Wireless sensing system, wireless sensing method, and measurement request device

Abstract

Provided is a radio sensing system comprising: a measurement request device 10 that has a plurality of AP1 to AP3 corresponding to different frequency bands f1 to f3 in a single casing; and a measurement device 10 that has a plurality of STA1 to STA3 corresponding to the different frequency bands f1 to f3 in a single casing. The measurement request device 10 transmits measurement signals in the plurality of frequency bands. The measurement device 20 receives the measurement signals in the plurality of frequency bands, and extracts propagation channel state information for each frequency band. A result of radio sensing directed to a space between the measurement request device 10 and the measurement device 20 is calculated on the basis of the propagation channel state information for each frequency band. If there is a frequency band (f3) in which transmission is not possible when execution of radio sensing is requested, the measurement request device 10 and the measurement device 20 transmit duplicate signals 36 of f2 using antenna units 16 and 26 that have been allocated to f3, as additional-use antenna units for f2.

Description

[Technical Field]

[0001] The present disclosure relates to a wireless sensing system, a wireless sensing method, and a wireless sensing device, and more particularly to a wireless sensing system, a wireless sensing method, and a wireless sensing device suitable for use in a multi-link device. [Background technology]

[0002] Non-Patent Document 1 below discloses a wireless sensing technology that uses propagation channel state information (CSI). In this technology, a measurement signal is transmitted wirelessly from a measurement requesting device such as an access point (AP) to a measuring device such as a station (STA). The measurement signal reflects the state of the propagation path on the way to the measuring device. The measuring device extracts propagation channel state information from the received measurement signal and returns a communication signal including that information to the measurement requesting device.

[0003] The measurement requesting device senses the propagation path based on the propagation channel state information included in the communication signal. This technology makes it possible to sense, for example, the positions of objects or people present on the propagation path between the measurement requesting device and the measuring device, or the open / close state of a door.

[0004] Non-Patent Document 2 below discloses the standard for wireless LANs defined by IEEE 802.11be. In the 802.11be standard, APs and STAs are provided with a Multi-Link Device (MLD) function. A device with MLD functionality has multiple wireless functions corresponding to different frequency bands within a single housing. Each wireless function for each frequency band can establish its own transmission path to establish high-speed, highly reliable communications. Multi-link transmission also has a synchronous mode in which multiple frequency bands are synchronized for transmission and reception, and an asynchronous mode in which each frequency band is independently used for transmission and reception. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Yang, Zheng, Zimu Zhou, and Yunhao Liu. "From RSSI to CSI: Indoor Localization via Channel Response." ACM Computing Surveys (CSUR) Vol. 46.2, Article 25, November 2013 [Non-patent document 2] E. Khorov, I. Levitsky and IF Akyildiz, "Current Status and Directions of IEEE 802.11be, the Future Wi-Fi 7," in IEEE Access, vol. 8, pp. 88664-88688, May 8, 2020 Summary of the Invention [Problem to be solved by the invention]

[0006] Under the IEEE 802.11be standard, it is conceivable to implement the wireless sensing described in Non-Patent Document 1 using the MLD described in Non-Patent Document 2. If a device with MLD functionality is available, the accuracy of wireless sensing can be improved by detecting CSI in multiple frequency bands and integrating them. Furthermore, by simultaneously performing sensing in all of the multiple frequency bands, multiple CSI can be obtained simultaneously, minimizing the time required to perform wireless sensing. For this reason, when implementing wireless sensing using MLD, it is desirable to use a synchronous mode in which all frequency bands are operated simultaneously.

[0007] However, the multiple wireless functions that make up the MLD may be placed in a state where they cannot start transmission due to restrictions such as the NAV (Network Allocating Vector) issued by other wireless devices. In other words, if another wireless device occupies a specific frequency band and transmits a NAV indicating the remaining time of that occupancy, the MLD that receives this notification will be unable to start transmission in that frequency band until the NAV becomes zero.

[0008] When some of the wireless functions that make up the MLD cannot start transmission, even if all wireless functions are commanded to transmit simultaneously, some of those wireless functions will not operate. In such a situation, resources such as antennas assigned to the unavailable frequency bands will be wasted and wireless sensing will be performed only on the few available frequency bands. In this case, sensing accuracy is likely to be lower than when wireless sensing is performed using all frequency bands.

[0009] The present disclosure has been made in consideration of the above-mentioned problems, and has as its first object to provide a wireless sensing system that can prevent sensing accuracy from decreasing significantly compared to normal when a multi-link device is made to perform wireless sensing in synchronous mode, even if some frequency bands are in a state where transmission is not possible.

[0010] A second object of the present disclosure is to provide a wireless sensing method that prevents sensing accuracy from decreasing significantly compared to normal when a multi-link device is made to perform wireless sensing in synchronous mode, even if some frequency bands are in a state where transmission is not possible.

[0011] A third object of the present disclosure is to provide a measurement request device that can prevent sensing accuracy from decreasing significantly compared to normal conditions when a multi-link device is made to perform wireless sensing in synchronous mode, even if some frequency bands are in a state where transmission is not possible. [Means for solving the problem]

[0012] In order to achieve the above object, a first aspect is a wireless sensing system including a measurement requesting device having multiple wireless functions corresponding to different frequency bands in a single housing, and a measuring device having multiple wireless functions corresponding to different frequency bands in a single housing, a process in which the measurement requesting device transmits measurement signals in a plurality of frequency bands; a process in which the measurement device receives the measurement signals in a plurality of frequency bands and extracts propagation channel state information for each frequency band; and calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information for each frequency band, It is desirable that at least one of the measurement requesting device and the measuring device is configured to, when a frequency band that cannot be transmitted exists when the execution of the wireless sensing is requested, execute a process of setting the wireless communication hardware resources allocated to that frequency band as additional usage resources to be used for transmitting overlapping signals in a frequency band that can be transmitted.

[0013] A second aspect is a wireless sensing method using a measurement requesting device having a plurality of wireless functions corresponding to different frequency bands in one housing, and a measuring device having a plurality of wireless functions corresponding to different frequency bands in one housing, the measurement requesting device transmitting measurement signals in a plurality of frequency bands; the measurement device receiving the measurement signals in a plurality of frequency bands and extracting propagation channel state information for each frequency band; calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information for each frequency band; When a frequency band that cannot be transmitted exists when the execution of the wireless sensing is requested, at least one of the measurement requesting device and the measuring device sets a wireless communication hardware resource that has been allocated to the frequency band as an additional use resource to be used for transmitting overlapping signals in a frequency band that can be transmitted; It is desirable to include:

[0014] A third aspect is a measurement requesting device that realizes a wireless sensing function based on the results of information communication with a measuring device having a plurality of wireless functions corresponding to different frequency bands in one housing, It has multiple wireless functions corresponding to different frequency bands in one housing, transmitting measurement signals in multiple frequency bands to the measurement device; receiving a notification signal transmitted by the measurement device for each frequency band, the notification signal including propagation channel state information extracted from the measurement signal for each frequency band; calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information extracted from the notification signal for each frequency band; a process of setting, when a frequency band that cannot be transmitted exists when the execution of the wireless sensing is requested, the wireless communication hardware resource that has been allocated to the frequency band in question as an additional use resource to be used for transmitting overlapping signals in a frequency band that can be transmitted; Preferably, the system is configured to execute the following: [Effects of the Invention]

[0015] According to the first to third aspects, when a multi-link device performs wireless sensing in synchronous mode, if some frequency bands are unavailable for transmission, the communication resources corresponding to those frequency bands can be utilized for signal transmission in other frequency bands. As a result, signal transmission over multiple links is realized in the other frequency bands, and sensing accuracy is improved compared to when signal transmission is performed over a single link. Therefore, according to these aspects, even if some frequency bands are unavailable for transmission, sensing accuracy can be prevented from decreasing significantly compared to normal. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a wireless sensing system according to a first embodiment of the present disclosure. [Figure 2] 2 is a block diagram for explaining the configuration of a measurement requesting device included in the wireless sensing system shown in FIG. 1. FIG. [Figure 3] 2 is a block diagram for explaining the configuration of a measurement device included in the wireless sensing system shown in FIG. 1. FIG. [Figure 4] 3 is a flowchart illustrating the flow of processing executed in the measurement request device shown in FIG. 2. [Figure 5] 3 is a flowchart illustrating the flow of processing executed in the measurement device shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0017] Embodiment 1 [Configuration of the First Embodiment] Fig. 1 is a diagram illustrating the configuration of a wireless sensing system according to a first embodiment of the present disclosure. As shown in Fig. 1, the wireless sensing system according to this embodiment includes a measurement request device 10 and a measurement device 20. Both the measurement request device 10 and the measurement device 20 have a multi-link device (MLD) function that complies with the IEEE 802.11be standard.

[0018] The measurement request device 10 includes multiple access points (APs). In this embodiment, the measurement request device 10 includes AP1, AP2, and AP3. AP1, AP2, and AP3 each support a different frequency band. Here, it is assumed that AP1, AP2, and AP3 support frequency bands f1, f2, and f3, respectively. The measurement request device 10 also includes three antenna units 12, 14, and 16.

[0019] Antenna units 12, 14, and 16 are all connected to three APs, AP1, AP2, and AP3, via a switching mechanism. For example, antenna unit 12 is normally connected to AP1 and is used to transmit and receive signals in frequency band f1. Then, in response to a command, antenna unit 12 can be connected to AP2 or AP3 and used to transmit and receive signals in frequency band f2 or frequency band f3. The same applies to antenna units 14 and 16.

[0020] The measurement device 20 includes multiple terminal devices (STAs). In this embodiment, the measurement device 20 includes STA1, STA2, and STA3. STA1, STA2, and STA3 correspond to different frequency bands, specifically, f1, f2, and f3, respectively. The measurement device 20 also includes three antenna units 22, 24, and 26.

[0021] Antenna units 22, 24, and 26, like antenna units 12, 14, and 16 included in measurement requesting device 10, are normally connected to STA1, STA2, or STA3, respectively, and are used to send and receive signals in frequency bands f1, f2, or f3, respectively. In response to a command, they can be connected to a different STA than normal, and can send and receive signals in a frequency band different from normal.

[0022] AP1 to AP3 included in the measurement request device 10 can send and receive wireless signals to and from STA1 to STA3 included in the measurement device 20. The measurement request device 10 and the measurement device 20 can then perform wireless sensing of the space between them. Wireless sensing makes it possible to detect the position and activity of objects present in the sensing target space.

[0023] When wireless sensing is requested, the measurement requesting device 10 and the measuring device 20 start communication in synchronous mode. As a result, if all of AP1 to AP3 and all of STA1 to STA3 are in a transmittable state, wireless signals 30 are transmitted and received simultaneously in all frequency bands f1 to f3.

[0024] However, there are cases where transmission restrictions are imposed on AP1 to AP3 and STA1 to STA3. For example, when another communication device using the same frequency band needs to occupy that frequency band for a certain period of time, it may notify the NAV indicating the remaining time of occupancy. The communication device that receives such a notification is required to refrain from starting transmission until the NAV reaches zero. For this reason, in the system of this embodiment, it is assumed that when a request is made to perform wireless sensing, one of AP1 to AP3 and STA1 to STA3 is in a state where transmission is not possible.

[0025] 1 illustrates the operation of this embodiment when one or both of AP3 and STA3 are unable to transmit when wireless sensing is requested. Specifically, AP1 and STA1 transmit and receive an f1 signal 32 in frequency band f1 via antenna units 12 and 22. AP2 and STA2 transmit and receive an f2 signal 34 in frequency band f2 via antenna units 14 and 24.

[0026] Since AP3 and STA3 are in a state where transmission is disabled, antenna units 16 and 26 are used to transmit and receive overlapping signals 36 of frequency band f2 between AP2 and STA2. In this way, when a synchronization mode of multiple frequency bands is requested, if transmission is disabled in some frequency bands, the wireless communication system of this embodiment utilizes the hardware resources that would have covered those frequency bands for communication in other available frequency bands.

[0027] 1, the propagation path of the f2 signal 34 and the propagation path of the overlapping signal 36 are not exactly the same. Therefore, even if both signals are in the same frequency band f2, the influence of the path state superimposed on the f2 signal 34 and the influence of the path state superimposed on the overlapping signal 36 are not the same. In addition, the overlapping signal 36 may have a higher reception strength than the reception strength of the f2 signal 34.

[0028] Therefore, when AP3 and STA3 are unable to transmit, it is possible to acquire more information about the propagation path by utilizing antenna units 16 and 26 for transmitting and receiving overlapping signal 36 rather than leaving them unnecessarily stopped. As a result, in the wireless sensing system of this embodiment, when measurement requesting device 10 and measuring device 20 perform wireless sensing in synchronous mode, it is possible to avoid a significant decrease in sensing accuracy compared to normal even in a situation where transmission is unavailable in some frequency bands.

[0029] [Details of the first embodiment] Hereinafter, with reference to FIGS. 2 and 3, the hardware configurations that the measurement requesting device 10 and the measurement device 20 each have for realizing the above functions will be described in detail.

[0030] Fig. 2 is a block diagram for explaining in detail the configuration of the measurement requesting device 10 in this embodiment. As shown in Fig. 2, the measurement requesting device 10 includes a control unit 40. The control unit 40 can be realized by a dedicated hardware circuit. Alternatively, the control unit 40 may include a processor and a memory, and realize desired functions by causing the processor to execute a program stored in the memory.

[0031] The control unit 40 includes a measurement request signal generation unit 42. When a request to execute wireless sensing occurs, the measurement request signal generation unit 42 generates a measurement request signal and provides the signal to the transmission units 44-1 to 44-3. The transmission unit 44-1 is provided in AP1 and is normally used for transmission in the frequency band f1 handled by AP1, but can be used for transmission in the frequency band f2 handled by AP2 or the frequency band f3 handled by AP3 in response to a command from the control unit 40. The transmission units 44-2 and 44-3 are provided in AP2 and AP3, respectively, and function in the same way as the transmission unit 44-1 in response to a command from the control unit 40.

[0032] When the transmitters 44-1 to 44-3 receive a measurement request signal from the measurement request signal generator 42, if they are in a state where transmission is not possible due to compliance with NAV or the like, they notify the controller 40 of this fact. When the controller 40 is notified by any of the transmitters 44-1 to 44-3 that transmission is not possible, it performs processing to allocate the hardware resources that were allocated to that frequency band to another frequency band where transmission is possible.

[0033] For example, if the transmitter 44-3 covering the frequency band f3 is in a state where transmission is disabled, the antenna unit 16 normally assigned to f3 is designated as an additional antenna unit to be used for transmission in the other frequency band f1 or f2, and one or both of the transmitters 44-1 and 44-2 are instructed to transmit overlapping signals using the additional antenna unit.

[0034] 2 illustrates a case where, under the above circumstances, the control unit 40 commands the transmitting unit 44-2 to use the antenna unit 16 as the additionally usable antenna unit. In this case, the measurement request signal for the frequency band f1 provided by the transmitting unit 44-1 is transmitted from the antenna unit 12 as the f1 signal 32. Then, the measurement request signal for the frequency band f2 provided by the transmitting unit 44-2 is transmitted from the antenna unit 14 as the f2 signal 34 and from the antenna unit 16 as the overlapping signal 36.

[0035] The measurement requesting device 10 also includes receiving units 46-1 to 46-3. The receiving unit 46-1 is provided in AP1 and corresponds to frequency band f1. Similarly, the receiving units 46-2 and 46-3 are provided in AP2 and AP3, respectively, and correspond to frequency bands f2 and f3. The receiving units 46-1 to 46-3 receive various signals received by the antenna units 12, 14, and 16 and provide the signals to the control unit 40.

[0036] For example, if frequency bands f1, f2, and f3 are all available and none of antenna units 12, 14, and 16 is set as an additionally usable antenna unit, the f1 signal is received by receiver 46-1 via antenna unit 12. The f2 signal is received by receiver 46-2 via antenna unit 14. The f3 signal is received by receiver 46-3 via antenna unit 16.

[0037] 1, when antenna unit 16 is set as an additionally used antenna unit that transmits and receives overlapping signal 36 of frequency band f2, antenna unit 16 receives the signal of frequency band f2 and provides it to receiving unit 46-2 as overlapping signal 36. In this case, receiving unit 46-2 distinguishes between f2 signal 34 transmitted from antenna unit 14 and overlapping signal 36 transmitted from antenna unit 16. Receiving units 46-1 and 46-3 also have the function of distinguishing between signals of the same frequency band when they are transmitted from two antennas.

[0038] After transmitting the measurement request signal, measurement request device 10 waits for a measurement preparation completion signal to be returned from measuring device 20. The measurement preparation completion signal is provided to control unit 40 via antenna units 12, 14, and 16 and receiving units 46-1 to 46-3.

[0039] The control unit 40 includes a measurement signal generation unit 48. The measurement signal generation unit 48 determines which of the frequency bands f1 to f3 is available for use, depending on which of the receiving units 46-1 to 46-3 has provided a measurement preparation completion signal. Then, the measurement signal generation unit 48 generates a measurement signal for performing wireless sensing, and provides the measurement signal to one of the transmitting units 44-1 to 44-3 that corresponds to the available frequency band.

[0040] Like the measurement request signal, the measurement signal is transmitted in the available frequency bands using all of the antenna units 12, 14, and 16. For example, in the case shown in FIG. 1, the measurement signal is transmitted from the antenna unit 12 as an f1 signal 32. The measurement signal is transmitted from the antenna unit 14 as an f2 signal 34. The measurement signal is transmitted from the antenna unit 16, which is set as the additionally used antenna unit, as an f2 duplicate signal 36.

[0041] After transmitting the measurement signal, the measurement request device 10 waits for a notification signal to be returned from the measurement device 20. The notification signal is provided to the control unit 40 via the antenna units 12, 14, and 16 and the receiving units 46-1 to 46-3. The control unit 40 then extracts the propagation channel state information CSI included in the notification signal, and performs location estimation or activity detection for the propagation path based on the result.

[0042] Fig. 3 is a block diagram for explaining in detail the configuration of measurement device 20 in this embodiment. As shown in Fig. 3, measurement device 20 includes multiple receiving units 50-1 to 50-3. Receiving units 50-1 to 50-3 are included in STA1 to STA3 and correspond to frequency bands f1 to f3. Receiving units 50-1 to 50-3 receive signals transmitted from measurement request device 10 via antenna units 22, 24, and 26 in the frequency bands assigned to them, respectively.

[0043] For example, when measurement request device 10 transmits measurement request signals in all frequency bands f1 to f3, those signals are received by receiving units 50-1 to 50-3 via antenna units 22, 24, and 26. On the other hand, when only some of receiving units 50-1 to 50-3 do not receive the measurement request signals, measurement request device 10 recognizes that the frequency bands corresponding to those parts are in an unusable state.

[0044] The measurement request signals received by the receiving units 50-1 to 50-3 are provided to the control unit 52. The control unit 52 can be realized by a dedicated hardware circuit. Alternatively, the control unit 52 may include a processor and a memory, and realize desired functions by causing the processor to execute a program stored in the memory.

[0045] When the control unit 52 receives the measurement request signal, it starts preparation for wireless sensing. Specifically, it recognizes all frequency bands for which the measurement request signal is received as usable frequency bands, and sets wireless devices corresponding to those frequency bands to synchronization mode.

[0046] The control unit 52 includes a measurement preparation completion signal generation unit 56. The measurement preparation completion signal generation unit 56 generates a measurement preparation completion signal when preparation for wireless sensing is complete. The generated measurement preparation completion signal is provided to one of the transmission units 58-1 to 58-3 that corresponds to the available frequency band.

[0047] Transmitting units 58-1 to 58-3 are provided in STA1 to STA3 and correspond to frequency bands f1 to f3. For example, if all frequency bands are available for use, a measurement preparation completion signal is provided to all of transmitting units 58-1 to 58-3. On the other hand, if some frequency bands are unavailable, for example, if frequency band f3 is unavailable as shown in FIG. 1, the measurement preparation completion signal is provided only to transmitting units 58-1 and 58-2. At this time, control unit 52 notifies transmitting units 58-1 and 58-2 of the antenna to be set as the additionally usable antenna unit and the frequency band of the overlapping signal to be transmitted from the additionally usable antenna unit.

[0048] When transmitting units 58-1 to 58-3 receive a measurement preparation completion signal, if they are in a state where transmission is not possible due to NAV restrictions or the like, they notify control unit 52 to that effect. In this case, control unit 52 recognizes the frequency band that is the subject of the notification as an unusable frequency band and instructs a transmitting unit corresponding to an available frequency band to transmit a measurement preparation completion signal again. Also in this case, control unit 52 notifies the transmitting unit of the antenna to be set as the additionally usable antenna unit and the frequency band of the overlapping signal to be transmitted from the additionally usable antenna unit.

[0049] 3 illustrates a case where, under the above circumstances, the control unit 52 commands the transmitting unit 58-2 to use the antenna unit 26 as the additionally usable antenna unit. In this case, the measurement preparation completion signal for the frequency band f1 provided by the transmitting unit 58-1 is transmitted from the antenna unit 22 as the f1 signal 32. Then, the measurement preparation completion signal for the frequency band f2 provided by the transmitting unit 58-2 is transmitted from the antenna unit 24 as the f2 signal 34 and from the antenna unit 26 as the overlap signal 36.

[0050] Thereafter, the measurement device 20 waits for reception of a measurement signal from the measurement request device 10. Then, when the receiving units 50-1 to 50-3 receive the measurement signal via the antenna units 12 to 16, the signal is provided to the propagation channel measuring unit 60. As described above, the measurement signal reflects the state of the propagation path. Meanwhile, the propagation channel measuring unit 60 stores the initial characteristics of the measurement signal that are known in advance. Then, the propagation channel measuring unit 60 detects propagation channel state information (CSI) from the difference between the characteristics superimposed on the actually received measurement signal and the initial characteristics. The CSI detected in this manner is provided to the notification signal generating unit 62.

[0051] The notification signal generator 62 provides the notification signal including the CSI generated by the propagation channel measurer 60 to one of the transmitters 58-1 to 58-3 that corresponds to the available frequency band. Then, the transmitters 58-1 to 58-3 transmit the notification signals including the CSI to the measurement request device 10 in the frequency band allocated to each of them.

[0052] [Processing flow in the first embodiment] Fig. 4 is a flowchart for explaining the flow of characteristic processing executed by the measurement requesting device 10. The routine shown in Fig. 4 is started every time a request to perform wireless sensing is generated. When this routine is started, it is first determined whether or not all of the frequency bands f1 to f3 are in a transmittable state (step 100).

[0053] If it is determined that all frequency bands are transmittable, a measurement request signal is transmitted in all frequency bands (step 102).

[0054] On the other hand, if it is determined in step 100 that any of the frequency bands is in a non-transmittable state, it is determined whether the antenna unit assigned to the non-transmittable frequency band corresponds to any of the other transmittable frequency bands (step 104). For example, if frequency band f3 is non-transmittable, it is determined whether antenna unit 16 corresponds to frequency band f1 or f2.

[0055] If the determination in step 104 is negative, it can be determined that the antenna unit assigned to the non-transmittable frequency band cannot be used in other frequency bands. In this case, the measurement request signal is transmitted in the transmittable frequency band by the process in step 102 without using the antenna.

[0056] On the other hand, if the determination in step 104 is positive, the antenna unit assigned to the non-transmittable frequency band is set as the additionally usable antenna unit, and the measurement request signal is transmitted using all antenna units (step 106). For example, if frequency band f3 is non-transmittable and antenna unit 16 corresponds to frequency band f2, antenna unit 16 is set as the additionally usable antenna unit for f2. Then, a measurement request signal is transmitted from antenna unit 12 in frequency band f1, and measurement request signals are transmitted from antenna units 14 and 16 in frequency band f2.

[0057] After the above process is completed, it is determined whether or not a measurement preparation completion signal has been received from the measurement device 20 (step 108). This process is repeated until it is confirmed that a measurement preparation completion signal has been received.

[0058] When reception of the measurement preparation completion signal is confirmed, measurement signals are transmitted in all of the frequency bands in which the signal was received (step 110). That is, measurement signals are transmitted in all frequency bands in which transmission and reception is possible between the measurement request device 10 and the measurement device 20. At this time, if there is an unavailable frequency band and an additional use antenna is set, the additional use antenna is used to transmit overlapping signals 36 in the available frequency bands, just as in the case of the measurement request signal.

[0059] Once the above process is complete, it is then determined whether or not a notification signal has been received from the measuring device 20 (step 112).

[0060] If reception of a communication signal is not confirmed, it is determined whether a predetermined time set as a waiting time has elapsed (step 114). If it is determined that the predetermined time has not yet elapsed, the processing of step 112 is executed again. On the other hand, if it is determined that the predetermined time has elapsed, it is determined that the communication signal could not be received for some reason, and the processing from step 100 onwards is executed again.

[0061] If reception of a communication signal is confirmed in step 112, it is determined that the communication required for wireless sensing has been completed, and the routine shown in Fig. 4 is terminated. Thereafter, the measurement requesting device 10 analyzes the notification signal for each frequency band, extracts the propagation channel state information (CSI) contained therein, and performs location detection or motion detection based on the extracted CSI.

[0062] Fig. 5 is a flowchart for explaining the flow of characteristic processing executed by the measurement device 20 in this embodiment. The routine shown in Fig. 5 is started when the measurement device 20 receives a measurement request signal from the measurement request device 10. When this routine is started, it is first determined whether or not the measurement request signal has been received in all frequency bands (step 120). As a result, if it is determined that the measurement request signal has been received in all frequency bands, the processing of step 124, which will be described later, is then executed.

[0063] On the other hand, if it is determined in step 120 that the measurement request signal has not been received in any of the frequency bands, the following process is executed to set an additional antenna to be used and acquire the measurement request signal (step 122). Step 122-1: An antenna unit assigned to a frequency band that does not receive a measurement request signal is set as an additionally used antenna unit. Step 122-2: The receiving units 50-1 to 50-3 also utilize the antenna unit set as the additionally used antenna unit to receive the measurement request signal. Step 122-3: The receiving units 50-1 to 50-3 select the signal from the antenna unit with the strongest signal strength.

[0064] After the above process is completed, it is determined whether the transmission mode of the measuring device 20 is set to the synchronous mode (step 124). If it is determined that the synchronous mode is set, the process of step 128, which will be described later, is executed.

[0065] On the other hand, if the setting of the synchronous mode is not recognized in step 124, the transmission mode of the measuring device 20 is changed to the synchronous mode. Furthermore, a record of "change required" is created so that the transmission mode can be returned to the asynchronous mode after the wireless sensing is completed (step 126).

[0066] When the above process is completed, a measurement preparation completion signal is transmitted in all frequency bands in which the measurement request signal was received (step 128). At this time, if some of the transmitting units 58-1 to 58-3 are unable to transmit, the antenna unit that covers the untransmittable frequency band is set as the additionally usable antenna unit, and transmission is performed using all antennas.

[0067] After the above process is completed, it is determined whether or not the measurement signal from the measurement requesting device 10 has been received in all frequency bands (step 130). If reception in all frequency bands is confirmed, the process of step 134, which will be described later, is then executed.

[0068] On the other hand, if it is determined that the measurement signal is not received in any of the frequency bands, the following process is executed (step 132), similar to the case of step 122 above. Step 132-1: An antenna unit assigned to a frequency band that does not receive a measurement signal is set as an additionally used antenna unit. Step 132-2: The receiving units 50-1 to 50-3 also utilize the antenna unit set as the additionally used antenna unit to capture the measurement signal. Step 132-3: The receiving units 50-1 to 50-3 select the signal from the antenna unit with the strongest signal strength.

[0069] After the above process is completed, the measurement device 20 measures the propagation channel state information CSI for each frequency band based on the received measurement signal, and then transmits a notification signal including the measured CSI in all available frequency bands (step 134).

[0070] The above process completes the process that the measuring device 20 must execute for wireless sensing. At this stage, the measuring device 20 determines whether or not "change required" is recorded in the control unit 52 (step 136).

[0071] If there is no record of "change required," the current routine is promptly terminated. On the other hand, if there is a record of "change required," the transmission mode of the measuring device 20 is returned to asynchronous mode, and the record of "change required" is cleared.

[0072] According to the above process, if some frequency bands are unavailable for transmission during wireless sensing, the measurement requesting device 10 and the measurement device 20 can use the hardware resources allocated to those frequency bands to transmit the overlap signal 36 in available frequency bands. As a result, more information is exchanged between the measurement requesting device 10 and the measurement device 20 than when those hardware resources are unavailable. Therefore, according to the wireless sensing system of this embodiment, even if some frequency bands are unavailable for transmission, it is possible to avoid a significant decrease in sensing accuracy compared to normal.

[0073] [Modification of the first embodiment] In the first embodiment described above, when a duplicate signal 36 is transmitted, the measurement device 20 is caused to select a signal with a stronger signal strength. This process is not limited to being performed by the measurement device 20, and a similar process may be performed by the measurement requesting device 10.

[0074] In the first embodiment described above, when the overlapping signal 36 is transmitted, a signal with a strong signal strength is selected and used, but the present disclosure is not limited to this. When the overlapping signal 36 is transmitted in some frequency bands, CSI may be detected from both the normal signal and the overlapping signal 36, and both may be reflected in the wireless sensing result.

[0075] In the first embodiment described above, when some frequency bands are unavailable, the hardware resources utilized in the available frequency bands are limited to the antenna unit, but the present disclosure is not limited to this.In addition to the antenna unit, all hardware resources corresponding to other frequency bands can be targets for additional use in the other frequency bands.

[0076] In the first embodiment described above, both the measurement requesting device 10 and the measurement device 20 set the hardware resources (antenna units) allocated to the unavailable frequency band as additionally usable resources (additionally usable antenna units) for transmitting and receiving overlapping signals in other available frequency bands, but the present disclosure is not limited to this. The additionally usable resources may be set in only one of the measurement requesting device 10 and the measurement device 20. [Explanation of symbols]

[0077] 10 Measurement request device 12, 14, 16, 22, 24, 26 Antenna section 20 Measuring Equipment 30 Radio Signal 32 f1 signal 34 f2 signal 36 Duplicate Signals 40, 52 Control section 42 Measurement request signal generator 44-1 to 44-3, 58-1 to 58-3 Transmitting section 46-1~46-3, 50-1~50-3 Receiver 48 Measurement signal generator 56 Measurement preparation complete signal generation section 60 Propagation channel measurement section 62 Notification signal generation unit

Claims

1. A wireless sensing system including a measurement requesting device having a plurality of wireless functions corresponding to different frequency bands in one housing, and a measuring device having a plurality of wireless functions corresponding to different frequency bands in one housing, a process in which the measurement requesting device transmits measurement signals in a plurality of frequency bands; a process in which the measurement device receives the measurement signals in a plurality of frequency bands and extracts propagation channel state information for each frequency band; and calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information for each frequency band, A wireless sensing system configured such that, when a frequency band that cannot be transmitted exists when the execution of wireless sensing is requested, at least one of the measurement requesting device and the measuring device executes a process of setting the wireless communication hardware resources allocated to the frequency band to additional usage resources to be used for transmitting overlapping signals in a frequency band that can be transmitted.

2. At least one of the measurement requesting device and the measuring device When execution of the wireless sensing is requested, a determination process for determining whether signals from the other side are received in all of the different frequency bands; a setting process for setting, when the signal from the other party is not received in a certain frequency band, the wireless communication hardware resource allocated to the certain frequency band as an additional use resource for receiving the overlapping signal in another frequency band; The wireless sensing system of claim 1 configured to perform the following:

3. the hardware resources include antenna units the number of which is equal to the number of the different frequency bands; the additional use resource includes an additional use antenna unit for receiving the overlapping signal; The wireless sensing system of claim 2, wherein the device that executes the discrimination process and the setting process, among the measurement request device and the measurement device, is configured to select the stronger signal from the overlapping signal received by the additionally used antenna unit and the signal in the same frequency band as the overlapping signal received by another antenna unit as the signal in that frequency band and use it as basic data for the wireless sensing.

4. the hardware resources include antenna units the number of which is equal to the number of the different frequency bands; the additional use resource includes an additional use antenna unit for receiving the overlapping signal; The wireless sensing system of claim 2, wherein the device that executes the discrimination process and the setting process, among the measurement request device and the measurement device, is configured to extract the propagation channel state information from both the overlapping signal received by the additionally used antenna unit and a signal in the same frequency band as the overlapping signal received by another antenna unit, and use both of the extracted information as basic data for the wireless sensing.

5. 3. The wireless sensing system according to claim 2, wherein at least one of the measurement request device and the measurement device is configured to set the hardware resource assigned to a non-transmittable frequency band as the additional usage resource to be used in one of the transmittable frequency bands when the hardware resource corresponds to one of the transmittable frequency bands.

6. the hardware resources include antenna units the number of which is equal to the number of the different frequency bands; the additional use resource includes an additional use antenna unit that transmits and receives the overlapping signal; 6. The wireless sensing system according to claim 2, wherein the measurement request device and the measurement device are configured to transmit and receive signals by utilizing all of the antenna units even when there is a frequency band in which transmission is prohibited.

7. A wireless sensing method using a measurement requesting device having a plurality of wireless functions corresponding to different frequency bands in one housing, and a measuring device having a plurality of wireless functions corresponding to different frequency bands in one housing, the measurement requesting device transmitting measurement signals in a plurality of frequency bands; the measurement device receiving the measurement signals in a plurality of frequency bands and extracting propagation channel state information for each frequency band; calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information for each frequency band; When a frequency band that cannot be transmitted exists when the execution of the wireless sensing is requested, at least one of the measurement requesting device and the measuring device sets a wireless communication hardware resource that has been allocated to the frequency band as an additional use resource to be used for transmitting overlapping signals in a frequency band that can be transmitted; A wireless sensing method comprising:

8. A measurement requesting device that realizes a wireless sensing function based on the results of information communication with a measuring device having multiple wireless functions corresponding to different frequency bands in a single housing, It has multiple wireless functions corresponding to different frequency bands in one housing, transmitting measurement signals in multiple frequency bands to the measurement device; receiving a notification signal transmitted by the measurement device for each frequency band, the notification signal including propagation channel state information extracted from the measurement signal for each frequency band; calculating a result of wireless sensing of a space between the measurement requesting device and the measuring device based on the propagation channel state information extracted from the notification signal for each frequency band; a process of setting, when a frequency band that cannot be transmitted exists when the execution of the wireless sensing is requested, the wireless communication hardware resource that has been allocated to the frequency band in question as an additional use resource to be used for transmitting overlapping signals in a frequency band that can be transmitted; a measurement requesting device configured to perform the steps of:

Images