JP6217752B2 - Wireless communication apparatus, wireless communication system, and wireless communication method - Google Patents

Description

  The present invention relates to a radio communication device, a radio communication system, and a radio communication method, and more particularly to a radio communication device, a radio communication system, and a radio communication method capable of controlling transmission power in a transmission station (control station).

  In wireless communication, control of transmission power at a transmission station is performed in order to suppress a decrease in reception power at a reception station due to deterioration of the state of a wireless transmission path (for example, rainfall). As a method for controlling this transmission power, for example, there is ATPC (Automatic Transmit Power Control). In ATPC, the receiving station (determination station) controls the transmission power in the transmitting station (control station) by comparing the received power with a predetermined power control determination threshold. The power control determination threshold is a threshold of received power at the receiving station (determination station) used for transmission power control.

  As a technique for performing optimal wireless communication, there is an adaptive modulation system that automatically switches a modulation system in accordance with the state of a wireless transmission path. As an adaptive modulation system, for example, there is AMR (Adaptive Modulation Radio). In the adaptive modulation scheme, a technique for switching a modulation scheme in accordance with received power at a receiving station (determination station) and a higher modulation scheme switching threshold has been proposed. The upper modulation scheme switching threshold is a threshold of received power at the receiving station (determination station) necessary for switching from the current modulation scheme to the upper modulation scheme. Further, the upper modulation scheme is a modulation scheme having a larger modulation multi-level number than the current modulation scheme.

  Specifically, for example, when the state of the wireless transmission path is good, the wireless communication device has a low tolerance for the deterioration of the state of the wireless transmission path, but has a large transmission capacity (for example, a modulation multi-level number). Communication is performed using a large multiplex modulation method. On the other hand, when the state of the wireless transmission path deteriorates, the wireless communication apparatus uses a modulation method (for example, a multiplex modulation method with a small modulation multi-level number) that has a small transmission capacity but a high tolerance to the deterioration of the wireless transmission line state To communicate.

  In relation to the above technique, for example, Patent Document 1 shows the difference between the maximum transmittable power of the communication signal transmission unit in the first communication apparatus and the transmission power when the communication signal is transmitted by the communication signal transmission unit. Based on the maximum received power data obtained based on the transmitted power remaining data and the received power data in the second communication device, and the required received power data respectively associated with a plurality of data rates. Thus, a communication system for determining a data rate (modulation method) is disclosed.

JP 2006-101345 A

  Here, in the ATPC described above, when the reception power at the reception station (determination station) is smaller than the power control determination threshold, the reception station (determination station) increases the reception power to the power control determination threshold by transmission power control. Therefore, control is performed so as to increase the transmission power in the transmission station (control station).

  On the other hand, for example, when the power control determination threshold is larger than the upper modulation scheme switching threshold, in order to control the transmission power so as to increase the received power and approach the power control determination threshold, the modulation scheme is set to the upper modulation scheme. It is necessary to switch. However, when the surplus value up to the upper limit of transmission power is not sufficient in the transmission station (control station), the transmission station (control station) is configured such that the reception power exceeds the upper modulation scheme switching threshold in the reception station (determination station). In this case, the transmission power cannot be increased. Therefore, the modulation method cannot be switched to the upper modulation method.

  However, the transmission station (control station) controls the transmission power to increase the transmission power even though the modulation system cannot be switched to the higher-order modulation system by the transmission power control. Therefore, in such a case, there is a problem that the transmitting station (control station) consumes useless power.

  Here, in the technique of Patent Document 1, target received power data (target SNR) is associated with each modulation method (data rate), and transmission power is controlled using the target received power data. . In the technique of Patent Document 1, transmission power control is performed as real-time processing, and modulation scheme change is performed as batch processing. That is, in the technique of Patent Document 1, the transmission power control and the modulation scheme change process are independent and independent processes.

  That is, in the technique of Patent Document 1, it is not possible to assume a case where it is necessary to change the modulation method to a higher-order modulation method when control is performed to increase the transmission power by transmission power control. Therefore, the technique of Patent Document 1 cannot solve the above problem.

  An object of the present invention is to solve such a problem, and it is possible to suppress wasteful transmission power consumption while maintaining communication quality even when transmission power control is performed. An object is to provide a wireless communication device, a wireless communication system, and a wireless communication method.

  A first wireless communication apparatus according to the present invention includes: a receiving unit that receives a wireless signal from another wireless communication apparatus; and an upper limit value of transmission power from a current transmission power of the wireless signal transmitted from the other wireless communication apparatus. The surplus value receiving means for receiving the surplus value up to the other radio communication device and the reception power of the radio signal received from the other radio communication device to control the transmission power in the other radio communication device Switching determination means for determining whether it is possible to switch from the current modulation scheme to a higher modulation scheme based on the received power and the surplus value when the power control determination threshold is smaller than When it is determined by the switching determination means that the switching is impossible, the received power is the quality assurance power that guarantees the communication quality in the current modulation scheme. And a transmission power control means for controlling to suppress the transmission power.

  A second wireless communication apparatus according to the present invention includes a transmission unit that transmits a wireless signal to another wireless communication apparatus, and a surplus from the current transmission power of the wireless signal transmitted by the transmission unit to an upper limit value of the transmission power A surplus value calculating means for calculating a value, and a power control determination threshold for controlling the transmission power in the transmitting means by the received power of the radio signal received by the other wireless communication apparatus in the other wireless communication apparatus If it is determined that it is impossible to switch from the current modulation scheme to the higher modulation scheme based on the received power and the surplus value in the other radio communication device, the other radio communication Transmission power that is controlled so as to suppress transmission power in the transmission means so that reception power in the apparatus becomes quality assurance power that guarantees communication quality in the current modulation scheme And a control means.

  A wireless communication system according to the present invention includes a surplus value calculating means for calculating a surplus value from a current transmission power to an upper limit value of transmission power in a transmitting-side wireless communication device; When the reception power of the wireless signal received by the wireless communication device is smaller than a power control determination threshold for controlling the transmission power of the wireless signal transmitted from the transmission-side wireless communication device, the reception-side wireless Based on the received power in the communication device and the surplus value, it is determined by the switching determination unit that it is possible to switch from the current modulation scheme to the higher modulation scheme, and the switching determination unit determines that switching is impossible. The reception side wireless communication device receives the quality assurance power that guarantees the communication quality in the current modulation scheme. And a transmission power control means for controlling to suppress the transmission power in line communication device.

  A first wireless communication method according to the present invention receives a wireless signal from another wireless communication device, and a surplus from a current transmission power of a wireless signal transmitted from the other wireless communication device to an upper limit value of transmission power. The value is received from the other wireless communication device, and the received power of the wireless signal received from the other wireless communication device is smaller than a power control determination threshold value for controlling transmission power in the other wireless communication device. In this case, based on the received power and the surplus value, it is determined whether or not it is possible to switch from the current modulation scheme to a higher modulation scheme. Control is performed so as to suppress the transmission power in the other wireless communication device so that the power becomes the quality assurance power that guarantees the communication quality in the current modulation scheme.

  A second wireless communication method according to the present invention transmits a wireless signal to another wireless communication device, calculates a surplus value from a current transmission power of the transmitted wireless signal to an upper limit value of transmission power, In another wireless communication device, when the reception power of the wireless signal received by the other wireless communication device is smaller than a power control determination threshold for controlling transmission power, the received power in the other wireless communication device And the surplus value, it is determined that it is impossible to switch from the current modulation scheme to the higher modulation scheme, and the received power in the other radio communication device guarantees communication quality in the current modulation scheme. Control is performed so as to suppress transmission power so that quality assurance power is obtained.

  According to the present invention, it is possible to provide a wireless communication device, a wireless communication system, and a wireless communication method capable of suppressing wasteful transmission power consumption while maintaining communication quality even when transmission power control is performed. it can.

It is a figure which shows the outline | summary of the radio | wireless communication apparatus concerning embodiment of this invention. 1 is a diagram showing a wireless communication system according to a first exemplary embodiment. FIG. 2 is a diagram illustrating a configuration of a control station according to the first embodiment. It is a figure which shows the structure of the determination station concerning Embodiment 1. FIG. FIG. 4 is a diagram illustrating radio frame data according to the first embodiment. FIG. 3 is a sequence diagram showing an overall operation of the wireless communication system according to the first exemplary embodiment. 3 is a flowchart showing determination processing in a determination station according to the first exemplary embodiment; 3 is a flowchart showing control processing in a control station according to the first exemplary embodiment; 6 is a diagram for explaining processing in the first embodiment. FIG. It is a figure for demonstrating the process concerning a comparative example. FIG. 3 is a diagram illustrating a configuration of a transmitting station according to a second embodiment. FIG. 3 is a diagram illustrating a configuration of a receiving station according to a second embodiment.

(Outline of the embodiment of the present invention)
Prior to the description of the embodiment, the outline of the embodiment according to the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an outline of a wireless communication device 1 according to an embodiment of the present invention. The wireless communication apparatus 1 includes a receiving unit 12, a surplus value receiving unit 14, a switching determination unit 16, and a transmission power control unit 18. Note that the wireless communication device 1 may be a determination station (receiving station), for example. Further, the following “other wireless communication device” may be a control station (transmission station), for example.

  The receiving unit 12 receives a radio signal from another radio communication device (for example, a control station). The surplus value receiving means 14 receives a surplus value from the current transmission power of the radio signal transmitted from the other radio communication apparatus to the upper limit value of the transmission power from the other radio communication apparatus. The switching determination unit 16 receives the received power and the surplus when the received power of the radio signal received from the other radio communication device is smaller than a power control determination threshold for controlling the transmission power in the other radio communication device. Based on the value, it is determined whether or not it is possible to switch from the current modulation scheme to the higher modulation scheme. The transmission power control unit 18 performs transmission in another wireless communication device so that the reception power becomes the quality assurance power that guarantees the communication quality in the current modulation scheme when the switching determination unit 16 determines that the switching is impossible. Control to suppress power.

According to the wireless communication device 1 according to the embodiment of the present invention, even when transmission power control is performed, wasteful transmission power consumption can be suppressed while maintaining communication quality. Even in the case where transmission power control is performed by a wireless communication system including a wireless communication device that is a determination station (receiving station) and a wireless communication device that is a control station (transmitting station), the communication quality can be reduced. It is possible to suppress wasteful transmission power consumption while maintaining it.
The switching determination unit 16 and the transmission power control unit 18 are provided in the wireless communication apparatus 1 that is a determination station (reception station), but may be provided in the wireless communication apparatus that is a control station (transmission station). Good. In this case, it is possible to suppress useless transmission power consumption while maintaining communication quality even when the transmission power control is performed by the wireless communication apparatus which is a control station (transmission station).

(Embodiment 1)
The first embodiment will be described below with reference to the drawings.
FIG. 2 is a diagram of the wireless communication system 50 according to the first embodiment. The wireless communication system 50 includes a control station 100 that is a wireless communication device and a determination station 200 that is a wireless communication device. The control station 100 and the determination station 200 are connected via a wireless line so that wireless communication is possible.

  Further, the control station 100 and the determination station 200 are connected to data lines 60 and 70, respectively. The data lines 60 and 70 are lines connected to a network such as a communication carrier or a provider carrier. The control station 100 and the determination station 200 transmit and receive user data such as packets or frames via the data lines 60 and 70. Here, the wireless communication system 50 may conform to, for example, Ethernet (registered trademark).

  The control station 100 and the determination station 200 may be digital microwave communication devices, for example. One of the control station 100 and the determination station 200 may be a mobile terminal or a wireless local area network (LAN) device, and the other may be a wireless base station or a wireless LAN base station.

  The control station 100 functions as a transmission station that transmits data to the determination station 200 via a wireless line. The determination station 200 functions as a receiving station that receives data from the control station 100 via a wireless line. That is, the control station 100 transmits a radio signal to the determination station 200. The determination station 200 determines how to control the transmission power in the control station 100 based on the received power when the radio signal is received and the power control determination threshold. Furthermore, the determination station 200 determines whether or not the modulation scheme can be switched to the higher modulation scheme based on the received power and the higher modulation scheme switching threshold. The control station 100 controls the transmission power according to the determination result of the transmission power control by the determination station 200. Further, the control station 100 switches the modulation scheme according to the determination result of whether or not the modulation scheme can be switched by the determination station 200.

  Here, in the first embodiment, the determination station 200 is the case where the received power is smaller than the power control determination threshold, and when the power control determination threshold is larger than the upper modulation scheme switching threshold, It is determined whether it is possible to switch the modulation method. When switching is not possible, the determination station 200 controls the transmission power in the control station 100 to be suppressed so that the reception power becomes quality-guaranteed reception power that guarantees communication quality in the current modulation scheme. Details will be described later.

  FIG. 3 is a diagram of a configuration of the control station 100 according to the first embodiment. The control station 100 includes an antenna 102, a transmission unit 110, a surplus value calculation unit 112, a surplus value multiplex processing unit 114, a reception unit 120, a control data extraction unit 122, an ATPC processing unit 124, a quality assurance power control unit 126, and a modulation scheme switching. Part 128. In FIG. 3, the antenna 102 is described as being provided separately for the transmission side and the reception side, but the antenna 102 may be shared by the transmission side and the reception side.

  FIG. 4 is a diagram of a configuration of the determination station 200 according to the first embodiment. The determination station 200 includes an antenna 202, a reception unit 210, a reception power calculation unit 220, an ATPC determination unit 222, a surplus value extraction unit 230, a higher-order modulation method switching determination unit 232, a quality assurance power control value calculation unit 234, and a modulation method switching notification. A generation unit 236, a control data multiplex processing unit 250, and a transmission unit 252 are included. In FIG. 4, the antenna 202 is described as being provided separately for the transmission side and the reception side, but the antenna 202 may be shared by the transmission side and the reception side.

  The transmission unit 110 of the control station 100 transmits a radio signal including transmission data received via the data line 60 to the determination station 200 via the antenna 102 and the radio line with the currently set transmission power. Wireless transmission. Details will be described later.

  The surplus value calculation unit 112 stores a transmission power upper limit that is an upper limit value of the transmission power of the control station 100. This transmission power upper limit may be, for example, a limit value of transmission power as a device of the control station 100, or may be a setting value set in advance by an administrator. Further, the surplus value calculation unit 112 acquires the current transmission power value from the transmission unit 110. Further, the surplus value calculation unit 112 compares the transmission power upper limit with the current transmission power value, and calculates a surplus value of transmission power (transmission power surplus value). For example, the surplus value calculation unit 112 may calculate the difference between the transmission power upper limit and the current transmission power value as the transmission power surplus value. Further, the surplus value calculation unit 112 outputs the calculated transmission power surplus value to the surplus value multiplex processing unit 114.

  The surplus value multiplexing processing unit 114 receives transmission data that is data to be transmitted via the data line 60. The surplus value multiplex processing unit 114 receives the transmission power surplus value from the surplus value calculation unit 112. Further, the surplus value multiplex processing unit 114 adds (multiplexes) the transmission power surplus value to the packet header or control information area provided in the transmission data, and radio frame data (described later with reference to FIG. 5). Is generated. Further, the surplus value multiplex processing unit 114 outputs the generated radio frame data to the transmission unit 110.

  The transmission unit 110 receives radio frame data from the surplus value multiplex processing unit 114. The transmission unit 110 performs a modulation process on the radio frame data using a currently set modulation scheme, and generates a modulation signal. Furthermore, the transmission unit 110 performs processing necessary for wireless transmission such as amplification on the generated modulated signal. Then, the transmission unit 110 wirelessly transmits a wireless signal including wireless frame data to the determination station 200 via a wireless line with currently set transmission power.

  FIG. 5 is a diagram illustrating radio frame data. As illustrated in FIG. 5, the radio frame data includes a header and transmission data (payload) that is data to be transmitted. The header includes a control station side control information area and a determination station side control information area. The control station side control information area is an area provided for adding information for controlling the determination station 200 from the control station 100. The determination station side control information area is an area provided for adding information for controlling the control station 100 from the determination station 200. The transmission power surplus value is written in the control station side control information area. The determination station side control information area will be described later.

  The receiving unit 210 (FIG. 4) of the determination station 200 receives a radio signal from the control station 100 via the radio line and the antenna 202. Here, the received signal is referred to as a received signal. The receiving unit 210 performs demodulation processing on the received signal using a currently set modulation method, and generates radio frame data. Furthermore, the reception unit 210 outputs the generated radio frame data to the surplus value extraction unit 230.

  The received power calculation unit 220 measures the received power of the received signal received by the determination station 200 and calculates a received power level (RSL). Further, the received power calculation unit 220 outputs the received power level to the ATPC determination unit 222 and the upper modulation scheme switching determination unit 232.

  The ATPC determination unit 222 performs processing for performing transmission power control such as ATPC. The ATPC determination unit 222 stores a power control determination threshold value. The ATPC determination unit 222 compares the received power level with a power control determination threshold value. When the received power level is lower than the power control determination threshold, the ATPC determination unit 222 outputs a control signal indicating that to the higher-order modulation method switching determination unit 232.

  On the other hand, when the received power level is greater than or equal to the power control determination threshold, the ATPC determination unit 222 decreases (DOWN) or maintains (HOLD) the transmission power of the control station 100. An ATPC control value is generated. Further, the ATPC determination unit 222 outputs the generated ATPC control value to the control data multiplex processing unit 250.

  Here, when the received power level is larger than the power control determination threshold, the ATPC determination unit 222 generates an ATPC control value for decreasing (DOWN) the transmission power, and the received power level is the same as the power control determination threshold. In this case, an ATPC control value for maintaining transmission power (HOLD) may be generated. When the received power level is higher than the power control determination threshold, the received power level has not decreased, and therefore the ATPC determination unit 222 may generate an ATPC control value for maintaining (HOLD) transmission power. .

  The ATPC control value may be a value indicating “0” in the case of HOLD. In the case of DOWN, the ATPC control value may be a value indicating that the transmission power is decreased by a predetermined minute power. Alternatively, the ATPC control value may be a value indicating that the transmission power is decreased by the difference between the reception power level and the power control determination threshold in the case of DOWN.

  The surplus value extraction unit 230 extracts a transmission power surplus value from the radio frame data from the reception unit 210. Further, surplus value extraction section 230 outputs the extracted transmission power surplus value to higher modulation scheme switching determination section 232. Further, the surplus value extraction unit 230 extracts transmission data (payload) from the radio frame data excluding the transmission power surplus value. Then, the surplus value extraction unit 230 transmits the transmission data (payload) to the data line 70 as reception data.

  Upper modulation scheme switching determination section 232 receives a control signal from ATPC determination section 222. In this case, the upper modulation scheme switching determination unit 232 receives the received power level from the received power calculation unit 220. Also, the upper modulation scheme switching determination unit 232 receives the transmission power surplus value from the surplus value extraction unit 230. Further, upper modulation scheme switching determination section 232 determines whether the modulation scheme can be switched to the upper modulation scheme based on the received power level and the transmission power surplus value.

  Specifically, upper modulation scheme switching determination section 232 calculates the received power upper limit from the received power level and the transmission power surplus value. Here, the reception power upper limit is the reception power when the determination station 200 receives the radio signal when the control station 100 transmits the radio signal with the transmission power upper limit. For example, the upper modulation scheme switching determination unit 232 may use the sum of the reception power level and the transmission power surplus value as the reception power upper limit. Further, the upper modulation scheme switching determination unit 232 may set a value obtained by subtracting the power attenuation in the radio channel from the sum of the reception power level and the transmission power surplus value as the reception power upper limit.

  Also, the upper modulation scheme switching determination unit 232 compares the calculated received power upper limit with a threshold (upper modulation scheme switching threshold) for switching the modulation scheme to the upper modulation scheme. Then, upper modulation scheme switching determination section 232 determines that switching to the upper modulation scheme is impossible when the received power upper limit is smaller than the upper modulation scheme switching threshold. On the other hand, upper modulation scheme switching determination section 232 determines that switching to the upper modulation scheme is possible when the received power upper limit is equal to or higher than the upper modulation scheme switching threshold.

  When it is determined that switching to the higher modulation scheme is impossible, the upper modulation scheme switching determination unit 232 outputs a control signal indicating that to the quality assurance power control value calculation unit 234. On the other hand, when it is determined that switching to the higher modulation scheme is possible, the upper modulation scheme switching determination unit 232 outputs a control signal indicating that to the modulation scheme switching notification generation unit 236.

  The quality assurance power control value calculation unit 234 calculates a quality assurance power control value when a control signal is received from the higher-order modulation method switching determination unit 232. Further, the quality assurance power control value calculation unit 234 outputs the calculated quality assurance power control value to the control data multiplex processing unit 250.

  Here, the quality assurance power control value is a control value for controlling the transmission power in the control station 100 to be suppressed so that the reception power in the determination station 200 becomes the quality assurance power. The quality assurance power is necessary and sufficient received power that guarantees communication quality in the current modulation scheme. That is, the quality assurance power control value calculation unit 234 has a function of controlling the transmission power of the control station 100 so that the reception power at the determination station 200 becomes reception power (quality assurance power) that guarantees communication quality. Yes. Note that. The quality assurance power may be a power value set in advance for each wireless communication device (determination station 200). In addition, quality assurance power may be provided for each modulation method.

The quality assurance power control value calculation unit 234 may calculate the quality assurance power control value by any one of the following methods, for example.
For example, the quality assurance power control value calculation unit 234 may calculate a value indicating that the power consumption decreases by a predetermined minute power as the quality assurance power control value.
Alternatively, for example, the quality assurance power control value calculation unit 234 calculates the difference between the received power level and the quality assurance power. Then, the quality assurance power control value calculation unit 234 may calculate the difference as the quality assurance power control value.

The modulation scheme switching notification generation unit 236 generates a modulation scheme switching notification when a control signal is received from the higher-order modulation scheme switching determination unit 232. Then, modulation scheme switching notification generation section 236 outputs the generated modulation scheme switching notification to control data multiplex processing section 250.
Here, the modulation scheme switching notification is a notification for controlling the control station 100 to switch the modulation scheme to the higher modulation scheme. When the control station 100 receives the modulation scheme switching notification, the control station 100 and the determination station 200 perform processing so as to switch the modulation scheme to the higher modulation scheme.

  The control data multiplexing processing unit 250 receives transmission data that is data to be transmitted from the determination station 200 to the control station 100 via the data line 70. In addition, the control data multiplex processing unit 250 receives an ATPC control value from the ATPC determination unit 222. In addition, the control data multiplex processing unit 250 receives a quality assurance power control value from the quality assurance power control value calculation unit 234. In addition, the control data multiplex processing unit 250 receives a modulation method switching notification from the modulation method switching notification generation unit 236.

  Here, in the first embodiment, the ATPC control value, the quality assurance power control value, and the modulation scheme switching notification are collectively referred to as control data. The control data multiplexing processing unit 250 adds (multiplexes) control data to a packet header or control information area provided in transmission data to generate radio frame data. Further, the control data multiplexing processing unit 250 outputs the generated radio frame data to the transmission unit 252.

  As illustrated in FIG. 5, an ATPC control value, a quality assurance power control value, and a modulation system switching notification are written as control data in the determination station side control information area in the radio frame data. That is, the determination station side control information area is provided with areas for writing the ATPC control value, the quality assurance power control value, and the modulation system switching notification.

  The transmission unit 252 receives the radio frame data from the control data multiplex processing unit 250. The transmission unit 252 performs modulation processing on the radio frame data using the currently set modulation scheme, and generates a modulation signal. Further, the transmission unit 252 performs processing necessary for wireless transmission such as amplification on the generated modulated signal. Then, the transmission unit 252 wirelessly transmits a wireless signal including the wireless frame data to the control station 100 via a wireless line.

  Although not shown, the determination station 200 may have a configuration for controlling a general adaptive modulation scheme. That is, the determination station 200 may transmit a switching notification for switching to the higher modulation scheme to the control station 100 when the received power level is equal to or higher than the higher modulation scheme switching threshold. Further, the determination station 200 may transmit a switching notification for switching to the lower modulation scheme to the control station 100 when the received power level is equal to or lower than the lower modulation scheme switching threshold.

  The receiving unit 120 (FIG. 3) of the control station 100 receives a radio signal from the determination station 200 via the radio line and the antenna 102. Here, the received signal is referred to as a received signal. The receiving unit 120 performs demodulation processing on the received signal using a currently set modulation scheme, and generates radio frame data. Furthermore, the receiving unit 120 outputs the generated radio frame data to the control data extracting unit 122.

  The control data extraction unit 122 extracts control data from the radio frame data from the reception unit 120. Further, the control data extraction unit 122 extracts transmission data (payload) from the radio frame data excluding the control data. Then, the control data extraction unit 122 transmits the transmission data (payload) to the data line 60 as reception data.

  Further, when the ATPC control value is extracted from the radio frame data, the control data extraction unit 122 outputs the ATPC control value to the ATPC processing unit 124. In addition, when the quality assurance power control value is extracted from the radio frame data, the control data extraction unit 122 outputs the quality assurance power control value to the quality assurance power control unit 126. In addition, when the modulation method switching notification is extracted from the radio frame data, the control data extraction unit 122 outputs the modulation method switching notification to the modulation method switching unit 128.

  When the ATPC processing unit 124 receives the ATPC control value from the control data extraction unit 122, the ATPC processing unit 124 controls the transmission power according to the ATPC control value as in the general ATPC processing. For example, when the ATPC control value is a value indicating “0”, the ATPC processing unit 124 may control the transmission unit 110 so as to maintain the transmission power (HOLD).

  For example, when the ATPC control value is a value indicating that the ATPC control value is decreased by the minute power, the ATPC processing unit 124 may control the transmitting unit 110 to decrease the transmission power by the minute power. Good. In this case, the ATPC processing unit 124 does not control the transmission power so that the reception power level at the determination station 200 reaches the power control determination threshold by only one process. That is, until the received power level at the determination station 200 reaches the power control determination threshold, the determination station 200 transmits a value indicating that the received power level is decreased by a minute amount to the control station 100. Then, each time the control station 100 receives a value indicating that the control station 100 decreases the minute power from the determination station 200, the ATPC processing unit 124 gradually determines the transmission power, and the received power level at the determination station 200 is determined as a power control determination. Control to approach the threshold.

  For example, when the ATPC control value is a value indicating that the difference between the received power level and the power control determination threshold is decreased, the ATPC processing unit 124 causes the transmission unit to decrease the transmission power by the difference. 110 may be controlled. In this case, the ATPC processing unit 124 can control the transmission power so that the reception power level at the determination station 200 reaches the power control determination threshold value by only one process.

  When the modulation scheme switching unit 128 receives the modulation scheme switching notification from the control data extracting unit 122, the modulation scheme switching unit 128 controls the transmission unit 110 to switch the modulation scheme to the higher modulation scheme in accordance with the modulation scheme switching notification. Specifically, the modulation scheme switching unit 128 controls the transmission unit 110 to perform processing for switching the modulation scheme to a higher modulation scheme.

  The transmission unit 110 increases the transmission power in accordance with the control of the modulation scheme switching unit 128 so that the reception power at the determination station 200 is equal to or higher than the upper modulation scheme switching threshold. Then, the transmission unit 110 transmits a notification (OK notification) indicating that the modulation scheme can be switched to the determination station 200. When receiving the OK notification, the determination station 200 makes preparations for switching the modulation scheme to the higher modulation scheme. On the other hand, the transmission unit 110 of the control station 100 performs modulation using the modulation scheme switched to the higher modulation scheme in the next communication after transmitting the OK notification, and transmits a radio signal. The determination station 200 demodulates the radio signal by the higher-order modulation method in the next communication that has received the OK notification.

  When the quality assurance power control unit 126 receives the quality assurance power control value from the control data extraction unit 122, the quality assurance power control unit 126 performs transmission so that the received power level at the determination station 200 becomes the quality assurance power according to the quality assurance power control value. Control power. For example, when the quality assurance power control value is a value indicating that the power is decreased by the minute power, the quality assurance power control unit 126 controls the transmission unit 110 to decrease the transmission power by the minute power. May be.

  In this case, the quality assurance power control unit 126 does not control the transmission power so that the reception power level at the determination station 200 reaches the quality assurance power by only one process. That is, until the received power level at the determination station 200 reaches the quality assurance power, the determination station 200 repeatedly transmits to the control station 100 a value indicating that the received power level is decreased by a minute amount. Then, every time the control station 100 receives a value indicating that the control station 100 decreases the minute power from the determination station 200, the quality assurance power control unit 126 gradually increases the transmission power, and the received power level at the determination station 200 is the quality. Control to approach the guaranteed power.

  Further, for example, when the quality assurance power control value is a value indicating that the difference between the received power level and the quality assurance power is decreased, the quality assurance power control unit 126 decreases the transmission power by the difference. The transmission unit 110 may be controlled. In this case, the quality assurance power control unit 126 can control the transmission power so that the reception power level at the determination station 200 reaches the quality assurance power by only one process.

  The overall operation according to the first embodiment will be described below. FIG. 6 is a sequence diagram illustrating an overall operation of the wireless communication system 50 according to the first embodiment. FIG. 7 is a flowchart (S20) showing a determination process in the determination station 200. FIG. 8 is a flowchart (S30) showing a control process in the control station 100.

  The control station 100 calculates a transmission power surplus value (S102). Specifically, the surplus value calculating unit 112 of the control station 100 compares the transmission power upper limit with the current transmission power value to calculate a transmission power surplus value. Next, the control station 100 wirelessly transmits the transmission power surplus value to the determination station 200 (S104). Specifically, the transmission unit 110 of the control station 100 wirelessly transmits the transmission power surplus value added (multiplexed) to the radio frame data to the determination station 200.

  The determination station 200 determines whether or not the received power level is smaller than the power control determination threshold (S202). Specifically, the ATPC determination unit 222 of the determination station 200 compares the received power level with a power control determination threshold value and determines whether or not the received power level is smaller than the power control determination threshold value.

  When the received power level is not smaller than the power control determination threshold (NO in S202), the determination station 200 transmits an ATPC control value for DOWN or HOLD of the transmission power in the control station 100 to the control station 100. (S204). Specifically, when the received power level is greater than or equal to the power control determination threshold, the ATPC determination unit 222 decreases (DOWN) or maintains the transmission power of the control station 100 (DOWN). ATPC control value for HOLD) is generated. The control data multiplexing processing unit 250 adds (multiplexes) the ATPC control value to the header portion of transmission data transmitted from the determination station 200 to the control station 100, thereby generating radio frame data. The transmission unit 252 transmits the radio frame data to the control station 100.

  On the other hand, when the received power level is lower than the power control determination threshold (YES in S202), the determination station 200 determines whether the power control determination threshold is higher than the modulation scheme switching threshold (S206). If the power control determination threshold is not greater than the modulation scheme switching threshold (NO in S206), the process transitions to S220. On the other hand, when the power control determination threshold is larger than the modulation scheme switching threshold (YES in S206), the determination station 200 calculates the received power upper limit (S210). Specifically, upper modulation scheme switching determination section 232 of determination station 200 calculates the received power upper limit from the received power level and the transmission power surplus value.

  The determination station 200 determines whether or not the modulation scheme can be switched to the higher modulation scheme (S212). Specifically, the upper modulation scheme switching determination unit 232 of the determination station 200 compares the received power upper limit with the upper modulation scheme switching threshold, and if the upper limit of the received power is smaller than the upper modulation scheme switching threshold, It is determined that the method cannot be switched. On the other hand, upper modulation scheme switching determination section 232 determines that switching to the upper modulation scheme is possible when the received power upper limit is equal to or higher than the upper modulation scheme switching threshold.

  When it is determined that switching to the higher modulation scheme is impossible (NO in S212), the determination station 200 transmits a quality assurance power control value to the control station 100 (S220). Specifically, the quality assurance power control value calculation unit 234 of the determination station 200 calculates a quality assurance power control value. The control data multiplexing processing unit 250 adds (multiplexes) the quality assurance power control value to the header portion of the transmission data transmitted from the determination station 200 to the control station 100 to generate radio frame data. The transmission unit 252 transmits the radio frame data to the control station 100.

  On the other hand, when it is determined that switching to the higher modulation scheme is possible (YES in S212), the determination station 200 transmits a modulation scheme switching notification to the control station 100 (S230). Specifically, the modulation scheme switching notification generation unit 236 of the determination station 200 generates a modulation scheme switching notification. The control data multiplexing processing unit 250 adds (multiplexes) the modulation scheme switching notification to the header portion of the transmission data transmitted from the determination station 200 to the control station 100 to generate radio frame data. The transmission unit 252 transmits the radio frame data to the control station 100.

As described above, the determination station 200 transmits the ATPC control value, the quality assurance power control value, or the modulation scheme switching notification to the control station 100 as control data (S106).
The control station 100 receives control data from the determination station 200 (S302). The control station 100 determines whether the control data is an ATPC control value, a quality assurance power control value, or a modulation scheme switching notification (S304).

  When it is determined that the control data is an ATPC control value (“ATPC control value” in S304), the control station 100 performs an ATPC process (S306). Specifically, when the control data extraction unit 122 extracts the ATPC control value, the ATPC processing unit 124 controls the transmission power according to the ATPC control value.

  When it is determined that the control data is the quality assurance power control value (“quality assurance power control value” in S304), the control station 100 transmits the transmission power so that the reception power level at the determination station 200 becomes the quality assurance power. Is suppressed (S308). Specifically, when the control data extraction unit 122 extracts the quality assurance power control value, the quality assurance power control unit 126 sets the received power level at the determination station 200 to the quality assurance power according to the quality assurance power control value. Thus, the transmission power is suppressed.

  When it is determined that the control data is a modulation scheme switching notification (“modulation scheme switching notification” in S304), the control station 100 increases the transmission power and performs a process for switching the modulation scheme to a higher modulation scheme. (S310). Specifically, when the control data extraction unit 122 extracts the modulation scheme switching notification, the modulation scheme switching unit 128 controls the transmission unit 110 to perform processing for switching the modulation scheme to a higher modulation scheme. I do. The transmission unit 110 increases the transmission power in accordance with the control of the modulation scheme switching unit 128 so that the reception power at the determination station 200 is equal to or higher than the upper modulation scheme switching threshold. And the transmission part 110 switches a modulation system to a high-order modulation system.

  The processing in the first embodiment will be further described with a specific example. FIG. 9 is a diagram for explaining processing in the first embodiment. In FIG. 9, the determination method is exemplified when the modulation scheme is QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 32QAM, and 64QAM, but the modulation scheme is not limited thereto.

The decision station 200 performs control using an adaptive modulation scheme such as AMR. That is, as illustrated in FIG. 9, as the reception power increases, the determination station 200 can determine to switch the modulation scheme to the higher modulation scheme. For example, in the case where the current modulation scheme is 32QAM, the determination station 200 determines to switch the modulation scheme to 64QAM, which is the upper modulation scheme, when the received power is equal to or higher than the upper modulation scheme switching threshold to 64QAM. To do. On the other hand, when the received power becomes equal to or less than the switching threshold value for 16QAM, the determination station 200 determines to switch the modulation method to 16QAM, which is a lower modulation method.
The determination station 200 also performs transmission power control like ATPC. The determination station 200 may compare the power control determination threshold set in advance with the received power level and control the received power to approach the power control determination threshold.

  Here, as illustrated in FIG. 9, it is assumed that the received power level is lower than the power control determination threshold and the power control determination threshold is higher than the upper modulation scheme switching threshold. Even if the reception power is maximized, the modulation system cannot be switched from the current 32QAM to the higher modulation system 64QAM unless the maximum reception power (reception power upper limit) is equal to or higher than the upper modulation system switching threshold. Therefore, even if the received power level is lower than the power control determination threshold value and control is performed so as to increase the transmission power in the control station 100 and the received power is increased, the current modulation scheme 32QAM It is not possible to switch to 64QAM, which is an upper modulation method. In other words, the received power level cannot be controlled to the power control determination threshold, and the received power level is increased even though the current modulation scheme, 32QAM, cannot be switched to the higher modulation scheme, 64QAM. If the transmission power is controlled, useless power is consumed.

  On the other hand, in the present embodiment, as described above, in the case described above, determination station 200 receives the transmission power surplus value from control station 100. The upper modulation scheme switching determination unit 232 of the determination station 200 calculates the reception power upper limit based on the transmission power surplus value and the reception power level. When the received power upper limit is smaller than the upper modulation scheme switching threshold value to 64QAM, upper modulation scheme switching determination section 232 determines that switching from 32QAM to 64QAM is impossible. In that case, the quality assurance power control value calculation unit 234 controls the transmission power of the control station 100 so that the reception power at the determination station 200 becomes the quality assurance power.

  In other words, when it is impossible to switch the modulation scheme to the higher modulation scheme, the determination station 200 controls the transmission power in the control station 100 so as to optimize the reception power to the quality assurance power. As a result, the transmission power is also suppressed so that the reception power level is suppressed to the quality assurance power, so that it is possible to suppress the wasteful power consumption. In other words, the transmission power can be suppressed regardless of the power control determination threshold, so that useless power can be suppressed from being consumed.

  Note that the range of received power that guarantees the communication quality is, for example, a switching threshold value for switching from 16QAM to a higher modulation method value to 64QAM when the current modulation method is 32QAM. The quality assurance power may be set anywhere as long as it is within this range, but is preferably set to a value close to the switching threshold to 16QAM, which is the lower limit, in order to suppress unnecessary power consumption.

  As described above, when the modulation scheme cannot be switched to the higher modulation scheme, the control station 100 can control the transmission power so that the reception power level at the determination station 200 reaches the quality assurance power. . Thereby, the control station 100 can suppress transmission power while maintaining communication quality. Therefore, useless power consumption of the wireless communication device can be suppressed.

(Comparative example)
Hereinafter, a comparative example will be described. In the comparative example, the processes in the higher-order modulation system switching determination unit 232 and the quality assurance power control value calculation unit 234 according to the first embodiment are not performed.
FIG. 10 is a diagram for explaining the processing according to the comparative example. In the example of FIG. 10, the current modulation scheme is 32QAM.

  When the reception power is smaller than the power control determination threshold, the determination station controls the control station to increase (UP) the transmission power in order to bring the reception power closer to the power control determination threshold. Here, a case is assumed in which the received power is smaller than the power control determination threshold and the power control determination threshold is larger than the upper modulation scheme switching threshold. In this case, when the received power upper limit is smaller than the upper modulation scheme switching threshold, the modulation scheme cannot be switched to 64QAM, which is the upper modulation scheme, even if the transmission power of the control station is increased. Further, the received power at the determination station does not reach the power control determination threshold.

  In other words, in the above case, the reception power level cannot be controlled to the power control determination threshold value, and the reception power level is increased although it is not possible to switch from 32QAM to 64QAM which is the higher modulation scheme. As described above, if transmission power is controlled, useless power is consumed. Specifically, the power between the transmission power corresponding to the quality assurance power and the controlled transmission power is wasted power.

  On the other hand, in the present embodiment, as described above, the determination station 200 performs control so as to optimize the received power to the quality assurance power when it is impossible to switch the modulation scheme to the higher modulation scheme. The transmission power in the station 100 is suppressed. As a result, the transmission power is also suppressed so that the reception power level is suppressed to the quality assurance power, so that it is possible to suppress the wasteful power consumption.

(Embodiment 2)
Next, a second embodiment will be described. The second embodiment is different from the first embodiment in that a transmitting station (control station) performs a determination process. In the following description, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the second embodiment, the control station 100 in FIG. 2 is replaced with the transmitting station 300, and the determination station 200 is replaced with the receiving station 400. That is, in the second embodiment, the transmitting station 300 and the receiving station 400 are connected so as to be capable of wireless communication via a wireless line, and user data such as packets are transmitted from the transmitting station 300 to the receiving station 400. Is transmitted.

  FIG. 11 is a diagram of a configuration of the transmission station 300 according to the second embodiment. The transmission station 300 includes an antenna 102, a transmission unit 110, a surplus value calculation unit 312, a reception unit 120, a control data extraction unit 320, an ATPC determination unit 322, an upper modulation scheme switching determination unit 332, a quality assurance power control value calculation unit 334, It has a modulation system switching notification generation unit 336, an ATPC processing unit 124, a quality assurance power control unit 126, and a modulation system switching unit 128. In FIG. 11, the antenna 102 is described as being provided separately for the transmission side and the reception side, but the antenna 102 may be shared by the transmission side and the reception side.

  FIG. 12 is a diagram of a configuration of the receiving station 400 according to the second embodiment. The reception station 400 includes an antenna 202, a reception unit 210, a reception power calculation unit 420, a threshold data storage unit 422, a control data multiplex processing unit 450, and a transmission unit 252. In FIG. 12, the antenna 202 is described as being provided separately for each of the transmission side and the reception side, but the antenna 202 may be shared by the transmission side and the reception side.

  The reception power calculation unit 420 (FIG. 12) of the reception station 400 calculates the reception power level in the same manner as the reception power calculation unit 220 of FIG. Further, received power calculation section 420 outputs the calculated received power level to control data multiplex processing section 450.

  The threshold data storage unit 422 stores data (threshold data) of the power control determination threshold and the upper modulation scheme switching threshold for the receiving station 400. The threshold data storage unit 422 outputs the threshold data to the control data multiplex processing unit 450 in order to transmit threshold data to the transmitting station 300.

  The control data multiplex processing unit 450 receives transmission data, which is data to be transmitted from the receiving station 400 to the transmitting station 300, via the data line 70, similarly to the control data multiplex processing unit 250 of FIG. Control data multiplex processing section 450 receives the received power level from received power calculation section 420. In addition, the control data multiplex processing unit 450 receives threshold data from the threshold data storage unit 422.

Here, in the second embodiment, the received power level and threshold data are collectively referred to as control data. The control data multiplex processing unit 450 adds (multiplexes) control data to the packet header or control information area provided in the transmission data in the same manner as the control data multiplex processing unit 250 to generate radio frame data. To do. Further, the control data multiplexing processing unit 450 outputs the generated radio frame data to the transmission unit 252.
In this way, the receiving station 400 can transmit the received power level and threshold data to the transmitting station 300.

  The surplus value calculation unit 312 (FIG. 11) of the transmission station 300 calculates the transmission power surplus value in the same manner as the surplus value calculation unit 112 of FIG. 3. In addition, surplus value calculation section 312 outputs the calculated transmission power surplus value to higher modulation scheme switching determination section 332.

  The control data extraction unit 320 extracts control data from the radio frame data from the reception unit 120 in the same manner as the control data extraction unit 122 of FIG. Further, the control data extraction unit 320 extracts transmission data (payload) from the radio frame data excluding the control data. Then, the control data extraction unit 320 transmits the transmission data (payload) to the data line 60 as reception data.

  Further, when the control data extraction unit 320 extracts the reception power level from the radio frame data, the control data extraction unit 320 outputs the reception power level to the ATPC determination unit 322 and the upper modulation scheme switching determination unit 332. In addition, when the control data extraction unit 320 extracts threshold data from the radio frame data, the control data extraction unit 320 outputs the threshold data to the ATPC determination unit 322 and the upper modulation scheme switching determination unit 332.

  The ATPC determination unit 322 has the same function as the ATPC determination unit 222 of FIG. Similar to the ATPC determination unit 222, the ATPC determination unit 322 compares the received power level with a power control determination threshold value. When the received power level is smaller than the power control determination threshold, the ATPC determination unit 322 outputs a control signal indicating that to the higher modulation scheme switching determination unit 332.

  On the other hand, when the received power level is greater than or equal to the power control determination threshold, the ATPC determination unit 322 decreases (DOWN) or maintains (HOLD) the transmission power of the control station 100. An ATPC control value is generated. Further, the ATPC determination unit 322 outputs the generated ATPC control value to the ATPC processing unit 124.

  Upper modulation scheme switching determination section 332 has the same function as upper modulation scheme switching determination section 232 in FIG. Upper modulation scheme switching determination section 332 receives a control signal from ATPC determination section 322. In this case, upper modulation scheme switching determination section 332 receives the received power level from control data extraction section 320. In addition, the upper modulation scheme switching determination unit 332 receives the transmission power surplus value from the surplus value calculation unit 312. Furthermore, in the same way as the upper modulation scheme switching determination section 232, the upper modulation scheme switching determination section 332 determines whether the modulation scheme can be switched to the upper modulation scheme based on the received power level and the transmission power surplus value. Determine whether.

  If the upper modulation scheme switching determination unit 332 determines that switching to the upper modulation scheme is impossible, the upper modulation scheme switching determination unit 332 outputs a control signal indicating that to the quality assurance power control value calculation unit 334. On the other hand, when determining that the switching to the higher modulation scheme is possible, the higher modulation scheme switching determination unit 332 outputs a control signal indicating that to the modulation scheme switching notification generation unit 336.

  The quality assurance power control value calculation unit 334 has the same function as the quality assurance power control value calculation unit 234 of FIG. The quality assurance power control value calculation unit 334 calculates a quality assurance power control value in the same manner as the quality assurance power control value calculation unit 234 when a control signal is received from the higher-order modulation method switching determination unit 332. Further, the quality assurance power control value calculation unit 334 outputs the calculated quality assurance power control value to the quality assurance power control unit 126.

  The modulation scheme switching notification generation unit 336 has the same function as the modulation scheme switching notification generation unit 236 of FIG. When the modulation method switching notification generation unit 336 receives a control signal from the higher-level modulation method switching determination unit 332, the modulation method switching notification generation unit 336 generates a modulation method switching notification. Then, modulation scheme switching notification generation section 336 outputs the generated modulation scheme switching notification to modulation scheme switching section 128.

  As in the second embodiment, even when the transmission station 300 is provided with the upper modulation scheme switching determination unit 332 and the quality assurance power control value calculation unit 334, the modulation scheme cannot be switched to the upper modulation scheme. , The transmission power at the transmission station 300 can be controlled so that the reception power at the reception station 400 becomes the quality assurance power. Therefore, also in Embodiment 2, the transmitting station 300 can suppress transmission power while maintaining communication quality. Therefore, useless power consumption of the wireless communication device can be suppressed.

  In the second embodiment, the process (S20) shown in FIG. Further, in this case, S104 of FIG. 6 is not necessary, and a process for the transmitting station 300 to receive control data from the receiving station 400 is added before the process of S20.

(Modification)
Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.
In the flowchart described above, the order of processing (steps) can be changed as appropriate. One or more of the plurality of processes (steps) may be omitted.
For example, in the flowchart of FIG. 7, the process of S210 may be performed before S206. Furthermore, the process of S206 is not necessary.

  Further, in the flowchart of FIG. 7, in the case of NO in S206, the process proceeds to S220. That is, when the power control determination threshold is not larger than the modulation scheme switching threshold, the determination station 200 transmits a quality assurance power control value to the control station 100. In other words, even when the power control determination threshold is not larger than the modulation scheme switching threshold, the transmission power of the control station 100 is suppressed so that the reception power at the determination station 200 is suppressed to quality assurance power. Thereby, transmission power can be suppressed regardless of the power control determination threshold.

  On the other hand, when the power control determination threshold is not larger than the modulation scheme switching threshold, the transmission power of the control station 100 may be controlled so that the reception power at the determination station 200 approaches the power control determination threshold. . That is, the determination station 200 may compare the received power upper limit with the power control determination threshold when the power control determination threshold is not larger than the modulation scheme switching threshold. Then, when the received power upper limit is equal to or higher than the power control determination threshold, the determination station 200 may control the transmission power of the control station 100 so that the received power becomes the power control determination threshold.

  In the above-described embodiment, the ATPC processing unit 124 and the quality assurance power control unit 126 are separately configured, but they may be integrated. That is, one component may perform ATPC processing and control the transmission power so that the reception power becomes the quality assurance power in the determination station 200. That is, one component may perform transmission power control. Also in the radio frame data, it is not necessary to distinguish between the ATPC control value and the quality assurance power control value in the determination station side control information area, and both may be used together such as “transmission power control value”.

In the above-described embodiment, it is assumed that data is transmitted from the control station 100 to the determination station 200. However, a radio signal may be transmitted from the determination station 200 to the control station 100. . In this case, the determination station 200 functions as a transmission station, and the control station 100 functions as a determination station.
Further, the control station 100 and the determination station 200 may have the same components. That is, the control station 100 may include the components of the determination station 200 illustrated in FIG. Similarly, the determination station 200 may include the components of the control station 100 illustrated in FIG.

  In the above-described embodiments, the present invention has been described as a hardware configuration, but the present invention is not limited to this. The present invention can also realize processing of each circuit in the wireless communication apparatus by causing a CPU (Central Processing Unit) to execute a computer program.

  In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  Although the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2013-157613 for which it applied on July 30, 2013, and takes in those the indications of all here.

DESCRIPTION OF SYMBOLS 1 Wireless communication apparatus 12 Receiving means 14 Surplus value reception means 16 Switching determination means 18 Transmission power control means 50 Wireless communication system 60 Data line 70 Data line 100 Control station 102 Antenna 110 Transmission part 112 Surplus value calculation part 114 Surplus value multiplexing process part 120 Reception Unit 122 Control Data Extraction Unit 124 ATPC Processing Unit 126 Quality Assurance Power Control Unit 128 Modulation Method Switching Unit 200 Determination Station 202 Antenna 210 Reception Unit 220 Received Power Calculation Unit 222 ATPC Determination Unit 230 Surplus Value Extraction Unit 232 Higher Modulation Method Switching Determination unit 234 Quality assurance power control value calculation unit 236 Modulation method switching notification generation unit 250 Control data multiplexing processing unit 252 Transmission unit 300 Transmitting station 312 Surplus value calculation unit 320 Control data extraction unit 322 ATPC determination unit 332 Upper modulation method switching determination unit 334 Quality Assurance Power Control value calculating unit 336 modulation mode switching notification generator 400 receiving station 420 receiving power calculating unit 422 threshold data storage unit 450 control data multiplexing processing unit

Claims (8)

Receiving means for receiving wireless signals from other wireless communication devices;
Surplus value receiving means for receiving a surplus value from the current transmission power of the radio signal transmitted from the other radio communication device to an upper limit value of the transmission power from the other radio communication device;
The received power of the radio signal received from the other radio communication device is smaller than a power control judgment threshold for controlling transmission power in the other radio communication device , and the power control judgment threshold is present When the threshold value is larger than the switching threshold value from the modulation method to the higher modulation method, the upper limit value of the received power is calculated based on the received power and the surplus value, and the upper limit value of the received power is compared with the switching threshold value. and determining switching determination means for determining whether or not it is possible to switch to the upper modulation scheme by,
When it is determined that the switching determination means cannot switch because the upper limit value of the received power is not equal to or higher than the switching threshold, so that the received power becomes quality assurance power that guarantees communication quality in the current modulation scheme, And a transmission power control means for controlling so as to suppress transmission power in the other wireless communication device. The wireless communication apparatus according to claim 1, further comprising: a modulation scheme switching unit that controls to increase transmission power and switch a modulation scheme to a higher modulation scheme when it is determined by the switching determination unit that switching is possible. Transmitting means for transmitting a wireless signal to another wireless communication device;
Surplus value calculating means for calculating a surplus value from the current transmission power of the radio signal transmitted by the transmitting means to the upper limit value of the transmission power;
In the other radio communication device, when the reception power of the radio signal received by the other radio communication device is smaller than a power control determination threshold for controlling transmission power in the transmission means , the power When the control determination threshold value is larger than the switching threshold value from the current modulation scheme to the higher modulation scheme, the upper limit value of the received power calculated based on the received power and the surplus value in the other radio communication device is the switching when the switching to the higher modulation scheme from the current modulation scheme and since they are not above the threshold value is determined to be impossible, the received power in the other radio communication apparatus, to guarantee the communication quality in the current modulation scheme quality And a transmission power control unit that controls the transmission unit to suppress transmission power so that guaranteed power is obtained. Surplus value calculating means for calculating a surplus value from the current transmission power to the upper limit value of the transmission power in the radio communication device on the transmitting side;
A power control determination threshold value for controlling the transmission power of the radio signal transmitted from the transmission-side radio communication apparatus by the reception power of the radio signal received from the transmission-side radio communication apparatus by the reception-side radio communication apparatus And when the power control determination threshold is larger than the switching threshold from the current modulation scheme to the higher modulation scheme , based on the received power and the surplus value in the radio communication device on the receiving side A switching determination means for calculating an upper limit value of the received power and determining whether or not it is possible to switch to the higher modulation scheme by comparing the upper limit value of the received power with the switching threshold ;
Since the upper limit value of the received power is not equal to or higher than the switching threshold value, the received power in the reception-side wireless communication device guarantees communication quality in the current modulation method when the switching determining unit determines that switching is not possible. And a transmission power control means for controlling so as to suppress transmission power in the transmission-side radio communication apparatus so as to obtain quality assurance power. The wireless communication system according to claim 4 , further comprising: a modulation scheme switching unit that controls to increase the transmission power and switch the modulation scheme to a higher modulation scheme when the switching determination unit determines that the switching is possible. At least the surplus value calculating means is provided in the wireless communication device on the transmission side,
The wireless communication system according to claim 4 , wherein at least the switching determination unit is provided in the reception-side wireless communication device. Receiving wireless signals from other wireless communication devices,
The surplus value from the current transmission power of the wireless signal transmitted from the other wireless communication device to the upper limit value of the transmission power is received from the other wireless communication device,
The received power of the radio signal received from the other radio communication device is smaller than a power control judgment threshold for controlling transmission power in the other radio communication device , and the power control judgment threshold is present When the threshold value is larger than the switching threshold value from the modulation method to the higher modulation method, the upper limit value of the received power is calculated based on the received power and the surplus value, and the upper limit value of the received power is compared with the switching threshold value. It determines whether it is possible to switch to the upper modulation scheme by,
When the determination is made that switching is not possible in the determination because the upper limit value of the reception power is not equal to or higher than the switching threshold, the other is set so that the reception power becomes quality assurance power that guarantees communication quality in the current modulation scheme. A wireless communication method for controlling to suppress transmission power in a wireless communication apparatus. Send wireless signals to other wireless communication devices,
Calculating a surplus value from the current transmission power of the transmitted radio signal to the upper limit value of the transmission power;
In the other wireless communication device, the reception power of the radio signal received by the other wireless communication device is smaller than a power control determination threshold value for controlling transmission power, and the power control determination threshold value is When the switching threshold value from the current modulation scheme to the higher modulation scheme is larger than the switching threshold , the upper limit value of the received power calculated based on the received power and the surplus value in the other wireless communication device does not exceed the switching threshold because when it is determined that is impossible to switch from the current modulation scheme to the upper modulation scheme, received power at the other radio communication apparatus, the quality assurance power to guarantee the communication quality in the current modulation scheme A wireless communication method for performing control so as to suppress transmission power.

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