JP6981387B2 - Receiver - Google Patents

Description

The present invention relates to a receiving technique, and more particularly to a receiving device for receiving a signal.

In a portable device that receives a GNSS (Global Navigation Satellite System) signal, when a wireless communication service such as a location location service is used, it is required to receive the GNSS signal by a high quality signal receiving technique. Further, in the wireless terminal, it is assumed that the GNSS receiving unit and the cellular transmitting unit coexist. In this case, a strong radio frequency signal in the cellular band may appear at the front end of the GNSS receiver. Such a strong radio frequency signal interferes with the reception of the GNSS signal and causes interference. In order to reduce the influence of this interference, a bandpass filter (Band Pass Filter) such as a surface acoustic wave (SAW) filter is included in the GNSS receiver. However, the SAW filter reduces the reception sensitivity of the GNSS signal. In view of this, a technique is disclosed in which a filter is inserted when the transmission power of the cellular transmitter exceeds the threshold value, and a filter is not inserted when the transmission power is below the threshold value. (See, for example, Patent Document 1).

International Publication No. 13/003818

When the transmission power of the cellular transmitter frequently switches between the case where the transmission power exceeds the threshold value and the case where the transmission power falls below the threshold value, the state of inserting and not inserting the filter is frequently switched. Due to such an operation, the level of the GNSS signal may change significantly, and the stability of the receiving operation may decrease.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a technique for stabilizing reception operation while improving the quality of received GNSS signals.

In order to solve the above problems, the receiving device of an embodiment of the present invention passes through an input unit that receives a signal, a filter that passes a signal having a partial bandwidth among the signals received by the input unit, and a filter. An amplification unit that amplifies the signal or the signal received by the input unit, a processing unit that processes the amplified signal in the amplification unit, a measurement unit that measures the magnitude of the current consumption of the amplification unit, and a consumption measurement measured by the measurement unit. Based on the magnitude of the current, it includes a control unit that controls whether the signal that has passed through the filter is input to the amplification unit or the signal received by the input unit is input to the amplification unit. The control unit (1) causes the amplification unit to input the signal received by the input unit when the receiving device changes from the stationary state to the moving state in the state where the signal that has passed through the filter is input to the amplification unit. (2) When the magnitude of the current consumption in the state where the signal received in the input unit is input to the amplification unit is larger than the threshold value, the signal that has passed through the filter is input to the amplification unit.

Another aspect of the invention is also a receiving device. This device has an input unit that receives signals, a filter that passes signals of a part of the bandwidth among the signals received at the input unit, and an amplification unit that amplifies the signal that has passed through the filter or the signal received at the input unit. A signal that has passed through a filter based on the processing unit that processes the amplified signal in the amplification unit, the measurement unit that measures the magnitude of the current consumption of the amplification unit, and the magnitude of the current consumption measured by the measurement unit. A control unit that controls whether the signal received by the input unit is input to the amplification unit, an additional input unit that inputs a signal different from the signal input by the input unit, and an additional input unit. It is provided with an additional processing unit that processes the signal input in the unit. The control unit adds that (1) when the receiver changes from a stationary state to a moving state, the magnitude of the current consumption in the state where the signal received by the input unit is input to the amplification unit is larger than the threshold value. If the strength of another signal processed in the processing unit increases, the signal that has passed through the filter is input to the amplification unit, and (2) the signal that has passed through the filter is input to the amplification unit, and additional processing is performed. When the strength of another signal processed in the unit decreases, the signal received in the input unit is input to the amplification unit.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs and the like are also effective as aspects of the present invention.

According to the present invention, the reception operation can be stabilized while improving the quality of the received GNSS signal.

It is a figure which shows the structure of the receiving device which concerns on Example 1. FIG. It is a flowchart which shows the receiving procedure by the receiving device of FIG. It is a flowchart which shows the switching procedure by the receiving device of FIG. It is a figure which shows the structure of the receiving device which concerns on Example 2. FIG. It is a figure which shows the structure of the communication apparatus which concerns on Example 3. FIG. It is a flowchart which shows the switching procedure by the communication device of FIG. It is a flowchart which shows the other switching procedure by the communication device of FIG.

(Example 1)
Before explaining the present invention in detail, first, an outline will be given. The first embodiment of the present invention relates to a receiving device that receives a signal such as a GNSS signal. When receiving a GNSS signal, if a strong interfering wave such as 1 / n harmonics of a signal used in a system other than GNSS is input from the antenna, the GNSS signal is due to non-linearity due to saturation of the LNA (Low Noise Amplifier). Harmonics are generated in the frequency band of. This harmonic deteriorates the quality of the received GNSS signal. In order to improve the interference wave resistance in receiving the GNSS signal, a filter such as a SAW filter is arranged between the antenna and the LNA.

In particular, by increasing the number of stages of the filter, the saturation resistance of LNA is improved, so that the interference wave resistance is improved. However, the loss of the pass band of the GNSS signal increases due to the increase in the number of stages of the filter. As a result, the reception C / N (Carrier to Noise ratio) when the GNSS signal is normally received is lowered due to the increase in the number of stages of the filter. In order to suppress the deterioration of the received C / N, it is necessary to minimize the configuration of the filter. That is, there is a trade-off relationship between the improvement of the received C / N and the improvement of the disturbance resistance when receiving the GNSS signal.

Here, the power of the GNSS signal input to the LNA near the antenna is usually small. Therefore, GNSS signals with a power that saturates are generally not received. In such a situation, the current of LNA increases when it is affected by the disturbing wave. That is, it can be said that the state in which the LNA current increases is an abnormal state.

Therefore, the receiving device according to the present embodiment monitors the magnitude of the current consumption of the LNA, and adds a filter when the magnitude of the current consumption is larger than the threshold value. On the other hand, the receiving device does not add a filter when the magnitude of the current consumption is less than or equal to the threshold value. In order to prevent frequent switching between the configuration with the filter added and the configuration without the filter added, the receiving device sets the filter when the configuration with the filter added changes from the stationary state to the operating state. Remove it and monitor the magnitude of LNA current consumption again. If the current consumption is less than or equal to the threshold, the receiver remains unfiltered. On the other hand, if the amount of current consumption is larger than the threshold value, the filter is added again.

FIG. 1 shows the configuration of the receiving device 100. The receiving device 100 includes an antenna 10, an input unit 12, a first switch 14, a second switch 16, a filter 18, an amplification unit 20, a processing unit 22, a resistor 24, a measurement unit 26, and a control unit 28, and the control unit 28 includes a control unit 28. , The determination unit 30 is included. The receiving device 100 is a device corresponding to GNSS. The antenna 10 receives the signal. The signal to be received by the antenna 10 is a GNSS signal, but as described above, it may include an interfering wave such as a 1 / n multiple wave of a signal used in a system other than GNSS. An example of a system other than GNSS is a cellular system. The input unit 12 receives the signal received by the antenna 10.

The first switch 14 is connected to the input unit 12 on one end side, and is connected to the second switch 16 and the filter 18 on the other end side. The second switch 16 is connected to the first switch 14 and the filter 18 on one end side, and is connected to the amplification unit 20 on the other end side. The filter 18 is arranged between the first switch 14 and the second switch 16. The filter 18 is a band-passing filter and passes the band of the GNSS signal. The first switch 14 and the second switch 16 operate in conjunction with each other in response to control from the control unit 28.

For example, the first switch 14 and the second switch 16 are directly connected (hereinafter referred to as "first connection state") or connected via a filter 18 (hereinafter referred to as "second connection state"). In the first connection state, the first switch 14 outputs a signal from the input unit 12 to the second switch 16. In the second connection state, the first switch 14 outputs the signal from the input unit 12 to the filter 18, and the filter 18 passes a signal having a bandwidth of a part of the received signals, and the result is the second. 2 Output to switch 16. In the initial state, it is in the first connection state. The second switch 16 outputs the signal from the second switch 16 to the amplification unit 20.

The amplification unit 20 is an LNA and amplifies the signal from the second switch 16. Therefore, the signal that has passed through the filter 18 or the signal that has been received by the input unit 12 and has not passed through the filter 18 is amplified. The amplification unit 20 outputs the amplified signal to the processing unit 22. The processing unit 22 receives the signal amplified by the amplification unit 20. The processing unit 22 processes the received signal. When the receiving device 100 is a device corresponding to GNSS, the processing unit 22 positions the position information of the receiving device 100 as processing. Since a known technique may be used for the process for positioning the position of the receiving device 100, the description thereof will be omitted here.

The resistor 24 is connected to the amplification unit 20, and the current of the amplification unit 20 flows through the resistor 24. The measuring unit 26 measures the magnitude of the current consumption of the amplification unit 20 by measuring the potential difference in the resistor 24. The measuring unit 26 sequentially outputs the magnitude of the measured current consumption to the control unit 28. The control unit 28 sequentially receives the magnitude of the current consumption measured by the measurement unit 26. As described above, if the antenna 10 receives only the GNSS signal, the power of the signal input to the amplification unit 20 is usually small even in the first connection state. For example, it is about −130 dBm. A GNSS signal that saturates the amplification unit 20, for example, a GNSS signal of about −20 dBm is not input to the amplification unit 20. Here, as the power of the signal input to the amplification unit 20 increases, the magnitude of the current consumption flowing through the amplification unit 20 increases. That is, in an abnormal state affected by a disturbing wave transmitted in the vicinity or by a radio device having a high output GNSS-related frequency, the magnitude of the current consumption flowing through the amplification unit 20 increases.

When the magnitude of the current consumption in the first connection state is larger than the threshold value, the control unit 28 switches the first switch 14 and the second switch 16 so as to change the first connection state to the second connection state. By switching, the signal that has passed through the filter 18 is input to the amplification unit 20. On the other hand, the control unit 28 maintains the first connection state when the magnitude of the current consumption in the first connection state is equal to or less than the threshold value. That is, the control unit 28 causes the amplification unit 20 to input a signal that has passed through the filter 18 or a signal that has not passed through the filter 18 based on the magnitude of the current consumption measured by the measurement unit 26.

After changing to the second connection state, the determination unit 30 sequentially receives the position information from the processing unit 22. The received location information is lined up at regular intervals. The determination unit 30 derives the difference value between the continuously received position information. The difference value indicates a value corresponding to the moving speed of the receiving device 100. When the difference value is smaller than a predetermined value (hereinafter, referred to as "resting state determination threshold value"), the determination unit 30 determines that the receiving device 100 is in a stationary state. On the other hand, when the difference value is equal to or higher than the threshold value for determining the stationary state, the determination unit 30 determines that the receiving device 100 is in the moving state.

When the determination unit 30 determines that the control unit 28 is in a stationary state, the control unit 28 stores the position information at that time in the processing unit 22. The processing unit 22 continues to output the stored position information for the duration of the stationary state. Even in that situation, the processing unit 22 continues positioning of the position information and continues to output the position information to the determination unit 30. On the other hand, when the determination unit 30 determines that the control unit 28 is in the moving state, the control unit 28 causes the processing unit 22 to output the positioning position information.

When the determination result in the determination unit 30 changes from the stationary state to the moving state, the control unit 28 switches the first switch 14 and the second switch 16 so as to change the second connection state to the first connection state. That is, when the receiving device 100 changes from the stationary state to the moving state in the second connection state, the control unit 28 causes the amplification unit 20 to input a signal that has not passed through the filter 18. The measuring unit 26 measures the magnitude of the current consumption of the amplification unit 20 in the first connection state. When the magnitude of the current consumption in the first connection state is larger than the threshold value, the control unit 28 switches the first switch 14 and the second switch 16 so as to return the first connection state to the second connection state. By switching, the signal that has passed through the filter 18 is input to the amplification unit 20 again. On the other hand, when the magnitude of the current consumption in the first connection state is equal to or less than the threshold value, the control unit 28 maintains the first switch 14 and the second switch 16 as they are in order to maintain the first connection state. As a result, the signal that has not passed through the filter 18 continues to be input to the amplification unit 20.

After the first switch 14 and the second switch 16 are switched from the first connection state to the second connection state, the measuring unit 26 may measure the magnitude of the current consumption in the second connection state. When the magnitude of the current consumption in the second connection state is larger than another threshold value, the control unit 28 sets the first switch 14 and the second switch 16 so as to return the second connection state to the first connection state. Switch. By switching, a signal that has not passed through the filter 18 is input to the amplification unit 20. Even if the filter 18 is used, if the magnitude of the current consumption of the amplification unit 20 is large, it can be said that the cause of the abnormal state is not a disturbing wave or there is a level of disturbing wave that cannot be prevented by the built-in filter. ..

This configuration can be realized by the CPU, memory, or other LSI of any computer in terms of hardware, and by programs loaded in memory in terms of software, but here it is realized by cooperation between them. It depicts a functional block that will be used. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

The operation of the receiving device 100 with the above configuration will be described. FIG. 2 is a flowchart showing a receiving procedure by the receiving device 100. The measuring unit 26 measures the magnitude of the current consumption of the amplification unit 20 (S10). If the magnitude of the current consumption is not larger than the threshold value (N in S12), the processing unit 22 executes positioning (S14), outputs position information (S16), and returns to step 10. If the magnitude of the current consumption is larger than the threshold value (Y in S12), the control unit 28 switches to the presence of the filter 18 (S18). When the determination unit 30 determines that it is in a stationary state (Y in S20), if the position information is not stored (N in S22), the processing unit 22 executes positioning (S24) and stores the position information. (S26) and output the position information (S28). If the position information is stored (Y in S22), the processing unit 22 outputs the position information (S28). Following this, the process returns to step 20.

If it is determined that the determination unit 30 is not in the stationary state (N in S20) and the previous time is also in the moving state (Y in S30), the processing unit 22 executes positioning (S32) and outputs position information (S34). ). Following this, the process returns to step 20. If the previous time is not in the moving state (N in S30), the processing unit 22 discards the position information (S36), the control unit 28 switches without the filter 18 (S38), and returns to step 10.

FIG. 3 is a flowchart showing a switching procedure by the receiving device 100. The control unit 28 switches to the presence of the filter 18 (S50). The measuring unit 26 measures the magnitude of the current consumption of the amplification unit 20 (S52). If the magnitude of the current consumption is larger than the threshold value (Y in S54), the control unit 28 switches without the filter 18 (S56). If the magnitude of the current consumption is not larger than the threshold value (N in S54), step 56 is skipped.

According to this embodiment, when the magnitude of the current consumption in the first connection state is larger than the threshold value, the second connection state is switched to, so that the influence of the disturbing wave can be reduced. Further, when the magnitude of the current consumption in the first connection state is equal to or less than the threshold value, the first connection state is maintained, so that the decrease in the reception C / N can be suppressed. Further, in the second connection state, when the state changes from the stationary state to the moving state, the state is returned to the first connection state and the magnitude of the current consumption is measured, so that the opportunity to measure the magnitude of the current consumption can be limited. Further, when the magnitude of the current consumption in the first connection state is larger than the threshold value, the second connection state is restored, so that the influence of the interference wave can be continuously reduced. Further, when the magnitude of the current consumption in the first connection state is equal to or less than the threshold value, the first connection state is maintained, so that the second connection state can be switched to the first connection state.

Further, when the first connection state is changed to the second connection state and then the stationary state is changed to the moving state, the opportunity to return to the first connection state is limited, so that the reception is received while improving the quality of the received signal. The operation can be stabilized. Further, in the stationary state in the second connection state, the stored position information is continuously output, so that the fluctuation of the position information can be prevented. In addition, when the magnitude of the current consumption in the second connection state is larger than another threshold value, it returns to the first connection state, so if it is not affected by the interference wave or the level of interference that cannot be prevented by the built-in filter. When there is a wave, the decrease of the received C / N can be suppressed.

(Example 2)
Next, Example 2 will be described. In the second embodiment, similarly to the first embodiment, in the receiving device that receives a signal such as a GNSS signal, the magnitude of the current consumption of the LNA is monitored, and when the magnitude of the current consumption is larger than the threshold value, a filter is used. to add. In the first embodiment, only adding a filter or not adding a filter is selected, but in the second embodiment, the filter has a multi-stage configuration and the number of filters is adjusted. The receiving device 100 according to the second embodiment is the same type as that in FIG. Here, the difference from the first embodiment will be mainly described.

FIG. 4 shows the configuration of the receiving device 100. This corresponds to the configuration of the portion sandwiched between the first switch 14 and the second switch 16 in FIG. 1, and the remaining portion is the same as in FIG. 1 and is omitted. In FIG. 1, only the filter 18 is included between the first switch 14 and the second switch 16. On the other hand, in FIG. 4, a first filter 40, an intermediate switch 42, and a second filter 44 are included between the first switch 14 and the second switch 16. The first switch 14 is connected to the input unit 12 (not shown) on one end side, and is connected to the second switch 16 and the first filter 40 on the other end side. The intermediate switch 42 is connected to the first filter 40 on one end side, and is connected to the second switch 16 and the second filter 44 on the other end side. The second switch 16 is connected to the first switch 14, the intermediate switch 42, and the second filter 44 on one end side, and is connected to the amplification unit 20 (not shown) on the other end side.

Therefore, the first filter 40 is arranged between the first switch 14 and the intermediate switch 42, and the second filter 44 is arranged between the intermediate switch 42 and the second switch 16. The first filter 40 and the intermediate switch 42 are band-passing filters and pass the band of the GNSS signal. These properties may be the same or different. The first switch 14, the second switch 16, and the intermediate switch 42 operate in conjunction with each other in response to control from the control unit 28.

For example, the first switch 14 and the second switch 16 may be directly connected (hereinafter, referred to as “first connection state”), or may be connected via the first filter 40 and the intermediate switch 42 (hereinafter, “second connection state”). It is connected via the first filter 40, the intermediate switch 42, and the second filter 44 (hereinafter referred to as "2-1 connection state") (hereinafter referred to as "2-2 connection state"). In the first connection state, the first switch 14 outputs a signal from the input unit 12 to the second switch 16. In the 2-1 connection state, the first switch 14 outputs the signal from the input unit 12 to the first filter 40, and the first filter 40 passes through a signal having a partial bandwidth among the received signals. The result is output to the second switch 16 via the intermediate switch 42.

In the 2nd-2nd connection state, the first switch 14 outputs the signal from the input unit 12 to the first filter 40, and the first filter 40 passes through a signal having a partial bandwidth among the received signals. The result is output to the second filter 44 via the intermediate switch 42. The second filter 44 passes a signal having a bandwidth of a part of the received signals, and outputs the result to the second switch 16. Here, too, the first connection state is set in the initial state.

The control unit 28 holds a first threshold value and a second threshold value as threshold values. Here, the first threshold value and the second threshold value may be the same value. When the magnitude of the current consumption in the first connection state is larger than the first threshold value, the control unit 28 changes the first connection state to the 2-1 connection state, so that the first switch 14 and the intermediate switch 42, switch the second switch 16. By switching, a signal that has passed through the first filter 40 is input to the amplification unit 20. On the other hand, the control unit 28 maintains the first connection state when the magnitude of the current consumption in the first connection state is equal to or less than the threshold value.

When the magnitude of the current consumption in the 2-1 connection state is larger than the second threshold value, the control unit 28 changes the 2-1 connection state to the 4-2 connection state, so that the intermediate switch 42 can be used. , The second switch 16 is switched. By switching, the signal that has passed through the first filter 40 and the second filter 44 in succession is input to the amplification unit 20. On the other hand, the control unit 28 maintains the 2-1 connection state when the magnitude of the current consumption in the 2-1 connection state is equal to or less than the second threshold value.

After changing to the 2-1 connection state or the 2-2 connection state, the determination unit 30 determines whether the receiving device 100 is in a stationary state or the receiving device 100 based on the position information sequentially received from the processing unit 22. Determines if is in a moving state. The processing of the control unit 28 and the processing unit 22 when the determination unit 30 determines that the state is stationary or the determination unit 30 determines that the state is moving is the same as before. Further, the processing of the control unit 28 when the determination result in the determination unit 30 changes from the stationary state to the moving state is the same as before.

According to this embodiment, since the 2-1 connection state and the 2-2 connection state are switched according to the magnitude of the current consumption in the amplification unit, the interference wave is suppressed while suppressing the decrease in the received C / N. The influence of can be suppressed.

(Example 3)
Next, Example 3 will be described. In the third embodiment, as in the past, in a communication device that receives a signal such as a GNSS signal, the magnitude of the current consumption of the LNA is monitored, and a filter is added when the magnitude of the current consumption is larger than the threshold value. do. When the influence of the disturbing wave is reduced by adding a filter, the current consumption of LNA is generally a normal value. Until now, when the state changes from a stationary state to an operating state, the filter is removed and the magnitude of the current consumption of LNA is monitored again. On the other hand, in an environment where the influence of the disturbing wave is originally small, it is preferable that the filter is not added in consideration of the received C / N. The third embodiment aims to increase the chance of determining that the addition of the filter is unnecessary in the situation where the addition of the filter is added. In order to cope with this, the communication device of the third embodiment also includes a communication system for transmitting and receiving a signal that can be an interfering wave of a GNSS signal, for example, a communication circuit corresponding to cellular. The communication device uses not only the magnitude of the current consumption of the LNA but also the strength of the signal received in the communication circuit to determine the addition of the filter or the necessity of adding the filter. Here, the differences from the past will be mainly explained.

FIG. 5 shows the configuration of the communication device 200. The communication device 200 includes an additional antenna 50, an additional input unit 52, and an additional processing unit 54 in addition to the receiving device 100 shown in FIG. The additional antenna 50 transmits and receives signals in a system other than GNSS, for example, a communication system such as a cellular system. The signal has a frequency at which a 1 / n multiple wave or the like can be an interfering wave of the GNSS signal. Hereinafter, the case where the signal is transmitted from the additional antenna 50 will be omitted, and the case where the signal is received by the additional antenna 50 will be described.

The additional input unit 52 is connected to the additional antenna 50 on one end side and connected to the additional processing unit 54 on the other end side, and inputs the signal received by the additional antenna 50. The additional processing unit 54 processes the signal input by the additional input unit 52. For example, the additional processing unit 54 executes a reception intensity measurement function, an amplification function, a demodulation function, and the like. The measuring function of the receiving function measures the strength of the signal received by the additional antenna 50. The measured intensity is shown, for example, as RSSI (Received Signal Strength Inspection). The additional input unit 52 outputs the measured intensity to the control unit 28.

When the determination result in the determination unit 30 changes from the stationary state to the moving state in the first connection state, the control unit 28 determines the magnitude of the current consumption in the first connection state and the signal strength measured by the additional processing unit 54. And confirm. The control unit 28 states that if the magnitude of the current consumption is larger than the threshold value and the signal strength increases, the current consumption and the signal strength are synchronized (hereinafter, referred to as "synchronous state"). judge. On the other hand, the control unit 28 is in a state in which the current consumption and the signal strength are not synchronized unless the magnitude of the current consumption is larger than the threshold value and the signal strength increases (hereinafter, referred to as "asynchronous state"). Is determined to be. In the synchronized state, it can be said that there is a high possibility that the current consumption of the amplification unit 20 is increased by the same radio wave as the signal received by the additional antenna 50. That is, it is presumed that the increase in current consumption is due to another signal, spurious of another signal (due to harmonics, intermodulation distortion with other frequencies, etc.), or noise caused by the source of another signal. Further, the control unit 28 changes the first connection state to the second connection state when the magnitude of the current consumption is larger than the threshold value regardless of whether it is in the synchronous state or the asynchronous state. The 1st switch 14 and the 2nd switch 16 are switched.

If the control unit 28 is determined to be in the asynchronous state in the second connection state, the control unit 28 executes the process described in the first embodiment. On the other hand, the control unit 28 confirms the strength of the signal measured by the additional processing unit 54 if it is determined to be in the synchronous state in the second connection state. When the signal strength decreases, the control unit 28 switches between the first switch 14 and the second switch 16 so as to change the second connection state to the first connection state. Here, when the signal strength measured by the additional processing unit 54 increases or decreases, the signal strength increases or decreases relatively with the passage of time, and the signal strength becomes higher than a predetermined value. May also include cases where it becomes larger or smaller.

The operation of the communication device 200 with the above configuration will be described. FIG. 6 is a flowchart showing a switching procedure by the communication device 200. The control unit 28 sets no filter 18 (S100). The measuring unit 26 measures the magnitude of the current consumption of the amplification unit 20 (S102). The additional processing unit 54 measures RSSI (S104). When the magnitude of the current consumption is larger than the threshold value (Y in S106) and the RSSI also increases (Y in S108), the control unit 28 determines that the synchronization state is in effect (S110). When RSSI does not increase (N in S108), the control unit 28 determines that the state is asynchronous (S112). The control unit 28 switches to the presence of the filter 18 (S114). When the magnitude of the current consumption is not larger than the threshold value (N in S106), the process is terminated.

FIG. 7 is a flowchart showing another switching procedure by the communication device 200. The control unit 28 sets the presence or absence of the filter 18 (S150). In the synchronous state (Y in S152), the additional processing unit 54 measures RSSI (S154). If RSSI decreases (Y in S156), the control unit 28 switches without the filter 18 (S158). If RSSI does not decrease (N in S156), the process ends. If it is not in the synchronous state (N in S152), the process of the first embodiment is executed (S160).

According to this embodiment, when the current consumption and the signal strength are synchronized, the second connection state is changed to the first connection state based on the signal strength, so that the first connection state can be lengthened. .. Moreover, since the first connection state becomes long, the reception C / N can be improved.

The present invention has been described above based on the examples. This embodiment is an example, and it is understood by those skilled in the art that various modifications are possible for each of these components and combinations of each processing process, and that such modifications are also within the scope of the present invention. ..

The determination unit 30 in the first to third embodiments determines whether the receiving device 100 is in a stationary state or a moving state based on the position information. However, the present invention is not limited to this, and for example, the determination unit 30 may determine whether the receiving device 100 is in a stationary state or a moving state based on the value acquired by the sensor mounted on the receiving device 100. .. The sensor is, for example, an acceleration sensor, a gyro sensor, a barometric pressure sensor, or a vehicle speed sensor. According to this modification, the degree of freedom of configuration can be improved.

10 antenna, 12 input unit, 14 1st switch, 16 2nd switch, 18 filter, 20 amplification unit, 22 processing unit, 24 resistance, 26 measurement unit, 28 control unit, 30 judgment unit, 100 receiver.

Claims (5)

The input section that receives signals and
A filter that passes a signal having a part of the bandwidth among the signals received at the input unit, and
An amplification unit that amplifies the signal that has passed through the filter or the signal received by the input unit.
A processing unit that processes the amplified signal in the amplification unit, and
A measuring unit that measures the magnitude of current consumption of the amplification unit,
Control to control whether the signal passed through the filter is input to the amplification unit or the signal received by the input unit is input to the amplification unit based on the magnitude of the current consumption measured by the measurement unit. With a department,
The control unit (1) amplifies the signal received by the input unit when the receiving device changes from a stationary state to a moving state in a state where the signal that has passed through the filter is input to the amplification unit. (2) When the magnitude of the current consumption in the state where the signal received by the input unit is input to the amplification unit is larger than the threshold value, the signal that has passed through the filter is transmitted to the amplification unit. A receiver characterized by allowing input. The processing unit executes processing for positioning the position information of the receiving device, and when the receiving device is in a stationary state, stores the positioned position information and then outputs the stored position information. The receiving device according to claim 1, wherein the receiving device continues to be used. The filter includes a first filter and a second filter.
The control unit holds a first threshold value and a second threshold value as threshold values.
When the magnitude of the current consumption in the state where the signal received by the input unit is input to the amplification unit is larger than the first threshold value, the control unit transfers the signal that has passed through the first filter to the amplification unit. And let me enter
When the magnitude of the current consumption in the state where the signal passing through the first filter is input to the amplification unit is larger than the second threshold value, the control unit continues the first filter and the second filter. The receiving device according to claim 1 or 2, wherein the signal passed through the device is input to the amplification unit. When the magnitude of the current consumption in the state where the signal passing through the filter is input to the amplification unit is larger than another threshold value, the control unit inputs the signal received by the input unit to the amplification unit. The receiving device according to claim 1 or 2, wherein the receiving device is returned so as to be caused. The input section that receives signals and
A filter that passes a signal having a part of the bandwidth among the signals received at the input unit, and
An amplification unit that amplifies the signal that has passed through the filter or the signal received by the input unit.
A processing unit that processes the amplified signal in the amplification unit, and
A measuring unit that measures the magnitude of current consumption of the amplification unit,
Control to control whether the signal passed through the filter is input to the amplification unit or the signal received by the input unit is input to the amplification unit based on the magnitude of the current consumption measured by the measurement unit. Department and
An additional input unit that inputs a signal different from the signal input in the input unit, and
It is provided with an additional processing unit that processes the signal input in the additional input unit.
In the control unit, (1) when the receiving device changes from a stationary state to a moving state, the magnitude of the current consumption in the state where the signal received by the input unit is input to the amplification unit is larger than the threshold value. If the strength of another signal processed by the additional processing unit increases, the signal that has passed through the filter is input to the amplification unit, and (2) the signal that has passed through the filter is input to the amplification unit. A receiving device characterized in that if the strength of another signal processed by the additional processing unit decreases in the input state, the signal received by the input unit is input to the amplification unit.

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