JP5173375B2 - Wireless communication apparatus and wireless communication method - Google Patents

Description

  The present invention relates to a wireless communication apparatus and a wireless communication method capable of performing processing related to transmission of wireless communication without receiving interference due to fading or the like.

In a wireless communication system including a base station and a wireless terminal, adaptive modulation control and transmission power control are performed in order to perform communication adapted to the propagation environment. The adaptive modulation control is to select a modulation scheme according to the communication environment from channel quality information such as SNR (Signal to Noise Ratio). Examples of the modulation scheme include BPSK (Binary Phase Shift Keying) and QPSK. (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), and the like. At this time, there is transmission power corresponding to each modulation method, and transmission power control is performed in accordance with the modulation method because the transmission power becomes larger as the modulation method with a higher data transmission rate such as 64QAM. However, since control delay occurs in these controls, information on the propagation environment several frames before the frame to be controlled is used. For example, in wireless communication where the moving speed of a wireless terminal is a certain level or more, Depending on the propagation environment, it may not make sense to control the transmission power. For this reason, a technique for predicting a change in the propagation environment has been proposed in order to follow the change in the propagation environment from the acquired reception level information (see, for example, Patent Document 1).
JP-A-6-152494

  In Patent Document 1 described above, transmission power control is performed in which the transmission level is linearly predicted from the reception level and prediction tracking control is performed. However, in a wireless communication system, when a wireless terminal is moving at high speed, the line quality frequently fluctuates due to the influence of fading or the like. The fluctuation period becomes smaller as the moving speed of the wireless terminal is faster. For this reason, the line quality information and the reception level of the received signal frequently fluctuate even within the frame. Therefore, even if the transmission level is linearly predicted from the reception level and the transmission power control is performed following the prediction, the line quality information in the frame and the reception level of the reception signal frequently fluctuate. In some cases, transmission power control cannot be performed.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is the receiver side even in a situation where the propagation environment changes rapidly due to, for example, a high speed movement of the transmission side device. It is an object of the present invention to provide a wireless communication apparatus and a wireless communication method that can perform processing related to transmission power without being affected by fluctuations in channel quality information.

  In order to solve the above-described problems, the present invention is a wireless communication device that wirelessly communicates with another wireless communication device using an adaptive modulation method, and the amplitude of the modulation signal in the modulation method of a predetermined signal section is constant. A determination unit that determines whether or not there is a first signal that controls transmission power after the predetermined signal interval when the amplitude of the modulation signal in the modulation scheme is constant as a result of the determination by the determination unit; If the amplitude of the modulation signal in the modulation scheme is not constant as a result of the determination by the control means and the determination means, the transmission power after the predetermined signal interval is controlled by means different from the first control means. And a second control means.

  According to the first feature, the wireless communication apparatus controls transmission power in wireless communication by different means depending on whether or not the amplitude of the modulation signal in the current modulation scheme is constant. Thereby, even in a situation where the propagation environment changes rapidly, it is possible to perform processing related to transmission power of wireless communication without being affected. Here, the signal section means one frame, one time slot, one spatial multiplexing slot, etc. allocated to wireless communication, and the predetermined signal section means that the wireless communication apparatus transmits data to other wireless communication apparatuses. It means a signal interval for transmission or a signal interval for receiving data from another wireless communication device.

  Further, in the wireless communication device according to the second invention, when the amplitude of the modulation signal in the current modulation system is constant as a result of the determination by the determination means, the reception level variation of the received signal in the predetermined signal section Grasping means for grasping information on the information, and in the first control means, the signal quality corresponding to the value in which the value indicating the reception level is relatively deteriorated in the information grasped by the grasping means The transmission power after the predetermined signal interval is controlled based on the information.

  According to the second feature, when the amplitude of the modulation signal in the current modulation scheme is constant, the radio communication device has a signal quality corresponding to a value in which the value indicating the reception level of the reception signal is relatively degraded. The transmission power in wireless communication is controlled using the information. Thereby, even in a situation where the propagation environment changes abruptly, it is possible to perform processing related to transmission of wireless communication without being affected by fluctuations in signal quality information. Further, the signal quality information corresponding to the value in which the value indicating the reception level is relatively deteriorated is a value indicating the other reception level except for the value indicating the reception level that is the best in the predetermined signal section. For example, in a predetermined signal section, (1) a value indicating a reception level that has deteriorated compared to a value indicating another reception level, and (2) a predetermined signal section Further, it means a value indicating a reception level in which a value indicating a reception level is deteriorated in a subdivided section. Furthermore, the value (1) or (2) in which the value indicating the reception level is degraded is not necessarily the value indicating the most deteriorated reception level in the predetermined signal section.

  In the wireless communication apparatus according to the third invention, the relatively deteriorated value is a value at which the value indicating the reception level is most deteriorated.

  Further, in the wireless communication device according to the fourth invention, when the amplitude of the modulation signal in the current modulation system is not constant as a result of the determination by the determination means, each of the plurality of known signals included in the predetermined signal section Acquisition means for acquiring the signal quality information of the signal quality, and in the second control means, the signal quality in which the signal quality is relatively degraded among the plurality of signal quality information acquired by the acquisition means The transmission power after the predetermined signal interval is controlled based on the information.

  According to the fourth feature, when the amplitude of the modulation signal in the current modulation scheme is not constant, the wireless communication device preferentially uses the signal quality information whose signal quality is relatively degraded, Controls the transmission power of wireless communication with the communication device. The signal quality information whose signal quality is relatively degraded is other signal quality information excluding signal quality information with the best signal quality among a plurality of signal quality information in a predetermined signal section, for example, In a predetermined signal section, (1) signal quality information in which the signal quality is degraded as compared with other signal quality information, and (2) signal quality is degraded in a section obtained by further subdividing the predetermined signal section. Signal quality information, (3) signal quality information in which signal quality of known signals arranged at a plurality of specific positions is degraded, and the like. Furthermore, the signal quality information in which the signal quality is degraded in (1) to (3) is not necessarily the signal quality information in which the signal quality is most degraded in a predetermined signal section.

  Further, in the wireless communication apparatus according to the fifth invention, a calculating means for calculating a difference between the plurality of signal quality information acquired by the acquiring means, and whether or not the difference calculated by the calculating means exceeds a predetermined value. A second determination means for determining, and when the difference exceeds the predetermined value as a result of the determination by the second determination means, the second control means is executed. To do.

  According to the fifth feature, when the difference between a plurality of pieces of signal quality information exceeds a predetermined value, the transmission power of wireless communication with another wireless communication device is controlled. Thereby, the process regarding transmission power is not frequently performed, and the processing load in the wireless communication apparatus can be further reduced. Here, the predetermined value is a threshold value serving as a determination criterion for estimating that another wireless communication apparatus is moving at high speed from the difference in the signal quality information. When this predetermined value is exceeded, other wireless communication is performed. Estimate that the device is moving at high speed. Also, calculating the difference means, for example, when there are two pieces of signal quality information in a predetermined signal section, the difference is calculated using the two signal quality information. Further, when there are three or more signal quality information in a predetermined signal section, (1) a plurality of signal quality information is compared, and the signal quality information with the best signal quality and the signal quality information with the most deterioration from the comparison result And calculating a difference from the two signal quality information, (2) comparing a plurality of signal quality information, the most deteriorated signal quality information, and a signal in the nearest known signal It means that the difference is calculated from the quality information.

  In the wireless communication apparatus according to the sixth invention, when the difference is equal to or less than the predetermined value as a result of the determination in the second determination, the signal quality in the plurality of signal quality information is relatively good. And third control means for controlling transmission power after the predetermined signal interval based on signal quality information.

  According to the sixth feature, when the calculated difference is equal to or smaller than the predetermined value, it can be estimated that the other wireless communication device is not moving at high speed. Even if the transmission processing of wireless communication based on the control is controlled, it is possible to perform processing related to transmission power without being affected by fluctuations in signal quality information accompanying a rapid change in propagation environment. The signal quality information with relatively good signal quality is other signal quality information excluding signal quality information with the most deteriorated signal quality among a plurality of signal quality information in a predetermined signal section. For example, in a predetermined signal section, (1) signal quality information with better signal quality than other signal quality information, and (2) signal quality information with better signal quality in a section obtained by further subdividing the predetermined signal section. (3) Signal quality information with good signal quality in known signals arranged at a plurality of specific positions, and the like. Furthermore, the signal quality information with good signal quality (1) to (3) is not necessarily the best signal quality information in a predetermined signal section.

  Further, in the wireless communication device according to a seventh aspect of the present invention, when the difference is equal to or less than the predetermined value as a result of the determination in the second determination, the predetermined signal interval for acquiring the plurality of signal quality information And a fourth control means for controlling the transmission power after the signal interval based on the signal quality information of the known signal arranged at the last part.

  According to the seventh feature, when the calculated difference is equal to or less than the predetermined value, it can be estimated that the other wireless communication device is not moving at high speed. However, it is assumed that the signal quality is deteriorated due to the influence of an obstacle or the like. Therefore, by controlling the transmission power of wireless communication based on the signal quality information acquired from the known signal arranged at the last part of the predetermined signal section, it is affected by a rapid change in the propagation environment. The processing related to the transmission power of the wireless communication can be performed without any problem.

  In the radio communication apparatus according to the eighth aspect of the invention, the signal quality information with relatively deteriorated signal quality is signal quality information with the most deteriorated signal quality in the plurality of signal quality information. It is characterized by that.

  In the wireless communication apparatus according to the ninth invention, the signal quality information having relatively good signal quality is signal quality information having the best signal quality in the plurality of signal quality information. To do.

  A radio communication method according to a tenth aspect of the present invention that realizes the present invention is a radio communication device that performs radio communication with another radio communication device using an adaptive modulation scheme, and is a modulation signal in a modulation scheme of a predetermined signal section. If the amplitude of the modulation signal in the modulation scheme is constant as a result of the determination in the determination unit, the transmission power after the predetermined signal interval is determined. If the amplitude of the modulation signal in the modulation scheme is not constant as a result of the determination by the first control means to be controlled and the determination means, the transmission power after the predetermined signal interval is expressed as the first control means And second control means for controlling by different means.

  Control of transmission power in wireless communication with another wireless communication apparatus can be executed in accordance with a modulation scheme adopted by the other wireless communication apparatus. Accordingly, even if the propagation environment changes suddenly due to the high-speed movement of the transmission-side wireless communication device or the like, the reception-side wireless communication device is not affected by fluctuations and is related to wireless communication transmission. Processing can be executed.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic.

  FIG. 1 is a diagram illustrating an example of a network to which a wireless communication method and a wireless communication device according to an embodiment of the present invention are applied. A base station 1 (wireless communication device) and a wireless terminal 3 (other wireless devices) Communication device).

  FIG. 2 is a block diagram showing a configuration of each main part of the base station 1 (wireless communication apparatus) included in the network shown in FIG. The base station 1 includes a transmission / reception unit 10 that transmits and receives data (signals), a demodulation unit 11 that demodulates received data, and a determination unit that determines whether or not the amplitude of a modulation signal in the currently used modulation scheme is constant. 12. A reception level acquisition unit 13 for selecting information indicating a reception level that is most deteriorated in the received reception level change, and a signal quality for acquiring signal quality information. Based on the information acquisition unit 14, the signal quality information, a modulation scheme in radio communication with the radio terminal 3 (another radio communication device), a control unit 15 that controls transmission power, and a modulation unit 16 that modulates data to be transmitted. Consists of

  The transmission / reception unit 10 transmits / receives data to / from the wireless terminal 3. Data transmitted from the wireless terminal 3 is received and output to the demodulator 11. In addition, the transmission data after modulation input from the modulation unit 16 is transmitted to the wireless terminal 3 at a transmission power value included in the information output from the control unit 15. Data transmission / reception is performed for each signal section allocated by the base station 1 in accordance with a wireless communication scheme with the wireless terminal 3. In the present embodiment, it is assumed that the base station 1 allocates one frame each for data transmission and reception as a signal section allocated to wireless communication with the wireless terminal 3. A plurality of known signals are arranged for each frame as a transmission unit of data to be transmitted and received (details will be described later). However, the signal interval is set according to the wireless communication system. For example, in the time division multiple access system, the time period is assigned to the wireless communication with the wireless terminal 3, and in the space division multiple access system, the space is used. Multiple slots, etc.

  The demodulation unit 11 demodulates the reception data input from the transmission / reception unit 10 according to the information related to the modulation scheme adopted by the wireless terminal 3 output from the control unit 15 and outputs the data to the determination unit 12 after demodulation. To do. In addition, the demodulated reception data is output to other components (not shown) in the base station 1.

  The determination unit 12 determines whether or not the amplitude of the modulation signal in the modulation scheme employed when the wireless terminal 3 currently transmits is constant (determination means). The modulation method with a constant amplitude of the modulation signal means that wireless communication is performed by a modulation method in which the envelope connecting the peak value of the waveform of the modulation signal always has a constant value, for example, a modulation method such as BPSK or QPSK. . The determination unit 12 obtains information regarding the modulation scheme adopted by the wireless terminal 3 that is output from the control unit 15 and performs determination. When the determination unit 12 determines that the modulation method in the wireless terminal 3 is a modulation method such as BPSK or QPSK, in which the envelope connecting the peak values of the modulation signal waveform is a constant value, the demodulated received data Is output to the reception level acquisition unit 13. On the other hand, the amplitude of the modulation signal in the modulation scheme currently employed when the wireless terminal 3 transmits is not constant, that is, the envelope connecting the peak values of the modulation signal waveform such as 16QAM or 64QAM is not a constant value. When it is determined that the modulation method is employed, the demodulated reception data is output to the signal quality information acquisition unit 14. Further, the determination unit 12 does not determine every time demodulated reception data is input, but determines when a notification is received from the control unit 15 that the modulation scheme adopted by the wireless terminal 3 has been changed. Then, depending on the determination result, it may simply be output to either the reception level acquisition unit 13 or the signal quality information acquisition unit 14.

  The reception level acquisition unit 13 determines that the amplitude of the modulation signal in the modulation scheme employed when the wireless terminal 3 currently transmits is constant, and the output reception data after demodulation is input. If the received data is received, the information regarding the fluctuation of the received level in the received data is grasped (a grasping means). At this time, the received data is a received signal received in one frame (predetermined signal section). In order to grasp the fluctuation of the reception level in the one frame, the value of the reception level that is most deteriorated in the envelope in the entire reception signal (reception data) received in one frame is stored, and the signal quality information Information about the value of the selected reception level is output to the acquisition unit 14.

  The signal quality information acquisition unit 14 calculates and acquires SINR (Signal to Interference and Noise Ratio) as signal quality information from the information regarding the value of the reception level output from the reception level acquisition unit 13. This SINR is the ratio of interference and noise power to the desired signal, and the higher the value, the better the signal quality. Then, the acquired information on SINR is output to the control unit 15.

  Further, the signal quality information acquisition unit 14 calculates and acquires SINR for each of a plurality of known signals included in the demodulated reception data output when the determination unit 12 determines that the predetermined condition is not met. (Acquisition means). Then, the plurality of acquired SINRs are compared, and the SINR used for calculating the difference is extracted. For example, when there are two SINRs, these two SINRs are extracted. On the other hand, when there are three or more SINRs, for example, in a plurality of specific known signals included in one frame or in a plurality of specific known signals included in a section obtained by further subdividing one frame, (1 ) Compare multiple SINRs and extract the SINR with the best signal quality and the most deteriorated SINR from the comparison result. (2) Compare the multiple SINRs and find the most degraded SINR. The SINR of the known signal in the latest may be extracted. Then, two SINRs are extracted to calculate a difference in signal quality (calculation means), and it is determined whether or not the difference exceeds a predetermined value (second determination means). Here, the predetermined value is a threshold value serving as a determination criterion for estimating whether or not the wireless terminal 3 is moving at a high speed (for example, 100 kmph or more) from the difference in SINR. If the difference in SINR exceeds this predetermined value, it can be estimated that the wireless terminal 3 is moving at high speed. On the other hand, if the difference is below the predetermined value, the wireless terminal 3 is moving but not moving at high speed. Or, it can be estimated that no movement is performed. Then, an SINR for selecting a modulation method is selected. Specifically, when it is estimated from the determination result that the wireless terminal 3 is moving at high speed, an SINR in which the signal quality is deteriorated is selected from the input SINR. On the other hand, when it is estimated from the determination result that the wireless terminal 3 is not moving at high speed, an SINR with good signal quality is selected from the input SINR. Then, information regarding the selected SINR is output to the control unit 15.

  When the difference is equal to or less than a predetermined value, the SINR acquired from the known signal arranged at the last part in the data (frame) from which the signal quality is acquired may be selected. In this case, the signal quality information acquisition unit 14 may output information related to SINR in the last known signal to the control unit 15.

  The signal quality information acquisition unit 14 described above calculates and acquires the reception data of one frame received by the base station 1 from the wireless terminal 3, that is, the SINR in Uplink, as the predetermined signal section, but is not limited thereto. It is not a thing. The base station 1 may acquire each SINR in each known signal calculated by the wireless terminal 3 that has received the data transmitted from the base station 1. In this case, one frame of transmission data transmitted by the base station in Downlink is a predetermined signal interval. At this time, it is only necessary to acquire the SINR in each corresponding known signal from the demodulated reception data output from the demodulator 11.

  The control unit 15 selects a modulation scheme (modulation class) from the information regarding each acquired SINR according to the determination result in the determination unit 12 output from the signal quality information acquisition unit 14, and selects the selected modulation scheme (modulation class). ) (First control means, second control means, third control means, and fourth control means). Then, information indicating the modulation scheme is output to the determination unit 12 and the modulation unit 16. In addition, information regarding the transmission power value is output to the transmission / reception unit 10. At this time, the control unit 15 selects a modulation class for performing adaptive modulation by referring to a table in which the SINR stored in the base station 1 in advance and each threshold value of the modulation class suitable for the SINR are associated with each other. You may do (refer FIG. 3). At this time, the modulation class in Uplink and Downlink is determined from the information regarding SINR output from the signal quality information acquisition unit 14. However, a plurality of SINRs (hereinafter referred to as SINR-BS) acquired by calculation by the base station 1 and a plurality of SINRs (hereinafter referred to as SINR-UT) from the wireless terminal 3 are acquired, and Using both of these two types of SINR, the modulation class in Downlink is selected from the SINR-BS, while the modulation class in Uplink is selected from the SINR-UT selected by the control unit 14 from the plurality of SINRs acquired from the wireless terminal 3. You may choose. In addition, when selecting a modulation class (modulation method) from the SINR information output from the control unit 15, the above-described table is referred to, and the SINR is determined based on a threshold value associated with a specific modulation class (modulation method). If it is large enough to fall within a predetermined value range, a modulation class one level lower than the specific modulation class may be selected instead of the specific modulation class set above the threshold. . Thereby, it is possible to suppress an increase in error rate due to a decrease in error tolerance that occurs due to selection of a modulation class.

  As a result, even if the SINR is temporarily improved, the error tolerance is low and the error rate is high, but a modulation scheme having a high bit rate is not selected. Therefore, it is not necessary to frequently perform processing for changing the modulation method again, and the processing load can be reduced. Furthermore, since the bit rate is low but error tolerance is high, stable wireless communication can be continued even in a situation where the error rate of data to be transmitted / received is low and the propagation environment due to fading changes rapidly.

  The modulation unit 16 modulates transmission data using the modulation scheme selected by the control unit 15 and outputs the modulated transmission data to the transmission / reception unit 10.

  FIG. 4 is a diagram illustrating fluctuations in the reception level of the reception signal in a frame (signal period). As a result of determination by the determination unit 12, when the amplitude value of the envelope that connects the peak of the waveform of the modulation signal, such as BPSK or QPSK, is fixed, the reception level acquisition unit 13 determines The demodulated received data is output from the unit 12. In modulation schemes such as BPSK and QPSK, the envelope that connects the peaks of the waveform of the modulation signal is constant as shown in the figure. The reception level acquisition unit 13 determines the reception level of the entire reception signal for each frame when the modulation method in which the amplitude value of the envelope connecting the peaks of the modulation signal waveform, which is a predetermined condition, is constant is adopted. Understand fluctuations. Then, the value (point P in FIG. 4) at which the reception level value is most deteriorated is selected from the grasped reception level fluctuation and stored, and information related to the reception level value is output to the signal quality acquisition unit 14. To do.

  FIG. 5 is a diagram illustrating a plurality of known signals arranged in a signal section (frame). As a result of the determination in the determination unit 12, when the modulation scheme employed is not constant in the value of the envelope connecting the peak values of the waveform of the modulation signal such as 16QAM or 64QAM, the signal quality information acquisition unit 14 Get the SINR of a known signal. In FIG. 5A, two known signals are arranged at the beginning and the end of the frame. The signal quality information acquisition unit 14 acquires SINR in each corresponding known signal from the demodulated reception data input from the demodulation unit 11. In FIG. 5B, three known signals are arranged at the head, middle, and tail in the frame. Similarly, at this time, the signal quality information acquisition unit 14 corresponds to each of the corresponding signals. SINR in a known signal to be acquired.

  Next, a series of processing flow in the base station 1 will be described with reference to FIG. 6 showing a processing flow in the base station 1.

  The base station 1 is connected to the wireless terminal 3 and performs wireless communication (see FIG. 1). At the start of this wireless communication, the base station 1 performs data transmission / reception after allocating one frame serving as a signal interval to the wireless terminal 3 for transmission and reception. In this allocated frame, two known signals are included (see FIG. 5A). The base station 1 receives data (signals) from the wireless terminal 3 during wireless communication with the wireless terminal 3 (step S20 in FIG. 6). Then, after demodulating the received data, it is determined whether or not the modulation method currently employed is a modulation method in which the amplitude value of the envelope connecting the peaks of the waveform of the modulation signal is a constant value. (Step S21 in FIG. 6). As a result of the determination, when a modulation method such as BPSK or QPSK in which the amplitude value of the envelope connecting the peak of the waveform of the modulation signal is constant is employed (corresponding to step S21 Yes in FIG. 6), the data after demodulation From this, the information regarding the fluctuation of the reception level in the entire frame is grasped (step S22 in FIG. 6), and the SINR is obtained from the worst value of the reception level (step S23 in FIG. 6). Then, a modulation scheme (modulation class) in adaptive modulation is selected based on the selected SINR, transmission power is controlled in accordance with the modulation scheme (step S24 in FIG. 6), and the process ends. On the other hand, if the result of determination in step S21 is that the amplitude value of the envelope connecting the peak of the modulation signal waveform such as 16QAM or 64QAM is not constant in the currently employed modulation system (corresponding to step S21 No in FIG. 6). The SINR is calculated for each of the plurality of known signals (step S25 in FIG. 6), and the SINR used for selecting the modulation scheme (modulation class) is selected (step S26 in FIG. 6). Then, a modulation scheme (modulation class) is selected based on the selected SINR, transmission power is controlled in accordance with the modulation scheme (step S24 in FIG. 6), and the process ends.

  Next, a flow of a series of processing will be described with reference to FIG. 7 showing a processing flow in step S25 of FIG. Next, the SINR1 and SINR2 acquired in step S24 in FIG. 6 are compared (step S250 in FIG. 7), and it is further determined whether or not the difference between the two SINRs exceeds a predetermined value (step in FIG. 7). S251). As a result of the determination, when it is determined that the SINR difference exceeds a predetermined value (corresponding to step S251 Yes in FIG. 7), the SINR having a deteriorated signal quality is selected (S252 in FIG. 5), and the process is performed. finish. On the other hand, if it is determined that the SINR difference is equal to or smaller than the predetermined value (corresponding to step S251 No in FIG. 7), an SINR with good signal quality is selected (step S253 in FIG. 7), and the process ends. To do.

  The present invention is not limited to the above embodiment. For example, although the present invention describes an embodiment in wireless communication in which the base station 1 is used as a wireless communication device and the wireless terminal 3 is used as another wireless communication device, the present invention is not limited to this. In the present invention, at least one of the wireless communication device and the other communication device may be a wireless terminal, and both wireless communication with a wireless terminal, for example, wireless between wireless terminals in multi-hop communication such as an ad hoc network. It is also effective in communication. In this case, the wireless terminal (other wireless communication device) includes the same components as the above-described base station (wireless communication device).

  Furthermore, in the above embodiment, the base station 1 (wireless communication apparatus) selects a modulation method for performing wireless communication. However, for example, the wireless terminal 3 (another wireless communication device) acquires signal quality information from a known signal in a predetermined signal section by using data transmitted from the base station 1, and selects a modulation method used for adaptive modulation. May be. Further, in the above embodiment, SINR is used as signal quality information. However, the signal quality information is not limited to this, but SNR (Signal to Noise Ratio), CNR (Carrier to Noise Ratio), CINR (Carrier to Interference and Noise Ratio), SIR (Signal to Interference power Ratio), CIR (Carrier to Interference power Ratio), or the like may be used.

It is a figure which shows the system configuration | structure of the radio | wireless communications system concerning embodiment of this invention. It is a figure which shows the functional block of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the table used for selection of the modulation system (modulation class) in the radio | wireless communication of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the fluctuation | variation of the reception level in the radio | wireless communication with another radio | wireless communication apparatus in the radio | wireless communication of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the signal area allocated to the radio | wireless communication with another radio | wireless communication apparatus in the radio | wireless communication of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the processing flow of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the processing flow of step S25 in FIG. 6 concerning embodiment of this invention.

Explanation of symbols

1: Base station (wireless communication device)
3: Wireless terminal (other wireless communication devices)
10: Transmission / reception unit 11: Demodulation unit 12: Determination unit 13: Reception level information acquisition unit 14: Signal quality information acquisition unit 15: Control unit 16: Demodulation unit

Claims (10)

A wireless communication device that wirelessly communicates with another wireless communication device using an adaptive modulation scheme,
Determining means for determining whether or not the amplitude of the modulation signal is a constant modulation method;
A first control unit that controls transmission power using signal quality information based on a received signal after the determination unit determines that the amplitude of the modulation signal is a constant modulation method;
Signal quality information in which the signal quality is relatively deteriorated among the signal quality information for each of a plurality of known signals included in the received signal after the determination means determines that the amplitude of the modulation signal is not a constant modulation method Second control means for controlling the transmission power based on :
A wireless communication apparatus comprising: The wireless communication device according to claim 1,
After the determination unit determines that the amplitude of the modulation method is a constant modulation method,
Grasping means for grasping information related to fluctuations in the reception level of the received signal in the first signal section;
Further comprising
The first control unit controls transmission power based on signal quality information corresponding to a value in which the value indicating the reception level is relatively deteriorated in the information grasped by the grasping unit.
A wireless communication apparatus. The wireless communication device according to claim 2,
The relatively deteriorated value is a value at which the value indicating the reception level is most deteriorated.
A wireless communication apparatus. The wireless communication apparatus according to any one of claims 1 to 3,
After the determination means determines that the amplitude of the modulation signal is not a constant modulation method,
Acquisition means for acquiring signal quality information for each of a plurality of known signals included in the second signal section;
Further comprising
The second control unit controls transmission power based on signal quality information in which signal quality is relatively deteriorated among the plurality of signal quality information acquired by the acquiring unit.
A wireless communication apparatus. The wireless communication apparatus according to claim 4, wherein
Calculating means for calculating a difference between the plurality of signal quality information acquired by the acquiring means;
Second determination means for determining whether or not the difference calculated by the calculation means exceeds a predetermined value;
Further comprising
As a result of the determination by the second determination means, when the difference exceeds the predetermined value, the second control means is executed.
A wireless communication apparatus. The wireless communication device according to claim 5, wherein
As a result of the determination in the second determination, if the difference is less than or equal to the predetermined value,
Third control means for controlling transmission power based on signal quality information having relatively good signal quality in the plurality of signal quality information;
A wireless communication apparatus, further comprising: The wireless communication device according to claim 5, wherein
As a result of the determination in the second determination, if the difference is less than or equal to the predetermined value,
Fourth control means for controlling transmission power based on signal quality information of a known signal arranged at the last part in the second signal section for acquiring the plurality of signal quality information;
A wireless communication apparatus, further comprising: The wireless communication device according to any one of claims 4 to 7,
The signal quality information in which the signal quality is relatively degraded,
The signal quality information in which the signal quality is most degraded in the plurality of signal quality information.
A wireless communication apparatus. The wireless communication apparatus according to claim 6, wherein
The signal quality information with relatively good signal quality is:
Among the plurality of signal quality information, the signal quality is the best signal quality information.
A wireless communication apparatus. A wireless communication method of a wireless communication device that wirelessly communicates with another wireless communication device using an adaptive modulation method,
A determination step of determining whether the amplitude of the modulation signal is constant;
A first control step of controlling transmission power using signal quality information based on the received signal after it is determined in the determining step that the modulation signal has a constant modulation method;
Signal quality information in which the signal quality is relatively degraded among the signal quality information for each of a plurality of known signals included in the received signal after it is determined in the determination step that the amplitude of the modulation signal is not a constant modulation method A second control step for controlling transmission power based on :
A wireless communication method comprising:

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