JP4615353B2 - Base station equipment - Google Patents

Description

  The present invention relates to a base station apparatus used in a mobile communication system, and more particularly to a base station apparatus that performs adaptive modulation based on a CQI (Channel Quality Indication) value.

  In recent years, mobile terminals (mobile stations) such as mobile phones have been developed to support multimedia for handling a large amount of still images, short-time moving images, and the like, and accordingly, a large-capacity and high-speed data transmission method has been developed. It is necessary. As this large-capacity and high-speed data transmission method, there is an HSDPA (High Speed Downlink Packet Access) method, and HS-PDSCH (High Speed) in which only the transmission speed in the downlink direction (direction from the base station to the mobile station) is increased. -Physical Downlink Shared Channel (high-speed downlink shared channel) etc. are being studied.

  In the HSDPA standard, there is adaptive modulation as one of techniques for realizing high speed. With adaptive modulation, the transmission path condition is estimated from the instantaneous SIR (Signal and Interference Ratio) value of the transmission path. If the transmission path condition is poor, the transmission rate is lowered and the error rate is lowered. This is a transmission method. As an example, a parameter CQI table (CQI mapping table) of transmission packet size (Transport Block Size), modulation method (16QAM (Quadrature Amplitude Modulation), QPSK (Quadrature Phase Shift Keying)), and code multiplex number (Nofcode) Is standardized by the 3GPP standard. Specifically, it is defined in Tables 7A, 7B, 7C, 7D, and 7E in Non-Patent Document 1 below. In this table, the larger the CQI value, the better the transmission path state.

  In a conventional mobile communication system, a mobile station measures an instantaneous SIR and reports a CQI value determined based on the measured SIR to the base station. Then, the base station determines the MCS based on the CQI value and the above table.

3GPP Specification TS25.214

  However, in the adaptive modulation applied in the conventional HSDPA standard, the processing delay time required for the mobile station to measure the SIR and convert it to the CQI value is actually reported to the base station. There is a delay due to the propagation delay time required when the base station determines the MCS based on the CQI value, and the processing delay time required until the base station transmits data. Therefore, for example, in a communication environment such as a mobile communication system in which the transmission path state fluctuates, there is a problem in that processing cannot follow the movement and transmission may not be performed with an appropriate MCS.

  The present invention has been made in view of the above, and it is an object of the present invention to determine an appropriate MCS according to a change in transmission path state, and thereby to obtain a base station apparatus that realizes higher-speed throughput. .

  In order to solve the above-described problems and achieve the object, a base station apparatus according to the present invention is a base station apparatus that determines an MCS to be used in adaptive modulation based on a CQI value included in a received signal, Correction means for correcting the CQI value according to a change in the transmission path state with the passage of time from the time when the mobile station measures the transmission path state to the time of actually transmitting the data after adaptive modulation; MCS determination means for determining MCS based on the CQI value.

  According to the present invention, the CQI value history holding unit is provided, and the current and / or future transmission path conditions are predicted based on the CQI value history and the latest CQI value held in the history holding unit. The value was corrected and the MCS was determined with the corrected CQI value. As a result, the problem due to the delay is solved, the data transmission efficiency is improved, and a base station apparatus that realizes a higher throughput can be obtained.

  Hereinafter, an embodiment of a base station apparatus (hereinafter referred to as a base station) according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of Embodiment 1 of a base station according to the present invention. The base station in the first embodiment includes a receiving antenna 1, a radio receiving unit 2, a demodulating unit 3, a reading unit 4, a correcting unit 5, an MCS determining unit 8, an adaptive modulating unit 9, and a radio transmitting unit that are features of the present invention. 10 and a transmission antenna 11. The correction unit 5 includes a CQI correction unit 6 and a CQI history holding unit 7.

  The radio reception unit 2 receives a radio signal including a CQI value transmitted from the mobile station via the reception antenna 1. The CQI value is a downlink quality index estimated on the mobile station side. This CQI value is a value determined by the mobile station measuring the SIR of the downlink signal from the base station and determined based on the measurement result, and is sent to the base station in a state where it is mapped to transmission data.

  The demodulator 3 demodulates the radio transmission signal that has been subjected to predetermined radio reception processing in the radio receiver 2. Then, the reading unit 4 reads the CQI value from the signal demodulated by the demodulation unit 3. Here, the read CQI value is a value at the time when the SIR of the downlink is measured on the mobile station side. However, there is a delay due to the processing time until the mobile station measures the downlink SIR and determines the CQI value. Further, after the base station selects the mobile station by the base station scheduler and determines the MCS, a delay due to the processing time also occurs in the process of actually transmitting the downlink data. That is, there is a possibility that the MCS determined by the base station is no longer appropriate for the mobile station. Therefore, in the present embodiment, an appropriate value is determined according to the fluctuation of the transmission path state over time from the time when the mobile station measures the transmission path state (SIR) to the time of actually transmitting the data after adaptive modulation. In order to determine the MCS and perform data transmission, the base station performs a correction process for the CQI value using the correction unit 5.

  In the correction unit 5, the CQI correction unit 6 predicts the current CQI value based on the history of CQI values held in the CQI history holding unit 7. Thereby, the correction of the CQI value is realized.

  After correcting the CQI value, the MCS determination unit 8 determines the MCS based on the CQI value corrected by the correction unit 5, and the adaptive modulation unit 9 performs adaptive modulation of data according to the MCS. Then, the data after the adaptive modulation is performed is transmitted from the transmission antenna 11 via the wireless transmission unit 10.

Here, an example of the operation of the CQI correction unit 6 will be specifically described. The CQI correction unit 6 predicts the CQI value by regression analysis, for example. For example, when the CQI value at the time t _i is CQI _i , (I = 0, n), the function CQI (t) at the time t in the CQI value can be expressed as the following equation (1).

…（１）

... (1)

  Although the regression analysis is a linear regression, even if other multiple regression algorithms are used, the gist of the present invention is not hindered.

  As described above, in the present embodiment, a history holding unit for holding a history of CQI values is provided, and a current and / or future transmission path state is predicted based on the history of CQI values. And the MCS is determined based on the corrected CQI value. As a result, the problem due to the delay is solved, the data transmission efficiency is improved, and a higher throughput can be realized.

Embodiment 2. FIG.
FIG. 2 is a diagram illustrating a configuration example of Embodiment 2 of a base station according to the present invention. The base station according to the second embodiment includes a read unit 4a and a correction unit 5a that characterize the present invention, instead of the read unit 4 and the correction unit 5 of the first embodiment described above. The correction unit 5a includes a CQI correction unit 6a and a TPC information holding unit 12. Hereinafter, in the present embodiment, a reading unit 4a and a correction unit 5a that are different from those of the first embodiment will be described.

  The reading unit 4a according to the present embodiment reads the CQI value and TPC information from the signal demodulated by the demodulating unit 3, and holds the read TPC information in the TPC information holding unit 12. In the correction unit 5a, the CQI correction unit 6a corrects the CQI value based on the TPC information held in the TPC information holding unit 12.

  The TPC is a bit value stored in the “Transmit Power Control field” in the uplink dedicated channel (Uplink DPCCH) standardized in TS25.214 in 3GPP. Here, the TPC bit will be briefly described. In the CDMA system, due to the nature of the system, transmission radio waves to other mobile stations belonging to the same base station interfere with the mobile station. For example, when the mobile station moves away from the base station, the received power decreases due to distance attenuation. Therefore, when the mobile station receives radio waves from the base station, the transmission power on the base station side must be reduced so that the received radio waves are not buried in the interference caused by the radio waves transmitted from the base station to other mobile stations. It needs to be bigger. In order to realize this, the mobile station monitors the received power. For example, when the received power decreases, the mobile station requests the base station to increase the transmission power. On the other hand, when the mobile station approaches the base station, the mobile station requests the base station to reduce the transmission power. These requests are made using the TPC bit stored in the TPC field.

  In the CQI correction unit 6a of the present embodiment using the TPC, for example, when the TPC is a value requesting an increase in base station transmission power, the mobile station is moving away from the base station, etc. Thus, it is determined that the SIR tends to decrease, and a certain value is subtracted from the CQI value read by the reading unit 4a. On the other hand, if the TPC is a value that requires a decrease in the base station transmission power, it is determined that the SIR tends to increase as in the situation where the mobile station is approaching the base station, etc. A constant value is added to the CQI value read in 4a.

  The CQI correction unit 6a can further improve the accuracy of correction by accumulating the TPCs after the most recent CQI value and correcting the CQI value based on the addition result. Similarly to the first embodiment described above, the regression analysis is performed on the TPC history and the latest TPC, and the correction accuracy is further improved by correcting the CQI value based on the regression analysis result. it can.

  Thus, in this embodiment, a TPC information holding unit is provided, and the current and / or future transmission path conditions are predicted based on the TPC information held in the TPC information holding unit, thereby correcting the CQI value. The MCS is determined based on the corrected CQI value. As a result, the above-described problem due to delay is solved, data transmission efficiency is improved, and higher throughput can be realized.

Embodiment 3 FIG.
FIG. 3 is a diagram illustrating a configuration example of the third embodiment of the base station according to the present invention. The base station in the third embodiment includes a read unit 4b and a correction unit 5b that are features of the present invention, instead of the read unit 4 and the correction unit 5 in the first embodiment. The correction unit 5b includes a CQI correction unit 6b and an fD information holding unit 13. Hereinafter, in the present embodiment, a reading unit 4b and a correction unit 5b different from those in the first and second embodiments will be described.

  The reading unit 4b according to the present embodiment reads the CQI value and fD information from the signal demodulated by the demodulating unit 3, and holds the read fD information in the fD information holding unit 13. In the correction unit 5b, the CQI correction unit 6b corrects the CQI value based on the fD information held in the fD information holding unit 13.

  Note that fD represents the Doppler frequency. Based on the Doppler frequency transition of the signal received by the mobile station, the base station determines whether the mobile station is moving away from or closer to the mobile station, or whether the distance from the mobile station remains the same. .

  In the CQI correction unit 6b of the present embodiment, for example, when it is determined that the mobile station is moving away from the base station based on the fD information (Doppler frequency information), it is determined that the SIR tends to decrease. Then, a certain value is subtracted from the CQI value read by the reading unit 4b. On the other hand, if it is determined that the mobile station is approaching the base station based on the transition of the fD information, it is determined that the SIR tends to increase, and the CQI read by the CQI reading unit 4b Add a certain value to the value.

  The CQI correction unit 6b further improves the accuracy of the correction by accumulating the fD information after the latest CQI value and correcting the CQI value based on the addition result. Can do. Similarly to the first embodiment described above, the regression analysis is performed on the fD information history and the latest fD information, and the CQI value is corrected based on the regression analysis result, thereby further improving the accuracy of the correction. be able to.

  As described above, in the present embodiment, an fD information holding unit is provided, and the current and / or future transmission path state is predicted based on the fD information held in the fD information holding unit, thereby correcting the CQI value. The MCS is determined based on the corrected CQI value. As a result, the above-described problem due to delay is solved, data transmission efficiency is improved, and higher throughput can be realized.

Embodiment 4 FIG.
FIG. 4 is a diagram illustrating a configuration example of Embodiment 4 of a base station according to the present invention. The base station in the fourth embodiment includes a reading unit 4c and a correcting unit 5c, which are features of the present invention, instead of the reading unit 4 and the correcting unit 5 in the first embodiment described above. The correction unit 5c includes a CQI correction unit 6c and a position information holding unit 14. Hereinafter, in the present embodiment, a reading unit 4c and a correction unit 5c different from those in the first, second, and third embodiments will be described.

  The reading unit 4 c according to the present embodiment reads the CQI value and position information from the signal demodulated by the demodulation unit 3 and holds the read position information in the position information holding unit 14. In the correction unit 5 c, the CQI correction unit 6 c corrects the CQI value based on the position information held in the position information holding unit 14.

  The location information is location information of the mobile station. When the mobile station transmits data received from a GPS (Global Positioning System) satellite to the base station, the base station receives position information (latitude / longitude information) of the mobile station based on the data received from the mobile station. To get. Based on the position information, the base station determines whether the mobile station is moving away from the mobile station, approaching the mobile station, or whether the distance from the mobile station does not change.

  In the CQI correction unit 6c of the present embodiment, for example, when it is determined that the mobile station is moving away from the base station based on the position information, it is determined that the SIR tends to decrease, and the reading unit 4c Then, a certain value is subtracted from the read CQI value. In contrast, if it is determined that the mobile station is approaching the base station, it is determined that the SIR tends to increase, and a constant value is set for the CQI value read by the reading unit 4c. Add.

  The CQI correction unit 6c can further improve the accuracy of correction by cumulatively adding position information after the most recent CQI value and correcting the CQI value based on the addition result. Further, similarly to the first embodiment described above, the regression analysis is performed on the position information history and the latest position information, and the correction accuracy is further improved by correcting the CQI value based on the regression analysis result. be able to.

  As described above, in the present embodiment, the CQI value is corrected by providing the position information holding unit and predicting the current and / or future transmission path state based on the position information held in the position information holding unit. The MCS is determined based on the corrected CQI value. As a result, the above-described problem due to delay is solved, data transmission efficiency is improved, and higher throughput can be realized.

Embodiment 5 FIG.
FIG. 5 is a diagram illustrating a configuration example of Embodiment 5 of a base station according to the present invention. The base station in the fifth embodiment includes a reading unit 4d and a correcting unit 5d, which are features of the present invention, instead of the reading unit 4 and the correcting unit 5 in the first embodiment described above. The correction unit 5d includes a CQI correction unit 6d and an ACK field error rate holding unit 15. Hereinafter, in the present embodiment, a reading unit 4d and a correction unit 5d that are different from the above-described first to fourth embodiments will be described.

  The reading unit 4d of the present embodiment reads the CQI value and the ACK field error rate from the signal demodulated by the demodulating unit 3, and holds the read ACK field error rate in the ACK field error rate holding unit 15. In the correction unit 5d, the CQI correction unit 6d corrects the CQI value based on the ACK field error rate held in the ACK field error rate holding unit 15.

  Here, the ACK field is standardized in HSDPA. It is standardized in HSDPA that the base station retransmits the packet when the mobile station cannot correctly receive the packet. Furthermore, it is standardized in HSDPA that the mobile station notifies the base station of information on whether or not packet retransmission is necessary by transmitting ACK or NACK.

  Further, in TS25.212 of 3GPP, when the ACK field of the HSDPA uplink (HS-DPCCH) indicates a 10-bit repeated pattern of value 1, it represents ACK, and 10 bits of value 0 When the repeated pattern is shown, it is standardized to represent NACK.

  That is, the CQI correction unit 6d determines whether the HSDPA uplink ACK field does not correspond to either a 10-bit repetition pattern of value 1 or a 10-bit repetition pattern of value 0, either ACK or NACK. Therefore, it is determined that an error due to interference has occurred in the upstream transmission path.

  When communication is performed using different channels (frequency bands) for normal uplink and downlink, it cannot be determined that the uplink transmission line state and the downlink transmission line state are similarly fluctuating. However, for the FDD (Frequency Division Duplex) mode when the uplink and downlink frequencies are small and the TDD (Time Division Duplex) mode using the same frequency for the uplink and downlink, the uplink transmission line state and It can be determined that the downlink transmission path state is similarly changing. This embodiment uses this.

  In the CQI correction unit 6d of the present embodiment, for example, the history of the ACK field error rate held in the ACK field error rate holding unit 15 and the latest ACK field error rate read out are analyzed, and the ACK field error is analyzed. When the rate is increasing, it is determined that the SIR tends to decrease as in the case where the mobile station is moving away from the base station, and a certain value is subtracted from the CQI value read by the reading unit 4d. On the other hand, when the ACK field error rate is decreasing, it is determined that the SIR tends to increase as in the case where the mobile station is approaching the base station, and the data is read by the reading unit 4d. A certain value is added to the CQI value.

  The CQI correction unit 6d further performs a regression analysis on the history of the ACK field error rate and the latest ACK field error rate in the same manner as in the first embodiment, and based on the ACK field error rate subjected to the regression analysis. Thus, the correction accuracy can be further improved by correcting the CQI value.

  Thus, in the present embodiment, an ACK field error rate holding unit is provided, and based on the ACK field error rate and the latest ACK field error rate held therein, current and / or future transmission path conditions are determined. The CQI value is corrected by prediction, and the MCS is determined based on the corrected CQI value. Thereby, the problem due to the delay is solved, the data transmission efficiency is improved, and a higher throughput can be realized.

Embodiment 6 FIG.
FIG. 6 is a diagram illustrating a configuration example of a base station according to the sixth embodiment of the present invention. The base station in the sixth embodiment includes a read unit 4e and a correction unit 5e, which are features of the present invention, instead of the read unit 4 and the correction unit 5 in the first embodiment described above. The correction unit 5e includes a CQI correction unit 6e and a CQI field error rate holding unit 16. Hereinafter, in the present embodiment, a reading unit 4e and a correction unit 5e that are different from the above-described first to fifth embodiments will be described.

  The reading unit 4e according to the present embodiment reads the CQI value and the CQI field error rate from the signal demodulated by the demodulation unit 3, and holds the read CQI field error rate in the CQI field error rate holding unit 16. In the correction unit 5e, the CQI correction unit 6e corrects the CQI value based on the CQI field error rate held in the CQI field error rate holding unit 16.

  The CQI field error rate is defined as follows, for example. According to 4.7.7 of TS25.212 in 3GPP, the mobile station uses 5 bits representing CQI of the CQI mapping table (TABLE 7D) shown in TS25.214 in 3GPP (hereinafter referred to as CQI data), 20 It is encoded into bit data, and then the encoded 20-bit data is stored in the CQI field of the HSDPA uplink (HS-DPCCH) and transmitted to the base station. Here, if the value of the CQI data before encoding is 1 to 15, all the bits 15 to 19 after encoding (0 origin, bit 19 is the MSB) are all encoded CQI data. It becomes '0'. On the other hand, when the value of the CQI data before encoding is 16 to 30, all the bits 15 to 19 after encoding are “1”. Based on this feature, the CQI correction unit 6e determines that the upstream QQI data bit 15 to bit 19 before decoding are all in the case where none of “0” or all “1” corresponds to “1”. It is determined that an error due to interference has occurred in the transmission path.

  In the CQI correction unit 6e of the present embodiment, as in the fifth embodiment, the same frequency is used in the FDD (Frequency Division Duplex) mode when the uplink and downlink frequencies are small, and in the uplink and downlink. In the TDD (Time Division Duplex) mode using, the fact that it is possible to determine that the uplink transmission line state and the downlink transmission line state are similarly changing is used. That is, the CQI correction unit 6e analyzes, for example, the CQI field error rate history held in the CQI field error rate holding unit 16 and the latest CQI field error rate read out above, and the CQI field error rate increases. In the case of the tendency, it is determined that the SIR tends to decrease as in the case where the mobile station is moving away from the base station, and a certain value is subtracted from the CQI value read by the reading unit 4e. On the other hand, when the CQI field error rate is decreasing, it is determined that the SIR tends to increase as in the case where the mobile station is approaching the base station, and is read by the reading unit 4e. A certain value is added to the CQI value.

  The CQI correction unit 6e further performs regression analysis on the history of the CQI field error rate and the latest CQI field error rate in the same manner as in the first to fifth embodiments, and based on the regression analysis result. By correcting the CQI value, the correction accuracy can be further improved.

  As described above, in the present embodiment, a CQI field error rate holding unit is provided, and the current and current CQI field error rates and the latest CQI are determined based on the current CQI field error rate holding unit. Alternatively, the CQI value is corrected by predicting the future transmission path state, and the MCS is determined based on the corrected CQI value. Thereby, the problem due to the delay is solved, the data transmission efficiency is improved, and a higher throughput can be realized.

Embodiment 7 FIG.
FIG. 7 is a diagram of a configuration example of the base station according to the seventh embodiment of the present invention. The base station in the seventh embodiment includes a reading unit 4f and a correcting unit 5f that are features of the present invention, instead of the reading unit 4 and the correcting unit 5 in the first embodiment described above. The correction unit 5f includes a CQI correction unit 6f and an uplink synchronization loss detection unit 17. Hereinafter, in the present embodiment, a reading unit 4f and a correction unit 5f different from those in the first to sixth embodiments will be described.

  The reading unit 4f of the present embodiment reads data for detecting the CQI value and the loss of uplink synchronization from the signal demodulated by the demodulating unit 3. In the correction unit 5f, the uplink synchronization loss detection unit 17 determines whether or not uplink synchronization loss has occurred based on the data for detecting the synchronization loss read to the reading unit 4f. The CQI correction unit 6f corrects the CQI value when the uplink synchronization loss detection unit 17 detects the uplink synchronization loss.

  In TS25.214 of 3GPP, the out-of-synchronization is not clearly defined, but the out-of-synchronization is exemplified in 4.3.1.3 in TS25.214. Loss of synchronization can be considered in the same way as loss of downlink synchronization. For example, the above 4.3.1.3 illustrates that it is possible to determine that a loss of synchronization has occurred when the error rate that occurs when reading information such as uplink TPC exceeds a specified value. Yes.

  In the CQI correction unit 6f of the present embodiment, as in the above-described fifth embodiment, the same frequency is used in the FDD (Frequency Division Duplex) mode when the uplink and downlink frequencies are small, and in the uplink and downlink. In the TDD (Time Division Duplex) mode using, the fact that it is possible to determine that the uplink transmission line state and the downlink transmission line state are similarly changing is used. That is, the CQI correction unit 6f determines that the SIR tends to decrease as in the situation where the mobile station is moving away from the base station when the out-of-synchronization detection unit 17 detects out-of-synchronization, for example. A constant value is subtracted from the CQI value read in 4f.

  As described above, in this embodiment, the uplink synchronization loss detection unit is provided, the CQI value is corrected based on the information of the uplink synchronization loss detection unit, and the MCS is determined based on the corrected CQI value. . Thereby, the problem due to the delay is solved, the data transmission efficiency is improved, and a higher throughput can be realized.

  In addition, although the process of the above Embodiment 1-7 was described as what can be implemented independently, it is not restricted to this, For example, the correction | amendment part (5,5a, 5b, 5c, 5d, 5e, and 5f) may be arbitrarily combined. Thereby, the accuracy of correction of the CQI value can be further improved.

  As described above, the base station apparatus according to the present invention is useful for a mobile communication system, and is particularly suitable for a base station apparatus that performs adaptive modulation based on a CQI value.

It is a figure which shows the structural example of Embodiment 1 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 2 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 3 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 4 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 5 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 6 of the base station apparatus concerning this invention. It is a figure which shows the structural example of Embodiment 7 of the base station apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception antenna 2 Wireless reception part 3 Demodulation part 4,4a, 4b, 4c, 4d, 4e, 4f Reading part 5,5a, 5b, 5c, 5d, 5e, 5f Correction part 6,6a, 6b, 6c, 6d, 6e, 6f CQI correction unit 7 CQI history holding unit 8 MCS determination unit 9 adaptive modulation unit 10 wireless transmission unit 11 transmitting antenna 12 TPC information holding unit 13 fD information holding unit 14 position information holding unit 15 ACK field error rate holding unit 16 CQI Field error rate holding unit 17 Uplink synchronization loss detection unit

Claims (2)

In a base station apparatus that determines an MCS to be used in adaptive modulation based on a CQI (Channel Quality Indication) value included in a received signal,
Correction means for correcting the CQI value according to a change in the transmission path state over time from the time when the mobile station measures the transmission path state to the time of actually transmitting the data after adaptive modulation;
MCS determination means for determining MCS based on the corrected CQI value;
Equipped with a,
The mobile station sets a specific bit pattern indicating ACK or a specific bit pattern indicating NACK in an ACK field composed of a plurality of bits, and notifies a data reception result,
The correction means includes
ACK field error rate holding means for holding an ACK field error rate that is a ratio when the ACK field included in the received signal does not indicate any bit pattern of ACK and NACK;
CQI correcting means for correcting a CQI value included in the received signal based on a predetermined number of past ACK field error rates and latest ACK field error rates held in the ACK field error rate holding means;
The base station apparatus comprising: a. Before Symbol C QI correction means, further,
Based on a predetermined number of past ACK field error rates and the latest ACK field error rate held in the ACK field error rate holding means, regression analysis is performed, and a CQI value included in the received signal is calculated based on the regression analysis result. The base station apparatus according to claim 1 , wherein correction is performed.

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