Wireless communication system, wireless communication method, and wireless signal receiving device

Abstract

This invention relates to a wireless communication system that is suitable for use in an environment where an interference wave is present, and has the objective of securing a desired communication quality in an environment where a carrier wave and an interference wave have to be present together. This wireless communication system comprises a transmission station 10 of which a transmission output 50-1 is variable, and a reception station 30 having a function to relay wireless signals. The reception station 30 comprises an attenuator for attenuating a received input, taken from an antenna, at a desired attenuation rate. The reception station 30 detects an intensity ratio C / I between a carrier wave C delivered from the transmission station 10 and reaching the antenna, and an interference wave I reaching the antenna. If the C / I of a received input 50-2 (e.g., 30 dB) is less than a required value (e.g., 35 dB), the reception station 30 requests the transmission station 10 for an increase 50-4 of transmission output, and further requests the attenuator for an attenuation of a received input 50-5, thereby obtaining an attenuated input 50-6 that satisfies specifications.

Description

[Technical Field]

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, and a wireless signal receiving device, and more particularly to a wireless communication system, a wireless communication method, and a wireless signal receiving device that are suitable for use in an environment where interference waves exist. [Background technology]

[0002] The following Patent Document 1 discloses a technology for preventing interference between communication signals when devices using adjacent frequencies are placed close to each other. Specifically, Patent Document 1 discloses a system that uses a wireless power transmitter that generates a power signal at a specific frequency for the purpose of power supply, and an adjacent frequency-using device that operates by receiving the power supply and generates a wireless signal at a frequency adjacent to the power signal.

[0003] In order to operate a device using an adjacent frequency, it is necessary to transmit a power signal to that device to ensure its operating power. On the other hand, if a device using an adjacent frequency emits a wireless signal in an environment where such a power signal is being transmitted, the former will interfere with the latter, and the desired communication quality cannot be achieved.

[0004] Patent Document 1 discloses a technique for avoiding interference between the two, in which a device using an adjacent frequency requests a wireless power transmitter to stop transmitting a power signal when the device transmits a wireless signal. When the transmission of the power signal is stopped, the interference wave disappears, and the wireless signal transmitted by the device using the adjacent frequency is transmitted properly. Therefore, the technique described in Patent Document 1 can solve the degradation of communication quality caused by the interference signal. [Prior art documents] [Patent documents]

[0005] Japanese Patent Publication No. 2012-235674 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 1 can only be used under conditions where the device generating the interference wave can respond to requests from the device receiving the interference wave. On the other hand, in a real environment, various devices frequently generate wireless signals independently, making it impossible to request the cessation of the interference wave. Therefore, the technology described in Patent Document 1 cannot provide a solution for avoiding interference under such conditions.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and its first objective is to provide a wireless communication system that can ensure desired communication quality in an environment where carrier waves and interference waves are unavoidably coexistent.

[0008] A second object of the present disclosure is to provide a wireless communication method for ensuring a desired communication quality in an environment where a carrier wave and an interference wave inevitably coexist.

[0009] A third object of the present disclosure is to provide a radio signal receiving device that can ensure a desired communication quality in an environment where a carrier wave and an interference wave inevitably coexist. [Means for solving the problem]

[0010] In order to achieve the above object, a first aspect is a wireless communication system including a transmitting station for a wireless signal having a variable transmission output and a receiving station having a function of relaying the wireless signal, The receiving station an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; A process of detecting C / I, which is an intensity ratio between a carrier wave C sent from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; a process of requesting the transmitting station to increase the transmission output when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the received input when the C / I is smaller than the requested value; Preferably, the system is configured to execute the following:

[0011] A second aspect is a wireless communication method using a transmitting station of a wireless signal having a variable transmission output and a receiving station having a function of relaying the wireless signal, the receiving station includes an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; detecting a C / I, which is an intensity ratio between a carrier wave C transmitted from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; requesting the transmitting station to increase the transmission power when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the receive input if the C / I is less than the requested value; It is desirable to include:

[0012] A third aspect is a radio signal receiving device having a function of relaying a radio signal transmitted from a transmitting station having a variable transmission output, an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; A process of detecting C / I, which is an intensity ratio between a carrier wave C sent from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; a process of requesting the transmitting station to increase the transmission output when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the received input when the C / I is smaller than the requested value; Preferably, the system is configured to execute the following: [Effects of the Invention]

[0013] According to the first to third aspects, it is possible to ensure a desired communication quality in an environment where a carrier wave and an interference wave inevitably coexist. [Brief explanation of the drawings]

[0014] [Figure 1]1 is a block diagram illustrating a configuration of a wireless communication system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram for explaining a characteristic operation of the wireless communication system shown in FIG. [Figure 3] 2 is a flowchart illustrating the flow of main processes executed in the wireless communication system shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiment 1 [Configuration of the First Embodiment] 1 is a block diagram illustrating the configuration of a wireless communication system according to a first embodiment of the present disclosure. The configuration described below can be configured using electronic circuits based on dedicated hardware. Alternatively, the dedicated hardware may be combined with a memory storing a program and a processing unit, and some of the processing may be performed by having the processing unit execute the program.

[0016] 1, the wireless communication system of this embodiment includes a wireless signal transmitting station 10. The transmitting station 10 includes an antenna 12 for transmitting and receiving wireless signals. A transmitting unit 16 included in an RF (Radio Frequency) unit 14 is connected to the antenna 12.

[0017] A control signal is provided to the transmitter 16 from a control unit 20 included in the monitoring and control unit 18. The control signal includes, for example, a command regarding transmission power. The transmitter 16 converts a signal provided from a signal providing unit (not shown) into a high-frequency signal and provides it to the antenna 12 at a transmission power specified by the control unit 20. The antenna 12 receives the signal and transmits it.

[0018] 1 includes a receiving station 30. The receiving station 30 has a function of receiving and relaying a radio signal transmitted from the transmitting station 10. For this reason, the receiving station 30 may be called a radio signal receiving device or a radio signal relay device.

[0019] The receiving station 30 is equipped with an antenna 32 for transmitting and receiving radio signals. The radio signals transmitted from the transmitting station 10 are received by the antenna 32. The radio signals transmitted by the receiving station 30 to relay the received signals are also transmitted from the antenna 32. However, the antenna for transmitting the radio signals from the receiving station 30 may be provided separately from the antenna 32.

[0020] The signal received by the antenna 32 is provided to a receiving unit 36 ​​included in an RF unit 34 of the receiving station 30. To realize a relay function, the receiving unit 36 ​​provides a received input to an attenuator 38 and calculates the C / I, i.e., the intensity ratio of the carrier wave to the interference wave, for the received input.

[0021] The C / I calculated by the receiver 36 is provided to a controller 42 included in the monitoring and control unit 40. The controller 42 has a function of determining whether the C / I has fallen below a preset threshold value. Based on the result of this determination, the controller 42 issues a command to the attenuator 38 and a request to the controller 20 of the transmitting station 10, as necessary.

[0022] The attenuator 38 attenuates the received input provided from the receiving unit 36 ​​in accordance with a command from the control unit 20. The signal processed by the attenuator 38 is provided to a transmitting unit (not shown) via a receiving port (not shown), and is transmitted as a radio signal from the antenna 32 or a separately provided antenna dedicated to transmission.

[0023] The control unit 42 of the receiving station 30 can issue a request to change the transmission power to the control unit of the transmitting station 10. In Fig. 1, for convenience, a dashed arrow representing the transmission power change request is drawn between the control unit 42 and the control unit 20, but this request is transmitted from the receiving station 30 to the transmitting station 10 in the form of a radio signal. When the control unit 20 of the transmitting station 10 receives the transmission power change request, it changes the transmission power command for the transmitting unit 16 in accordance with the request.

[0024] As described above, the wireless communication system of this embodiment can achieve the following four functions. (1) The receiving station 30 can detect a decrease in the C / I of the radio signal transmitted from the transmitting station. (2) The receiving station 30 can appropriately attenuate the receiving input and send the attenuated signal to the receiving port. (3) The receiving station 30 can request the transmitting station 10 to change the transmission output. (4) The transmitting station 10 can change the transmission power of the transmission signal in response to a request from the receiving station.

[0025] [Characteristic operation of the first embodiment] Fig. 2 is a diagram for explaining a characteristic operation of the wireless communication system of this embodiment. The upper left part of Fig. 2 shows a state in which a transmitting station 10 transmits a signal composed of a carrier wave (C) at a transmission output 50-1. The upper part of Fig. 2 also shows an example in which an interference source 52 exists between the transmitting station 10 and the receiving station 30, and the carrier wave (C) emitted from the transmitting station 10 reaches the receiving station 30 together with an interference wave (I) emitted from the interference source 52.

[0026] 2 shows how the input 50-2, which contains a mixture of the carrier wave (C) and the interference wave (I), is received by the receiving station 30. Here, it is assumed that the C / I of the received input 50-2 is "30 dB."

[0027] When the transmitting station 10 and the receiving station 30 share a frequency with an interference source 52, the radio signal emitted by the interference source 52 may become an interference wave (I). Once the interference wave (I) reaches the receiving station 30, the receiving station 30 cannot attenuate it by itself. However, to ensure the desired communication quality, the receiving station 30 must transmit a signal having a C / I that meets the standard.

[0028] If it were possible to weaken the transmission output of the radio signal emitted by the interference source 52 or to change the installation location of the interference source 52, it would be possible to satisfy the above requirement by suppressing the strength of the interference wave (I) reaching the receiving station 30. However, if the operator that manages the interference source 52 is different from the operator that operates the transmitting station 10 and the receiving station 30, coordination between the operators would be necessary, making the above change an extremely large-scale undertaking.

[0029] Another method for increasing the C / I is to increase the transmission output of the carrier wave (C) emitted from the transmitting station 10. However, for devices that relay wireless signals, such as the receiving station 30 in this embodiment, there may be restrictions on the strength of the relayed signal. For example, if the receiving station 30 is a device that must meet the inspection standards related to the Radio Law of Japan, the signal that reaches the receiving port of the receiving station 30 must comply with the standard receiving input value specified by the inspection standards. For this reason, the transmission output used by the transmitting station 10 cannot be increased arbitrarily.

[0030] In the following, under this background, an outline of the processing that the wireless communication system of this embodiment performs to make the receiving station 30 function as a relay device without requiring coordination with other carriers and while complying with the standard receiving input value regulations will be described.

[0031] As described above, the upper part of Fig. 2 shows an example in which the C / I of the receiving input 50-2 is "30 dB." In the following explanation, it is assumed that the standard receiving input value that the receiving station 30 must comply with is "35 dB." Therefore, in this case, the C / I of the receiving input 50-2 is "5 dB" short of the standard receiving input value.

[0032] If the C / I of the receiving input 50-2 is insufficient relative to the required C / I, the control unit 42 of the receiving station 30 requests the attenuator 38 to attenuate the signal strength corresponding to the C / I deficiency, and requests the transmitting station 10 to increase the output power corresponding to the C / I deficiency. That is, in the above example, the attenuator 38 of the receiving station 30 is requested to attenuate the receiving input by 5 dB, and the transmitting station 10 is requested to increase the transmission power by 5 dB.

[0033] The upper right side of Figure 2 shows the attenuated input 50-3, which is generated when the attenuator 38 receives the above command and attenuates the receive input 50-2 by 5 dB. As shown in the figure, the attenuated input 50-3 is a signal whose intensity is 5 dB lower than the receive input 50-2 and has a C / I of 30 dB. This input 50-3 still does not meet the standard receive input value.

[0034] 2 shows a transmission output 50-4 generated by the transmitting station 10 increasing its transmission output in response to the transmission output change request. The intensity of this output 50-4 is increased by 5 dB compared to the output 50-1 before the transmission output change.

[0035] The bottom center of Figure 2 shows the received input 50-5 generated when the transmission output 50-4, whose intensity has been increased by 5 dB, and the interference wave (I) from the interference source 52 reach the receiving station 30. While the intensity of the carrier wave (C) is increased, the intensity of the interference wave (I) remains unchanged, so the C / I of the received input 50-5 changes to 35 dB. However, because the intensity of this input 50-5, including the interference wave (I), exceeds the standard received input value, it does not meet the standards of the Radio Law-related examination criteria as it is.

[0036] The lower right side of Figure 2 shows an attenuated input 50-6 generated by the attenuator 38 attenuating the receiving input 50-5 by 5 dB. As shown in the figure, the attenuated input 50-6 is a signal with an intensity that is 5 dB lower than the receiving input 50-5 and a C / I of 35 dB. This input 50-6 satisfies the standard receiving input value requirements. In this embodiment, the attenuator 38 of the receiving station 30 provides the attenuated input 50-6 thus generated to the receiving port. Therefore, the receiving station 30 of this embodiment can relay wireless signals while maintaining the desired communication quality, even in an environment where a carrier wave and an interference wave inevitably coexist.

[0037] [Processing flow in the first embodiment] 3 is a flowchart illustrating the flow of main processes executed in the wireless communication system of this embodiment. As shown in FIG. 3, when the receiving station 30 receives a wireless signal, the RF unit 34 detects a decrease in the C / I of the received input (step 100).

[0038] Next, the monitoring and control unit 40 calculates the amount of C / I attenuation, that is, the amount of shortfall relative to the C / I that should be ensured (e.g., a standard received input value) (step 102). Next, the attenuator 38 is controlled so that the received input is attenuated by an amount of intensity corresponding to the shortfall (step 104). As a result, the attenuator 38 attenuates the received input provided from the receiving unit 36 ​​by an amount corresponding to the C / I shortfall (step 106).

[0039] The receiving station 30 also calculates the current transmission power value (step 108) and then transmits a transmission power change request to the transmitting station 10 to increase the transmission power by an amount corresponding to the C / I deficiency (step 110).

[0040] When the transmitting station 10 receives the transmission power change request, the monitoring and control unit 18 controls the transmission power to meet the received request (step 112). As a result, the transmission power is changed in the RF unit 14, and a signal whose intensity is increased by a value corresponding to the C / I deficiency is transmitted (step 114).

[0041] The receiving station 30 receives the increased carrier (C) along with the unchanged interference (I). The attenuator 38 is controlled to attenuate the received input, thereby improving the C / I of the received input so that the required standard is met (step 116).

[0042] As described above, the wireless communication system of this embodiment can appropriately improve the C / I ratio even in an environment where a carrier wave and an interference wave inevitably coexist. Therefore, this system can continue to provide stable, excellent communication quality even in an environment where an interference wave occurs, without requiring significant cost or effort, and while complying with regulations such as the Radio Law.

[0043] [Modification of the first embodiment] In the first embodiment described above, the receiving station 30 is configured to include the attenuator 38 in the RF unit 34. However, the present disclosure is not limited to this. The configuration of the present disclosure may be realized by installing an external attenuator 38 in an existing receiving station that does not include an attenuator. [Explanation of symbols]

[0044] 10 Transmitting Station 20, 42 Control section 30 receiving stations 36 Receiving unit 38 Attenuator 50-1, 50-4 transmission output 50-2, 50-5 Receiver Input 50-3, 50-6 attenuation input

Claims

1. A wireless communication system comprising a transmitting station for a wireless signal having a variable transmission output and a receiving station having a function of relaying the wireless signal, The receiving station: an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; A process of detecting C / I, which is an intensity ratio between a carrier wave C sent from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; a process of requesting the transmitting station to increase the transmission output when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the received input when the C / I is smaller than the requested value; a process of transmitting the signal processed by the attenuator as a relay signal of a radio signal; is configured to run The relay signal is used under conditions where a strength limit is imposed on the relay signal and the relay signal is required to have a C / I that meets the relay standard; A wireless communication system in which the required value is a C / I that meets the relay standard.

2. The receiving station: configured to execute a process of calculating a shortfall of the C / I of the received input taken from the antenna with respect to the required value; the process of requesting an increase in transmission power is a process of requesting an increase in transmission power to correspond to the shortage, The process of requesting attenuation of the received input is a process of determining attenuation of the received input corresponding to the insufficiency.

10. The wireless communication system of claim 1.

3. 3. The wireless communication system according to claim 1, wherein the required value is a standard reception input value defined by the Radio Law-related examination standards.

4. 4. The wireless communication system according to claim 1, wherein the attenuator is externally added to an existing receiving station that does not have an attenuator.

5. A wireless communication method using a transmitting station of a wireless signal having a variable transmission output and a receiving station having a function of relaying the wireless signal, the receiving station includes an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; detecting a C / I, which is an intensity ratio between a carrier wave C transmitted from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; requesting the transmitting station to increase the transmission power when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the receive input if the C / I is less than the requested value; transmitting the signal processed by the attenuator to the receiving station as a relay signal of a radio signal; Including, The relay signal is used under conditions where a strength limit is imposed on the relay signal and the relay signal is required to have a C / I that meets the relay standard; A wireless communication method in which the required value is a C / I that meets the relay standard.

6. calculating a deficiency of the C / I of the received input taken from the antenna with respect to the required value; the step of requesting an increase in transmission power is a step of requesting an increase in transmission power corresponding to the shortage, The step of requesting attenuation of the received input is a step of obtaining attenuation of the received input corresponding to the shortage. The wireless communication method according to claim 5.

7. A radio signal receiving device having a function of relaying a radio signal transmitted from a transmitting station having a variable transmission output, an attenuator for attenuating the received input taken from the antenna by a desired attenuation factor; A process of detecting C / I, which is an intensity ratio between a carrier wave C sent from the transmitting station and arriving at the antenna and an interference wave I arriving at the antenna; a process of requesting the transmitting station to increase the transmission output when the C / I is smaller than a required value to be secured; requesting the attenuator to attenuate the received input when the C / I is smaller than the requested value; a process of transmitting the signal processed by the attenuator as a relay signal of a radio signal; is configured to run The relay signal is used under conditions where a strength limit is imposed on the relay signal and the relay signal is required to have a C / I that meets the relay standard; A radio signal receiving device in which the required value is a C / I that meets the relay standard.

8. The wireless signal receiving device configured to execute a process of calculating a shortfall of the C / I of the received input taken from the antenna with respect to the required value; the process of requesting an increase in transmission power is a process of requesting an increase in transmission power to correspond to the shortage, The process of requesting attenuation of the received input is a process of determining attenuation of the received input corresponding to the insufficiency.

8. The radio signal receiving device according to claim 7.

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