here, when it is determined that the position comparison unit 120 is away from the base station and the reception circuit strength signal 25 is determined to be equal to or lower than the second threshold level v2 by the comparison circuit 3, the intermittent reception control circuit 5 Intermittent reception in the intermittent reception section 123 is performed. In this case, simple measurement sufficient to determine the presence or absence of the received radio wave is performed on the received electric field strength for all communication frequencies in each ON section.

  Next, when the receiving device approaches the base station and the comparison circuit 3 determines that the received electric field strength at the communication frequency of the base station is equal to or lower than the second threshold, the reception control circuit 111 is stored in the storage unit 112. Further, the communication frequency of the base station is selected using the channel selection means 113, and sampling is performed with the time for measuring the received electric field strength set to a time that can sufficiently remove the influence of signals of other communication frequencies. The measurement is performed in a time shorter than the measurement time of the communication frequency stored in the storage unit 112, which is sufficient to determine the presence or absence of the received radio wave at the other communication frequency.

  Subsequently, when the receiving apparatus further approaches the base station and the received electric field strength signal 25 exceeds the second threshold level v2 at time t1, the comparison circuit 3 determines that the communication area is approached, and reception is performed. The control circuit 111 selects a communication frequency exceeding the second threshold level v2 using the channel selection means 113, and the operation control circuit 4 continuously turns on the power supply of the receiving circuit 1. Then, the receiving apparatus enters the receiving circuit power ON section (continuous receiving section) 23) in the continuous receiving state from the intermittent receiving state, and continuously measures the received electric field strength.

  Thereafter, when the received electric field strength signal 25 exceeds the first threshold level v1 at time t2, the comparison circuit 3 determines that the receiving device has entered the communication area, and outputs the determination result to the determination circuit 8. Then, the operation control circuit 4 turns on the power of the demodulation circuit 2 and enters the demodulation circuit power supply ON section 24. As a result, the received signal input from the antenna 7 through the receiving circuit 1 to the demodulating circuit 2 is output as a demodulated signal.

  According to the receiving apparatus of the present embodiment, in a small area communication such as narrow area communication or wireless LAN, even when there are a plurality of communication frequencies, information on the position of the base station and the communication frequency stored in the storage unit in advance is obtained. It is possible to efficiently select the best communication frequency.

  Furthermore, according to the receiving apparatus of the present embodiment, in the reception standby state with the base station outside the communication area, etc., perform accurate measurement over time for the communication frequency of the approaching base station, This frequency can be measured in a short time. As a result, the overall measurement time can be shortened and power consumption can be reduced. In addition, power consumption is reduced by supplying power to the receiving circuit and demodulation circuit only to the necessary parts.

  The receiving apparatus according to the present embodiment is characterized in that intermittent reception control is performed on a base station stored in advance in the storage unit 112. However, for a base station not stored in the storage unit, a new The position when the base station is found is measured by the position detection means 161 and stored in the storage means 112 together with the communication frequency, so that it can be used when passing through the base station next time.

(Tenth embodiment)
FIG. 19 is a diagram showing a semiconductor integrated circuit for communication provided with a receiving apparatus according to the tenth embodiment of the present invention. That is, when the receiving apparatus according to the present invention is shown in a circuit diagram, it is as shown in FIG. However, detailed description of the same components as those of the other embodiments described above is omitted. In the figure, specific examples of circuits of each part of the reception circuit 1, the demodulation circuit 2, the comparison circuit 3, the intermittent reception control circuit 5, the operation control circuit 4, the determination circuit 8, the signal processing circuit 9, and the CPU 10 in each of the above-described embodiments. Is shown.

  The semiconductor integrated circuit for communication according to the present embodiment is obtained by integrating the receiving devices according to the first to ninth embodiments and providing them on a semiconductor chip. That is, the semiconductor integrated circuit for a receiving device of this embodiment includes a receiving circuit 1, a demodulating circuit 2, a comparing circuit 3, an intermittent receiving control circuit 5, an operation control circuit 4, a determination circuit 8, a signal processing circuit 9, All or part of the CPU 10 is integrated on a semiconductor substrate.

  As a result, devices that transmit and receive information to and from the base station can be integrated on one chip.

  For example, the transmission / reception IC and the control unit illustrated in FIG. 19 may be integrated on different semiconductor chips.

(Eleventh embodiment)
A transmitting / receiving apparatus according to an eleventh embodiment of the present invention includes a receiving apparatus according to the first to ninth embodiments and a baseband circuit (signal processing) that processes a received demodulated signal or generates a transmission modulation signal. Circuit) and a transmitter for generating a transmission signal based on the transmission modulation signal are mounted on a circuit board.

  The transmission / reception device of this embodiment is small, can be easily incorporated into a wireless communication device, can be in a reception standby state with low current consumption outside the communication area, and can perform bidirectional communication with a base station (roadside wireless communication device). can do.

  This transmitter / receiver has the same effect even if the substrate is divided.

(Twelfth embodiment)
A transmitting / receiving apparatus according to a twelfth embodiment of the present invention includes a receiving apparatus according to the first to ninth embodiments and a baseband circuit (signal processing) that processes a received demodulated signal or generates a transmission modulation signal. Circuit), a transmission device that generates a transmission signal based on the transmission modulation signal, and an antenna. Further, a CPU may be further provided. According to this configuration, bidirectional communication with the base station (roadside radio apparatus) can be enabled, and power consumption outside the communication area can be reduced.

  Such a transmission / reception device requires high-speed and large-capacity data exchange, for example, payment of charges in the ETC system, acquisition of information by DSRC, bidirectional exchange of information with GPS, and at gas stations Information can be provided between the base station and the mobile station for payment.

(13th Embodiment)
FIG. 20 is a view showing a transportation apparatus according to the thirteenth embodiment of the present invention. This transportation apparatus is equipped with the receiving apparatus (for example, an ETC system mounted on a passenger car) in each of the above-described embodiments.

  As shown in FIG. 20, the transport apparatus of this embodiment includes the transmission / reception apparatus described in the twelfth embodiment, a power supply apparatus, and an antenna. The vehicle speed detection device corresponds to, for example, the speed detection means 31 shown in FIG. 4 and may be provided outside the reception device.

  According to this configuration, even when the transport device is moving, the delay in starting reception is reduced, and the reception circuit intermittently receives signals outside the communication area, thereby reducing power consumption in the communication standby state compared to the conventional case. be able to.

  For example, if the receiving apparatus according to the present invention is used for a DSRC system having seven communication frequencies, an intermittent period is used for a frequency with a low received electric field strength (a signal transmitting unnecessary information at a predetermined location). Can be controlled such as shortening the reception time and shortening the reception time, and excessive power consumption can be reduced.

(Fourteenth embodiment)
FIGS. 21A and 21B are diagrams showing a portable wireless communication apparatus according to the fourteenth embodiment of the present invention.

  As shown in FIG. 21 (a), the portable wireless communication device of the present invention includes the transmission / reception device according to the eleventh embodiment having an antenna and a battery that functions as a power source for the external transmission / reception device.

  FIG. 21B is an enlarged view of the transmission / reception apparatus. The transmission / reception device includes an operation button for operating a function menu displayed on the display screen, a card insertion slot for inserting a card such as a credit card, a card ejection button, and a liquid crystal display screen for displaying information received from the base station. A forced reception button for manually turning on the power of the reception circuit, an error display unit for displaying a communication error with the base station, and a standby display unit indicating that communication with the base station can be started It has. By pressing the forced reception button, it is possible to forcibly switch from the intermittent reception state to the continuous reception state even when the level of the electric field strength signal does not exceed the second threshold value. Therefore, because the mobile device is portable, the reception device is not stable, and the received electric field strength cannot be stably received, so that the start of reception is delayed despite being close to the desired base station. Can be prevented.

  According to this configuration, the application range of the transmission / reception device can be expanded to other than the vehicle transmission / reception device. For example, since the portable wireless communication device can be carried, for example, information such as a comment transmitted in the theme park can be received. In addition, communication can be made possible in any place and scene such as confirmation of the ranking in the marathon goal. The receiving apparatus of the present invention can reduce power consumption by operating each circuit at a necessary time. Therefore, this portable wireless communication device can operate for a long time by charging the battery once. A function menu is displayed on the screen. By selecting and executing the function menu, information can be displayed and money can be settled with a credit card.

(Fifteenth embodiment)
The receiving apparatus of the present invention is useful for a wireless communication system. By using the receiving device described in the first to ninth embodiments as a receiving device of a base station or mobile station, wireless two-way communication is possible. When the base station and the mobile station are not within the communicable range, power consumption can be reduced by performing intermittent reception at either one of the base station or the mobile station and setting the communication standby state.

(Sixteenth embodiment)
FIG. 22 is a diagram illustrating an example of a communication apparatus according to the sixteenth embodiment of the present invention. As shown in the figure, the communication device of the present embodiment can communicate with the receiving device according to the first to ninth embodiments, an error display unit that displays a communication error with the base station, and the base station. A standby display unit indicating that the sound is sounded, and a speaker that emits a warning sound. By inserting an external card (not shown) into the card insertion slot, communication with the base station becomes possible. For example, when the level of the electric field strength signal exceeds the second threshold value when the card is not inserted, the standby display unit blinks red, or the speaker emits a warning sound to prompt the card insertion. Accordingly, communication errors between the communication apparatus and the base station can be prevented within the communicable area with the base station.

  Furthermore, the communication apparatus according to the present embodiment may include a forced reception button that turns on the power of the receiving circuit and enables communication with the base station, as in the fourteenth embodiment.

  In each of the above embodiments, the case where the power of the receiving circuit 1 is turned on at the same time as the time t1 when the received electric field strength signal 25 exceeds the second threshold level v2 has been described, but at least between the time t1 and the time t2. It suffices as long as the power of the receiving circuit is turned on without delay at the time t2 when entering the communication area.

  Note that, in the drawings according to the above embodiments, the signal section 20 which is a portion including information to the own station in the received demodulated signal and a signal which is a portion not including information to the own station in the received demodulated signal Although the section 21 shows a case in which a constant time interval is maintained and is repeated alternately, it goes without saying that the present invention is not limited to this. Further, although the case where the demodulated signal is output by the signal section 20 while entering the communication area is shown, it is needless to say that the demodulated signal may be output after being delayed from the signal section 21.

  The receiving apparatus of the present invention is preferably used for communication devices used for small area communication and small area communication represented by wireless LAN.

It is a block diagram which shows an example of a structure of the receiver which concerns on the 1st Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 1st Embodiment of this invention. It is a figure which shows the determination method of the reception start level in the receiver which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 3rd Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 4th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 4th Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 5th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 5th Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 6th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 6th Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 7th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 7th Embodiment of this invention. It is a figure which shows another example of the control method of the receiver which concerns on the 7th Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 8th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 8th Embodiment of this invention. It is a block diagram which shows the structure of the receiver which concerns on the 9th Embodiment of this invention. It is a figure which shows the control method of the receiver which concerns on the 9th Embodiment of this invention. It is a figure which shows the semiconductor integrated circuit for receivers which concerns on the 10th Embodiment of this invention. It is a figure which shows the transport apparatus which concerns on the 13th Embodiment of this invention. It is a figure which shows the portable radio | wireless communication apparatus which concerns on the 14th Embodiment of this invention. It is a figure which shows an example of the transmission / reception apparatus and transport apparatus which concern on the 16th Embodiment of this invention. It is a block diagram which shows the structure of the communication apparatus used for the conventional narrow area communication. It is a figure which shows the communication operation | movement of the conventional communication apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception circuit 2 Demodulation circuit 3 Comparison circuit 4 Operation control circuit 5 Intermittent reception control circuit 7 Antenna 8 Determination circuit 9 Signal processing circuit 10 CPU
20, 21, 22 Signal section 23 Reception circuit power supply ON section 24 Demodulation circuit power supply ON section 25, 121, 151 Reception field strength signal 26 First threshold 27 Second threshold 31 Speed detection means 41, 42 Reception circuit power ON section 43, 44 Second threshold 91 Position detection means 92, 112 Storage means 99, 120 Position comparison means 111 Reception control circuit 112 Storage means 113 Tuning means 122 Third threshold 123, 124 Intermittent reception section 161 Position detection means

Claims (45)

A receiving device for receiving a signal transmitted from a base station,
A receiving circuit that outputs a received electric field strength of the signal received via an antenna as a received electric field strength signal;
The level of the reception electric field intensity signal output from the receiving circuit, the receiving device indicates that it is a communication area, wherein the first and the first threshold is a communication start level for communication with the base station A comparison circuit that uses a second threshold value that is lower than the threshold value and indicates a field strength measurement level at which continuous operation of the receiving circuit is started , and outputs the comparison result;
An intermittent reception control circuit for outputting a periodic signal for intermittently operating the reception circuit;
An operation control circuit for controlling the operation of the reception circuit based on the comparison result of the comparison circuit;
The operation control circuit intermittently operates the reception circuit based on the periodic signal when the level of the reception field strength signal is lower than the second threshold as a result of the comparison by the comparison circuit, and the reception field strength signal When the level of the signal is equal to or higher than the second threshold, the receiving circuit is operated continuously. The receiving circuit further has a function of amplifying and outputting the received signal,
A demodulating circuit that demodulates the amplified signal and outputs the demodulated signal;
The receiving apparatus according to claim 1, wherein the operation control circuit controls an operation of the demodulation circuit.   3. The reception according to claim 2, wherein the operation control circuit operates the demodulation circuit when a level of the received electric field strength signal exceeds the first threshold as a result of comparison in the comparison circuit. apparatus.   The operation control circuit supplies a first clock signal to the demodulation circuit when the level of the received electric field strength signal exceeds the first threshold as a result of comparison in the comparison circuit. Item 3. The receiving device according to Item 2. A signal processing circuit for processing the demodulated signal output from the demodulation circuit;
An arithmetic processing unit that arithmetically processes the demodulated signal processed by the signal processing circuit;
The operation control circuit supplies a second clock signal to the signal processing circuit and the arithmetic processing unit when the level of the received electric field strength signal is lower than the second threshold as a result of comparison in the comparison circuit; The receiving device according to claim 2, wherein the receiving device is controlled. The second threshold includes a first boundary value lower than the second threshold and a second boundary value higher than the second threshold;
When the level of the received electric field strength signal increases and exceeds the second boundary value, the receiving circuit shifts from intermittent operation to continuous operation,
The receiving apparatus according to claim 1, wherein the receiving circuit shifts from a continuous operation to an intermittent operation when the level of the received electric field strength signal decreases to reach the first boundary value. It further comprises speed detecting means for detecting the moving speed of the receiving device and outputting the detected speed as a speed signal,
The receiving device according to claim 1, wherein the comparison circuit varies the second threshold value according to the speed signal.   8. The comparison circuit according to claim 7, wherein when the moving speed of the receiving device increases, the comparison circuit varies the second threshold value so that a difference between the first threshold value and the second threshold value increases. The receiving device described in 1. The receiving apparatus according to claim 1, wherein the intermittent reception control circuit varies the period of the periodic signal according to the received electric field strength signal.   The receiving apparatus according to claim 9, wherein the intermittent reception control circuit shortens the period of the periodic signal when the level of the received electric field strength signal increases. It further comprises speed detecting means for detecting the moving speed of the receiving device and outputting the detected speed as a speed signal,
The receiving apparatus according to claim 1, wherein the intermittent reception control circuit varies a period of the periodic signal in accordance with the speed signal.   The receiving apparatus according to claim 11, wherein the intermittent reception control circuit shortens the period of the periodic signal when the moving speed of the receiving apparatus increases. Storage means for storing location information of the base station;
Further comprising position detecting means for detecting the position of the receiving device,
2. The intermittent reception control circuit varies the period of the periodic signal in accordance with a comparison result between a position of the base station stored in the storage unit and a detection result of the position detection unit. The receiving device according to any one of 5 to 5.   The receiving apparatus according to claim 13, wherein the intermittent reception control circuit shortens the period of the periodic signal when the distance between the base station and the receiving apparatus decreases. A reception control circuit for controlling a reception time for the reception circuit to receive the signal;
The comparison circuit compares the level of the received electric field strength signal using the first threshold, the second threshold, and a third threshold that is lower than the second threshold and indicates the presence or absence of the signal to be received. And
When the level of the received electric field strength signal exceeds the third threshold as a result of the comparison in the comparison circuit, the reception control circuit is more than when the level of the received electric field strength signal is equal to or lower than the third threshold. The receiving apparatus according to claim 1, wherein the reception time is increased.   16. The receiving apparatus according to claim 15, wherein the intermittent reception control circuit lengthens the period of the periodic signal when the level of the received electric field strength signal is equal to or less than the third threshold value. A reception control circuit for measuring a rate of change in the received electric field strength;
The receiving apparatus according to claim 1, wherein the reception control circuit varies a reception time of the receiving circuit according to the rate of change. A reception control circuit for controlling a reception time for the reception circuit to receive the signal;
Storage means for storing the position of the base station and the frequency information of the signal transmitted by the base station;
Further comprising position detecting means for detecting the position of the receiving device,
The reception control circuit varies the reception time according to a comparison result between a position of the base station stored in the storage unit and a detection result of the position detection unit. Receiver.   The receiving apparatus according to claim 18, wherein when the distance between the base station and the receiving apparatus decreases, the receiving time is lengthened. A channel selection means for selecting one frequency signal received by the receiving circuit from a plurality of frequency signals based on an output of the reception control circuit;
The channel selection means selects a frequency signal in which the level of the received electric field strength signal exceeds the second threshold value from the plurality of frequency signals as a result of comparison in the comparison circuit, and the reception circuit is selected. The receiving apparatus according to claim 18, wherein the receiving apparatus receives the frequency signal. The first threshold is in a range of −60 dBm to −70 dBm,
The receiving apparatus according to claim 1, wherein the second threshold value is in a range of -70 dBm or more and -90 dBm or less.   A semiconductor integrated circuit in which the receiving device according to claim 1 is integrated on a semiconductor substrate. A receiving device according to any one of claims 1 to 21,
A transmitter that outputs the signal processed by the receiver to the base station;
A transmission / reception apparatus comprising: an antenna that receives a signal transmitted from the base station and outputs the signal to the reception circuit and outputs the signal output from the transmission apparatus to the base station.   24. The transmission / reception apparatus according to claim 23, further comprising a notification unit that notifies that a level of the received electric field strength signal exceeds the second threshold value as a result of comparison by the comparison circuit. The transmission / reception device according to claim 23 or 24,
A transportation device comprising: a power supply device that supplies power to the transceiver device. The transmission / reception device according to claim 23 or 24,
A portable transmission / reception device comprising a battery for supplying power to the transmission / reception device.   A communication device comprising: the receiving device according to any one of claims 1 to 21; and a transmitting device that outputs a processed signal processed by the receiving device to the base station. A receiving method using a receiving device for receiving a signal transmitted from a base station,
A first step of receiving the signal received via an antenna by a receiving circuit;
A second step of outputting the received electric field strength of the received signal from the receiving circuit as a received electric field strength signal;
The level of the output the received field strength signal, indicates that the receiving device is a communication area, than the first threshold value and the first threshold is a communication start level for communication with said base station A third step of comparing with a second threshold that is a low value and indicates a field strength measurement level at which continuous operation of the receiver circuit is initiated ;
A fourth step of intermittently operating the receiving circuit when the level of the received electric field strength signal is lower than the second threshold as a result of the comparison;
And a fifth step of continuously operating the receiving circuit when the level of the received electric field strength signal is equal to or higher than the second threshold as a result of the comparison.   6. The method according to claim 6, further comprising a sixth step of operating a demodulation circuit that demodulates the signal received by the reception circuit when the level of the received electric field strength signal is equal to or higher than the first threshold as a result of the comparison. Item 29. The reception method according to Item 28.   30. The receiving method according to claim 29, wherein the sixth step provides a clock signal for demodulation operation to the demodulation circuit.   The fourth and fifth steps include a step of providing a clock signal to a signal processing circuit for processing a signal output from the receiving circuit and an arithmetic processing unit for arithmetic processing of the signal processed signal. The receiving method according to claim 28.   In the third step, the second threshold value and the received electric field strength signal are controlled by hysteresis control using a first boundary value lower than the second threshold value and a second boundary value higher than the second threshold value. The receiving method according to claim 28, further comprising a step of comparing the level. Before the third step,
A seventh step of detecting a moving speed of the receiving device and outputting the detected moving speed as a speed signal;
The receiving method according to any one of claims 28 to 32, further comprising an eighth step of changing the second threshold value according to the speed signal.   The eighth step is characterized in that, when the moving speed increases, the second threshold value is varied so that a difference between the first threshold value and the second threshold value is widened. The receiving method described.   The reception according to any one of claims 28 to 32, wherein the fourth step includes a ninth step of changing a cycle of the intermittent operation according to the received electric field strength signal. Method.   36. The reception method according to claim 35, wherein, in the ninth step, the period of the intermittent operation is shortened when the level of the received electric field strength signal is high. A tenth step of detecting a moving speed of the receiving device and outputting the detected moving speed as a speed signal;
33. The reception method according to claim 28, further comprising an eleventh step of changing a cycle of the intermittent operation according to the speed signal.   38. The receiving method according to claim 37, wherein, in the eleventh step, the cycle of the intermittent operation is shortened when the moving speed increases. Detecting the position of the receiving device;
Calculating a distance between the position of the base station stored in the receiving device and the detected position of the receiving device;
The said 4th process further includes the 12th process which fluctuates the period of the said intermittent operation | movement according to the calculated said distance, It is any one of Claim 28 to 32 characterized by the above-mentioned. Reception method.   40. The reception method according to claim 39, wherein, in the twelfth step, when the distance between the base station and the reception apparatus decreases, the cycle of the intermittent operation is shortened. The third step further includes a step of indicating presence / absence of a signal to be received and comparing a level of the received electric field strength signal with a third threshold value smaller than the second threshold value,
In the fourth step, as a result of the comparison, when the level of the received electric field strength signal exceeds a third threshold value, the reception electric field strength signal level is lower than that when the received electric field strength signal level is equal to or lower than the third threshold value. The receiving method according to any one of claims 28 to 32, further comprising a step of increasing a receiving time of the circuit.   33. The method according to any one of claims 28 to 32, wherein the fourth step includes a step of changing a reception time for the reception circuit to receive the signal in accordance with a rate of change of the received electric field strength. The receiving method described in 1. Detecting the position of the receiving device;
Calculating a distance between the position of the base station stored in the receiving device and the detected receiving device;
33. The method according to claim 28, wherein the fourth step includes a step of changing a reception time during which the reception circuit receives the signal according to the calculated distance. The receiving method described.   29. The method according to claim 28, further comprising: selecting a signal whose level of the received electric field strength signal is equal to or higher than the second threshold value among the plurality of received signals after the third step. 33. The reception method according to any one of 32.   45. The reception according to any one of claims 28 to 44, wherein the fifth step includes a step of notifying that a level of the received electric field strength signal is equal to or higher than the second threshold value. Method.

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