Communication device and program

Abstract

To provide a communication device for appropriately controlling frequency of sensing processing.SOLUTION: A communication device includes transmission means for transmitting a sensing signal, and detection means for detecting an obstacle by receiving a reception result of the sensing signal from a wireless device that receives the sensing signal. The detection means periodically executes a first process of detecting obstacles by receiving, from the wireless device, first reception results for each of the plurality of reception beams of a first sensing signal transmitted by each of a plurality of transmission beams, and when tracking a first obstacle detected in the first reception results, executes a second process. In the second process, the detection means notifies the wireless device of a resource for transmitting a second sensing signal and a combination of a target transmission beam and a target reception beam, and receives, from the wireless device, a second reception result for the target reception beam of the second sensing signal transmitted by the target transmission beam using the resource.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to sensing technology using a communication device. [Background technology]

[0002] Non-Patent Document 1 discloses various use cases of sensing services in mobile communication networks. In one of the configurations disclosed in Non-Patent Document 1, a base station (BS), which is a wireless communication device, transmits a signal for sensing (hereinafter referred to as a sensing signal), and a wireless device (WD) feeds back the reception result of the sensing signal to the base station, thereby allowing the mobile communication network to collect sensing data. Based on the collected sensing data, the mobile communication network detects the environment of the area where the base station provides service (hereinafter referred to as a service area), for example, obstacles that may obstruct the propagation of wireless signals. Note that obstacles include stationary objects such as buildings and moving objects such as vehicles. By using a signal used for communication as a sensing signal, communication and sensing can be performed efficiently.

[0003] Patent Document 1 discloses a system called ISAC (Integrated Sensing and Communication) that integrates sensing signals and communication signals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 205961 [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TR 22.837,V19.0.0,June 2023 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, as shown in FIG. 1, BS1 is configured to transmit N (N is an integer equal to or greater than 1) transmit beams T#1 to T#N, and WD2 is configured to receive M (M is an integer equal to or greater than 1) receive beams R#1 to R#M. Also, BS1 is configured to transmit a sensing signal using each of the N transmit beams at a transmission timing, which is a recurring timing. Note that, for example, a downlink reference signal (RS) specified in 3GPP (registered trademark) can be used as the sensing signal. For example, a channel state information (CSI)-RS or a positioning reference signal (PRS) can be used as the sensing signal.

[0007] WD2 receives the sensing signals transmitted by BS1 using each of the N transmission beams and each of the M reception beams, thereby obtaining a total of N × M reception results. BS1 can detect an obstacle and its location based on the direction of the transmission beam that transmitted the sensing signal, the direction of the reception beam that WD2 received the sensing signal, and the delay between BS1 transmitting the sensing signal and WD2 receiving the sensing signal. For example, as shown in Figure 2, when WD2 receives a sensing signal transmitted using transmission beam T#1 using reception beam R#2, it can detect the presence of obstacle 3 shown in Figure 2. Furthermore, if obstacle 3 is moving, the frequency of the sensing signal received using reception beam R#2 shifts due to the Doppler effect depending on the obstacle's moving speed and direction. Therefore, BS1 can determine the moving speed and direction of obstacle 3 based on the Doppler shift of the sensing signal. WD#2 feeds back each reception result to BS1. The feedback information may include the received power, propagation delay, and frequency Doppler shift of the sensing signal for each combination of transmitting beam and receiving beam.

[0008] For example, if it is desired to track a fast-moving obstacle, it is necessary to shorten the transmission period of the sensing signal. However, the transmission periods of RSs such as CSI-RS and PRS, which are expected to be used as sensing signals, are defined by standards and are not sufficient to track a fast-moving obstacle. For this reason, it is possible to define and use resources for new sensing signals with shorter transmission periods. However, transmitting sensing signals at short intervals even in situations where there is no need to track a fast-moving obstacle increases the overhead for sensing. Furthermore, increasing the frequency of sensing increases the amount of calculations required by the BS and WD.

[0009] The present disclosure provides a technique for appropriately controlling the frequency of sensing processing. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a communication device comprises a transmitting means for transmitting a sensing signal using each of a plurality of transmission beams, and a detecting means for detecting an obstacle by receiving a reception result of the sensing signal from a wireless device that receives the sensing signal using each of a plurality of reception beams, wherein the detecting means periodically performs a first process for detecting an obstacle by receiving a first reception result of a first sensing signal transmitted using each of the plurality of transmission beams using each of the plurality of reception beams from the wireless device, and when tracking a first obstacle detected in the first reception result, performs a second process, wherein the detecting means notifies the wireless device of a resource for transmitting a second sensing signal and a combination of a target transmission beam and a target reception beam, and receives from the wireless device a second reception result of the second sensing signal transmitted using the target transmission beam using the resource using the target reception beam. [Effects of the Invention]

[0011] According to the present disclosure, the frequency of sensing processing can be appropriately controlled. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of a sensing configuration. [Figure 2] FIG. 10 is a diagram showing an example of obstacle detection. [Figure 3] FIG. 4 is an explanatory diagram of a first process and a second process. [Figure 4] FIG. 1 is a sequence diagram according to one embodiment. [Figure 5] FIG. 10 is a diagram showing an example of a reception result. [Figure 6] FIG. 10 is a diagram showing another example of a reception result. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a base station device. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0014] FIG. 1 shows a sensing configuration used to explain the embodiment. As shown in FIG. 1, BS1 is configured to transmit N transmission beams T#1 to T#N. WD2 is also configured to receive M reception beams R#1 to R#M. Note that at least one of N and M is an integer equal to or greater than 2, and the other is an integer equal to or greater than 1. Alternatively, N and M are both integers equal to or greater than 2. WD2 feeds back to BS1 the reception results of the sensing signals transmitted by BS1. For example, if BS1 transmits sensing signals using each of N transmission beams and WD2 receives sensing signals using each of M reception beams, WD2 feeds back N×M reception results to BS1. Note that while FIG. 1 shows only one WD2, BS1 can perform the sensing process described below individually with each of the multiple WD2s.

[0015] In this embodiment, the sensing process includes two processes, a first process and a second process. FIG. 3 is an explanatory diagram of the relationship between the first process and the second process. As shown in FIG. 3, the first process is repeated in a period T1. The BS1 transmits a first sensing signal using each of N transmission beams in each period T1. The first sensing signal is, for example, a downlink RS such as CSI-RS or PRS, and the period T1 follows the period of the RS used as the first sensing signal, such as CSI-RS or PRS. The WD2 receives the first sensing signal using each of M reception beams in each period T1 and feeds back the N×M reception results to the BS1. As a result, the BS1 detects obstacles present in its service area in each period T1.

[0016] The second process is executed as needed, such as when tracking one or more obstacles detected in the first process. BS1 transmits a second sensing signal in the second process, and notifies WD2 of the resources used for transmitting the second sensing signal each time. In FIG. 3, the second process is executed five times within the period T1 from when the first process is executed until the next first process is executed. Therefore, obstacles moving at a fast speed can be tracked. Furthermore, BS1 does not execute the second process constantly, but executes it only as needed, thereby suppressing the execution of unnecessary sensing processes. In other words, the frequency of sensing processes can be appropriately controlled.

[0017] Fig. 4 is a sequence diagram according to this embodiment. In the sequence of Fig. 4, S1 and S2 are sequences of a first process, and S4 to S7 are sequences of a second process. Furthermore, S3 is a process for determining whether or not to execute the second process.

[0018] BS1 transmits a first sensing signal to WD2 using each of N transmission beams at S1. As described above, the first sensing signal is a downlink RS. At S2, WD2 transmits reception results (first reception results) of the first sensing signals transmitted using each of the N transmission beams at each of M reception beams to BS1. BS1 detects an obstacle based on a total of N × M first reception results. FIG. 5A shows an example of a first reception result. In the following description, N = M = 8. That is, BS1 is configured to transmit transmission beams T#1 to T#8, and WD2 is configured to receive reception beams R#1 to R#M. #nm (n and m are integers from 1 to 8) in FIG. 5A corresponds to the first reception result of the first sensing signal transmitted using transmission beam T#n and received using reception beam R#m. Hereinafter, the first reception result indicated by #nm will be referred to as first reception result #nm. The shaded first reception results #32 and #67 in Figure 5(A) indicate first reception results in which an obstacle is detected. That is, in the example of Figure 5(A), a first obstacle is detected in the first reception result of reception beam R#2 of the first sensing signal transmitted by transmission beam T#3, and a second obstacle different from the first obstacle is detected in the first reception result of reception beam R#7 of the first sensing signal transmitted by transmission beam T#6. As described above, the moving speed of the obstacle relative to the WD can be estimated based on the Doppler shift amount of the first sensing signal.

[0019] In S3, BS1 determines based on a predetermined criterion whether or not there is an obstacle to be tracked, based on the first reception result received in S2. If there is no obstacle to be tracked, the second process is not performed, and therefore the processes of S4 to S7 are omitted. If there is an obstacle to be tracked, BS1 performs the second process shown in S4 to S7. The following description will be given assuming that BS1 has decided in S3 to track the first obstacle detected in the first reception result #32 of FIG. 5(A).

[0020] In S4, BS1 notifies WD2 of the tracking configuration for the first obstacle. The tracking configuration includes an identifier (target ID) assigned to the first obstacle by BS1, radio resources used to transmit the second sensing signal in S5, and a detection range. The target ID is used to identify an obstacle when tracking multiple obstacles, and is included in the second reception result transmitted by WD2 in S6. The radio resources are indicated by a combination of time resources and frequency resources. The detection range indicates a combination of a transmission beam and a reception beam from which WD2 should receive the second sensing signal.

[0021] Figure 5(B) shows an example of a detection range that BS1 notifies WD2. The shaded area in Figure 5(B) indicates the detection range. According to Figure 5(B), BS1 notifies WD2 that WD2 will acquire the reception results of the second sensing signal transmitted using transmission beam T#2 at each of reception beams R#1 to R#3, the reception results of the second sensing signal transmitted using transmission beam T#3 at reception beams R#1 and R#3, and the reception results of the second sensing signal transmitted using transmission beam T#4 at reception beams R#1 to R#3, and feed them back to BS1 as second reception results.

[0022] BS1 can set the detection range based on, for example, the moving speed of the first obstacle determined based on the Doppler shift amount of the first reception result #32. That is, BS1 can estimate an area where the first obstacle is likely to be present at the timing of transmitting the second sensing signal based on the moving speed of the first obstacle, and set a combination of a transmitting beam and a receiving beam that can detect an obstacle in the estimated area as the detection range. Furthermore, when determining the moving direction of the first obstacle, the detection range can be set based on the moving speed and moving direction of the first obstacle. FIG. 6(A) shows an example of a case where the detection range is set based on the moving speed and moving direction of the first obstacle.

[0023] BS1 can further determine the size of the detection range based on the moving speed of the first obstacle determined based on the Doppler shift amount of the first reception result #32. As an example, the detection range can be made larger as the moving speed of the first obstacle increases.

[0024] In S5, BS1 transmits a second sensing signal using the resources notified to WD2 in S4. Note that the second sensing signal may be configured to be transmitted only using transmission beams included in the detection range. In S6, WD2 transmits a second reception result to BS1. The second reception result includes the reception result of the second sensing signal in each of the detection ranges notified to WD2 in S4.

[0025] BS1 determines whether a first obstacle is detected in the second reception results received in S6. For example, assume that BS1 notifies WD2 of the detection range shown in FIG. 5(B) in S4 and acquires eight second reception results in S6. If BS1 detects an obstacle in only one of the eight second reception results, it may determine that the obstacle is a first obstacle. Furthermore, if BS1 detects an obstacle in only one of the eight second reception results, but the moving speed or direction of the obstacle is significantly different from what was determined when first reception result #32 was received, it may determine that the obstacle is not a first obstacle. In this case, BS1 may determine that it failed to track the first obstacle. Furthermore, if BS1 detects an obstacle in two or more of the eight second reception results, it may determine the first obstacle from the multiple obstacles based on the movement speed and movement direction of the first obstacle determined when first reception result #32 was received and the movement speeds and movement directions of the multiple obstacles detected in each of the multiple second reception results. Note that if it is determined that none of the multiple obstacles are the first obstacle, BS1 may determine that it has failed to track the first obstacle. Furthermore, if it does not detect an obstacle in any of the eight second reception results, BS1 may determine that it has failed to track the first obstacle.

[0026] Also, when BS1 performs a second process for tracking a first obstacle among a plurality of WD2s, BS1 can also determine whether the first obstacle is detected in the second reception results from each WD2 by using the second reception results received from each of the plurality of WD2s.

[0027] When BS1 fails to track the first obstacle, in S7, it determines to stop the second process. On the other hand, when BS1 determines that the first obstacle is detected in the second reception results, it determines to continue the second process. In this case, BS1 performs the second process shown in S4 to S7 again. Note that even if the first obstacle is detected in the second reception results, the tracking of the first obstacle can be stopped when a predetermined condition is satisfied. For example, when it is determined that the first obstacle has moved outside the service area of BS1 at the timing of executing the next second process, BS1 can stop tracking the first obstacle.

[0028] When continuing the second process, the detection range notified in S4 of the next second process can be determined based on the second reception results in S6 immediately before. As an example, when the first obstacle is detected in the second reception result #43 in the reception beam #R3 of the second sensing signal transmitted by the transmission beam #T4, BS1 can notify WD2 of the detection range shown in FIG. 6(B) in S4 of the next second process.

[0029] In this embodiment, WD2 transmits to BS1 the reception results including information on the received sensing signal, for example, received power, propagation delay, and Doppler shift amount, and BS1 has detected an obstacle. However, the configuration may also be such that WD2 detects an obstacle and notifies BS1 of the combination of the transmission beam and reception beam that detected the obstacle, as well as the moving speed and / or moving direction.

[0030] <Configuration of BS1> FIG. 7 shows an example of the configuration of BS1. Note that FIG. 7 shows only the parts necessary for explaining the embodiment, and omits parts of BS1 that are not necessary for explaining the embodiment. The transmitter 11 is configured to transmit signals including sensing signals using each of a plurality of transmission beams. The receiver 12 is configured to receive signals using at least one reception beam. For example, the receiver 12 is configured to receive reception results transmitted by WD2. The detector 10 controls sensing processing including first processing and second processing. The detector 10 detects obstacles based on reception results of sensing signals received from WD2.

[0031] In the first process, the detection unit 10 causes the transmission unit 11 to transmit a first sensing signal using each of a plurality of transmission beams. The first sensing signal is, for example, a downlink RS such as CSI-RS or PRS, and the resource for transmitting the first sensing signal is also known to the WD2. The detection unit 10 obtains from the WD2 first reception results for each of a plurality of reception beams of the first sensing signal transmitted using each of the plurality of transmission beams, and detects an obstacle. The resource for transmitting the first reception results is also determined in advance between the BS1 and the WD2. The detection unit 10 periodically executes the first process.

[0032] The detection unit 10 executes a second process when tracking an obstacle. In the second process, the detection unit 10 notifies the WD2 of the resources for transmitting the second sensing signal and the combination of the target transmission beam and the target reception beam. After notifying the WD2, the BS1 transmits the second sensing signal using the resources notified to the WD2. The second sensing signal is transmitted at least by the target transmission beam notified to the WD2. After transmitting the second sensing signal, the BS1 receives from the WD2 a second reception result of the second sensing signal transmitted by the target transmission beam by the target reception beam. Note that there may be one or more combinations of target transmission beams and target reception beams notified to the WD2, and the combination may be determined based on the combination of transmission beams and reception beams that last detected the obstacle to be tracked. The detection unit 10 may determine the combination of target transmission beams and target reception beams to be notified to the WD2 based on the moving speed and / or moving direction of the obstacle to be tracked. Furthermore, the detection unit 10 may determine the number of combinations of target transmitting beams and target receiving beams to notify the WD2 based on the moving speed of the obstacle being tracked. The time interval of the resources that the BS1 can use to transmit the second sensing signal is set to be shorter than the period of the first process.

[0033] The BS1 may be realized by a single device, or may be composed of multiple devices located in different locations, such as a radio unit (RU), a distributed unit (DU), a central unit (CU), a baseband unit (BBU), and a remote radio unit (RRU). Furthermore, the function of the detector 10 in FIG. 7 may be provided in an external communication device connected to the BS1. Furthermore, while the BS (base station device) 1 has been described as transmitting a sensing signal, the device transmitting the sensing signal is not limited to a base station device in a mobile communication network, but may be a wireless communication device such as a wireless LAN access point device. Furthermore, the WD2 is not limited to a wireless device in a mobile communication network, but may be any wireless device that accesses a wireless communication device such as the BS1 according to any wireless communication standard.

[0034] The present disclosure further provides a program executable on one or more processors. The program includes instructions that, when executed by one or more processors of an apparatus, cause the apparatus to function as a communications apparatus, such as a BS1. The present disclosure also provides a non-transitory computer-readable storage medium having the program stored thereon. The present disclosure also provides a sensing method according to the content described in FIGS. 3 and 4. The present disclosure also provides a program for causing an apparatus having one or more processors to execute the method, and a non-transitory computer-readable storage medium having the program stored thereon.

[0035] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0036] This configuration makes it possible to appropriately control the frequency of sensing processing, thereby contributing to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which states, "Build resilient infrastructure, promote sustainable industrialization, and foster innovation." [Explanation of symbols]

[0037] 11: Transmitter, 10: Detector

Claims

1. a transmitting means for transmitting a sensing signal using each of a plurality of transmission beams; a detection means for detecting an obstacle by receiving reception results of the sensing signals from wireless devices that receive the sensing signals via each of a plurality of reception beams; Equipped with the detection means periodically executes a first process for detecting an obstacle by receiving from the wireless device a first reception result for each of the plurality of reception beams of a first sensing signal transmitted by each of the plurality of transmission beams, and executes a second process when tracking a first obstacle detected in the first reception result; In the second processing, the detection means notifies the wireless device of the resource for transmitting the second sensing signal and the combination of the target transmitting beam and the target receiving beam, and receives from the wireless device the second reception result at the target receiving beam of the second sensing signal transmitted at the target transmitting beam using the resource.

2. The communication device of claim 1, wherein the detection means determines one or more combinations of the target transmit beam and the target receive beam based on the combination of the first transmit beam and the first receive beam that detected the first obstacle and notifies the wireless device of the combination.

3. The communication device according to claim 2 , wherein the detection means determines the one or more combinations further based on a Doppler shift amount of the first transmission beam received by the wireless device in the first reception beam.

4. The communication device according to claim 3 , wherein the detection means determines the number of the one or more combinations based on the amount of Doppler shift.

5. The communication device described in claim 2, wherein when the detection means performs the next second processing due to the detection of the first obstacle in the second reception result, the detection means determines one or more combinations of the target transmission beam and the target receiving beam to notify the wireless device for the next second processing based on the combination of the target transmission beam and the target receiving beam that detected the first obstacle.

6. The communication device according to claim 5 , wherein a period from when the second process is performed until when the next second process is performed is shorter than a cycle of the first process.

7. The communication device according to claim 1 , wherein the first sensing signal is a downlink reference signal (RS).

8. The communication device of claim 7 , wherein the first sensing signal includes at least one of a channel state information (CSI)-RS and a positioning reference signal (PRS).

9. A program that, when executed by one or more processors of a device having one or more processors, causes the device to function as a communication device according to any one of claims 1 to 8.

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