JP2013070282A - Receiver, reception system and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver capable of preventing deterioration of wireless communication quality appropriately while taking account of the weather condition, and to provide a reception system and a communication control method.SOLUTION: A monitoring device 200 determines whether or not the radio wave propagation loss of each wireless base station 100 deteriorates based on the weather information in the installation site of the wireless base station 100, and transmits an NF control command signal for designating reduction of noise figure to the wireless base station 100 if the radio wave propagation loss deteriorates. The wireless base station 100 reduces the noise figure thereof according to the designation of noise figure reduction, by reducing the amount of attenuation of a built-in attenuator.

Description

  The present invention relates to a receiver, a reception system, and a communication control method.

  In wireless communication between a wireless base station and a wireless terminal, degradation of wireless communication quality due to radio wave propagation loss becomes a problem. In particular, when a radio terminal exists at the outer edge of the communication area of the radio base station, when the radio wave propagation loss increases, the radio signal intensity from the radio terminal is reduced in the radio base station. For this reason, wireless communication cannot be continued.

  With respect to such a problem, in the technique described in Patent Document 1, the radio base station includes a detection circuit, a variable attenuator, and an input power control unit. The detection circuit detects the power of the received radio signal, and the input power control unit controls the attenuation amount of the built-in variable attenuator based on the detected power (reception power). When the received power is small, the attenuation is reduced, so that deterioration of reception sensitivity due to the variable attenuator can be suppressed.

JP 2010-114481 A

  The radio wave propagation loss at the radio base station depends on the weather conditions. For this reason, it is required to prevent deterioration of wireless communication quality in consideration of weather conditions.

  The present invention has been made in view of such problems, and provides a receiver, a reception system, and a communication control method capable of appropriately preventing deterioration of wireless communication quality in consideration of weather conditions. With the goal.

In order to achieve the above object, a receiver according to the first aspect of the present invention provides:
A receiver for receiving a radio signal,
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit according to weather conditions;
It is characterized by providing.

In order to achieve the above object, a receiving system according to the second aspect of the present invention provides:
A receiving system comprising a receiver that receives a radio signal and a monitoring device that monitors the receiver,
The receiver
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit;
With
The monitoring device includes an instruction unit that instructs the control unit,
The instructing unit instructs the control unit to control the noise figure in the receiver according to weather conditions,
The control unit controls an attenuation amount of the attenuation unit in accordance with an instruction from the instruction unit.

In order to achieve the above object, a communication control method according to a third aspect of the present invention includes:
A communication control method in a receiver that receives a radio signal,
The attenuation amount of the attenuation unit for attenuating the radio signal is controlled according to the weather condition.

  According to the present invention, it is possible to appropriately prevent deterioration of wireless communication quality in consideration of weather conditions.

It is a figure which shows the structure of the radio | wireless communications system which concerns on one Embodiment of this invention. It is a figure which shows the structure of the wireless base station which concerns on one Embodiment of this invention. It is a figure which shows the structure of the monitoring apparatus which concerns on one Embodiment of this invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on one Embodiment of this invention. It is a figure which shows an example of the weather information which concerns on one Embodiment of this invention. It is a figure which shows an example of the radio base station information which concerns on one Embodiment of this invention.

  Hereinafter, a receiver, a reception system, and a communication control method according to an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration of Radio Communication System As shown in FIG. 1, a radio communication system as a reception system according to an embodiment of the present invention includes radio base stations 100-1, 100-2, 100-3 as receivers, And a monitoring device 200 for monitoring weather conditions.

  Each of the radio base stations 100-1 to 100-3 forms a cell as a communication area. Further, the radio base stations 100-1 to 100-3 perform radio communication with radio terminals (not shown) existing in the cell.

(2) Configuration of Radio Base Station As shown in FIG. 2, radio base stations 100-1 to 100-3 (hereinafter, the radio base stations 100-1 to 100-3 are collectively referred to as a radio base station 100 as appropriate). ) Includes a low noise amplifier (LNA) 1, an attenuator 2, a frequency down-conversion unit 3, a control unit 4, and an interface (I / F) unit 5. FIG. 2 shows only the configuration related to the present invention in the radio base station 100.

  The LNA 1 receives and amplifies a radio signal (reception signal) received from a radio terminal, which is received by an antenna (not shown) at the preceding stage. The received signal is a signal in a radio frequency band (RF) that is a high frequency band. Further, the LNA 1 outputs the amplified received signal to the attenuator 2.

  The attenuator 2 receives the amplified received signal from the LNA 1. The attenuator 2 attenuates the electric field strength of the received reception signal after amplification to an appropriate level. Further, the attenuator 2 outputs the attenuated received signal to the frequency down-conversion unit 3.

  The frequency down-conversion unit 3 includes a local oscillator and a mixer (not shown). The frequency down-conversion unit 3 inputs the received signal after attenuation from the attenuator 2. The frequency down-conversion unit 3 converts the attenuated received signal into an intermediate frequency band. Further, the frequency down-conversion unit 3 outputs the received signal after frequency conversion to a demodulator (not shown) at the subsequent stage.

  The control unit 4 is configured by a CPU (Central Processing Unit) or the like. The control unit 4 controls the entire radio base station 100. For example, the control unit 4 performs processing related to control of the attenuation amount of the attenuator 2.

  The I / F unit 5 communicates with the monitoring device 200. For example, a communication line such as an optical fiber is laid between the I / F unit 5 and the monitoring device 200. The I / F unit 5 receives a signal from the monitoring device 200 via a communication line.

(3) Configuration of Monitoring Device As shown in FIG. 3, the monitoring device 200 includes a control unit 11, a memory 12, and an interface (I / F) unit 13. FIG. 3 shows only the configuration related to the present invention in the monitoring device 200.

  The control unit 11 is configured by a CPU or the like. The control unit 11 controls the entire monitoring device 200. In addition, the monitoring apparatus 200 includes a weather information acquisition unit 21, a position information acquisition unit 22, and an instruction unit 23 in order to perform processing related to the attenuation control of the attenuator 2 in the radio base station 100.

  The memory 12 stores various information necessary for processing of the monitoring device 200. The I / F unit 13 communicates with the radio base station 100. The I / F unit 13 communicates with an external device (not shown) that transmits weather information.

(4) Operation of Radio Communication System Next, the operation of the radio communication system will be described with reference to the sequence diagram shown in FIG. The monitoring device 200 acquires weather information indicating the weather condition at the installation location of the radio base station 100 (step S101).

  Specifically, the weather information acquisition unit 21 in the control unit 11 acquires weather information from an external device via the I / F unit 13. The weather information shown in FIG. 5 includes target area information and weather forecast information. The target area information is information on a target area for weather information. In the present embodiment, the target area information is configured by a set of longitude and latitude of the outer edge of the area. The weather forecast information is the weather forecast information of the area indicated by the target area information. In the present embodiment, the weather forecast information includes weather information such as sunny, cloudy, rainy, rainy, snowy, and snowstorms. The external device transmits weather information to the monitoring device 200 periodically (for example, every hour). Alternatively, the weather information acquisition unit 21 requests weather information from an external device at a predetermined timing, and the external device transmits weather information in response to the request.

  Next, the monitoring apparatus 200 predicts whether or not a condition for worsening radio wave propagation loss in the radio base station 100 is satisfied based on the acquired weather information (step S102). Specifically, the position information acquisition unit 22 in the control unit 11 acquires wireless base station information stored in advance in the memory 12. The radio base station information shown in FIG. 6 is prepared for each radio base station 100. The radio base station information includes a radio base station ID and installation position information. The radio base station ID is identification information of the corresponding radio base station 100. The installation position information is information indicating the installation position of the corresponding radio base station 100. In the present embodiment, the installation position information is configured by the longitude and latitude of the installation position.

  The instruction unit 23 in the control unit 11 compares the installation position information in the radio base station information corresponding to each of the radio base stations 100-1 to 100-3 with the target area information in the latest weather information, It is determined whether the longitude and latitude of the installation position information are present in an area formed by a set of longitude and latitude in the target area information. When it is determined that the longitude and latitude of the installation position information are within an area formed by the set of longitude and latitude in the target area information, the instruction unit 23 displays the weather information as a radio base station corresponding to the installation position information. Acquired as weather information indicating weather conditions at 100 installation locations.

  Next, the instructing unit 23 predicts whether or not a condition that radio wave propagation loss in the radio base station 100 deteriorates is satisfied based on weather information at the installation location of the radio base station 100. In the present embodiment, the radio wave propagation loss in the radio base station 100 means an radio wave propagation loss in the uplink direction from the radio terminal toward the radio base station 100. In the present embodiment, the instruction unit 23 indicates that the latest weather forecast information at the installation location of the radio base station 100 is rain, wind, rain, snow, snowstorm, and the previous weather forecast information at the installation location of the radio base station 100 is When it is clear and cloudy, it is determined that the condition that the radio wave propagation loss is considered to be satisfied is satisfied. In other cases, it is determined that the condition that the radio wave propagation loss is assumed to be deteriorated is not satisfied.

  If the condition that the radio wave propagation loss in the radio base station 100 is considered to deteriorate is not satisfied, the operation after the acquisition of weather information at the installation location of the radio base station 100 in step S101 is repeated.

  On the other hand, when the condition that the radio wave propagation loss in the radio base station 100 is considered to deteriorate is satisfied, the monitoring apparatus 200 transmits an NF control command signal that instructs the radio base station 100 to lower the noise figure. The radio base station 100 receives an NF control command signal instructing a decrease in noise figure (step S103).

  Here, the NF control command signal is a signal for the monitoring apparatus 200 to instruct the radio base station 100 to lower or increase the noise figure (NF: Noise Figure) in the radio base station 100. The noise figure (noise figure from LNA1 to frequency down-conversion unit 3) NF in radio base station 100 is NF1 as the noise figure of LNA1, NF2 as the noise figure of frequency down-conversion unit 3, and as ATT1 and LNA1 as the loss at attenuator 2. When the gain is G1, NF = NF1 + (NF2 + ATT1-1) / G1 is calculated. Therefore, the noise figure in the radio base station 100 depends on the loss (attenuation amount) in the attenuator 2.

  Specifically, when the condition that the radio wave propagation loss in the radio base station 100 is considered to be deteriorated, the instruction unit 23 in the control unit 11 of the monitoring apparatus 200 instructs the reduction of the noise figure in the radio base station 100. NF control command signal is generated and output to the I / F unit 13 together with the identification information of the radio base station 100 that is the transmission destination of the NF control command signal. The I / F unit 13 transmits an NF control command signal for instructing a reduction in noise figure to the radio base station 100 specified by the identification information. The I / F unit 5 of the radio base station 100 receives the NF control command signal and outputs it to the control unit 4.

  Next, the radio base station 100 reduces the attenuation amount of the attenuator 2 in response to an instruction to reduce the noise figure (step S104). Specifically, the control unit 4 reduces the attenuation amount of the attenuator 2 when receiving the NF control command signal instructing the noise figure to decrease. Here, the decrease in the attenuation amount means that the attenuation amount is lower than the attenuation amount at the present time, or that the attenuation amount is equal to or less than a predetermined value. When the attenuation amount is reduced by the control unit 4, the attenuator 2 attenuates the amplified received signal from the LNA 1 with the new attenuation amount after the reduction.

  On the other hand, after transmitting the NF control command signal instructing the noise figure to decrease, the monitoring apparatus 200 acquires weather information indicating the weather condition at the installation location of the radio base station 100 (step S105). Specifically, as in step S <b> 101, the weather information acquisition unit 21 in the control unit 11 acquires weather information from an external device via the I / F unit 13.

  Next, the monitoring apparatus 200 predicts whether or not the condition for improving the radio wave propagation loss in the radio base station 100 is satisfied based on the acquired weather information (step S106). Specifically, as in step S <b> 102, the position information acquisition unit 22 in the control unit 11 acquires radio base station information stored in advance in the memory 12. The instruction unit 23 compares the installation position information in the radio base station information corresponding to each of the radio base stations 100-1 to 100-3 with the target area information in the latest weather information, and determines the longitude of the installation position information. And whether or not the latitude exists in an area formed by a set of longitude and latitude in the target area information. When it is determined that the longitude and latitude of the installation position information are within an area formed by the set of longitude and latitude in the target area information, the instruction unit 23 displays the weather information as a radio base station corresponding to the installation position information. Acquired as weather information indicating weather conditions at 100 installation locations.

  Next, the instruction unit 23 predicts whether or not a condition that radio wave propagation loss in the radio base station 100 is considered to be improved is satisfied based on weather information at the installation location of the radio base station 100. In the present embodiment, the instruction unit 23 indicates that the latest weather forecast information at the installation location of the radio base station 100 is clear and cloudy, and the previous weather forecast information at the installation location of the radio base station 100 is rain, wind and rain, In the case of snow or snowstorm, it is determined that the condition that the radio wave propagation loss is considered to be improved is satisfied, and in other cases, it is determined that the condition that the radio wave propagation loss is considered to be improved is not satisfied.

  If the condition that the radio wave propagation loss in the radio base station 100 is considered to be improved is not satisfied, the operation after the acquisition of the weather information at the installation location of the radio base station 100 in step S105 is repeated.

  On the other hand, when the condition that the radio wave propagation loss in the radio base station 100 is considered to be improved is satisfied, the monitoring apparatus 200 transmits an NF control command signal that instructs the radio base station 100 to increase the noise figure. The radio base station 100 receives an NF control command signal instructing an increase in noise figure (step S107).

  Specifically, when the condition that radio wave propagation loss in the radio base station 100 is considered to be improved is satisfied, the instruction unit 23 in the control unit 11 of the monitoring apparatus 200 instructs the increase of the noise figure in the radio base station 100. NF control command signal is generated and output to the I / F unit 13 together with the identification information of the radio base station 100 that is the transmission destination of the NF control command signal. The I / F unit 13 transmits an NF control command signal instructing an increase in noise figure to the radio base station 100 specified by the identification information. The I / F unit 5 of the radio base station 100 receives the NF control command signal and outputs it to the control unit 4.

  Next, the radio base station 100 increases the attenuation amount of the attenuator 2 in response to an instruction to increase the noise figure (step S108). Specifically, the control unit 4 increases the attenuation amount of the attenuator 2 when receiving an NF control command signal instructing an increase in noise figure. Here, the increase in the attenuation amount means that the attenuation amount is higher than the attenuation amount at the present time, or that the attenuation amount is equal to or greater than a predetermined value. When the attenuation amount is increased by the control unit 4, the attenuator 2 attenuates the amplified reception signal from the LNA 1 with the new attenuation amount after the increase. The control unit 4 may return the attenuation amount of the attenuator 2 to the attenuation amount before the decrease in step S104.

(5) Operational Effects As described above, in the mobile communication system according to the present embodiment, the monitoring device 200 causes the radio wave propagation loss of the radio base station 100 to deteriorate based on the weather information at the place where the radio base station 100 is installed. It is determined whether or not the condition to be considered is satisfied. If the condition to be considered to be deteriorated is satisfied, an NF control command signal for instructing a reduction in noise figure is transmitted to the radio base station 100. The radio base station 100 reduces the noise figure of the radio base station 100 by reducing the attenuation amount of the attenuator 2 in response to an instruction to reduce the noise figure. Since the radio communication quality is improved by reducing the noise figure of the radio base station 100, the radio base station 100 can receive a signal from the radio terminal even in a weather situation that deteriorates the radio wave propagation loss. .

  In addition, the monitoring apparatus 200 transmits an NF control command signal instructing a reduction in noise figure to the radio base station 100, and then, based on weather information at the installation location of the radio base station 100, the radio wave propagation of the radio base station 100 It is determined whether or not the condition that the loss is considered to be improved is satisfied. When the condition that the loss is considered to be improved is satisfied, an NF control command signal that instructs to increase the noise figure is transmitted to the radio base station 100. The radio base station 100 raises the noise figure of the radio base station 100 by raising the attenuation amount of the attenuator 2 in response to an instruction to raise the noise figure. By increasing the noise figure of the radio base station 100, it is possible to obtain a radio wave propagation loss according to weather conditions.

(6) Other Embodiments In the above-described embodiments, the case where the attenuation amount of the attenuator 2 is controlled in the radio base station 100 as a receiver has been described. However, the present invention can be applied to receivers other than the radio base station 100 as well. Moreover, the weather forecast information in the above-described embodiment is merely an example, and may be other weather forecast information indicating the weather situation.

  In addition, the present invention is not limited by the description of the above-described embodiment and the drawings, and appropriate modifications and the like can be added to the above-described embodiment and the drawings.

  Moreover, although a part or all of said embodiment can be described also as the following additional remarks, it is not restricted to the following.

(Appendix 1)
A receiver for receiving a radio signal,
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit according to weather conditions;
A receiver comprising:

(Appendix 2)
When the weather condition satisfies a condition that the radio wave propagation loss of the receiver is assumed to deteriorate, the control unit reduces the attenuation amount of the attenuation unit according to a noise figure reduction instruction notified from the outside. The receiver according to appendix 1, wherein control is performed to lower the frequency.

(Appendix 3)
The control unit performs control to reduce the attenuation amount of the attenuation unit when a weather condition at a place where the receiver is installed satisfies a condition that radio wave propagation loss of the receiver is considered to deteriorate. The receiver according to Appendix 1 or 2.

(Appendix 4)
A receiving system comprising a receiver that receives a radio signal and a monitoring device that monitors the receiver,
The receiver
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit;
With
The monitoring device includes an instruction unit that instructs the control unit,
The instructing unit instructs the control unit to control the noise figure in the receiver according to weather conditions,
The reception system according to claim 1, wherein the control unit controls an attenuation amount of the attenuation unit in accordance with an instruction from the instruction unit.

(Appendix 5)
The monitoring device includes a weather information acquisition unit that acquires weather information indicating the weather condition,
The instruction unit instructs the control unit to reduce the attenuation amount of the attenuation unit when the weather condition indicated by the weather information satisfies a condition that the radio wave propagation loss of the receiver is considered to deteriorate. The receiving system according to appendix 4, wherein the receiving system is performed.

(Appendix 6)
The monitoring device includes an installation position information acquisition unit that acquires installation position information indicating an installation position of the receiver,
The instruction unit, when the weather condition at the installation location of the receiver indicated by the installation location information satisfies a condition that the radio wave propagation loss of the receiver is considered to deteriorate, 6. The receiving system according to appendix 4 or 5, wherein a reduction instruction is given.

(Appendix 7)
A communication control method in a receiver that receives a radio signal,
A communication control method, comprising: controlling an attenuation amount of an attenuation unit that attenuates the radio signal according to weather conditions.

1 LNA
2 Attenuator 3 Frequency down-conversion unit 4 Control unit 5 I / F unit 11 Control unit 12 Memory 13 I / F unit 21 Weather information acquisition unit 22 Location information acquisition unit 23 Instruction unit 100-1, 100-2, 100-3 Wireless Base station 200 Monitoring device

Claims (7)

A receiver for receiving a radio signal,
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit according to weather conditions;
A receiver comprising:   When the weather condition satisfies a condition that the radio wave propagation loss of the receiver is assumed to deteriorate, the control unit reduces the attenuation amount of the attenuation unit according to a noise figure reduction instruction notified from the outside. The receiver according to claim 1, wherein the control is performed to reduce the frequency.   The control unit performs control to reduce the attenuation amount of the attenuation unit when a weather condition at a place where the receiver is installed satisfies a condition that radio wave propagation loss of the receiver is considered to deteriorate. The receiver according to claim 1 or 2. A receiving system comprising a receiver that receives a radio signal and a monitoring device that monitors the receiver,
The receiver
An attenuation unit for attenuating the radio signal;
A control unit for controlling the attenuation amount of the attenuation unit;
With
The monitoring device includes an instruction unit that instructs the control unit,
The instructing unit instructs the control unit to control the noise figure in the receiver according to weather conditions,
The reception system according to claim 1, wherein the control unit controls an attenuation amount of the attenuation unit in accordance with an instruction from the instruction unit. The monitoring device includes a weather information acquisition unit that acquires weather information indicating the weather condition,
The instruction unit instructs the control unit to reduce the attenuation amount of the attenuation unit when the weather condition indicated by the weather information satisfies a condition that the radio wave propagation loss of the receiver is considered to deteriorate. The receiving system according to claim 4, wherein the receiving system is performed. The monitoring device includes an installation position information acquisition unit that acquires installation position information indicating an installation position of the receiver,
The instruction unit, when the weather condition at the installation location of the receiver indicated by the installation location information satisfies a condition that the radio wave propagation loss of the receiver is considered to deteriorate, The receiving system according to claim 4 or 5, wherein an instruction for lowering is given. A communication control method in a receiver that receives a radio signal,
A communication control method, comprising: controlling an attenuation amount of an attenuation unit that attenuates the radio signal according to weather conditions.

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