JP4738437B2 - Wireless device - Google Patents

Description

  The present invention relates to a radio apparatus capable of controlling a variable communication speed. In particular, the present invention relates to a wireless device that controls so that the communication speed varies according to environmental variations.

  In recent years, a cdma2000 1x-EV DO (hereinafter referred to as “EV-DO”) system has been developed as a next-generation high-speed wireless communication system. The EV-DO method is a method in which the cdma2000 1x method, which is an extension of the cdmaOne method and is adapted to the third generation method, is further specialized in data communication to increase the transmission rate. Here, “EV” means Evolution, and “DO” means Data Only.

  In the EV-DO system, the configuration of the uplink radio interface from the radio communication terminal to the base station is almost the same as that of the cdma2000 1X system. As for the downlink radio interface configuration from the base station to the radio communication terminal, the bandwidth defined in 1.23 MHz is the same as that of the cdma2000 1x method, but the modulation method, the multiplexing method, etc. are greatly different from those of the cdma2000 1x method. . As for the modulation scheme, QPSK, 8-PSK, and 16QAM in the EV-DO scheme are switched according to the downlink reception state in the radio communication terminal, in contrast to QPSK and HPSK used in the cdma2000 1x scheme. As a result, when the reception state is good, a high transmission rate with low error resistance is used, and when the reception state is bad, a transmission rate with low error but high error resistance is used.

  In addition, a multiplexing method for simultaneously performing communication from one base station to a plurality of wireless communication terminals is not code division multiple access (CDMA) used in the cdmaOne method or the cdma2000 1x method. The time is divided in units of 1/600 seconds, and communication is performed with only one wireless communication terminal within that time. Further, the wireless communication terminals to be communicated are switched every unit time to communicate with a plurality of wireless communication terminals. Use time division multiple access (TDMA) to perform.

  The wireless communication terminal measures the carrier-to-interference wave ratio (hereinafter referred to as “CIR: Carrier to Interference power Ratio”) of the pilot signal as the reception state of the downlink from the base station to be communicated, The reception state at the reception timing is predicted, and the expected “maximum transmission rate that can be received at a predetermined error rate or less” is notified to the base station as a data rate control bit (hereinafter referred to as “DRC: Data Rate Control bit”). To do. Here, the predetermined error rate depends on the system design, but is usually about 1%. The base station receives DRCs from a plurality of radio communication terminals, and the scheduler function in the base station determines which radio communication terminal to communicate with in each time division unit. Therefore, the highest possible transmission rate is used based on the DRC from the wireless communication terminal.

The EV-DO system enables a maximum transmission rate of 2.4 Mbps (Mega-bit per second) per sector in the downlink with the above configuration. However, this transmission rate is the total amount of data communication with a plurality of wireless communication terminals to which one base station is connected in one frequency band and one of a plurality of sectors, which is usually a plurality of frequencies. If the band is used, the transmission rate also increases.
JP 2002-300634 A

  As described above, the transmission rate in the EV-DO downlink depends on the reception state of the wireless communication terminal, and is 2.4 Mbps when the reception state is the best in the stationary state. In this case, the average is reduced to about 500 to 700 kbps, and to a few tens of kbps when the reception state in a stationary state is not good. For this reason, in a low-speed moving state where the user using the wireless communication terminal is walking or in a substantially stationary state, a significant decrease in transmission rate may occur depending on the location. In order to avoid this state by the user's operation, a conventional mobile phone uses a so-called antenna mark display, a warning sound, or the like that notifies the user of the reception state. For example, in a cdmaOne mobile phone, a reception state based on Ec / Io (total input power versus energy per chip) is notified.

  However, the transmission rate in the EV-DO downlink is influenced not only by the instantaneous value of the CIR but also by correction by statistical data such as prediction and error rate of data transmission in the past downlink. An error may be included only in the original reception state. Furthermore, since the fluctuation of the transmission rate due to the fluctuation of the reception state is larger than that of the PDC mobile phone and the cdmaOne mobile phone, the reception state measurement requires higher accuracy.

  On the other hand, the transmission power of the wireless communication terminal in the uplink is controlled by the base station in the same way as the cdma2000 1x system, but the maximum transmission power is limited to, for example, about +23 dBm (200 mW) to +24 dBm (about 250 mW) due to legal regulations and the like. Is done. The base station instructs each wireless communication terminal to increase or decrease the transmission power as needed so that the received power from each wireless communication terminal becomes a substantially constant value or satisfies the required quality. In accordance with the instruction, each wireless communication terminal adjusts transmission power within a range equal to or less than the maximum transmission power. When the wireless communication terminal is located at a long distance from the base station, the base station instructs the wireless communication terminal to increase the transmission power when it becomes difficult for the uplink signal to reach the base station. However, when the transmission power of the wireless communication terminal reaches the maximum transmission power, the wireless communication terminal cannot increase the transmission power any more, so that the uplink DRC does not reach the base station, and as a result, downlink data transmission can be performed. Disappear.

  In addition, since the demodulator in the wireless communication terminal has an AGC (Automatic Gain Control), the transmission rate depends only on the CIR within the AGC operating range and is generally not affected by the received signal power. On the other hand, when the received signal power falls below the AGC operating range, the CIR deteriorates rapidly and the downlink signal cannot be received.

  The present inventor has recognized the above situation and made the present invention, and an object of the present invention is to provide a wireless device that notifies an index related to communication quality. Another object of the present invention is to provide a wireless device that outputs an index related to communication quality. Also provided is a radio apparatus for deriving an index relating to communication quality suitable for a communication system in which the data communication speed varies greatly depending on the signal reception state and communication may be disconnected due to other factors. There is.

  One embodiment of the present invention is a wireless device. This apparatus includes a receiving means for receiving a signal transmitted from a base station apparatus, a measuring means for measuring a signal-to-interference wave ratio of the received signal, and a detecting means for detecting a predetermined power value from the received signal. And a calculating means for calculating a correction value based on a preset reference value and the detected power value, and a correcting means for correcting the measured signal-to-interference wave ratio with the calculated correction value.

  The signal transmitted from the base station apparatus includes instruction information regarding transmission power when transmitting a predetermined signal to the base station apparatus, and the detection means transmits the transmission signal included in the received signal as the predetermined power value. The calculation means detects the transmission power value of the signal to be transmitted from the instruction information regarding the power, and sets the maximum transmittable power value as the reference value, and based on the maximum transmittable power value and the transmission power value of the signal to be transmitted The correction value may be calculated. The detecting means detects the received power value of the received signal as the predetermined power value, and the calculating means sets the minimum receivable power value as the reference value, and receives the minimum receivable power value and the received signal. A correction value may be calculated based on the power value. The calculation means may set the correction value to zero when the detected power value is not in a predetermined range.

  “Instruction information related to transmission power” includes direct information for instructing the transmission power value and indirect information for instructing increase / decrease from the current transmission power value so that the transmission power value can be finally determined. If it is good.

  The communication speed of the signal transmitted from the base station apparatus is variable, and the wireless apparatus further derives a predicted value of the communication speed of the signal transmitted in the future by the base station apparatus from the corrected signal-to-interference wave ratio. And a notification means for notifying a user of a predicted value of a communication speed of a signal to be transmitted in the future. Further, the communication speed of the signal transmitted from the base station apparatus is variable, and the wireless apparatus further predicts the communication speed of the signal transmitted in the future by the base station apparatus from the corrected signal-to-interference wave ratio. And an output unit that outputs a predicted value of a communication speed of a signal transmitted in the future.

With the above device, in order to derive the communication speed prediction value after correcting the actually measured signal-to-interference ratio with the correction value based on the transmission power value and the reception power value, the communication speed prediction value The accuracy can be increased.
It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to notify an index related to communication quality.

(Embodiment 1)
The first embodiment relates to a technique for displaying a communication quality indicator for notifying a user of a communication status for a terminal device in the cdma2000 1x-EV DO system described above. In the present embodiment, as a communication quality index, a downlink CIR corresponding to DRC is corrected with a correction value, and then an index indicating a communication speed is derived from the corrected CIR. The correction value is derived based on the difference between the maximum transmittable power value that can be transmitted by the terminal device and the transmission power value that the terminal device is currently transmitting. This difference is that if the transmission power value of the terminal device has reached the maximum transmittable power value, the base station device cannot increase the transmission power even if the base station device is instructed to increase the transmission power. As a result, it is reflected that the uplink is more likely to be disconnected as a result of not being able to obtain the received power. From this, it is possible to communicate at a high communication speed based on the current CIR. However, since there is a high possibility of disconnection of the uplink, the communication speed considering the future decrease in the communication speed is set. Notify the indicator. As a result, the user can more reliably recognize the communication status.

  FIG. 1 shows a communication system 100 according to the first embodiment. The communication system 100 includes a network 10, a base station device 12, a base station antenna 14, a terminal antenna 16, a terminal device 18, and a PC 20.

  The terminal device 18 is connected to the PC 20 or used by the user alone. In addition, a terminal antenna 16 is provided.

  The base station device 12 is connected to the network 10 and also connects to the terminal device 18. In FIG. 1, one terminal device 18 connected to the base station device 12 is used, but a plurality of terminal devices 18 may be used. In addition, a base station antenna 14 is provided.

  A signal is transmitted from the base station apparatus 12 to the terminal apparatus 18 via the downlink 60, and a signal is transmitted from the terminal apparatus 18 to the base station apparatus 12 via the uplink 62. The downlink 60 includes control signals and data signals including pilot signals and transmission power instruction signals, and the uplink 62 includes DRC, data signals, and the like.

  FIG. 2 shows the configuration of the terminal device 18. The terminal device 18 includes an RF unit 22, a baseband processing unit 24, a CPU 26, a memory 28, a display unit 30, an operation unit 32, and an external IF unit 34. The RF unit 22 includes a duplexer 40, a demodulator 42, and a modulator. 44, the baseband processing unit 24 includes a decoder 46, a predictor 48, a CIR-DRC conversion table 50, an encoder 52, and a MUX 54.

  The demodulator 42 demodulates the signal received via the terminal antenna 16 and the duplexer 40. Here, it is assumed that the received signal is modulated by any one of QPSK, 8PSK, and 16QAM. Also, the received power value 206 is calculated from the received signal and output to the CPU 26.

  The decoder 46 performs spectrum despreading processing on the demodulated signal. Here, when there is received data 200 assigned to the terminal device 18, the received data 200 is output to the CPU 26. A transmission power instruction signal for indicating the transmission power instructed by the base station apparatus 12 is extracted from the control signal, and the power control information 202 is derived based on the extracted signal and output to the CPU 26. Further, a pilot signal is extracted from the control signal, a CIR value 204 is calculated based on the pilot signal, and output to the CPU 26 and the predictor 48.

  The predictor 48 derives the next CIR value 208 at the next reception slot timing from the CIR value 204. There is no clear prediction method in the standard, but examples include a linear prediction method.

  The next CIR value 208 is converted into the DRC 210 by the CIR-DRC conversion table 50. FIG. 3 shows an example of a CIR-DRC conversion table, which is from Qualcomm's document, IEEE Communications Magazine, July 2000, "CDMA / HDR: A Bandwidth-Efficient High-Speed WiresUssorUrUsSerfUrSrUsUrSrUsUrUsUrU". Is. DRC may be a value corresponding to the communication speed as shown in FIG.

  The CPU 26 internally processes the received data 200 or transmits the received data 200 to the PC 20 connected to the outside via the external IF unit 34. A communication quality index for notifying the user based on the DRC 210 and other data is derived and displayed on the display unit 30 in the form of an antenna mark or the like. Further, this index may be sent to the external PC 20 by the external IF unit 34, and an application such as moving image transmission or VoIP in the PC 20 may perform QoS control based on the index. For example, if the communication speed decreases, the requested communication speed requested by DRC is decreased, and if the reliability of the communication speed decreases, the communication data buffer is enlarged and the data signal is prefetched. Further, the power control information 202 is processed, the current transmission power value is corrected, and a new transmission power value 212 is determined. A data signal generated by the CPU 26 or input from the PC 20 via the external IF unit 34 is output as transmission data 214.

  The MUX 54 multiplexes the transmission data 214 and the DRC 210.

  The encoder 52 performs spread spectrum processing on the multiplexed signal.

  The modulator 44 modulates the spread spectrum signal, and the signal is transmitted to the base station apparatus 12 via the duplexer 40 and the terminal antenna 16.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of an arbitrary computer, and in terms of software, it is realized by a program having a reservation management function loaded in memory. A configuration including the CPU 26, the baseband processing unit 24, the RF unit 22, and the like is illustrated. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  FIG. 4 shows a processing flow for deriving a communication speed index as a communication quality index. Signals are input to the demodulator 42 and the decoder 46 in FIG. 2 (S10). The decoder 46 derives the CIR value 204, and the predictor 48 further derives the next CIR value 208 (S12). That is, the predictor 48 predicts the CIR at the next reception timing from the CIR value 204 and calculates the next CIR value 208. The CIR-DRC conversion table 50 converts the next CIR value 208 into the DRC 210. The decoder 46 detects the power control information 202 (S14). Further, the CPU 26 corrects the current transmission power value with the transmission power control information 202 to derive the transmission power value. The CPU 26 calculates a correction value from a difference (unit dB) between the transmission power value (unit dBm) and the maximum transmittable power value (unit dBm) and a conversion value based on the difference (S16). Specifically, if the difference between the transmission power value and the maximum transmittable power value is 10 dB or more, the correction value is set to 0. On the other hand, when the difference is 10 dB or less, the correction value is calculated as follows.

[Expression 1] Correction value = (− 2) × (10− (transmission power value−maximum transmittable power value))
Here, the unit of the correction value is dB. The correction value may be derived from the transmission power value using a table shown in FIG. 5 instead of calculation. After calculating the correction value, the CPU 26 corrects the next CIR value 208 with the correction value (S18). This is performed as follows.

[Expression 2] Correction CIR value = Next CIR value + Correction value Here, the unit of the correction CIR value is dB. The CPU 26 derives a communication speed index from the corrected CIR value (S20). This derivation is executed using the CIR-DRC conversion table 50 shown in FIG. 5 when the unit of the communication speed index is the communication speed.

  The CPU 26 displays the communication speed index on the display unit 30 or outputs it from the external IF unit 34 (S22). FIGS. 6A to 6B show display contents of the display unit 30. FIG. The antenna bar 300 and the speed indicator 302 indicate the communication speed index. FIG. 6A shows the case where the speed indicator 302 is displayed as a number, and FIG. 6B shows the case where the speed indicator 302 is displayed as a graph. Moreover, you may notify a user with the LED lighting pattern shown in FIG. Here, the difference between the flashing 1 and the flashing 2 is that the flashing 2 has a higher ratio of lighting.

According to this embodiment, since the communication speed index is derived based on the value obtained by correcting the measured downlink CIR, the accuracy of the communication speed index can be further increased. Further, since the “difference between the transmission power value and the maximum transmittable power value” is used as the correction value, the reception power at the terminal device is good, and even in an environment where high CIR / high DRC and high communication speed can be expected, transmission power If the value is close to the maximum transmittable power value in the future, the transmission power value will reach the maximum transmittable power value in the future. It can be reflected in the communication speed index.
(Embodiment 2)
The second embodiment relates to a technique for displaying an index indicating a communication speed based on CIR corrected as a communication quality index for a terminal device in the EV-DO system, as in the first embodiment. In the first embodiment, the correction value is derived based on the transmission power value. However, in the second embodiment, the minimum receivable power value that can be received by the terminal device and the received power value that is currently received by the terminal device. Derived based on the difference. The difference is that the communication speed depends on the CIR in the AGC operating range of the terminal device and is not affected by the received power value. However, when the received power value falls below the AGC operating range, the CIR rapidly deteriorates and the downlink This reflects the fact that the line is likely to be disconnected. As a result, it is possible to communicate at a high communication speed based on the current CIR. However, since the possibility of disconnection of the downlink is high, the communication speed considering the future decrease in the communication speed is required. Notify the indicator.

  As the terminal device 18 in the second embodiment, the one shown in FIG. 2 is effective. Further, the processing flow for deriving the communication speed index in the second embodiment is effective as shown in FIG. Here, the processes of step 14 and step 16 are different. Corresponding to step 14, demodulator 42 detects received power value 206. Corresponding to step 16, a correction value is calculated from the difference (unit dB) between the received power value 206 (unit dBm) and the minimum receivable power value (unit dBm) and a converted value based on the difference. Specifically, the minimum receivable power value is −104 dBm, and the correction value is 0 if the difference between the received power value 206 and the minimum receivable power value is 10 dB or more. On the other hand, when the difference is 10 dB or less, the correction value is calculated as follows.

[Expression 3] Correction value = 10− (Received power value−Minimum receivable power value)
The correction value may be derived from the received power value 206 using a table shown in FIG. 8 instead of calculation.

According to the present embodiment, since the “difference between the received power value and the minimum receivable power value” is used as the correction value, the downlink CIR is high, but it is close to the lower limit of the strength at which the downlink signal can be received. In this case, the communication interruption due to the inability to receive the downlink signal from the base station apparatus can be reflected in the communication speed index in advance. Furthermore, since the transmission power value is not used, the present invention can be applied to the case where a signal from the base station apparatus is received but not transmitted.
(Embodiment 3)
In the embodiments described so far, the communication quality index is displayed for the user to recognize the communication status. In the present embodiment, the terminal device outputs the communication quality indicator to an application used in a predetermined network, and the application refers to the communication quality indicator and sets the communication speed and the like. That is, when an application such as streaming video is used on a wireless communication network such as the EV-DO system, the communication speed that can be transmitted and received on the wireless communication network depends on various factors such as changes in the radio wave environment and the generation of traffic by other users. Therefore, it is difficult to secure a communication speed that can be used for streaming by an application.

  When an application transmits video on the premise of a high communication speed, if the communication speed can be secured, high-quality image quality can be obtained, but if the communication speed falls below the assumed value due to fluctuations, Degradation of quality such as missing information or stop of video occurs. On the other hand, when video is transmitted on the premise of low communication speed in preparation for fluctuations in communication speed, only low-quality moving images can be obtained regardless of the actual communication speed. The communication quality index derived by the terminal device is used for setting the communication speed.

  FIG. 9 shows the configuration of the application system according to the present embodiment. FIG. 9 includes a server 56 in addition to the configuration of the communication system 100 in FIG. Here, an application client is operated on the PC 20. The terminal device 18 determines DRC and quality information that is a communication quality index based on the received pilot signal, received power, and transmission power from the base station device 12, transmits the DRC to the base station, and notifies the PC 20 of the quality information. To do. The PC 20 estimates the communication speed that can be used on the traffic channel of the EV-DO system on the basis of the quality information, and various information such as the free capacity of the reception buffer and the error rate of the reception data signal. Is transmitted to the server 56 via the terminal device 18, the base station device 12, and the network 10, and based on this, the server 56 increases or decreases the communication speed of the moving image data to be transmitted.

According to the present embodiment, the communication quality index can be used as a criterion for QoS (Quality of Service) control by notifying the communication quality index to an application in a PC or a network.
(Embodiment 4)
In this embodiment, a combination of an EV-DO method and a cdma2000 1x method combined terminal or a plurality of wireless methods, and a method of selecting and communicating with an optimum communication method according to the environment (hereinafter referred to as “seamless communication”), A communication speed index that is a communication quality index is used as a parameter for determining the communication quality of the EV-DO system.

  FIG. 10 shows an example of a selection operation of a plurality of systems according to the present embodiment. As a plurality of systems, an EV-DO system, a simple mobile phone, and a W-LAN (Wireless-LAN) are used. Here, time is shown on the horizontal axis, and throughput in each system is shown on the vertical axis. For W-LAN, only usable or unusable is shown. Specifically, if the EV-DO communication speed index is about 90 kbps, the reception field strength is expected to be about 128 kbps for a simple mobile phone, and if the W-LAN is out of service area, the simple mobile phone is selected and the environment changes. If the EV-DO communication speed index is about 200 kbps, control such as switching to the EV-DO method is performed.

  FIG. 11 shows a flowchart of the selection operation of a plurality of systems. Here, priorities are set in the order of W-LAN, EV-DO, and simple mobile phone, and the system is selected. The quality information is acquired for the EV-DO system, the RSSI value is acquired for the W-LAN, and the throughput is acquired for the simple mobile phone (S100). When the RSSI value of the W-LAN is larger than −90 dBm (Y in S102), the W-LAN is selected (S114). On the other hand, when the RSSI value of the W-LAN is −90 dBm or less (N in S102) and the quality information of the EV-DO method is larger than the threshold (Y in S104), the EV-DO method is selected (S116). ). On the other hand, if the EV-DO quality information is below the threshold (N in S104) and the throughput of the simple mobile phone is greater than 64 kbps (Y in S106), the simple mobile phone is selected (S118). .

  On the other hand, when the throughput of the simple mobile phone is 64 kbps or less (N in S106) and the W-LAN can be used (Y in S108), the W-LAN is selected (S114). On the other hand, when the W-LAN cannot be used (N in S108) and the EV-DO method can be used (Y in S110), the EV-DO method is selected (S116). On the other hand, when the EV-DO system is not usable (N in S110) and when the simple mobile phone is usable (Y in S112), the simple mobile phone is selected (S118). On the other hand, when the simplified mobile phone cannot be used (N in S112), connection is disabled (S120). The above processing is continued for a period of receiving data (Y in S122), but ends when no data is received (N in S122).

  According to the present embodiment, a more accurate selection criterion can be provided by using a communication quality index for the EV-DO scheme as a system selection criterion in seamless communication.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In the first embodiment, the CPU 26 calculates the correction value for the communication speed index from the transmission power value, and in the second embodiment, the CPU 26 calculates the correction value from the reception power value 206. However, the calculation of the correction value is not limited to these. For example, the correction based on the transmission power value 212 and the correction based on the reception power value 206 may be performed simultaneously. According to this modification, the relationship between the transmission power value 212 and the reception power value 206 does not correspond one-to-one because of the transmission power control of the uplink 62, and as a result, the downlink 60 can receive the minimum power value. It is possible to cope with the case where the communication quality deterioration due to approaching and the communication quality deterioration due to the uplink 62 approaching the maximum transmittable power value do not occur simultaneously.

  In Embodiment 1, the display unit 30 displays the antenna bar 300 and the speed indicator 302 as communication speed indicators. However, the display on the display unit 30 is not limited to this, and the speed indicator 302 may not be displayed, only the antenna bar 300 may be displayed, and the received power value may be displayed on the antenna bar 300. Further, the user may be notified in the form of vibration. With this modification, the display content of the display unit 30 becomes clearer to the user.

1 is a configuration diagram showing a communication system according to Embodiment 1. FIG. It is a figure which shows the structure of the terminal device of FIG. It is a figure which shows the CIR-DRC conversion table of FIG. It is a processing flow which shows derivation | leading-out of the communication speed parameter | index of FIG. It is a figure which shows the correspondence table of the transmission power value of FIG. 2, and a correction value. FIGS. 6A to 6B are diagrams showing display contents of the display unit of FIG. It is a figure which shows the LED lighting pattern of the display part of FIG. FIG. 10 is a diagram showing a correspondence table between received power values and correction values according to the second embodiment. FIG. 10 is a diagram illustrating a configuration of an application system according to a third embodiment. FIG. 10 is a diagram illustrating a selection operation of a plurality of systems according to a fourth embodiment. It is a flowchart which shows selection operation | movement of the several system of FIG.

Explanation of symbols

  10 network, 12 base station device, 14 base station antenna, 16 terminal antenna, 18 terminal device, 20 PC, 22 RF unit, 24 baseband processing unit, 26 CPU, 28 memory, 30 display unit, 32 operation unit, 34 external IF unit, 40 duplexer, 42 demodulator, 44 modulator, 46 decoder, 48 predictor, 50 CIR-DRC conversion table, 52 encoder, 54 MUX, 56 server, 60 downlink, 62 uplink , 100 communication system, 200 reception data, 202 power control information, 204 CIR value, 206 reception power value, 208 next CIR value, 210 DRC, 212 transmission power value, 214 transmission data, 300 antenna bar, 302 speed indicator.

Claims (5)

Receiving means for receiving a signal transmitted from the base station device;
Measuring means for measuring a signal-to-interference ratio of the received signal;
Detecting means for detecting a predetermined power value from the received signal;
Based on the preset reference value and the detected power value, and correcting means calculates a correction value, corrects the measured signal-to-interference ratio correction value the calculated,
A wireless device comprising: The detection means detects a received power value of the received signal as the predetermined power value,
The correction means sets a minimum receivable power value as the reference value, and calculates the correction value based on the minimum receivable power value and the received power value of the received signal. The wireless device according to 1. 3. The radio apparatus according to claim 1, wherein the correction unit sets the correction value to zero when the detected power value is not a value in a predetermined range. 4. The communication speed of the signal transmitted from the base station device is variable,
The wireless apparatus further includes an estimation unit for deriving a predicted value of a communication speed of a signal transmitted in the future by the base station apparatus from the corrected signal-to-interference wave ratio,
A notification means for notifying a user of a predicted value of a communication speed of a signal transmitted in the future;
Wireless device according to any one of claims 1 to 3, characterized in that it comprises a. The communication speed of the signal transmitted from the base station device is variable,
The wireless apparatus further includes an estimation unit for deriving a predicted value of a communication speed of a signal transmitted in the future by the base station apparatus from the corrected signal-to-interference wave ratio,
Output means for outputting a predicted value of the communication speed of the signal transmitted in the future;
Wireless device according to any one of claims 1 to 3, characterized in that it comprises a.