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

Technical Field

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

Background Art

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

[0003] This SRS is transmitted from the UE (User Equipment) to the base station. Regarding the setting of the SRS on the UE side, when SPS (Semi-Persistent Scheduling) is set by the base station, the UE periodically transmits the SPS SRS to the base station. Also, the UE monitors the DCI (Downlink Control Information). Then, when the UE is instructed to transmit an aperiodic SRS by the DCI, the UE transmits the aperiodic SRS to the base station. Also, the periodic SRS is transmitted from the UE at a predetermined period.

[0004] As a related technique, there is the technique described in Patent Document 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

[0007] Base stations perform channel estimation by referring to SRS transmitted from the UE. However, the radio environment between the base station and the UE may fluctuate between the reception of one SRS and the reception of the next. In such cases, the accuracy of channel estimation may deteriorate. In particular, when SPS is applied, the impact of this deterioration in channel estimation accuracy can persist over a long period of time. As a result, the communication quality in the Radio Access Network (RAN) may deteriorate.

[0008] In view of the above problems, the object of the present invention is to provide a control device and the like that can improve the accuracy of channel estimation. [Means for solving the problem]

[0009] In one embodiment of the present invention, the control device is a control device for controlling 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 comprises correlation acquisition means for acquiring a correlation between two channel estimation results that are different in time, and control means for controlling the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation.

[0010] In another embodiment of the present invention, the control method is 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 method obtains a correlation between two channel estimation results that are different in time, and controls the transmission of the reference signal by the transmitting device to the receiving device according to 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, wherein the control program enables the computer to perform a correlation acquisition function that acquires a correlation between two channel estimation results that are different in time, and a control function that controls the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation. [Effects of the Invention]

[0012] According to the present invention, it becomes possible to improve the accuracy of channel estimation. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows an example configuration of a control device according to the first embodiment of the present invention. [Figure 2] This figure shows an example of the operation flow of the control device according to the first embodiment of the present invention. [Figure 3] This figure shows an example of the configuration of a system including a control device according to a second embodiment of the present invention. [Figure 4] This figure shows an example of the configuration of a control device according to a second embodiment of the present invention. [Figure 5] This figure shows an example of the operation flow of the control device according to the second embodiment of the present invention. [Figure 6] This figure shows examples of the operation flow of the control device according to the second to fourth embodiments of the present invention. [Figure 7] This figure shows examples of the operation flow of the control device according to the second to fourth embodiments of the present invention. [Figure 8] It is a diagram showing a configuration example of a system including a control device according to a third embodiment of the present invention. [Figure 9] It is a diagram showing a configuration example of a control device according to a third embodiment of the present invention. [Figure 10] It is a diagram showing an example of an operation flow of a control device according to a third embodiment of the present invention. [Figure 11] It is a diagram showing a configuration example of a system including a control device according to a fourth embodiment of the present invention. [Figure 12] It is a diagram showing a configuration example of a control device according to a fourth embodiment of the present invention. [Figure 13] It is a diagram showing an example of an operation flow of a control device according to a fourth embodiment of the present invention. [Figure 14] It is a diagram showing an example of a hardware configuration according to each embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0014] [First Embodiment] The first embodiment of the present invention will be described. A specific example of the control device 10 in the first embodiment is 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] FIG. 1 shows a configuration example of the control device 10 of the present embodiment. The control device 10 of the present embodiment includes a correlation acquisition unit 11 and a control unit 12.

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

[0017] The correlation acquisition unit 11 acquires the correlation between the results of two channel estimations that are different in time.

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

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

[0020] The correlation acquisition unit 11 acquires the correlation between the results of two channel estimations that are different in time (step S101).

[0021] The control unit 12 controls the transmission of a 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 comprising 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 channel estimation results that are different in time. The control unit 12 controls the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation. As a result, the control device 10 can grasp fluctuations in the wireless environment based on the magnitude of the correlation and control the transmission of the reference signal according to the fluctuations in the wireless environment. Therefore, it becomes possible to improve the accuracy of channel estimation.

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

[0024] First, Figure 3 shows an example of the system configuration including the control device 20 of this embodiment. This system includes the control device 20 and the 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 transmitting device 60 is a base station. In this case, one or more control devices 20 can be connected to the transmitting device 60. In this case, the reference signal is transmitted from the base station to the terminal device.

[0027] Next, Figure 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 estimation unit 24, a correlation acquisition 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 a reference signal. The estimation unit 24 can use any method for channel estimation.

[0030] The reference signal is, for example, an SRS. The transmitter 60 periodically transmits SRS according to the settings for the SRS transmission period. The transmitter 60 can also transmit SRS when instructed by the control device 20 to transmit an aperiodic SRS.

[0031] The correlation acquisition unit 21 acquires the correlation between two channel estimation results that are different in time. 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. Alternatively, for example, the correlation acquisition unit 21 may calculate the correlation between the latest channel estimation result and the channel estimation result performed most recently prior to the latest channel estimation.

[0032] For example, suppose an SRS is transmitted in the nth slot, and the slot that transmitted the SRS most recently before the nth slot was the npth slot. In this case, the correlation acquisition unit 21 calculates the correlation ρ between the channel estimation result based on the SRS of the nth slot and the channel estimation result based on the SRS of the npth slot.

[0033] The control unit 22 controls the transmission of the reference signal according to the magnitude of the correlation ρ calculated by the correlation acquisition unit 21. In this embodiment, the control unit 22 controls the transmission of the reference signal by sending instructions regarding the transmission of the reference signal to the transmission device 60.

[0034] For example, the control unit 22 shortens the transmission interval of the reference signal when low correlation conditions occur frequently. This allows for more reference signals to be transmitted per unit time, enabling the control device 20 to increase the frequency of channel estimation. As a result, when the wireless environment fluctuates frequently, channel estimation is performed in accordance with the fluctuations. Therefore, the accuracy of channel estimation can be improved. The specific control method will be described later.

[0035] Next, Figure 5 shows an example of the 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 channel estimation performed this time and, for example, the result of the channel estimation performed last time (step S203).

[0038] The control unit 22 controls the transmission of the reference signal according to the magnitude of the correlation ρ (step S204). In the case of 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 transmission device 60.

[0039] Next, a specific method of control performed by the control unit 22 will be described using FIG. 6. FIG. 6 is 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. Tρa < Tρb < Tρc < Tρd. Note that two correlation thresholds, Tρb and Tρc, may be used. In this case, in FIG. 6, the correlation threshold Tρa may be regarded as the lower limit value of the possible values of the correlation ρ, and Tρd may be regarded as the upper limit value of the possible values of the correlation ρ.

[0041] When the correlation ρ satisfies Tρa < ρ < Tρb (YES in step S301), the control unit 22 adds 1 to the counter Nab (step S302). Also, when the correlation ρ satisfies Tρc < ρ < Tρd (YES in step S303), the control unit 22 adds 1 to the counter Ncd (step S304). Note that 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, at regular intervals or each time channel estimation is performed a predetermined number of times.

[0042] Next, the control unit 22 compares counters Nab and Ncd (step S305). When the wireless environment fluctuates frequently, many conditions occur where the correlation ρ is small. Therefore, when the wireless environment fluctuates frequently, counter Nab becomes larger than counter Ncd. In this case, the control unit 22 controls the transmission interval of the reference signal to be reduced.

[0043] More specifically, if counter Nab is greater than counter Ncd (YES in step S305), the control unit 22 further compares counter Nab with counter threshold Tab. If counter Nab is less than or equal to 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 for the transmitting device 60 as a setting related to SRS. By shortening the transmission period of the reference signal in this way, the control unit 20 can increase the frequency of channel estimation. As a result, when the wireless environment fluctuates frequently, channel estimation is performed in accordance with the fluctuations.

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

[0045] When shortening the SRS transmission interval by changing the SRS transmission period, it takes longer to reconfigure the SRS resources than when transmitting aperiodic SRS. Also, aperiodic SRS has higher priority than semi-persistent SRS and periodic SRS. More specifically, if the OFDM (Orthogonal Frequency Division Multiplexing) symbols of aperiodic SRS and semi-persistent or periodic SRS overlap, the transmitter 60 transmits only the aperiodic SRS (Non-Patent Literature 1). Therefore, the control unit 22 can shorten the reference signal transmission interval in a shorter time than changing the transmission period by instructing the transmitter 60 to transmit aperiodic SRS when the wireless environment is fluctuating more frequently.

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

[0047] If counter Ncd is greater than counter threshold Tcd (YES in step S309), it indicates that a high correlation ρ occurs more frequently. In this case, it can be inferred that the wireless environment is more stable. Therefore, in this case, the control unit 22 sets the transmitter 60 to lengthen the period of the reference signal (step S311). For example, the control unit 22 sets a longer period SPS as a setting for SRS for the transmitter 60. Alternatively, in step S311, the control unit 22 may lengthen the period of, for example, the periodic SRS. Lengthening the transmission period of the reference signal in this way can reduce the power required for transmitting and receiving the reference signal. Furthermore, the transmitter 60 can improve its throughput.

[0048] For example, the transmitting device 60 can use a symbol in which the SRS does not exist and a PRB (physical resource block) as other UL (Uplink) channels. Other UL channels are, for example, PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), and the like. For example, the transmitting device 60 can improve the UL throughput by using a symbol in which the SRS does not exist and a PRB as PUSCH.

[0049] Next, another example of the specific method of control performed by the control unit 22 will be described using FIG. 7. FIG. 7 is an example of the operation flow of the control device 20 of the present embodiment and is a specific example of step S204 in FIG. 5.

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

[0051] When 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 channel estimation is performed a predetermined number of times.

[0052] Next, the control unit 22 compares the counter Ne with the counter threshold value Te. When the counter Ne is greater than the counter threshold value Te (YES in step S403), the radio environment is in a state where it fluctuates frequently. In this case, the control unit 22 performs control to shorten the transmission interval of the reference signal. For example, the transmitting device 60 is caused to transmit an aperiodic 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 radio environment fluctuates frequently, channel estimation is performed following the fluctuation.

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

[0054] Furthermore, in step S307 in Figure 6 and step S404 in Figure 7, the control unit 22 performs control to shorten the reference signal transmission interval. Alternatively, 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 in one SRS transmission.

[0055] Channel estimation is performed within PRBs containing SRS symbols. Increasing the number of SRS symbols in a slot or the number of PRBs used in a single SRS transmission increases the number of PRBs subject to channel estimation. Therefore, when the wireless environment fluctuates frequently, increasing the number of SRS symbols and PRBs can suppress the decrease in channel estimation accuracy. As a result, the accuracy of channel estimation can be improved.

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

[0057] Furthermore, the control unit 22 may, instead of increasing the transmission interval of the reference signal, perform control to reduce at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission (step S311 in Figure 6). This improves the throughput of data other than the reference signal among the data transmitted from the transmitting device 60 to the control unit 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 comprising 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 channel estimation results that are different in time. The control unit 22 controls the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation. As a result, the control device 20 can grasp fluctuations in the wireless environment based on the magnitude of the correlation and control the transmission of the reference signal according to fluctuations in the wireless environment. Therefore, it becomes possible to improve the accuracy of channel estimation.

[0059] Furthermore, the control unit 22 controls the transmission interval of the reference signal when the number of times the correlation is less than the correlation threshold is greater than the number of comparison values. Specifically, the comparison values ​​are, for example, the counter Ncd in Figure 6 and the counter threshold Te in Figure 7. The control to reduce the transmission interval is either a control to shorten the transmission period of the reference signal, or a control to have the transmitting device transmit a non-periodic reference signal. This allows the frequency of channel estimation to be increased by increasing the transmission frequency of the reference signal when there are many fluctuations in the wireless environment, thereby improving the accuracy of channel estimation.

[0060] Furthermore, the control unit 22 increases the transmission interval of the reference signal when the number of times the correlation is greater than the correlation threshold is greater than the comparison value. Specifically, the comparison value is, for example, the counter threshold Tcd in Figure 6. This improves the throughput of data other than the reference signal when the wireless environment is stable.

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

[0062] Furthermore, the control unit 22 may increase at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission if the number of times the correlation is less than the correlation threshold is greater than the comparison value. Specifically, the comparison value is, for example, the counter Ncd in Figure 6 or the counter threshold Te in Figure 7. This suppresses the decrease in channel estimation accuracy when there are many fluctuations in the wireless environment and improves the accuracy of channel estimation.

[0063] Furthermore, 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 in one SRS transmission if the number of times the correlation is greater than the correlation threshold is greater than the comparison value. Specifically, the comparison value is, for example, the counter threshold Tcd in Figure 6. This can improve the throughput of data other than the reference signal.

[0064] Furthermore, the control device 20 in 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 the reference signal. The estimation unit 24 performs channel estimation. The correlation acquisition unit 21 calculates the correlation. The control unit 22 controls the transmission of the reference signal by sending instructions regarding the transmission of the reference signal to the transmitting device. In this way, the control device 20 can realize the processing of this embodiment.

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

[0066] First, Figure 8 shows an example of the system configuration including the control device 30 of this embodiment. This system includes the control device 30 and the 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] Next, Figure 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 acquisition unit 31, and a control unit 32.

[0070] The transmitting unit 35 transmits a reference signal to the receiving device 70.

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

[0072] The correlation acquisition unit 31 acquires the correlation between two channel estimation results that are different in time. 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 channel estimation results that are different in time.

[0073] The control unit 32 controls the transmission of the reference signal according to 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 35.

[0074] Next, Figure 10 shows an example of the 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 results of the channel estimation performed this time and, for example, the results of the channel estimation performed last time (step S502).

[0077] The control unit 32 controls the transmission of the reference signal according to 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 according to the control unit 32's control. The specific control method is the same as in the second embodiment (Figures 6 and 7), so a detailed explanation is 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 comprising 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 channel estimation results that are different in time. The control unit 32 controls the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation. As a result, the control device 30 can grasp fluctuations in the wireless environment based on the magnitude of the correlation and control the transmission of the reference signal according to the fluctuations in the wireless environment. Therefore, it becomes 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 channel estimation result from the receiving device 70. The correlation acquisition unit 31 calculates the correlation. In this way, the control device 30 can realize the processing of this embodiment.

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

[0081] First, Figure 11 shows an example of the system configuration including the control device 40 of this embodiment. This system includes the control device 40 and the 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] Next, Figure 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 acquisition unit 41, and a control unit 42.

[0085] The transmitting unit 45 transmits a reference signal to the receiving device 70.

[0086] The correlation acquisition unit 41 acquires the correlation between two channel estimation results that are different in time. The correlation acquisition unit 41 in this embodiment receives the correlation ρ from the receiving device 70. 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 in the second embodiment are performed by the receiving device 70.

[0087] The control unit 42 controls the transmission of the reference signal according to the magnitude of the correlation ρ 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, Figure 13 shows an example of the operation flow of the control device 40 of this embodiment.

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

[0090] The control unit 42 controls the transmission of the reference signal according to 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 according to the control unit 42's control. The specific control method is the same as in the second embodiment (Figures 6 and 7), so a detailed explanation is 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 comprising 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 channel estimation results that are different in time. The control unit 42 controls the transmission of the reference signal by the transmitting device to the receiving device according to the magnitude of the correlation. As a result, the control device 40 can grasp the fluctuations in the wireless environment based on the magnitude of the correlation and control the transmission of the reference signal according to the fluctuations in the wireless environment. Therefore, it becomes possible to improve the accuracy of channel estimation.

[0092] Furthermore, the control device 40 in 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 acquisition unit 41 receives the correlation from the receiving device 70. In this way, the control device 40 can realize the processing of this embodiment.

[0093] [Example Hardware Configuration] This section describes an example of hardware resource configurations for implementing the control devices (10, 20, 30, 40) in each embodiment of the present invention described above using a single information processing device (computer). Note that the control device may be implemented using at least two information processing devices, either physically or functionally. Furthermore, the control device may be implemented as a dedicated device. Also, only some of the functions of the control device may be implemented using information processing devices.

[0094] Figure 14 is a schematic diagram showing an example of the hardware configuration of an information processing device capable of realizing the control devices of each embodiment of the present invention. The information processing device 90 includes a communication interface 91, an input / output interface 92, an arithmetic unit 93, a storage device 94, a non-volatile storage device 95, and a drive device 96.

[0095] For example, the correlation acquisition unit 11 and control unit 12 in Figure 1 can be implemented using the arithmetic unit 93.

[0096] The communication interface 91 is a communication means for the control device of each embodiment to communicate with an external device by wire and / or wirelessly. If the control device is implemented using at least two information processing devices, these devices may be connected via the communication interface 91 to enable mutual communication.

[0097] The input / output interface 92 is a human-machine interface, such as a keyboard as an example of an input device, or a display as an output device.

[0098] The arithmetic unit 93 is implemented by a general-purpose CPU (Central Processing Unit) or microprocessor, as well as multiple electrical circuits. The arithmetic unit 93 can, for example, read various programs stored in the non-volatile memory device 95 into the memory device 94 and execute processing according to the read programs.

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

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

[0101] The drive device 96 is, for example, a device that processes data reading and writing to the 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 disc, magneto-optical disc, or semiconductor flash memory.

[0103] Each embodiment of the present invention may be implemented, for example, by configuring a control device with an information processing device 90 illustrated in Figure 14, and supplying this control device with a program capable of realizing the functions described in each embodiment above.

[0104] In this case, the embodiment can be realized by having the arithmetic unit 93 execute the program supplied to the control device. Furthermore, it is also possible to configure some, rather than all, of the functions of the control device in the information processing device 90.

[0105] Furthermore, the above program may be recorded on the recording medium 97 and stored in the non-volatile storage device 95 as appropriate during the shipment or operation phase of the control device. In this case, the method of supplying the above program may be to install it into the control device using an appropriate jig during the manufacturing phase before shipment or during the operation phase. Alternatively, the method of supplying the above program may be to download it from an external source via a communication line such as the Internet, or other general procedures.

[0106] Some or all of the above embodiments may also be described as follows, but are not limited to the following:

[0107] (Note 1) A control device for controlling 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, Correlation acquisition means for acquiring the correlation between two channel estimation results that are different in time, Control means for controlling the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. A control device equipped with the following features.

[0108] (Note 2) The control means performs control to reduce the transmission interval of the reference signal when the number of times the correlation is less than the correlation threshold is greater than the number of comparison values. The control device described in Appendix 1.

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

[0110] (Note 4) 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 the comparison value. The control device described in Appendix 1.

[0111] (Note 5) The aforementioned reference signal is the Sounding Reference Signal (SRS). The control device described in Appendix 1.

[0112] (Note 6) 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 in one SRS transmission when the number of times the correlation is less than the correlation threshold is greater than the number of comparison values. The control device described in Appendix 5.

[0113] (Note 7) 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 in one SRS transmission when the number of times the correlation is greater than the correlation threshold is greater than the comparison value. The control device described in Appendix 5.

[0114] (Note 8) The control device is the receiving device, A reference signal receiving means for receiving the aforementioned reference signal, Estimation means for performing channel estimation and Furthermore, The correlation acquisition means calculates the correlation, The control means controls the transmission of the reference signal by transmitting instructions regarding the transmission of the reference signal to the transmitting device. The control device described in Appendix 1.

[0115] (Note 9) The control device is the transmitting device, A transmitting means for transmitting the aforementioned reference signal to the receiving device, A result receiving means for receiving the channel estimation result from the receiving device. Furthermore, The correlation acquisition means calculates the correlation. The control device described in Appendix 1.

[0116] (Note 10) The control device is the transmitting device, Transmitting means for transmitting the reference signal to the receiving device Furthermore, The correlation acquisition means receives the correlation from the receiving device. The control device described in Appendix 1.

[0117] (Note 11) 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, Obtain the correlation between the results of two channel estimations that are different in time, Depending on the magnitude of the correlation, the transmitting device controls the transmission of the reference signal to the receiving device. Control method.

[0118] (Note 12) A computer-readable recording medium that stores 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, On the computer, A correlation acquisition function that acquires the correlation between two channel estimation results that are different in time, A control function that controls the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. A computer-readable recording medium containing a control program that enables this functionality.

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

[0120] This application claims priority based on Japanese Patent Application No. 2022-134134, filed on 25 August 2022, and incorporates all of its disclosures herein. [Explanation of Symbols]

[0121] 10, 20, 30, 40 Control devices 11, 21, 31, 41 Correlation acquisition unit 12, 22, 32, 42 Control Unit 23 Reference signal receiving unit 24 Estimation part 35, 45 Transmitter 36 Result receiving unit 60 Transmitter 70 Receiving device 90 Information Processing Equipment 91 Communication Interface 92 Input / Output Interfaces 93 Arithmetic unit 94 Storage device 95 Non-volatile memory devices 96 Drive unit 97 Recording media

Claims

1. A control device for controlling 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, Correlation acquisition means for acquiring the correlation between two channel estimation results that are different in time, Control means for controlling the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. Equipped with, The control means controls, in controlling the transmission of the reference signal, at least one of the number of SRS (Sounding Reference Signal) symbols in one slot and the number of PRB (Physical Resource Block) used in one SRS transmission, or controls the transmission interval of the reference signal. The control means performs control to reduce the transmission interval of the reference signal when the number of times the correlation is less than the correlation threshold is greater than the number of comparison values. Control device.

2. A control device for controlling 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, Correlation acquisition means for acquiring the correlation between two channel estimation results that are different in time, Control means for controlling the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. Equipped with, The control means controls, in controlling the transmission of the reference signal, at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, or controls the transmission interval of the reference signal. 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 the comparison value. Control device.

3. A control device for controlling 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, Correlation acquisition means for acquiring the correlation between two channel estimation results that are different in time, Control means for controlling the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. Equipped with, The control means controls, in controlling the transmission of the reference signal, at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, or controls the transmission interval of the reference signal. The aforementioned reference signal is 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 used in one SRS transmission when the number of times the correlation is less than the correlation threshold is greater than the number of comparison values. Control device.

4. A control device for controlling 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, Correlation acquisition means for acquiring the correlation between two channel estimation results that are different in time, Control means for controlling the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. Equipped with, The control means controls, in controlling the transmission of the reference signal, at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, or controls the transmission interval of the reference signal. The aforementioned reference signal is 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 used in one SRS transmission when the number of times the correlation is greater than the correlation threshold is greater than the comparison value. Control device.

5. The control device is the receiving device, A reference signal receiving means for receiving the aforementioned reference signal, Estimation means for performing channel estimation and Furthermore, The correlation acquisition means calculates the correlation, The control means controls the transmission of the reference signal by transmitting instructions regarding the transmission of the reference signal to the transmitting device. The control device according to any one of claims 1 to 4.

6. The control device is the transmitting device, A transmitting means for transmitting the aforementioned reference signal to the receiving device, A result receiving means for receiving the channel estimation result from the receiving device. Furthermore, The correlation acquisition means calculates the correlation. The control device according to any one of claims 1 to 4.

7. The control device is the transmitting device, Transmitting means for transmitting the reference signal to the receiving device Furthermore, The correlation acquisition means receives the correlation from the receiving device. The control device according to any one of claims 1 to 4.

8. A control method for 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, Obtain the correlation between the results of two channel estimations that are different in time, Depending on the magnitude of the correlation, the transmission of the reference signal by the transmitting device to the receiving device is controlled. In controlling the transmission of the reference signal, control at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, or control the transmission interval of the reference signal. In controlling the transmission of the aforementioned reference signal, If the number of times the correlation is less than the correlation threshold is greater than the number of comparison values, control is performed to reduce the transmission interval of the reference signal. When the number of times the correlation is greater than the correlation threshold is greater than the comparison value, control is performed to increase the transmission interval of the reference signal. If the reference signal is an SRS, and the number of times the correlation is less than the correlation threshold is greater than the number of comparison values, control is provided to increase at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, and If the reference signal is an SRS, and the number of times the correlation is greater than the correlation threshold is greater than the comparison value, control reduces at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission. Perform one of the following controls: Control method.

9. 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, On the computer, A correlation acquisition function that acquires the correlation between two channel estimation results that are different in time, A control function that controls the transmission of the reference signal by the transmitting device to the receiving device, according to the magnitude of the correlation. To make it happen, The control function controls, in controlling the transmission of the reference signal, at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, or controls the transmission interval of the reference signal. The control function described above is: If the number of times the correlation is less than the correlation threshold is greater than the number of comparison values, control is performed to reduce the transmission interval of the reference signal. When the number of times the correlation is greater than the correlation threshold is greater than the comparison value, control is performed to increase the transmission interval of the reference signal. If the reference signal is an SRS, and the number of times the correlation is less than the correlation threshold is greater than the number of comparison values, control is provided to increase at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission, and If the reference signal is an SRS, and the number of times the correlation is greater than the correlation threshold is greater than the comparison value, control reduces at least one of the number of SRS symbols in one slot and the number of PRBs used in one SRS transmission. Perform one of the following controls: Control program.

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