JP2018033068A - Communication terminal, controller, communication method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a receiving circuit by discriminating situation where a high power radio signal is received in a more preferable mode.SOLUTION: A communication terminal includes a communication unit for transmitting and receiving radio waves, an altitude information acquisition unit for acquiring altitude information indicating an altitude of own terminal, an altitude difference calculation unit for acquiring altitude information of another terminal different from the own terminal, and calculating an altitude difference between the own terminal and another terminal, based on the altitude information of the own terminal and another terminal, a power detector for detecting a power value of reception signal based on reception results of the radio waves, a position determination unit for determining whether or not the own terminal is located in the vicinity of a base station, a high place determination unit for determining that the own terminal is located at a high place, if both altitude difference and power value exceed thresholds, and a control unit for controlling a gain of the reception signal when determination is made that the own terminal is located at the high place.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication terminal, a control device, a communication method, a control method, and a program.

  In recent years, with the advancement of communication technology, the miniaturization of various devices, and the spread of communication infrastructure for wireless communication such as base stations, etc., it has been configured so that users can carry it, such as mobile phones and smartphones. Wireless communication terminals (hereinafter also referred to as “portable wireless terminals”) have become widespread.

JP 2010-68529 A

  On the other hand, as a portable wireless terminal as described above, a worker who performs maintenance work or management work on a facility (for example, a base station tower) in which a radio base station antenna in operation is installed communicates even during the work. There is a need to provide a portable wireless terminal that can be used for this purpose. However, in a situation where an operator works while climbing the base station tower while holding the portable radio terminal, a high-power radio signal (radio wave) is emitted from the base station antenna. In some cases, the dynamic range of the receiving circuit of the type wireless terminal may be exceeded and the receiving circuit may be damaged.

  On the other hand, for example, Patent Document 1 discloses an example of a mechanism for protecting a predetermined receiving circuit when a high-power wireless signal is received. However, there is a need for a mechanism for more accurately discriminating the situation where an operator is climbing up the base station tower and more reliably protecting the reception circuit of the portable wireless terminal held by the operator. ing.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to determine a situation in which a high-power radio signal is received in a more preferable manner and to provide a receiving circuit. It is to provide a mechanism that can be protected.

In order to solve the above problems, according to an aspect of the present invention, a communication unit that transmits and receives radio waves, and
An altitude information acquisition unit that acquires altitude information indicating the altitude of the own terminal, and the altitude information of the other terminal is acquired from another terminal different from the own terminal, and the altitude information of each of the own terminal and the other terminal is obtained. An altitude difference calculating unit that calculates an altitude difference between the terminal and the other terminal; a power detecting unit that detects a power value of a received signal based on the reception result of the radio wave; and A position determination unit that determines whether or not the mobile terminal is located in the vicinity of the altitude, a height determination unit that determines that the terminal is in a high place when both the altitude difference and the power value are equal to or greater than a threshold value, When it is determined that the own terminal is in a high place, a communication terminal is provided that includes a control unit that controls a reception gain of the reception signal.

  The position determination unit may determine whether the terminal is located in the vicinity of the base station based on the power value detected by the power detection unit.

  A reception signal strength detection unit that detects a power value of the reception signal in which the reception gain is controlled, and the position determination unit is configured such that the power value detected by the power detection unit is equal to that of the reception signal strength detection unit. When the value near the upper limit of the dynamic range is indicated, it may be determined that the own terminal is located in the vicinity of the base station.

  The position determination unit may acquire position information indicating the position of the terminal, and may determine whether the terminal is located in the vicinity of the base station based on the acquired position information.

  The position information indicating the position of the own terminal may be information based on a detection result of the position coordinates of the own terminal.

  The altitude difference calculation unit acquires position information indicating positions of the own terminal and the other terminal, and based on the acquired position information, both the own terminal and the other terminal are located within a predetermined range. In this case, the altitude difference between the own terminal and the other terminal may be calculated.

  The altitude difference calculation unit acquires position information indicating positions of the own terminal and the other terminal, and based on the acquired position information, the other is predetermined with respect to one of the own terminal and the other terminal. The altitude difference between the own terminal and the other terminal may be calculated.

  The position information of the other terminal may be information based on a detection result of the power value of the received signal received by the other terminal.

  The position information of the other terminal may be information based on a detection result of the position coordinate of the other terminal.

  An amplifying unit for amplifying the received signal, connected to the communication unit, having a first terminal and a second terminal, the first terminal connected to the amplifying unit, and the second terminal A switching unit connected to a bypass path that bypasses the amplification unit, and the control unit may control the reception gain of the received signal by switching the switching unit.

  In order to solve the above problem, according to another aspect of the present invention, the first calculated based on altitude information indicating the altitude of each of the first communication terminal and the second communication terminal that transmit and receive radio waves. Whether or not both the altitude difference between the second communication terminal and the second communication terminal and the detection result of the power value of the received signal based on the reception result of the radio wave by the first communication terminal are greater than or equal to a threshold value An acquisition unit that acquires a determination result indicating whether or not the first communication terminal is at a high place, and the first communication terminal when the first communication terminal is determined to be at a high place. And a control unit that controls a reception gain of the communication terminal.

  In order to solve the above-mentioned problem, according to another aspect of the present invention, the computer is different from the terminal itself in that it transmits / receives radio waves and acquires altitude information indicating the altitude of the terminal itself. Obtaining the altitude information of the other terminal from another terminal, calculating an altitude difference between the own terminal and the other terminal based on the altitude information of the own terminal and the other terminal, and the radio wave When detecting the power value of the received signal based on the reception result of the above, determining whether the terminal is located in the vicinity of the base station, and when both the altitude difference and the power value are equal to or greater than a threshold value A communication method including: determining that the terminal is in a high place; and controlling a reception gain of the radio wave when the terminal is determined to be in a high place. The

  In order to solve the above problem, according to another aspect of the present invention, the computer is calculated based on altitude information indicating the altitudes of the first communication terminal and the second communication terminal that transmit and receive radio waves. Both the altitude difference between the first communication terminal and the second communication terminal and the detection result of the power value of the received signal based on the reception result of the radio wave by the first communication terminal are greater than or equal to the threshold value. Taking a determination result indicating whether or not the first communication terminal is in a high place based on whether or not the first communication terminal is in a high place, Controlling a reception gain of the first communication terminal is provided.

  In order to solve the above-mentioned problem, according to another aspect of the present invention, transmission / reception of radio waves to a computer, acquisition of altitude information indicating the altitude of the own terminal, and the own terminal are different. Obtaining the altitude information of the other terminal from another terminal, calculating an altitude difference between the own terminal and the other terminal based on the altitude information of the own terminal and the other terminal, and the radio wave When detecting the power value of the received signal based on the reception result of the above, determining whether the terminal is located in the vicinity of the base station, and when both the altitude difference and the power value are equal to or greater than a threshold value In addition, a program is provided for determining that the terminal is in a high place and controlling the reception gain of the radio wave when the terminal is determined to be in a high place. The

  In order to solve the above-mentioned problem, according to another aspect of the present invention, the computer is calculated based on altitude information indicating the altitudes of the first communication terminal and the second communication terminal that transmit and receive radio waves to the computer. Both the altitude difference between the first communication terminal and the second communication terminal and the detection result of the power value of the received signal based on the reception result of the radio wave by the first communication terminal are greater than or equal to the threshold value. Taking a determination result indicating whether or not the first communication terminal is in a high place based on whether or not the first communication terminal is in a high place, There is provided a program for controlling a reception gain of a first communication terminal.

  As described above, according to the present invention, there is provided a mechanism capable of discriminating a situation where a high-power radio signal is received in a more preferable manner and protecting the receiving circuit.

4 is an explanatory diagram for describing an overview of a communication terminal according to an embodiment of the present disclosure. FIG. It is an example of the hardware constitutions of the communication terminal which concerns on the embodiment. It is the block diagram which showed an example of the function structure of the communication terminal which concerns on the same embodiment. It is the flowchart which showed an example of the flow of an example of a communication terminal which concerns on the embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Overview>
First, an example of an environment in which a communication terminal according to an embodiment of the present disclosure is applied will be described with reference to FIG. 1, and technical problems of the communication terminal according to the embodiment will be organized. FIG. 1 is an explanatory diagram for explaining an outline of a communication terminal according to the present embodiment.

  In FIG. 1, reference numeral 500 a indicates a facility where the radio base station antenna 300 is installed (hereinafter also referred to as “base station tower”). Reference numeral 500b indicates another steel tower in which the radio base station antenna 300 is not installed. Reference numerals 100a to 100f schematically indicate communication terminals configured to be communicable with a base station via wireless communication. Examples of such communication terminals include portable wireless communication terminals (that is, portable wireless terminals) such as so-called smartphones and tablet terminals as indicated by reference numerals 100a to 100e. As another example, the communication terminal is configured as a vehicle-mounted device including a wireless device configured to be able to communicate with a base station or another wireless communication terminal via wireless communication, as indicated by reference numeral 100f. It may be. In the following description, the communication terminals 100a to 100f may be simply referred to as “communication terminal 100” unless otherwise distinguished.

  As shown in FIG. 1, in a base station tower 500a where a radio base station antenna 300 in operation is installed, a case where a worker holding a communication terminal 100 (for example, a portable radio terminal) performs maintenance work, It can be assumed that the station administrator performs management work. At that time, the worker may hold the communication terminal 100 for communication and climb the base station tower 500a to perform work. In such a case, since a high-power radio signal (radio wave) is emitted from the radio base station antenna 300, the dynamic range of the reception circuit of the communication terminal 100 may be exceeded and the reception circuit may be damaged. is there.

  That is, when a higher power than expected is input to the receiver circuit, even if the receiver circuit of a general wireless communication terminal is damaged or can be received, AGC (Automatic Gain Control) convergence is achieved. Since it takes time to demodulate, it may take time to demodulate the first packet received. In many cases, the reception circuit waits for reception with the AGC at the maximum gain so that a signal with the minimum reception power can be demodulated. Therefore, in such a receiving circuit, when detecting a power larger than the minimum received power, feedback control is performed such as adjusting the signal level of the received signal using AGC or the like, detecting the received power again, and controlling the AGC. Repeat until the receivable signal level is reached. Therefore, in the case of such a control method, when a relatively high power wireless signal (radio wave) is received, the signal level of the received signal is relatively adjusted to adjust the received signal to a level that can be demodulated. It will take a long time.

  In view of such a situation, the communication terminal 100 according to the present embodiment determines a situation in which a user (for example, a worker) holding the mobile terminal climbs the base station tower 500a in which the radio base station antenna 300 is installed. In accordance with the determination result, a mechanism for protecting the receiving circuit and demodulating the received signal is provided. Therefore, hereinafter, the communication terminal according to the present embodiment will be described in more detail.

<2. Hardware configuration>
Next, an example of the hardware configuration of the communication terminal according to the present embodiment will be described with reference to FIG. 2, particularly focusing on the configuration of the receiving unit. FIG. 2 is an example of a hardware configuration of the communication terminal according to the present embodiment.

  As shown in FIG. 2, the communication terminal 100 according to the present embodiment includes an antenna element 101, a transmission / reception selector switch 103, a high power detection unit 105, RF switches 107a and 107b, a high frequency amplifier (LNA: Low Noise Amplifier). ) 111, RSSI detection unit 131, reception amplifier 113, band pass filter 115, mixer 117, AGC unit 119, comparator 133, altitude difference detection unit 140, AND gate 135, and communication control unit 127. Including. The AGC unit 119 includes a variable gain amplifier (VGA) 121, a low-pass filter 123, and an AD converter 125. The altitude difference detection unit 140 includes an altitude sensor 141 and an altitude difference calculation unit 143.

  The antenna element 101 is configured to be able to transmit and receive a radio signal (radio wave) in a desired band, and is connected to the antenna port of the transmission / reception selector switch 103.

  The transmission / reception selector switch 103 includes an antenna port, a transmission port, and a reception port, and is configured to be able to selectively switch a port electrically connected to the antenna port between the transmission port and the reception port. . A series of configurations corresponding to a transmission unit is connected to the transmission port of the transmission / reception selector switch 103. As a specific example, a PA (Power Amplifier) is connected to the transmission port, and a transmission signal amplified by the PA is input. That is, at the time of transmission, the antenna port and the transmission port are electrically connected, and a transmission signal is supplied to the antenna element 101. Thus, the transmission signal is radiated from the antenna element 101 to the space as a radio signal (radio wave). In FIG. 2, the detailed configuration of the transmission unit is not shown.

  In addition, a series of configurations corresponding to a reception unit is connected to the reception port of the transmission / reception selector switch 103. Specifically, the reception port is connected to the input side of the high power detection unit 105. One terminal of the RF switch 107 a is connected to the output side of the high power detection unit 105. That is, at the time of reception, the antenna port and the reception port are electrically connected. As a result, a radio signal (radio wave) in space is converted into a received signal by the antenna element 101, and the received signal is supplied to one terminal of the RF switch 107 a via the high power detector 105.

  In addition, the high power detection unit 105 detects the power value of the input reception signal and outputs information indicating the detection result of the power value to the comparator 133.

  The comparator 133 acquires information indicating the detection result of the power value of the received signal from the high power detection unit 105, and compares the acquired information with a predetermined threshold value. The comparator 133 supplies a predetermined control signal to the one-step cloud input terminal of the AND gate 135 when the power value of the received signal is equal to or greater than the threshold value.

  The altitude sensor 141 is connected to the altitude difference calculation unit 143. That is, the altitude sensor 141 detects the altitude and outputs altitude information based on the detection result to the altitude difference calculation unit 143.

  The altitude difference calculation unit 143 can be configured by, for example, a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), or a microcomputer. The altitude difference calculation unit 143 calculates an altitude difference between the own terminal (that is, the communication terminal 100 provided with the altitude difference calculation unit 143) and another terminal (that is, the external communication terminal 100). The altitude difference calculation unit 143 acquires altitude information indicating the altitude of the terminal from the altitude sensor 141. The altitude difference calculation unit 143 receives altitude information indicating the altitude of the other terminal from the other terminal. The altitude difference calculation unit 143 calculates the altitude difference between the local terminal and the other terminal based on the acquired altitude information of the local terminal and the other terminal. The altitude difference calculation unit 143 supplies a control signal based on the calculation result of the altitude difference between the own terminal and the other terminal to the other input terminal of the AND gate 135.

  The AND gate 135 has one input terminal connected to the comparator 133, and the other input terminal connected to the altitude difference calculation unit 143. The AND gate 135 has an output terminal connected to the communication control unit 127. That is, the AND gate 135 supplies a control signal to the communication control unit 127 according to the calculation result based on the control signal supplied from each of the comparator 133 and the altitude difference calculation unit 143. As a more specific example, communication control is performed from the AND gate 135 when the power value of the received signal by the high power detection unit 105 is equal to or greater than the threshold value and the calculation result of the altitude difference by the altitude difference calculation unit 143 is equal to or greater than the threshold value. A predetermined control signal is supplied to the unit 127.

  The RF switch 107 a has a connection destination of a terminal to which the output side of the high power detection unit 105 is connected, a terminal connected to the input side of the high frequency amplifier 111, and a terminal connected to a bypass path 109 that bypasses the high frequency amplifier 111. Selectively switch between. In addition, one terminal of the RF switch 107b is connected to the receiving circuit in the subsequent stage, and the connection destination of the terminal is connected to a terminal connected to the output side of the high-frequency amplifier 111, and a terminal connected to the bypass path 109. Selectively switch between. The RF switches 107a and 107b are switched by the communication control unit 127 described later so as to be linked to each other. Based on such a configuration, by switching the RF switches 107a and 107b, the reception signal output from the high power detection unit 105 passes through either the path to which the high-frequency amplifier 111 is connected or the bypass path 109. Then, it is supplied to the receiving circuit in the subsequent stage. This makes it possible to selectively control the reception gain of the received signal, that is, selectively control whether or not the power of the received signal is attenuated.

  The high frequency amplifier 111 amplifies and outputs the power value (signal level) of the input signal (that is, the received signal). By providing the high-frequency amplifier 111, for example, a reception signal based on a reception result of a radio signal (radio wave) attenuated with propagation in a radio propagation path is amplified so that it can be decoded in a more preferable manner. It becomes possible.

  The received signal transmitted via either the path to which the high-frequency amplifier 111 is connected or the bypass path 109 is demultiplexed by, for example, a splitter or the like, and a series of receiving circuits (that is, the receiving amplifier 113) located in the subsequent stage. , The band pass filter 115, the mixer 117, and the AGC unit 119) and the RSSI detection unit 131.

  The RSSI detection unit 131 detects the power value (signal level) of the reception signal whose reception gain is controlled as the RF switches 107a and 107b are switched, and sends a control signal based on the detection result of the power value to the communication control unit 127. Supply.

  The reception signal input to the reception circuit side is amplified by the reception amplifier 113, and then the signal component of a predetermined frequency band is supplied to the mixer 117 through the band pass filter 115. Then, the received signal is down-converted from the RF (Radio Frequency) band signal to the BB (Base Band) band signal by the mixer 117 and supplied to the AGC unit 119.

  The AGC unit 119 controls not only the magnitude of the power value (signal level) of the input received signal but also the power value of the received signal to a predetermined level, and converts the analog received signal into a digital signal. Convert to Specifically, as shown in FIG. 2, the received signal input to the AGC unit 119 is first controlled by the variable gain amplifier 121 so that the power value becomes a predetermined level. Note that the gain of the variable gain amplifier 121 is controlled by the communication control unit 127 based on the detection result of the power value of the received signal by the RSSI detection unit 131. The received signal whose power value is controlled by the variable gain amplifier 121 passes through the low-pass filter 123, so that the high-frequency component is cut and a signal component in a predetermined frequency band is supplied to the AD converter 125. The AD converter 125 converts the input analog reception signal into a digital signal, and then supplies the digital reception signal to the communication control unit 127.

  The communication control unit 127 can be configured by, for example, a DSP, FPGA, microcomputer, or the like. The communication control unit 127 generates a transmission signal and decodes a reception signal supplied from the AGC unit 119. In addition, the communication control unit 127 receives a control signal based on the detection result of the power value of the received signal from the RSSI detection unit 131, and controls the gain of the variable gain amplifier 121 based on the detection result.

  Further, the communication control unit 127 switches the RF switches 107 a and 107 b based on the control signal supplied from the AND gate 135. As a specific example, when a control signal is supplied from the AND gate 135, the communication control unit 127 switches each of the RF switches 107a and 107b to the bypass path 109 side. Thereby, when the detection result of the power value by the high power detection unit 105 is equal to or greater than the threshold and the calculation result of the altitude difference by the altitude difference calculation unit 143 is equal to or greater than the threshold, the reception output from the high power detection unit 105 A signal is supplied to the bypass 109 (ie, the high frequency amplifier 111 is bypassed).

  Note that the hardware configuration of the communication terminal 100 according to the present embodiment described above is merely an example, and is not necessarily limited to the example described above. As a specific example, the case where the receiving circuit is configured as a direct conversion type circuit has been described above as an example, but the receiving circuit may be configured as a heterodyne type circuit. In addition, the series of configurations described above may be configured as one chip using an IC or the like, or a part of the configuration may be configured as another chip. As a more specific example, the communication control unit 127 and other configurations may be provided in separate chips. In this case, the chip provided with the communication control unit 127 corresponds to an example of a “control device”. Further, as long as the above-described series of operations can be realized, some of the above-described configurations may be externally attached to the communication terminal 100.

  The example of the hardware configuration of the communication terminal according to the present embodiment has been described above with reference to FIG. 2, particularly focusing on the configuration of the receiving unit.

<3. Functional configuration>
Next, an example of a functional configuration of the communication terminal according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of a functional configuration of the communication terminal according to the present embodiment. As shown in FIG.

  As shown in FIG. 3, the communication terminal 100 according to the present embodiment includes an antenna element 101, a wireless communication unit 151, an altitude information acquisition unit 153, a power detection unit 155, a storage unit 157, a control unit 160, including. The antenna element 101 corresponds to the antenna element 101 shown in FIG.

  The wireless communication unit 151 is configured to transmit and receive signals. For example, the wireless communication unit 151 receives a signal (downlink signal) transmitted from a base station, and transmits a signal (uplink signal) to the base station.

  The altitude information acquisition unit 153 corresponds to the altitude sensor 141 shown in FIG. The altitude information acquisition unit 153 detects the altitude and outputs information indicating the detection result of the altitude to the control unit 160.

  The power detection unit 155 is configured to detect the power value of the received signal, and corresponds to, for example, the high power detection unit 105 and the RSSI detection unit 131 illustrated in FIG. The power detection unit 155 detects the power value of the input reception signal and outputs information indicating the detection result of the power value to the control unit 160.

  The storage unit 157 temporarily or permanently stores a program for operating the communication terminal 100 and various data. The storage unit 157 can be configured by, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device.

  The control unit 160 is a configuration for controlling a series of operations of the communication terminal 100, and may be configured by, for example, a CPU, DSP, FPGA, microcomputer, or the like. Specifically, as illustrated in FIG. 3, the control unit 160 includes a communication control unit 161, an altitude difference calculation unit 163, a position determination unit 165, and an altitude determination unit 167.

  The altitude difference calculation unit 163 may correspond to, for example, the altitude difference calculation unit 143 described above with reference to FIG. In this case, the altitude difference calculation unit 163 determines whether the own terminal and the other terminal are based on altitude information indicating the altitude of the own terminal (that is, the communication terminal 100) and altitude information indicating the altitude of the other terminal. Calculate the altitude difference between. As a more specific example, the altitude difference calculation unit 163 performs a cluster analysis that combines altitude information of its own terminal and altitude information of one or more other terminals, at a point where the own terminal has an altitude relative to other terminals. It is determined whether or not it is located. If the altitude difference calculation unit 163 determines that the own terminal is located at a point where altitude is at least relative to some other terminals, the altitude difference between the own terminal and the other terminal is determined. The difference may be calculated. By calculating the altitude difference as described above, it is possible to determine whether or not the terminal is located at a high place based on the altitude difference.

  As another example, the altitude difference calculation unit 163 may calculate an altitude difference between the own terminal (that is, the communication terminal 100) and the ground. More specifically, the altitude difference calculation unit 163 acquires the measurement result of the position coordinates of the terminal by GPS (Global Positioning System), and compares the position coordinates with map information and the like to indicate the position coordinates. Identify the elevation of the location. Then, the altitude difference calculation unit 163 may calculate the altitude difference between the own terminal and the ground by comparing the specified altitude with altitude information indicating the altitude of the own terminal. By calculating the altitude difference as described above, it is possible to determine whether or not the terminal is located at a high place based on the altitude difference.

  It is noted that altitude difference calculation section 163 is provided when both the own terminal (that is, communication terminal 100) and another terminal are located within a predetermined range (for example, when located in a region near base station tower 500A). The altitude difference between the terminal itself and the other terminal may be calculated.

  As another example, the altitude difference calculation unit 163 determines whether the altitude difference calculation unit 163 is connected between the own terminal and the other terminal according to the relative positional relationship between the own terminal (that is, the communication terminal 100) and the other terminal. The altitude difference may be calculated. As a specific example, the altitude difference calculation unit 163 determines the altitude difference between the own terminal and the other terminal when the other of the own terminal and the other terminal is located within a predetermined range. May be calculated.

  The position determination unit 165 determines whether or not the own terminal (that is, the communication terminal 100) is located in the vicinity of the base station. As a specific example, the position determination unit 165 indicates that the detection result of the power value of the received signal by the power detection unit 155 is a value near the upper limit of the dynamic range of a predetermined device (for example, the RSSI detection unit 131 shown in FIG. 2). Is determined to be located in the vicinity of the base station. As another example, the position determination unit 165 acquires the measurement result of the position coordinates of the terminal by GPS, and collates the position coordinates with map information or the like, so that the terminal is located in the vicinity of the base station. It may be determined whether or not.

  The high place determination unit 167 determines whether or not the own terminal (that is, the communication terminal 100) is located at a so-called high place such as an upper part of a steel tower in which an antenna of the base station is installed. Specifically, the height determination unit 167 has an altitude difference calculated by the altitude difference calculation unit 163 equal to or greater than a predetermined threshold, and the power value of the received signal detected by the power detection unit 155 is a predetermined threshold. In the above case, it is determined that the terminal is located at the above-described high place (that is, the upper part of the steel tower where the base station antenna or the like is installed).

  The communication control unit 161 performs a demodulation process on a signal (that is, a received signal) received from the base station by the wireless communication unit 151 based on a predetermined communication method, thereby converting the data transmitted from the base station. Demodulate. Also, the communication control unit 161 generates a transmission signal by performing modulation processing on the data to be transmitted based on a predetermined communication method, and the generated transmission signal is transmitted from the wireless communication unit 151 to the base station. You may control as follows.

  In addition, the communication control unit 161 may control various operations of the wireless communication unit 151. As a specific example, the communication control unit 161 may control the gain of the VGA corresponding to the reception unit in the wireless communication unit 151 based on the detection result of the power value of the received signal by the power detection unit 155. . In addition, when the altitude determination unit 167 determines that the terminal is located at the above-described high place, the communication control unit 161 includes a part of devices (for example, the wireless communication unit 151 corresponding to the reception unit) (for example, The various switches may be controlled so that the high-frequency amplifier 111) shown in FIG. 2 is bypassed.

  Heretofore, an example of the functional configuration of the communication terminal according to the present embodiment has been described with reference to FIG.

<4. Processing>
Subsequently, an example of a flow of a series of processes of the communication terminal according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing an example of the processing flow of an example of the communication terminal according to the present embodiment.

  As illustrated in FIG. 4, when the communication terminal 100 detects the power value of the received signal and the detection result indicates a value near the upper limit of the dynamic range of the RSSI detection unit 131, the communication terminal 100 is located in the vicinity of the base station. It is determined (for example, approaching the base station tower 500a) (S101).

  For example, when the communication terminal 100 determines that the terminal is located in the vicinity of the base station (S101, YES), the communication terminal 100 detects the altitude of the terminal by a predetermined detection device such as an altitude sensor (S103). . At this time, the communication terminal 100 may detect the altitude of the own terminal at a predetermined cycle (more preferably, a cycle faster than the speed at which the altitude changes as the worker climbs the tower).

  Next, the communication terminal 100 transmits altitude information based on the altitude detection result of the own terminal (hereinafter also referred to as “altitude information of the own terminal”) to the other terminal, and the altitude information regarding the altitude of the other terminal from the other terminal. (Hereinafter, also referred to as “altitude information of other terminals”) is acquired (S105). Then, the communication terminal 100 detects an altitude difference between the own terminal and the other terminal by analyzing the altitude information of the own terminal and the altitude information of the other terminal acquired from the other terminal in combination (or analysis). (S109). As a specific example, the communication terminal 100 uses a cluster analysis based on altitude information of its own terminal and altitude information of other terminals, and is a terminal to be analyzed based on a parameter called altitude (that is, its own terminal and other terminals). And detecting (or calculating) an altitude difference between the own terminal and another terminal based on the classification result. Thereby, the communication terminal 100 can determine whether or not the terminal itself is located at a point where the altitude is higher than the other terminals (in other words, whether the terminal is located at a high place).

  When the altitude difference between the own terminal and another terminal is detected (S109, YES), the communication terminal 100 confirms whether the high power detection unit 105 has detected high power (S111). When the high power detection unit 105 detects high power (S111, YES), the communication terminal 100 allows the received signal to pass through the bypass 109 (that is, the high frequency amplifier 111 is bypassed). Each of the RF switches 107a and 107b is switched to the bypass path 109 side (S113). With such control, the received signal is supplied to the receiving amplifier 113 via the bypass 109, amplified by the receiving amplifier 113, and then supplied to the AGC unit 119 via the bandpass filter 115 and the mixer 117.

  The received signal supplied to the AGC unit 119 is controlled by the AGC unit 119 so that the power value becomes a predetermined level (S115), and is converted from an analog signal to a digital signal and then decoded.

  On the other hand, when the terminal 100 is not located near the base station (S101, NO), the communication terminal 100 does not execute a series of processes indicated as reference numerals S103 to S113. In addition, when the communication terminal 100 cannot detect the altitude difference between the own terminal and the other terminal, for example, when the altitude information cannot be acquired from the other terminal (S109, NO), The processes indicated as reference signs S111 and S113 are not executed. Similarly, when the high power detection unit 105 does not detect high power (S111, YES), the communication terminal 100 does not execute the process indicated by reference numeral S113. In these cases, the RF switches 107a and 107b are not switched to the bypass path 109 side. Therefore, the reception signal is supplied to the reception amplifier 113 via the high frequency amplifier 111, amplified by the reception amplifier 113, and then supplied to the AGC unit 119 via the band pass filter 115 and the mixer 117.

  Heretofore, an example of a flow of a series of processes of the communication terminal according to the present embodiment has been described with reference to FIG.

<5. Conclusion>
As described above, the communication terminal 100 according to the present embodiment calculates an altitude difference between the own terminal and the other terminal based on altitude information indicating the altitudes of the own terminal and the other terminal. Communication terminal 100 detects the power value of the received signal based on the reception result of the radio wave. Communication terminal 100 controls the reception gain of the received signal based on the calculated altitude difference and the detected power value when the terminal is located in the vicinity of the base station. More specifically, when both the calculated altitude difference and the detected power value are equal to or greater than the threshold, the communication terminal 100 determines that the terminal is at a high place, such as a high frequency amplifier (LNA) or the like. The reception gain is controlled by bypassing at least some of the devices constituting the reception circuit.

  With such a configuration, the communication terminal 100 according to the present embodiment more reliably determines a situation where a user (for example, a worker) holding the mobile terminal climbs the base station tower 500a, and responds to the determination result. Thus, the receiving circuit can be protected and the received signal can be demodulated.

  More specifically, in a general communication terminal, since a radio signal (radio wave) is attenuated by propagating through a radio propagation path, the received signal is amplified by amplifying the received signal with a high frequency amplifier (LNA). Demodulation can be performed in a more preferable manner. On the other hand, in the vicinity of the radio base station antenna 300, since the attenuation amount of the radio signal due to the propagation of the radio propagation path is small, a signal having a power value that does not need to be amplified by the high frequency amplifier (LNA) is received. . Even in such a situation, according to the communication terminal according to the present embodiment, the high frequency amplifier (LNA) is bypassed, so that the high frequency amplifier can achieve both protection and demodulation of the received signal. Become.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above-described embodiment, an example in which a high-frequency amplifier (LNA) is bypassed as a protection target has been described, but it is needless to say that a device to be protected is not necessarily limited to a high-frequency amplifier (LNA).

DESCRIPTION OF SYMBOLS 100 Communication terminal 101 Antenna element 103 Transmission / reception changeover switch 105 High power detection part 107a, 107b RF switch 109 Bypass path 111 High frequency amplifier 113 Reception amplifier 115 Band pass filter 117 Mixer 119 AGC part 121 Variable gain amplifier 123 Band pass filter 125 AD converter 127 Communication control unit 131 RSSI detection unit 133 Comparator 135 AND gate 140 Altitude difference detection unit 141 Altitude sensor 143 Altitude difference calculation unit 151 Wireless communication unit 153 Altitude information acquisition unit 155 Power detection unit 157 Storage unit 160 Control unit 161 Communication control unit 163 Altitude Difference calculation unit 165 Position determination unit 167 Height determination unit 300 Radio base station antenna 500a Base station tower

Claims (15)

A communication unit for transmitting and receiving radio waves;
An altitude information acquisition unit that acquires altitude information indicating the altitude of the terminal;
The altitude information of the other terminal is acquired from another terminal different from the own terminal, and the altitude difference between the own terminal and the other terminal is calculated based on the altitude information of the own terminal and the other terminal. An altitude difference calculation unit to
A power detector that detects a power value of a received signal based on the reception result of the radio wave;
A position determination unit that determines whether or not the terminal is located near a base station;
When both the altitude difference and the power value are equal to or higher than a threshold value, an altitude determination unit that determines that the terminal is at an altitude
A control unit that controls a reception gain of the received signal when the terminal is determined to be in a high place;
A communication terminal.   The communication terminal according to claim 1, wherein the position determination unit determines whether or not the own terminal is located in the vicinity of the base station based on the power value detected by the power detection unit. A reception signal strength detection unit that detects a power value of the reception signal in which the reception gain is controlled;
The position determination unit, when the power value detected by the power detection unit indicates a value near the upper limit of the dynamic range of the received signal strength detection unit, the own terminal is located in the vicinity of the base station The communication terminal according to claim 2, wherein the determination is made.   The position determination unit acquires position information indicating the position of the own terminal, and determines whether the own terminal is located in the vicinity of the base station based on the acquired position information. The communication terminal described.   The communication terminal according to claim 4, wherein the position information indicating the position of the terminal is information based on a detection result of the position coordinates of the terminal. The altitude difference calculator is
Obtaining location information indicating the location of each of the terminal and the other terminal;
Based on the acquired position information, when both the own terminal and the other terminal are located within a predetermined range, the altitude difference between the own terminal and the other terminal is calculated.
The communication terminal according to claim 1. The altitude difference calculator is
Obtaining location information indicating the location of each of the terminal and the other terminal;
Based on the acquired position information, the altitude difference between the own terminal and the other terminal is calculated when the other of the own terminal and the other terminal is located within a predetermined range. To
The communication terminal according to claim 1.   The communication terminal according to claim 6 or 7, wherein the position information of the other terminal is information based on a detection result of the power value of the received signal received by the other terminal.   The communication terminal according to claim 6 or 7, wherein the position information of the other terminal is information based on a detection result of a position coordinate of the other terminal. An amplifying unit for amplifying the received signal;
Connected to the communication unit, having a first terminal and a second terminal, the first terminal being connected to the amplification unit, and the second terminal being connected to a bypass path bypassing the amplification unit. Switching unit,
With
The control unit controls the reception gain of the reception signal by switching the switching unit.
The communication terminal as described in any one of Claims 1-9. An altitude difference between the first communication terminal and the second communication terminal calculated based on altitude information indicating the altitudes of the first communication terminal and the second communication terminal that transmit and receive radio waves; A determination indicating whether or not the first communication terminal is at a high place, based on whether or not both of the detection results of the power value of the received signal based on the reception result of the radio wave by one communication terminal are greater than or equal to a threshold value An acquisition unit for acquiring results;
A control unit that controls a reception gain of the first communication terminal when it is determined that the first communication terminal is in a high place;
A control device comprising: Computer
Sending and receiving radio waves,
Acquiring altitude information indicating the altitude of the terminal,
The altitude information of the other terminal is acquired from another terminal different from the own terminal, and the altitude difference between the own terminal and the other terminal is calculated based on the altitude information of the own terminal and the other terminal. To do
Detecting the power value of the received signal based on the reception result of the radio wave;
Determining whether the terminal is located near a base station;
When both the altitude difference and the power value are greater than or equal to a threshold, determining that the terminal is in a high place;
Controlling the reception gain of the radio wave when it is determined that the terminal is in a high place;
Including a communication method. Computer
An altitude difference between the first communication terminal and the second communication terminal calculated based on altitude information indicating the altitudes of the first communication terminal and the second communication terminal that transmit and receive radio waves; A determination indicating whether or not the first communication terminal is at a high place, based on whether or not both of the detection results of the power value of the received signal based on the reception result of the radio wave by one communication terminal are greater than or equal to a threshold value Taking the result,
Controlling the reception gain of the first communication terminal when it is determined that the first communication terminal is at a high place;
Including a control method. On the computer,
Sending and receiving radio waves,
Acquiring altitude information indicating the altitude of the terminal,
The altitude information of the other terminal is acquired from another terminal different from the own terminal, and the altitude difference between the own terminal and the other terminal is calculated based on the altitude information of the own terminal and the other terminal. To do
Detecting the power value of the received signal based on the reception result of the radio wave;
Determining whether the terminal is located near a base station;
When both the altitude difference and the power value are greater than or equal to a threshold, determining that the terminal is in a high place;
Controlling the reception gain of the radio wave when it is determined that the terminal is in a high place;
A program that executes On the computer,
An altitude difference between the first communication terminal and the second communication terminal calculated based on altitude information indicating the altitudes of the first communication terminal and the second communication terminal that transmit and receive radio waves; A determination indicating whether or not the first communication terminal is at a high place, based on whether or not both of the detection results of the power value of the received signal based on the reception result of the radio wave by one communication terminal are greater than or equal to a threshold value Taking the result,
Controlling the reception gain of the first communication terminal when it is determined that the first communication terminal is at a high place;
A program that executes

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