Transmitting node and wireless communication system

Abstract

Provided is a transmitting node in a wireless communication system in which: the transmitting node transmits a sensing signal; a receiving node receives the sensing signal, measures wireless quality at the time of receiving the sensing signal, and transmits a measurement result to the transmitting node; and the transmitting node uses the measurement result to sense a target. The transmitting node comprises: a transmission unit that transmits a first sensing signal having a first directivity and a second sensing signal having a second directivity; a reception unit that receives, from the receiving node, a first measurement result regarding the wireless quality at the time of receiving the first sensing signal at the receiving node and a second measurement result regarding the wireless quality at the time of receiving the second sensing signal at the receiving node; and a control unit that performs a first determination process for determining an excluded receiving node to be excluded from sensing from among a plurality of the receiving nodes according to the reception quality in the first measurement result, estimates a reflection position of the second signal from the second measurement result, performs a second determination process for determining, according to the estimated estimation position, the excluded receiving node from among the receiving nodes other than the excluded receiving node determined by the first determination process, and transmits a quality report stop instruction that instructs the excluded receiving nodes not to transmit the measurement result.

Description

Transmission Node and Wireless Communication System

[0001] The present invention relates to a transmission node and a wireless communication system.

[0002] In recent years, in wireless communication systems, the integration of the physical space and the cyber space has been expected (Cyber Physical Fusion), and sensing technologies for acquiring target location information and movement information (direction, speed, acceleration) have attracted attention.

[0003] For example, in the sixth generation of wireless communication (6G), a sensing function has been introduced into the wireless communication system in ISAC (Integrated Sensing and Communication). The communication device can perform sensing using the frequency band and hardware used for wireless communication.

[0004] Sensing is performed, for example, using reflected waves from a target. The transmission node transmits a sensing signal (sensing signal) and physically reflects it at the target. Then, the receiving node receives the reflected wave, measures the wireless quality, and transmits the measurement result to the transmission node. The transmission node calculates the reflection position of the sensing signal based on the measurement result and estimates the position as the target position.

[0005] Technologies related to sensing are described in the following prior art documents.

[0006] WO2024 / 134906, Japanese Patent Application Laid-Open No. 2024-504784

[0007] However, when there are multiple receiving nodes, if all receiving nodes transmit measurement results, a large number of messages will be transmitted in a short time, resulting in a decrease in the efficiency of wireless resources.

[0008] Therefore, one disclosure aims to provide a transmission node and a wireless communication system that can efficiently use wireless resources in sensing.

[0009] A transmitting node in a wireless communication system in which a transmitting node transmits a sensing signal, a receiving node receives the sensing signal, measures the wireless quality at the time of reception of the sensing signal, transmits the measurement result to the transmitting node, and the transmitting node uses the measurement result to sense a target, the transmitting node comprises a transmitting unit that transmits a first sensing signal having a first directionality and a second sensing signal having a second directionality, a first measurement result of the wireless quality at the time of reception of the first sensing signal at the receiving node, and a second measurement result of the wireless quality at the time of reception of the second sensing signal at the receiving node The system includes: a receiving unit that receives the results from the receiving node; a control unit that performs a first determination process to determine which receiving nodes to be excluded from sensing from a plurality of the receiving nodes according to the reception quality in the first measurement result; estimates the reflection position of the second sensing signal from the second measurement result; and performs a second determination process to determine which receiving nodes to be excluded from sensing from the receiving nodes other than the receiving nodes determined in the first determination process according to the estimated position; and transmits a quality report stop instruction to the excluded receiving nodes, instructing them not to transmit the measurement results.

[0010] One disclosure indicates that wireless resources can be used efficiently in sensing.

[0011] Figure 1 shows an example configuration of the wireless communication system 10. Figure 2 shows an example configuration of the transmitting node 200. Figure 3 shows an example configuration of the receiving node 100. Figure 4 shows an example of the processing flowchart of the sensing receiving node determination process S10. Figure 5 shows an example of the sequence of the sensing receiving node determination process S10. Figure 6 shows an example of the processing flowchart of the first determination process S11. Figure 7 shows an example where the reflected wave reaches the receiving node 100-1 at a reception level above the first threshold. Figure 8 shows an example where the reflected wave does not reach the receiving node 100-2 at a reception level above the first threshold. Figure 9 shows examples of the reception levels in Figures 7 and 8. Figure 10 shows an example of the processing flowchart of the second determination process S13. Figure 11 shows examples of signal arrival at receiving nodes 100-1 and 100-2. Figure 12 shows an example of signal arrival at receiving node 100-3. Figure 13 shows an example of an estimated circle obtained by measuring the reflection position from the measurement results of the receiving node 100.

[0012] [First Embodiment] The first embodiment will now be described.

[0013] Figure 1 shows an example configuration of a wireless communication system 10. The wireless communication system 10 includes a transmitting node 200, receiving nodes 100-1 to 100-3, and a target 300. The wireless communication system 10 is a communication system in which the transmitting node 200 performs sensing processing. Sensing processing is a process that uses the reflection of radio waves to acquire information about the target 300. The information acquired (estimated) by the sensing processing includes, for example, the position information and movement information (direction, velocity, acceleration, etc.) of the target 300.

[0014] The transmitting node 200 is a device that wirelessly connects with the receiving nodes 100-1 to 100-3 to perform wireless communication, and is, for example, a base station device such as eNodeB or gNodeB.

[0015] The receiving nodes 100-1 to 100-3 (hereinafter sometimes referred to as receiving node 100) are devices that wirelessly connect to and communicate with the transmitting node 200, and are, for example, terminal devices.

[0016] Target 300 is the object to be sensed and is an object that reflects radio waves (including sensing signals).

[0017] In the sensing process, the transmitting node 200 transmits a sensing signal B1. The target 300 reflects the transmitted sensing signal B1 and generates a reflected wave B2. The receiving node 100-1 receives the reflected wave B2 and measures the radio quality. The receiving node 100-1 transmits a reception quality report M3, which includes the measured radio quality, to the transmitting node 200. The transmitting node 200 uses the received radio quality and the transmitted sensing signal B1 to calculate (estimate) the target's location and movement information.

[0018] Note that the arrangement and number of receiving nodes 100 in Figure 1 are just an example; for example, there may be two or fewer receiving nodes 100, or four or more receiving nodes 100, and they may be placed in other locations.

[0019] Sensing signal B1 is a CP-OFDM signal or a DFT-s-OFDM signal, such as RS (Reference Signal) SRS, CSI-RS (Channel State Information - Reference Signal), SSB, PDSCH, PUSCH, or a newly defined sensing-specific signal.

[0020] Furthermore, a dedicated sensing signal is a signal used exclusively for sensing, such as a chirp signal whose frequency changes over time, as used in FMCW (Frequency Modulated Continuous Wave).

[0021] In the wireless communication system 10, the receiving nodes 100 that transmit reception quality reports in sensing are limited. The limitation of receiving nodes 100 in the wireless communication system 10 is carried out, for example, by removing receiving nodes 100 that have low value for use in sensing. The limitation of receiving nodes 100 is carried out, for example, in two stages. The first stage is an exclusion process based on the reception level of signals other than direct waves. The second stage is an exclusion process based on the estimated position of the target 300.

[0022] <Example Configuration of Transmitting Node 200> Figure 2 shows an example configuration of the transmitting node 200. The transmitting node 200 has a CPU (Central Processing Unit) 210, storage 220, memory 230, antenna 240, and wireless communication circuit 250.

[0023] Storage 220 is an auxiliary storage device such as flash memory, HDD (Hard Disk Drive), or SSD (Solid State Drive) that stores programs and data. Storage 220 stores the sensing control program 221 and the sensing reception node determination program 222.

[0024] Memory 230 is an area for loading programs stored in storage 220. Memory 230 may also be used as an area for programs to store data.

[0025] The wireless communication circuit 250 is a device that communicates wirelessly with the receiving node 100 via the antenna 240. The transmitting node 200 transmits and receives signals (messages) with the receiving node 100 via the wireless communication circuit 250. The wireless communication circuit 250 also transmits sensing signals.

[0026] The CPU 210 is a processor that loads programs stored in the storage 220 into the memory 230, executes the loaded programs, builds each part, and performs each process.

[0027] The CPU 210 constructs the control unit, receiving unit, and transmitting unit by executing the sensing control program 221, and performs sensing control processing. Sensing control processing is the process of controlling wireless communication between the target 300 and the receiving node 100. In the wireless communication control processing, the transmitting node 200 wirelessly connects with the receiving node 100, transmits signals to the receiving node 100, and receives signals from the receiving node 100. In the wireless communication control processing, the transmitting node 200 uses the reception quality report received from the receiving node 100 and the transmitted sensing signals to calculate (estimate) the target's position information, speed information, etc.

[0028] The CPU 210 constructs the control unit, receiving unit, and transmitting unit by executing the sensing receiving node determination program 222, and performs the sensing receiving node determination process. The sensing receiving node determination process is the process of determining the receiving nodes 100 that will be targeted for transmission of the reception quality report used for sensing. In the sensing receiving node determination process, the transmitting node 200 determines the target receiving nodes 100 according to the quality report received from the receiving nodes 100. The transmitting node 200 also sends a quality report stop instruction to the receiving nodes 100 that are not targeted, instructing them to stop sending quality reports.

[0029] The CPU 210 constructs the control unit, receiving unit, and transmitting unit by executing the first decision module 2221 of the sensing receiving node determination program 222, and performs the first decision process. The first decision process is the process of determining which receiving nodes 100 will not be subject to transmission of reception quality reports used for sensing. The transmitting node 200 transmits a first sensing signal and receives the first sensing signal and the measurement results of the reception quality of the reflected wave of the first sensing signal from the receiving nodes 100. The transmitting node 200 then determines which receiving nodes 100 will be excluded (not used) from the sensing process. The transmitting node 200 transmits a quality report stop instruction to the excluded receiving nodes 100. The first sensing signal is, for example, an omnidirectional signal.

[0030] The CPU 210 constructs the control unit, receiving unit, and transmitting unit by executing the second determination module 2222 of the sensing receiving node determination program 222, and performs the second determination process. The second determination process is the process of determining which receiving nodes 100 will not be subject to transmission of reception quality reports used for sensing. The transmitting node 200 transmits a second sensing signal and receives the second sensing signal and the measurement results of the reception quality of the reflected wave of the second sensing signal from the receiving nodes 100. The transmitting node 200 then determines which receiving nodes 100 will be excluded (not used) from the sensing process. The transmitting node 200 sends a quality report stop instruction to the excluded receiving nodes 100. The second sensing signal is, for example, a plurality of directional signals, each having an index (identifier), and is a signal that can be identified on the receiving side.

[0031] <Example Configuration of Receiving Node 100> Figure 3 is a diagram showing an example configuration of a receiving node 100. The receiving node 100 has a CPU 110, storage 120, memory 130, antenna 140, and wireless communication circuit 150.

[0032] Storage 120 is an auxiliary storage device such as flash memory, HDD, or SSD that stores programs and data. Storage 120 stores sensing program 121, first sensing signal reception program 122, and second sensing signal reception program 123.

[0033] Memory 130 is an area for loading programs stored in storage 120. Memory 130 may also be used as an area for programs to store data.

[0034] The wireless communication circuit 150 is a device that communicates wirelessly with the transmitting node 200 via the antenna 140. The receiving node 100 transmits and receives signals (messages) with the transmitting node 200 via the wireless communication circuit 150.

[0035] The CPU 110 performs sensing processing by executing the sensing program 121. The sensing processing involves receiving the reflected wave of the signal transmitted by the transmitting node 200, measuring the wireless quality, and transmitting the measurement results to the transmitting node.

[0036] The CPU 110 performs quality report stop processing by executing the quality report stop module 1211 of the sensing program 121. The quality report stop processing is the process of receiving a quality report stop instruction from the transmitting node 200 and not transmitting (stopping) the received quality report in subsequent sensing processes. The receiving node 100 will also stop the second quality report in the same way as the received quality report.

[0037] The CPU 110 performs the first sensing signal reception process by executing the first sensing signal reception program 122. The first sensing signal reception process involves receiving the first sensing signal and the reflected wave of the first sensing signal transmitted by the transmitting node 200, measuring the wireless quality, and transmitting the measurement results to the transmitting node 200. The wireless quality is, for example, the received power (including RSRP) for each measurement time. The receiving node 100 includes the measurement results in the first quality report and transmits it to the transmitting node 200. The first quality report includes, for example, a delay profile.

[0038] The CPU 110 performs the second sensing signal reception process by executing the second sensing signal reception program 123. The second sensing signal reception process involves receiving the second sensing signal and the reflected wave of the second sensing signal transmitted by the transmitting node 200, measuring the wireless quality, and transmitting the measurement results to the transmitting node 200. Wireless quality is, for example, the received power (including RSRP) for each signal (for each signal identifier). The receiving node 100 includes the measurement results in the second quality report and transmits it to the transmitting node 200. However, if the receiving node 100 has received, for example, a command from the transmitting node 200 to stop the reception quality report, it will not measure the wireless quality or transmit the second quality report.

[0039] <Sensing Receiver Node Determination Process> The transmitting node 200 executes the sensing receiver node determination process S10 at a predetermined timing. The predetermined timing is, for example, a predetermined interval. The predetermined interval is measured, for example, by the transmitting node 200 or the receiving node 100. Alternatively, the predetermined timing may be, for example, when it is detected that the variation in the measurement results (reception level, channel information, etc.) of the reception quality report reported from the receiving node 100 has exceeded a predetermined threshold. Note that multiple thresholds may be set, and the processing to be performed may be divided depending on which threshold is exceeded, such as performing only the first determination process, only the second determination process, or both.

[0040] Figure 4 shows an example of a processing flowchart for the sensing receiver node determination process S10. The transmitting node 200 performs the first determination process S11. The first determination process is a process that excludes receiver nodes 100 from sensing if the received power of the reflected wave other than the direct wave of the first sensing signal is lower than the first threshold. Details of the first determination process will be described later.

[0041] The transmitting node 200 sends a quality reporting stop instruction to the receiving node 100, which has been excluded from sensing (S12).

[0042] The transmitting node 200 performs the second decision process S13. The second decision process estimates the position where the reflected wave was reflected (the position of the target or reflector) from the received power and reception direction (phase) of the reflected wave other than the direct wave of the second sensing signal at the receiving node 100, and determines the sensing target according to the estimated position. For example, the transmitting node 200 targets receiving nodes 100 where the estimated positions are clustered in the vicinity, and excludes the other receiving nodes 100. Details of the second decision process will be described later.

[0043] The transmitting node 200 sends a quality reporting stop instruction to the receiving node 100, which was excluded from sensing (S13), and terminates the process.

[0044] FIG. 5 is a diagram showing an example of the sequence of the sensing reception node determination process S10. The sequence in FIG. 5 shows an example in the case where the reception nodes 100-2 and 100-3 are excluded from sensing.

[0045] The transmission node 200 executes the first determination process S11. In the first determination process, the transmission node 200 transmits a first sensing signal (S100). The first sensing signal is an omnidirectional signal. The first sensing signal reaches the reception node 100 as, for example, a direct wave and as a reflected wave reflected by the target 300 or other reflectors.

[0046] When the reception node 100 receives the first sensing signal, it measures the reception quality and transmits a first quality report including the measurement result to the transmission node 200 (S101, S102, S103).

[0047] When the transmission node 200 receives the first quality report, it determines that the reception node 100-2 is excluded from the target and transmits a quality report stop instruction to the reception node 100-2 (S104).

[0048] The transmission node 200 executes the second determination process S13. In the second determination process, the transmission node 200 transmits a second sensing signal (S105, S106). The second sensing signal is a directional signal. The second sensing signal is, for example, shifted by a predetermined angle, assigned different indexes respectively, and transmitted sequentially. The second sensing signal reaches the reception node 100 as, for example, a direct wave and as a reflected wave reflected by the target 300 or other reflectors.

[0049] The reception nodes 100-1 and 3 other than the reception node 100-2 excluded from the target in the first determination process S11 measure the reception quality of the second sensing signal and transmit a second quality report including the measurement result to the transmission node 200 (S107, S108).

[0050] When the transmission node 200 receives the second quality report, it determines that the reception node 100-3 is excluded from the target and transmits a quality report stop instruction to the reception node 100-3 (S109).

[0051] <1. First Decision Process> The first decision process will now be explained. Figure 6 shows an example of a processing flowchart for the first decision process S11.

[0052] The transmitting node 200 selects the first receiving node 100 (S11-1). The first receiving node 100 is selected from all candidate receiving nodes 100 that are to be sensed.

[0053] The transmitting node 200 searches the measurement results of the selected receiving node to see if there is a reception level exceeding the first threshold other than the direct wave (S11-2). If there is a reception level exceeding the first threshold (Yes in S11-3), the transmitting node 200 determines that it is a receiving node to be subjected to the second decision process (S11-4). The receiving node to be subjected to the second decision process refers to the receiving node 100 that is subject to the second decision process.

[0054] On the other hand, if the transmitting node 200 does not have a reception level exceeding the first threshold (No. in S11-3), it determines that the receiving node is one to be stopped (S11-5) and sends a quality report stop instruction to that receiving node (S11-6).

[0055] Then, if there are any unselected receiving nodes 100 (Yes in S11-7), the transmitting node 200 selects the next receiving node from the unselected receiving nodes 100 (S11-8) and repeats the process from S11-2.

[0056] The transmitting node 200 then repeats the process until there are no more unselected receiving nodes 100 (No. in S11-7), and then terminates the process.

[0057] A concrete example of the first decision process will be explained below. The following example is one in which receiving node 100-1 is the receiving node targeted for the second decision process, and receiving node 100-2 is the node targeted for termination.

[0058] Figure 7 shows an example where the reflected wave reaches the receiving node 100-1 at a reception level above the first threshold. The transmitting node 200 transmits the first sensing signal. The sensing signal is expressed as signal B11 for the signal that directly reaches the receiving node 100-1 and signal B12 for the signal that arrives after reflection, but it is assumed that it is a part of the first sensing signal, which is an omnidirectional signal.

[0059] The first sensing signal B11 transmitted by the transmitting node 200 reaches the receiving node 100-1 directly. On the other hand, the first sensing signal B12 transmitted by the transmitting node 200 is reflected by the target 300 and reaches the receiving node 100-1 indirectly as a reflected wave B13 at or above the first reception level.

[0060] Figure 8 shows an example where the reflected wave does not reach the receiving node 100-2 because the reception level is above the first threshold. The transmitting node 200 transmits the first sensing signal. The sensing signal is expressed as signal B14 for the signal that directly reaches the receiving node 100-2, and as signal B16 for the signal that is reflected and reaches (or does not reach) it, but it is assumed that it is part of the first sensing signal, which is an omnidirectional signal.

[0061] The first sensing signal B14 transmitted by the transmitting node 200 reaches the receiving node 100-2 directly. On the other hand, the first sensing signal B15 transmitted by the transmitting node 200 is reflected by the target 300 to become the reflected wave B16, but is blocked by the obstacle 400 and reaches the receiving node 100-2 (or does not reach it) at a reception level below the first threshold.

[0062] Figure 9 shows examples of reception levels in Figures 7 and 8. Figure 9(A) shows an example of the reception level of receiving node 100-1, and Figure 9(B) shows an example of the reception level of receiving node 100-2.

[0063] As shown in Figure 9(A), signal B13 is reflected off target 300 and travels a longer distance than the direct signal B11, reaching receiving node 100-1 later than signal B11. Here, the reception level at the timing of B13 is lower than the reception level at the timing of B11, but is above the first threshold. Since the reception level of signal B13, which is other than the direct wave (signal B11), exceeds the first threshold, the transmitting node 200 determines receiving node 100-1 to be the target receiving node for the second decision process (S11-4 in Figure 6).

[0064] According to Figure 9(B), signal B16 is reflected off target 300 and travels a longer distance than the direct signal B14, reaching receiving node 100-2 later than signal B14. Here, the reception level at the timing of B16 is lower than the reception level at the timing of B14, and is below the first threshold (or possibly 0). Since the reception level of signal B16, which is other than the direct wave (signal B14), is below the first threshold, the transmitting node 200 determines receiving node 100-1 to be a receiving node to be stopped (S11-5 in Figure 6).

[0065] Thus, in the first decision process S11, for example, receiving nodes 100 whose received power of reflected waves is low due to the influence of distance or obstacles can be excluded.

[0066] <2. Second Decision Process> The second decision process will now be explained. Figure 10 shows an example of a processing flowchart for the second decision process S13.

[0067] The transmitting node 200 selects the receiving node 100 from the receiving nodes targeted for the second decision process (S13-1). The receiving nodes targeted for the second decision process are the receiving nodes 100 that were not excluded in the first decision process S11.

[0068] The transmitting node 200 estimates the reflection position from the measurement results of the selected receiving node 100. For example, the transmitting node 200 creates an estimated circle at a predetermined distance centered on the estimated position (S13-2).

[0069] If there are any unselected receiving nodes 100 (Yes in S13-3), the transmitting node 200 selects the next receiving node from the unselected receiving nodes 100 (S13-4) and repeats the process from S13-2.

[0070] Then, the transmitting node 200 repeats process S13-2 until there are no more unselected receiving nodes 100 (No. in S13-3).

[0071] The transmitting node 200 creates estimated circles for all receiving nodes 100, and then determines which receiving nodes 100 to use for sensing based on the overlap of the estimated circles (S13-5). The transmitting node 200 then sends a quality reporting stop instruction to the receiving nodes 100 that are not used for sensing (S13-6), and terminates the process.

[0072] A specific example of the second decision process will be explained. The following example is one in which receiving node 100-3 is the receiving node to be stopped.

[0073] Figure 11 shows an example of signal arrival at receiving nodes 100-1 and 100-2. Transmitting node 200 transmits second sensing signals B21 and B22. Receiving node 100-1 directly receives the second sensing signal B21 and receives the reflected wave B23 of the second sensing signal B22 reflected by target 300.

[0074] Furthermore, the transmitting node 200 transmits the second sensing signals B24 and B25. The receiving node 100-2 directly receives the second sensing signal B24 and receives the reflected wave B26 of the second sensing signal B25 reflected by the target 300.

[0075] Figure 12 shows an example of signal arrival at receiving node 100-3. Transmitting node 200 transmits second sensing signals B27, B29, and B30. Receiving node 100-3 directly receives second sensing signal B29 and receives reflected wave B31 of second sensing signal B30 reflected by a reflective object 500 (e.g., a wall) that is not the target 300. Reflected wave B28 of second sensing signal B27 reflected by target 300 is blocked by obstacle 400 and therefore does not reach receiving node 100-3.

[0076] Figure 13 shows an example of an estimated circle obtained by measuring the reflection position from the measurement results of the receiving node 100. The estimated circle is a circle with a predetermined distance as the radius centered on the estimated position of the reflected wave.

[0077] The transmitting node 200 calculates estimated circle 1 from the measurement results of the receiving node 100-1. Estimated circle 1 is a circle centered at the point where the direction of the second sensing signal B22 and the direction of the reflected wave (the signal received by the receiving node 100-1) B23 intersect.

[0078] Furthermore, the transmitting node 200 calculates estimated circle 2 from the measurement results of the receiving node 100-2. Estimated circle 2 is a circle centered at the point where the direction of the second sensing signal B25 and the direction of the reflected wave (the signal received by the receiving node 100-2) B26 intersect.

[0079] Furthermore, the transmitting node 200 calculates estimated circle 3 from the measurement results of the receiving node 100-3. Estimated circle 3 is a circle centered at the point where the direction of the second sensing signal B30 and the direction of the reflected wave (the signal received by the receiving node 100-3) B31 intersect.

[0080] The transmitting node 200 determines which receiving node 100 to use for sensing based on the overlap of the respective estimated circles (S12-5 in Figure 10). For example, if two or more estimated circles overlap, the transmitting node 200 determines the receiving node corresponding to those estimated circles as the receiving node 100 to be used for sensing. In the case of Figure 13, since estimated circle 1 and estimated circle 2 overlap, the transmitting node 200 determines receiving nodes 100-1 and 100-2 as the receiving nodes 100 to be used for sensing. On the other hand, receiving node 100-3 is an excluded receiving node 100 that is not used for sensing, and a quality report stop instruction is sent to it.

[0081] In the example shown in Figure 13, the case where two or more estimated circles overlap is used as an example, but the transmitting node 200 may set the threshold for the number of overlapping estimated circles to N (where N is an integer of 3 or more).

[0082] In the second decision process S13, estimated circles that overlap with only a small number of receiving nodes 100 (one in Figure 13) are considered to be based on noise-like reflections rather than on reflected waves from the target 300. The second decision process S13 selects the receiving nodes 100 according to their estimated positions, and may be selected based on factors other than the overlap of estimated circles, such as the variability (density) of the estimated positions of each receiving node 100. Furthermore, if multiple transmitting nodes 200 are detected in areas with different overlaps of estimated circles, the area with the largest number of overlaps may be selected as the sensing target.

[0083] [Other Embodiments] The sensing reception node determination process S10 does not have to perform either the first determination process S11 or the second determination process S13. If the sensing reception node determination process S10 is performed multiple times periodically or aperiodicly, the transmitting node 200 may refer to, for example, the reception level acquired in the previous session, to determine whether or not to perform the first determination process S11 and the second determination process S13.

[0084] Furthermore, the first sensing signal and the second sensing signal may be newly established signals or existing signals. Also, the first sensing signal and the second sensing signal may be signals such as CP-OFDM signals, DFT-s-OFDM signals, RS, SRS, CSI-RS, SSB, PDSCH, PUSCH, etc.

[0085] Furthermore, the transmitting node 200 may periodically acquire the location of the receiving node 100. The receiving node 100 may also include its own location information in any or all of the first quality report, second quality report, and reception quality report. The transmitting node 200 may also use the location information of the receiving node 100 in calculating the estimated circle.

[0086] Furthermore, in the first decision process S11, the transmitting node 200 may use an error rate or the like as an alternative to the reception level. Also, in the first decision process S11, the transmitting node 200 may consider the distance to the receiving node 100 calculated from the location information of the receiving node 100, in addition to the reception level. For example, the transmitting node 200 may exclude receiving nodes 100 that are farther away than a predetermined distance, even if the reception level is higher than a predetermined level.

[0087] 10: Wireless communication system 100: Receiving node 110: CPU 120: Storage 121: Sensing program 1211: Quality report stop module 122: First sensing signal receiving program 123: Second sensing signal receiving program 130: Memory 140: Antenna 150: Wireless communication circuit 200: Transmitting node 210: CPU 220: Storage 221: Sensing control program 222: Sensing receiving node determination program 2221: First determination module 2222: Second determination module 230: Memory 240: Antenna 250: Wireless communication circuit 300: Target 400: Obstacle 500: Reflector

Claims

1. A transmitting node in a wireless communication system in which a transmitting node transmits a sensing signal, a receiving node receives the sensing signal, measures the wireless quality at the time of reception of the sensing signal, transmits the measurement result to the transmitting node, and the transmitting node uses the measurement result to sense a target, comprising: a transmitting unit that transmits a first sensing signal having a first directionality and a second sensing signal having a second directionality; a receiving unit that receives a first measurement result of the wireless quality at the time of reception of the first sensing signal at the receiving node and a second measurement result of the wireless quality at the time of reception of the second sensing signal at the receiving node from the receiving node; a first determination process that determines an excluded receiving node from a plurality of the receiving nodes according to the reception quality in the first measurement result; a second determination process that estimates the reflection position of the second sensing signal from the second measurement result and determines an excluded receiving node from the receiving nodes other than the excluded receiving node determined in the first determination process according to the estimated position, A transmitting node having a control unit that transmits a quality report stop instruction to the excluded receiving node, instructing it not to transmit the measurement results.

2. The transmission node according to claim 1, wherein the control unit determines in the first determination process that the reception level of the reflected wave of the first sensing signal is less than a first threshold, and the transmission node is therefore excluded from the target receiving node.

3. The transmitting node according to claim 1, wherein in the second determination process, the control unit determines the first receiving node to be an excluded receiving node if there is no estimated position corresponding to another receiving node within a first distance of the estimated position corresponding to the first receiving node.

4. The transmitting node according to claim 1, wherein the control unit transmits the quality report stop instruction to the excluded receiving node determined in the first determination process before executing the second determination process, and prevents the excluded receiving node from transmitting the second measurement result.

5. The transmission node according to claim 1, wherein the control unit performs the first decision process and the second decision process for each first period.

6. A wireless communication system in which a transmitting node transmits a sensing signal, a receiving node receives the sensing signal, measures the wireless quality at the time of reception of the sensing signal, transmits the measurement result to the transmitting node, and the transmitting node uses the measurement result to perform sensing of a target, wherein the transmitting node transmits a first sensing signal having a first directionality and a second sensing signal having a second directionality, receives a first measurement result of the wireless quality at the time of reception of the first sensing signal at the receiving node and a second measurement result of the wireless quality at the time of reception of the second sensing signal at the receiving node from the receiving node, performs a first determination process to determine which receiving nodes to be excluded from sensing from a plurality of the receiving nodes according to the reception quality in the first measurement result, estimates the reflection position of the second sensing signal from the second measurement result, performs a second determination process to determine which receiving nodes to be excluded from sensing from the receiving nodes other than the excluded receiving nodes determined in the first determination process according to the estimated position, and transmits a quality report stop instruction to the excluded receiving nodes instructing them not to transmit the measurement result. A wireless communication system in which, upon receiving the first sensing signal, the receiving node measures the wireless quality of the first sensing signal and transmits the first measurement result, including the measurement result, to the transmitting node; upon receiving the second sensing signal, the receiving node measures the wireless quality of the second sensing signal and transmits the second measurement result, including the measurement result, to the transmitting node; and upon receiving a quality reporting stop instruction from the transmitting node, the transmitting node stops transmitting the measurement results thereafter.

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