Control device, control method, and control program

Abstract

In order to enable the improvement of the accuracy of channel estimation, this control device controls a system provided with a transmission device that transmits a reference signal to a reception device, and with the reception device that carries out channel estimation by using the reference signal, the control device comprising: a correlation acquisition means for acquiring a correlation between two results of the channel estimation different in time; and a control means for controlling the transmission of the reference signal from the transmission device to the reception device in accordance with the magnitude of the correlation.

Description

Control device, control method, and recording medium

[0001] The present invention relates to a control device and the like.

[0002] The base station can perform channel estimation by referring to an SRS (Sounding Reference Signal).

[0003] This SRS is transmitted from a UE (User Equipment) to a base station. Regarding the SRS configuration on the UE side, when SPS (Semi-Persistent Scheduling) is configured by the base station, the UE periodically transmits an SPS SRS to the base station. The UE also monitors DCI (Downlink Control Information). Then, when the DCI instructs the UE to transmit an aperiodic SRS, the UE transmits the aperiodic SRS to the base station. The periodic SRS is transmitted from the UE at a predetermined cycle.

[0004] A related technique is described in Patent Document 1.

[0005] JP 2011-015394 A

[0006] 3GPP TS 38.300 V16.9.0 (2022-06), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; NR and NG-RAN Overall Description; Stage 2 (Release 16)"

[0007] A base station performs channel estimation by referring to an SRS transmitted from a UE. However, the radio environment between the base station and the UE may change between receiving the previous SRS and receiving the next SRS. In such a case, the accuracy of the channel estimation may deteriorate. In particular, when SPS is applied, the effect of the deterioration in the accuracy of the channel estimation may continue for a long period of time. As a result, the communication quality in a radio access network (RAN) may deteriorate.

[0008] In view of the above-mentioned problems, an object of the present invention is to provide a control device and the like that makes it possible to improve the accuracy of channel estimation.

[0009] In one aspect of the present invention, the control device is a control device that controls a system comprising a transmitting device that transmits a reference signal to a receiving device and the receiving device that performs channel estimation using the reference signal, and is equipped with a correlation acquisition means that acquires the correlation between two temporally different channel estimation results, and a control means that controls the transmission of the reference signal by the transmitting device to the receiving device depending on the magnitude of the correlation.

[0010] In another aspect of the present invention, a control method is a control method for a system comprising a transmitting device that transmits a reference signal to a receiving device and the receiving device that performs channel estimation using the reference signal, wherein the control method obtains a correlation between two time-varying channel estimation results and controls the transmission of the reference signal by the transmitting device to the receiving device depending on the magnitude of the correlation.

[0011] In another aspect of the present invention, a control program recorded on a computer-readable recording medium is a control program for a system comprising a transmitting device that transmits a reference signal to a receiving device and the receiving device that performs channel estimation using the reference signal, and causes a computer to realize a correlation acquisition function that acquires the correlation between two time-different channel estimation results and a control function that controls the transmitting device's transmission of the reference signal to the receiving device depending on the magnitude of the correlation.

[0012] According to the present invention, it is possible to improve the accuracy of channel estimation.

[0013] FIG. 1 is a diagram illustrating an example of the configuration of a control device according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of the operation flow of a control device according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating an example of the configuration of a system including a control device according to a second embodiment of the present invention. FIG. 4 is a diagram illustrating an example of the configuration of a control device according to a second embodiment of the present invention. FIG. 5 is a diagram illustrating an example of the operation flow of a control device according to the second to fourth embodiments of the present invention. FIG. 6 is a diagram illustrating an example of the configuration of a system including a control device according to a third embodiment of the present invention. FIG. 7 is a diagram illustrating an example of the configuration of a control device according to a third embodiment of the present invention. FIG. 8 is a diagram illustrating an example of the operation flow of a control device according to the third embodiment of the present invention. FIG. 9 is a diagram illustrating an example of the configuration of a system including a control device according to a fourth embodiment of the present invention. FIG. 10 is a diagram illustrating an example of the configuration of a control device according to a fourth embodiment of the present invention. FIG. 11 is a diagram illustrating an example of the operation flow of a control device according to the fourth embodiment of the present invention. FIG. 12 is a diagram illustrating an example of the hardware configuration of each embodiment of the present invention.

[0014] [First embodiment] A first embodiment of the present invention will be described. Specific examples of the control device 10 in the first embodiment are the control device 20 in the second embodiment, the control device 30 in the third embodiment, and the control device 40 in the fourth embodiment, which will be described later.

[0015] 1 shows an example of the configuration of a control device 10 according to this embodiment. The control device 10 according to this embodiment includes a correlation acquisition unit 11 and a control unit 12.

[0016] The control device 10 controls a system including a transmitting device and a receiving device. The transmitting device transmits a reference signal to the receiving device. The receiving device performs channel estimation using the reference signal.

[0017] The correlation acquisition unit 11 acquires the correlation between two time-different channel estimation results.

[0018] The control unit 12 controls the transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation.

[0019] Next, FIG. 2 shows an example of an operation flow of the control device 10 of this embodiment.

[0020] The correlation acquisition unit 11 acquires the correlation between two time-different channel estimation results (step S101).

[0021] The control unit 12 controls the transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation (step S102).

[0022] As described above, in the first embodiment of the present invention, the control device 10 includes a correlation acquisition unit 11 and a control unit 12. The control device 10 controls a system including a transmitting device and a receiving device. The transmitting device transmits a reference signal to the receiving device. The receiving device performs channel estimation using the reference signal. The correlation acquisition unit 11 acquires the correlation between two time-varying channel estimation results. The control unit 12 controls the transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation. This enables the control device 10 to grasp fluctuations in the radio environment based on the magnitude of the correlation and control the transmission of the reference signal according to the fluctuations in the radio environment. This makes it possible to improve the accuracy of channel estimation.

[0023] Second Embodiment Next, a control device 20 according to a second embodiment of the present invention will be described. A specific example of the control device 10 according to the first embodiment is the control device 20 according to the second embodiment. This embodiment is an example in which the control device 20 is a receiving device that receives a reference signal.

[0024] First, Fig. 3 shows an example of the configuration of a system including the control device 20 of this embodiment. This system includes the control device 20 and a transmitting device 60. The control device 20 is a receiving device that receives a reference signal. The transmitting device 60 transmits the reference signal to the control device 20 (receiving device). The reference signal is used for channel estimation. Communication between the control device 20 and the transmitting device 60 is performed by wired communication or wireless communication.

[0025] For example, the control device 20 is a base station. In this case, the transmitting device 60 is a terminal device. In this case, one or more transmitting devices 60 can be connected to the control device 20. In this case, the reference signal is transmitted from the terminal device to the base station.

[0026] Furthermore, for example, the control device 20 may be a terminal device. In this case, the transmission device 60 is a base station. In this case, one or more control devices 20 can be connected to the transmission device 60. In this case, the reference signal is transmitted from the base station to the terminal device.

[0027] 4 shows an example of the configuration of the control device 20 of this embodiment. The control device 20 includes a reference signal receiving unit 23, an estimating unit 24, a correlation obtaining unit 21, and a control unit 22.

[0028] The reference signal receiving unit 23 receives a reference signal from the transmitting device 60 .

[0029] The estimation unit 24 performs channel estimation using the reference signal. The estimation unit 24 can use any method for channel estimation.

[0030] The reference signal is, for example, an SRS. The transmitting device 60 periodically transmits the SRS in accordance with a setting related to the SRS transmission period. The transmitting device 60 can also transmit the SRS when instructed by the control device 20 to transmit an aperiodic SRS.

[0031] The correlation acquisition unit 21 acquires the correlation between two time-different channel estimation results. In this embodiment, the correlation acquisition unit 21 calculates the correlation. For example, the correlation acquisition unit 21 may calculate the correlation between the latest channel estimation result and the channel estimation result performed a predetermined time before the latest channel estimation. Also, for example, the correlation acquisition unit 21 may calculate the correlation between the latest channel estimation result and the channel estimation result performed immediately before the latest channel estimation.

[0032] For example, suppose that an SRS is transmitted in the n-th slot, and the slot in which the SRS was transmitted immediately before the n-th slot among the slots before the n-th slot is the (n-p)-th slot. In this case, the correlation acquisition unit 21 calculates the correlation ρ between the result of channel estimation based on the SRS in the n-th slot and the result of channel estimation based on the SRS in the (n-p)-th slot.

[0033] The control unit 22 controls the transmission of the reference signal depending on the magnitude of the correlation ρ calculated by the correlation acquisition unit 21. In the present embodiment, the control unit 22 controls the transmission of the reference signal by transmitting an instruction regarding the transmission of the reference signal to the transmission device 60.

[0034] For example, when a state where correlation is low frequently occurs, the control unit 22 performs control to shorten the transmission interval of the reference signal. This allows the number of reference signals transmitted per unit time to increase, and the control device 20 can increase the frequency of channel estimation. As a result, when the wireless environment fluctuates frequently, channel estimation is performed to follow the fluctuations. This makes it possible to improve the accuracy of channel estimation. Specific control methods will be described later.

[0035] Next, FIG. 5 shows an example of an operation flow of the control device 20 of this embodiment.

[0036] The reference signal receiving unit 23 receives a reference signal from the transmitting device 60 (step S201). The estimation unit 24 performs channel estimation using the reference signal (step S202).

[0037] The correlation acquisition unit 21 calculates the correlation ρ between the result of the currently performed channel estimation and, for example, the result of the previously performed channel estimation (step S203).

[0038] The control unit 22 controls the transmission of the reference signal depending on the magnitude of the correlation ρ (step S204). In this embodiment, the control unit 22 controls the transmission of the reference signal by transmitting an instruction regarding the transmission of the reference signal to the transmitting device 60.

[0039] Next, a specific method of control performed by the control unit 22 will be described with reference to Fig. 6. Fig. 6 shows an example of the operation flow of the control device 20 of this embodiment, and is a specific example of step S204 in Fig. 5.

[0040] In the example shown in Fig. 6, four correlation thresholds Tρa, Tρb, Tρc, and Tρd are used, where Tρa<Tρb<Tρc<Tρd. Note that only two correlation thresholds, Tρb and Tρc, may be used. In this case, in Fig. 6, the correlation threshold Tρa can be regarded as the lower limit of the possible values ​​of the correlation ρ, and Tρd can be regarded as the upper limit of the possible values ​​of the correlation ρ.

[0041] If the correlation ρ satisfies Tρa<ρ<Tρb (YES in step S301), the control unit 22 increments the counter Nab by 1 (step S302). If the correlation ρ satisfies Tρc<ρ<Tρd (YES in step S303), the control unit 22 increments the counter Ncd by 1 (step S304). The initial values ​​of the counters Nab and Ncd are 0. The counters Nab and Ncd are reset to 0 at a predetermined timing. The reset timing may be, for example, every predetermined time or every time a predetermined number of channel estimations are performed.

[0042] Next, the control unit 22 compares the counters Nab and Ncd (step S305). When the wireless environment fluctuates frequently, a state in which the correlation ρ is small often occurs. Therefore, when the wireless environment fluctuates frequently, the counter Nab becomes larger than the counter Ncd. Therefore, in this case, the control unit 22 performs control to shorten the transmission interval of the reference signal.

[0043] More specifically, if the counter Nab is greater than the counter Ncd (YES in step S305), the control unit 22 further compares the counter Nab with a counter threshold Tab. If the counter Nab is equal to or less than the counter threshold Tab (NO in step S306), the control unit 22 shortens the transmission period of the reference signal. For example, the control unit 22 sets a shorter SPS period as the SRS-related setting for the transmitting device 60. By shortening the transmission period of the reference signal in this way, the control device 20 can increase the frequency of channel estimation. As a result, when the wireless environment frequently changes, channel estimation is performed in accordance with the changes.

[0044] If the counter Nab is greater than the counter threshold Tab (YES in step S306), the wireless environment is fluctuating more frequently. In this case, the control unit 22 causes the transmitting device 60 to transmit an aperiodic reference signal (step S308). For example, the control unit 22 instructs the transmitting device 60 to transmit an aperiodic SRS.

[0045] When the SRS transmission interval is shortened by changing the SRS transmission period, it takes more time to reconfigure the SRS resources than when aperiodic SRS is transmitted. Furthermore, aperiodic SRS has a higher priority than semi-persistent SRS or periodic SRS. More specifically, when the OFDM (Orthogonal Frequency Division Multiplexing) symbols of the aperiodic SRS overlap with those of the semi-persistent SRS or periodic SRS, the transmitting device 60 transmits only the aperiodic SRS (see Non-Patent Document 1). Therefore, by instructing the transmitting device 60 to transmit the aperiodic SRS when the wireless environment fluctuates more frequently, the control unit 22 can shorten the reference signal transmission interval in a shorter time than by changing the transmission period.

[0046] If the counter Nab is equal to or less than the counter Ncd (NO in step S305), a state in which the correlation ρ is large occurs frequently. If the correlation ρ is large, it is estimated that fluctuations in the wireless environment are small. In this case, the control unit 22 further compares the counter Ncd with the counter threshold Tcd. Then, if the counter Ncd is equal to or less than the counter threshold Tcd (NO in step S309), the control unit 22 maintains the current transmission period of the reference signal (step S310).

[0047] If the counter Ncd is greater than the counter threshold Tcd (YES in step S309), a state in which the correlation ρ is large occurs more frequently. In this case, it is estimated that the radio environment is more stable. Therefore, in this case, the control unit 22 sets the transmission device 60 to have a longer reference signal period (step S311). For example, the control unit 22 sets the SPS with a longer period as the SRS-related setting for the transmission device 60. Furthermore, in step S311, the control unit 22 may, for example, lengthen the period of a periodic SRS. In this way, lengthening the transmission period of the reference signal can reduce the power required for transmitting and receiving the reference signal. Furthermore, the transmission device 60 can improve throughput.

[0048] For example, the transmitting device 60 can use a symbol and a PRB (physical resource block) in which no SRS exists as another UL (Uplink) channel. The other UL channel is, for example, a PUSCH (Physical Uplink Shared Channel) or a PUCCH (Physical Uplink Control Channel). For example, the transmitting device 60 can improve the UL throughput by using a symbol and a PRB in which no SRS exists as a PUSCH.

[0049] Next, another example of a specific method of control performed by the control unit 22 will be described with reference to Fig. 7. Fig. 7 shows an example of an operation flow of the control device 20 of this embodiment, and is a specific example of step S204 in Fig. 5.

[0050] In the example shown in FIG. 7, one correlation threshold Tρe is used.

[0051] If the correlation ρ satisfies ρ<Tρe (YES in step S401), the control unit 22 adds 1 to the counter Ne (step S402). The initial value of the counter Ne is 0. The counter Ne is reset to 0 at a predetermined timing. The reset timing may be, for example, every predetermined time or every time a predetermined number of channel estimations are performed.

[0052] Next, the control unit 22 compares the counter Ne with the counter threshold Te. If the counter Ne is greater than the counter threshold Te (YES in step S403), the wireless environment is frequently fluctuating. In this case, the control unit 22 performs control to shorten the transmission interval of the reference signal. For example, the control unit 22 causes the transmitting device 60 to transmit a non-periodic reference signal (step S404). Alternatively, the control unit 22 may perform control to shorten the transmission period of the reference signal in step S404. By shortening the transmission interval of the reference signal, the control unit 22 can increase the frequency of channel estimation. As a result, when the wireless environment frequently fluctuates, channel estimation is performed to track the fluctuations.

[0053] If the counter Ne is equal to or smaller than the counter threshold Te (NO in step S403), a state in which the correlation ρ is large occurs frequently. In this case, it is estimated that the wireless environment is stable. Therefore, the control unit 22 maintains the current transmission period of the reference signal (step S405).

[0054] Note that the control unit 22 performs control to shorten the reference signal transmission interval in step S307 in Fig. 6 and step S404 in Fig. 7. Instead of this control, the control unit 22 may perform control to increase at least one of the number of SRS symbols in one slot and the number of PRBs (Physical Resource Blocks) used for one SRS transmission.

[0055] Channel estimation is performed within a PRB including an SRS symbol. When the number of SRS symbols within one slot or the number of PRBs used for one SRS transmission is increased, the number of PRBs subject to channel estimation increases. Therefore, when the radio environment fluctuates frequently, the number of SRS symbols or the number of PRBs can be increased to suppress a decrease in the accuracy of channel estimation. As a result, the accuracy of channel estimation can be improved.

[0056] Furthermore, the control unit 22 can cause the transmitting device 60 to transmit a non-periodic reference signal in step S308 in Fig. 6 or step S404 in Fig. 7. In this case, the control unit 22 may perform control to increase at least one of the number of SRS symbols in one slot and the number of PRBs used for one SRS transmission for the non-periodic reference signal.

[0057] Alternatively, instead of lengthening the transmission interval of the reference signal, the control unit 22 may perform control to reduce at least one of the number of SRS symbols in one slot and the number of PRBs used for one SRS transmission (step S311 in FIG. 6 ), thereby improving the throughput of data other than the reference signal among the data transmitted from the transmitting device 60 to the control device 20.

[0058] As described above, in the second embodiment of the present invention, the control device 20 includes a correlation acquisition unit 21 and a control unit 22. The control device 20 controls a system including a transmitting device and a receiving device. The transmitting device transmits a reference signal to the receiving device. The receiving device performs channel estimation using the reference signal. The correlation acquisition unit 21 acquires the correlation between two time-varying channel estimation results. The control unit 22 controls the transmission of the reference signal from the transmitting device to the receiving device depending on the magnitude of the correlation. This enables the control device 20 to grasp fluctuations in the radio environment based on the magnitude of the correlation and control the transmission of the reference signal depending on the fluctuations in the radio environment. This makes it possible to improve the accuracy of channel estimation.

[0059] Furthermore, when the number of times the correlation is smaller than the correlation threshold is greater than a comparison value, the control unit 22 performs control to shorten the transmission interval of the reference signal. Specifically, the comparison value is, for example, the counter Ncd in FIG. 6 or the counter threshold Te in FIG. 7. Furthermore, the control to shorten the transmission interval is control to shorten the transmission period of the reference signal or control to cause the transmitting device to transmit a non-periodic reference signal. As a result, when there are frequent fluctuations in the wireless environment, the frequency of channel estimation can be increased by increasing the transmission frequency of the reference signal, thereby improving the accuracy of channel estimation.

[0060] Furthermore, when the number of times the correlation is greater than the correlation threshold is greater than the comparison value, the control unit 22 performs control to increase the transmission interval of the reference signal. Specifically, the comparison value is, for example, the counter threshold value Tcd in Fig. 6. This makes it possible to improve the throughput of data other than the reference signal when the wireless environment is stable.

[0061] The reference signal may be an SRS, which allows the control device 20 to implement the above-described control using the SRS.

[0062] Furthermore, when the number of times that the correlation is smaller than the correlation threshold is greater than a comparison value, the control unit 22 may perform control to increase at least one of the number of SRS symbols in one slot and the number of PRBs used for one SRS transmission. Specifically, the comparison value is, for example, the counter Ncd in Fig. 6 or the counter threshold Te in Fig. 7. This makes it possible to suppress a decrease in the accuracy of channel estimation when there are frequent fluctuations in the radio environment and improve the accuracy of channel estimation.

[0063] Furthermore, when the number of times the correlation is greater than the correlation threshold is greater than the comparison value, the control unit 22 may perform control to reduce at least one of the number of SRS symbols in one slot and the number of PRBs used for one SRS transmission. Specifically, the comparison value is, for example, the counter threshold value Tcd in FIG. 6. This can improve the throughput of data other than the reference signal.

[0064] The control device 20 of this embodiment is a receiving device. The control device 20 further includes a reference signal receiving unit 23 and an estimation unit 24. The reference signal receiving unit 23 receives a reference signal. The estimation unit 24 performs channel estimation. The correlation acquisition unit 21 calculates correlation. The control unit 22 controls the transmission of the reference signal by transmitting an instruction regarding the transmission of the reference signal to the transmitting device. This allows the control device 20 to realize the processing of this embodiment.

[0065] [Third Embodiment] Next, a control device 30 according to a third embodiment of the present invention will be described. A specific example of the control device 10 according to the first embodiment is the control device 30 according to the third embodiment. This embodiment is an example in which the control device 30 is a transmitting device that transmits a reference signal.

[0066] First, Fig. 8 shows an example of the configuration of a system including the control device 30 of this embodiment. This system includes the control device 30 and a receiving device 70. The control device 30 is a transmitting device that transmits a reference signal to the receiving device 70. The receiving device 70 receives the reference signal. The reference signal is used for channel estimation. Communication between the control device 30 and the receiving device 70 is performed by wired communication or wireless communication.

[0067] For example, the control device 30 may be a terminal device. In this case, the receiving device 70 is a base station. In this case, one or more control devices 30 can be connected to the receiving device 70. In this case, the reference signal is transmitted from the terminal device to the base station.

[0068] Furthermore, for example, the control device 30 may be a base station. In this case, the receiving device 70 is a terminal device. In this case, one or more receiving devices 70 can be connected to the control device 30. In this case, the reference signal is transmitted from the base station to the terminal device.

[0069] 9 shows an example of the configuration of the control device 30 of this embodiment. The control device 30 includes a transmitting unit 35, a result receiving unit 36, a correlation obtaining unit 31, and a control unit 32.

[0070] The transmitter 35 transmits the reference signal to the receiver 70 .

[0071] The result receiving unit 36 ​​receives the result of the channel estimation from the receiving device 70. The channel estimation is performed by the receiving device 70. That is, the processing of the reference signal receiving unit 23 and the processing of the estimation unit 24 of the control device 20 of the second embodiment are performed by the receiving device 70.

[0072] The correlation acquisition unit 31 acquires the correlation between two time-varying channel estimation results. Similar to the correlation acquisition unit 21 of the control device 20, the correlation acquisition unit 31 of this embodiment calculates the correlation between two time-varying channel estimation results.

[0073] The control unit 32 controls the transmission of the reference signal in accordance with the magnitude of the correlation ρ calculated by the correlation acquisition unit 31. In this embodiment, the control unit 32 controls the transmission of the reference signal by the transmission unit .

[0074] Next, FIG. 10 shows an example of an operation flow of the control device 30 of this embodiment.

[0075] The result receiving unit 36 ​​receives the channel estimation result from the receiving device 70 (step S501).

[0076] The correlation acquisition unit 31 calculates the correlation ρ between the result of the current channel estimation and, for example, the result of the previous channel estimation (step S502).

[0077] The control unit 32 controls the transmission of the reference signal depending on the magnitude of the correlation ρ (step S503). In this embodiment, the control unit 32 controls the transmission of the reference signal by the transmission unit 35. The transmission unit 35 transmits the reference signal in accordance with the control of the control unit 32. The specific control method is the same as in the second embodiment (FIGS. 6 and 7), and therefore description thereof will be omitted.

[0078] As described above, in the third embodiment of the present invention, the control device 30 includes a correlation acquisition unit 31 and a control unit 32. The control device 30 controls a system including a transmitting device and a receiving device. The transmitting device transmits a reference signal to the receiving device. The receiving device performs channel estimation using the reference signal. The correlation acquisition unit 31 acquires the correlation between two time-varying channel estimation results. The control unit 32 controls the transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation. This enables the control device 30 to grasp fluctuations in the radio environment based on the magnitude of the correlation and control the transmission of the reference signal according to the fluctuations in the radio environment. This makes it possible to improve the accuracy of channel estimation.

[0079] In this embodiment, the control device 30 is a transmitting device. The control device 30 further includes a transmitting unit 35 and a result receiving unit 36. The transmitting unit 35 transmits a reference signal to the receiving device 70. The result receiving unit 36 ​​receives the result of the channel estimation from the receiving device 70. The correlation obtaining unit 31 calculates the correlation. This allows the control device 30 to realize the processing of this embodiment.

[0080] [Fourth embodiment] Next, a control device 40 according to a fourth embodiment of the present invention will be described. A specific example of the control device 10 according to the first embodiment is the control device 40 according to the fourth embodiment. This embodiment is an example in which the control device 40 is a transmitting device that transmits a reference signal.

[0081] First, Fig. 11 shows an example of the configuration of a system including the control device 40 of this embodiment. This system includes the control device 40 and a receiving device 70. The control device 40 is a transmitting device that transmits a reference signal to the receiving device 70. The receiving device 70 receives the reference signal. The reference signal is used for channel estimation. Communication between the control device 40 and the receiving device 70 is performed by wired communication or wireless communication.

[0082] For example, the control device 40 may be a terminal device. In this case, the receiving device 70 is a base station. In this case, one or more control devices 40 can be connected to the receiving device 70. In this case, the reference signal is transmitted from the terminal device to the base station.

[0083] Furthermore, for example, the control device 40 may be a base station. In this case, the receiving device 70 is a terminal device. In this case, one or more receiving devices 70 can be connected to the control device 40. In this case, the reference signal is transmitted from the base station to the terminal device.

[0084] 12 shows an example of the configuration of the control device 40 of this embodiment. The control device 40 includes a transmitting unit 45, a correlation obtaining unit 41, and a control unit 42.

[0085] The transmitter 45 transmits the reference signal to the receiver 70 .

[0086] The correlation acquisition unit 41 acquires the correlation between two time-different channel estimation results. The correlation acquisition unit 41 of this embodiment receives the correlation ρ from the receiving device 70. The channel estimation and correlation calculation are performed by the receiving device 70. That is, the processing of the reference signal receiving unit 23, the processing of the estimation unit 24, and the processing of the correlation acquisition unit 21 of the control device 20 of the second embodiment are performed by the receiving device 70.

[0087] The control unit 42 controls the transmission of the reference signal in accordance with the magnitude of the correlation p received by the correlation acquisition unit 41. In this embodiment, the control unit 42 controls the transmission of the reference signal by the transmission unit 45.

[0088] Next, FIG. 13 shows an example of an operation flow of the control device 40 of this embodiment.

[0089] The correlation acquisition unit 41 receives the correlation p (step S601). Channel estimation and calculation of the correlation p are performed in the receiving device 70.

[0090] The control unit 42 controls the transmission of the reference signal depending on the magnitude of the correlation ρ (step S602). In this embodiment, the control unit 42 controls the transmission of the reference signal by the transmission unit 45. The transmission unit 45 transmits the reference signal in accordance with the control of the control unit 42. The specific control method is the same as in the second embodiment (FIGS. 6 and 7), and therefore description thereof will be omitted.

[0091] As described above, in the fourth embodiment of the present invention, the control device 40 includes a correlation acquisition unit 41 and a control unit 42. The control device 40 controls a system including a transmitting device and a receiving device. The transmitting device transmits a reference signal to the receiving device. The receiving device performs channel estimation using the reference signal. The correlation acquisition unit 41 acquires the correlation between two time-varying channel estimation results. The control unit 42 controls the transmission of the reference signal from the transmitting device to the receiving device depending on the magnitude of the correlation. This enables the control device 40 to grasp fluctuations in the radio environment based on the magnitude of the correlation and control the transmission of the reference signal depending on the fluctuations in the radio environment. This makes it possible to improve the accuracy of channel estimation.

[0092] Furthermore, the control device 40 of this embodiment is a transmitting device. The control device 40 further includes a transmitting unit 45. The transmitting unit 45 transmits a reference signal to the receiving device 70. The correlation acquiring unit 41 receives the correlation from the receiving device 70. This allows the control device 40 to realize the processing of this embodiment.

[0093] [Hardware Configuration Example] An example of the configuration of hardware resources for realizing the control device (10, 20, 30, 40) in each of the above-described embodiments of the present invention using one information processing device (computer) will be described. Note that the control device may be physically or functionally realized using at least two information processing devices. The control device may also be realized as a dedicated device. Also, only some of the functions of the control device may be realized using an information processing device.

[0094] 14 is a diagram illustrating an example of the hardware configuration of an information processing device that can realize the control device according to each embodiment of the present invention. The information processing device 90 includes a communication interface 91, an input / output interface 92, a computing device 93, a storage device 94, a nonvolatile storage device 95, and a drive device 96.

[0095] For example, the correlation acquisition unit 11 and the control unit 12 in FIG.

[0096] The communication interface 91 is a communication means for the control device of each embodiment to communicate with an external device via a wired or / and wireless connection. When the control device is realized using at least two information processing devices, the devices may be connected to each other via the communication interface 91 so as to be able to communicate with each other.

[0097] The input / output interface 92 is a man-machine interface including a keyboard as an example of an input device and a display as an output device.

[0098] The arithmetic unit 93 is realized by a general-purpose central processing unit (CPU), a microprocessor, or other arithmetic processing device, and a plurality of electric circuits. The arithmetic unit 93 is capable of, for example, reading various programs stored in a nonvolatile storage device 95 into the storage device 94 and executing processing in accordance with the read programs.

[0099] The storage device 94 is a memory device such as a RAM (Random Access Memory) that can be accessed by the arithmetic device 93, and stores programs, various data, etc. The storage device 94 may be a volatile memory device.

[0100] The nonvolatile storage device 95 is a nonvolatile storage device such as a ROM (Read Only Memory) or a flash memory, and is capable of storing various programs, data, and the like.

[0101] The drive device 96 is, for example, a device that processes reading and writing of data from and to a recording medium 97, which will be described later.

[0102] The recording medium 97 is any recording medium capable of recording data, such as an optical disk, a magneto-optical disk, or a semiconductor flash memory.

[0103] Each embodiment of the present invention may be realized, for example, by configuring a control device using the information processing device 90 illustrated in FIG. 14 and supplying a program to this control device that can realize the functions described in each of the above embodiments.

[0104] In this case, the embodiment can be realized by having the arithmetic unit 93 execute a program supplied to the control unit. Also, it is possible to configure some, but not all, of the functions of the control unit in the information processing unit 90.

[0105] Furthermore, the program may be recorded on a recording medium 97 and stored in the nonvolatile storage device 95 as appropriate when the control device is shipped or when it is in operation. In this case, the program may be supplied by installing it in the control device using an appropriate jig during the manufacturing stage before shipping or during operation. The program may also be supplied by a general procedure such as downloading it from an external source via a communication line such as the Internet.

[0106] Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0107] (Supplementary Note 1) A control device that controls a system including a transmitting device that transmits a reference signal to a receiving device and the receiving device that performs channel estimation using the reference signal, the control device comprising: a correlation acquisition means that acquires the correlation between two temporally different channel estimation results; and a control means that controls the transmission of the reference signal by the transmitting device to the receiving device depending on the magnitude of the correlation.

[0108] (Supplementary Note 2) The control device according to Supplementary Note 1, wherein the control means performs control to reduce the transmission interval of the reference signal when the number of times the correlation is smaller than the correlation threshold is greater than a comparison value.

[0109] (Supplementary Note 3) The control device according to Supplementary Note 2, wherein the control to reduce the transmission interval is control to shorten a transmission period of the reference signal or control to cause the transmitting device to transmit the reference signal non-periodic.

[0110] (Supplementary Note 4) The control device according to Supplementary Note 1, wherein the control means performs control to increase the transmission interval of the reference signal when the number of times the correlation is greater than the correlation threshold is greater than a comparison value.

[0111] (Supplementary Note 5) The control device according to Supplementary Note 1, wherein the reference signal is a sounding reference signal (SRS).

[0112] (Supplementary Note 6) The control device according to Supplementary Note 5, wherein the control means performs control to increase at least one of the number of SRS symbols in one slot and the number of PRBs (Physical Resource Blocks) used for one SRS transmission when the number of times the correlation is smaller than a correlation threshold is greater than a comparison value.

[0113] (Supplementary Note 7) The control device according to Supplementary Note 5, wherein the control means performs control to reduce at least one of the number of SRS symbols in one slot and the number of PRBs (Physical Resource Blocks) used for one SRS transmission when the number of times the correlation is greater than a correlation threshold is greater than a comparison value.

[0114] (Supplementary Note 8) The control device according to Supplementary Note 1, wherein the control device is the receiving device and further comprises: a reference signal receiving means for receiving the reference signal; and an estimation means for performing the channel estimation; the correlation acquisition means calculates the correlation; and the control means controls transmission of the reference signal by transmitting an instruction regarding transmission of the reference signal to the transmitting device.

[0115] (Supplementary Note 9) The control device according to Supplementary Note 1, wherein the control device is the transmitting device and further comprises: a transmitting means for transmitting the reference signal to the receiving device; and a result receiving means for receiving the result of the channel estimation from the receiving device, and the correlation obtaining means calculates the correlation.

[0116] (Supplementary Note 10) The control device according to Supplementary Note 1, wherein the control device is the transmitting device, and further comprises: a transmitting means for transmitting the reference signal to the receiving device; and the correlation obtaining means receives the correlation from the receiving device.

[0117] (Supplementary Note 11) A control method for a system including a transmitting device that transmits a reference signal to a receiving device, and the receiving device that performs channel estimation using the reference signal, the control method comprising: obtaining a correlation between two temporally different channel estimation results; and controlling transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation.

[0118] (Supplementary Note 12) A computer-readable recording medium having recorded thereon a control program for a system including a transmitting device that transmits a reference signal to a receiving device, and the receiving device that performs channel estimation using the reference signal, the computer-readable recording medium having recorded thereon a control program that causes a computer to realize: a correlation acquisition function that acquires the correlation between two temporally different channel estimation results; and a control function that controls the transmission of the reference signal by the transmitting device to the receiving device depending on the magnitude of the correlation.

[0119] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0120] This application claims priority based on Japanese Patent Application No. 2022-134134, filed on August 25, 2022, the disclosure of which is incorporated herein in its entirety.

[0121] 10, 20, 30, 40 Control device 11, 21, 31, 41 Correlation acquisition unit 12, 22, 32, 42 Control unit 23 Reference signal receiving unit 24 Estimation unit 35, 45 Transmission unit 36 ​​Result receiving unit 60 Transmission device 70 Reception device 90 Information processing device 91 Communication interface 92 Input / output interface 93 Arithmetic unit 94 Storage device 95 Non-volatile storage device 96 Drive device 97 Recording medium

Claims

1. A control device for controlling a system including a transmitting device that transmits a reference signal to a receiving device, and the receiving device that performs channel estimation using the reference signal, A correlation acquisition means for acquiring a correlation between two time-different channel estimation results; a control means for controlling transmission of the reference signal from the transmitting device to the receiving device in accordance with the magnitude of the correlation; A control device comprising:

2. the control means performs control to reduce a transmission interval of the reference signal when the number of times that the correlation is smaller than the correlation threshold is greater than a comparison value. The control device according to claim 1 .

3. the control means performs control to increase a transmission interval of the reference signal when the number of times that the correlation is greater than the correlation threshold is greater than a comparison value. The control device according to claim 1 .

4. The reference signal is a Sounding Reference Signal (SRS), The control means performs control to increase at least one of the number of SRS symbols in one slot and the number of PRBs (Physical Resource Blocks) used for one SRS transmission when the number of times the correlation is smaller than the correlation threshold is greater than a comparison value. The control device according to claim 1 .

5. The reference signal is a Sounding Reference Signal (SRS), The control means performs control to reduce at least one of the number of SRS symbols in one slot and the number of PRBs (Physical Resource Blocks) used for one SRS transmission when the number of times the correlation is greater than the correlation threshold is greater than a comparison value. The control device according to claim 1 .

6. the control device is the receiving device, A reference signal receiving means for receiving the reference signal; an estimation means for performing the channel estimation; Further equipped with The correlation acquisition means calculates the correlation, the control means controls the transmission of the reference signal by transmitting an instruction regarding the transmission of the reference signal to the transmitting device. The control device according to claim 1 .

7. the control device is the transmission device, a transmitting means for transmitting the reference signal to the receiving device; a result receiving means for receiving the result of the channel estimation from the receiving device; Further equipped with The correlation acquisition means calculates the correlation. The control device according to claim 1 .

8. the control device is the transmission device, A transmitting means for transmitting the reference signal to the receiving device. Further equipped with The correlation acquisition means receives the correlation from the receiving device. The control device according to claim 1 .

9. A control method for a control device that controls a system including a transmitting device that transmits a reference signal to a receiving device, and the receiving device that performs channel estimation using the reference signal, comprising: Obtaining a correlation between two of said channel estimation results that differ in time; controlling transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation; Control methods.

10. A control program for a system including a transmitting device that transmits a reference signal to a receiving device, and the receiving device that performs channel estimation using the reference signal, On the computer, a correlation acquisition function for acquiring a correlation between two time-different channel estimation results; a control function of controlling transmission of the reference signal from the transmitting device to the receiving device according to the magnitude of the correlation; A control program that realizes this.