Reconfigurable surface device

Abstract

The present disclosure provides a reconfigurable surface device, comprising: a receiving unit configured to receive subarray partitioning setting information transmitted from a base station; a reconfigurable panel; and a processing unit configured to partition the reconfigurable panel into M subarrays based on the subarray partitioning setting information, M being a positive integer greater than 1, wherein the subarray partitioning setting information is determined based on a distance between a target device and the reconfigurable panel, and N subarrays of the M subarrays serve one target device, N being a positive integer greater than 1 and less than or equal to M.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a reconfigurable surface device in a next-generation mobile communication system. BACKGROUND

[0002] A communication system such as 5G, 6G, etc. will use a millimeter wave band and a higher frequency band for communication to increase a wireless data transmission rate. However, a wireless communication system using a millimeter wave band and a higher frequency band has a smaller coverage, and for this reason, a scheme of using a reconfigurable surface device (RIS: Reconfigurable Intelligent Surface) including a reconfigurable panel (Reconfigurable Panel) to increase the coverage of the communication system is proposed.

[0003] The reconfigurable surface device has a low cost and low power consumption, and provides a new possibility for solving the coverage and capacity problems of a mobile communication system.

[0004] Since the larger the area of the RIS panel is, the more gain it can provide, considering the path loss from a base station (BS) to the RIS and the path loss from the RIS to a user terminal (UE), a RIS panel with a large area is usually required to provide sufficient gain to compensate for the path loss of the BS-RIS-UE cascade channel.

[0005] However, a large-size RIS panel can cause a problem of a large near-field range. For example, a 1m by 1m RIS panel operating in a millimeter wave band has a near-field range of about 100 meters. Therefore, a large number of users can be in the near-field range of the RIS. However, a conventional beamforming (BF) method based on a discrete Fourier transform (DFT) is designed for a far field, and has a low gain in a near field.

[0006] In order to improve the near-field gain of a large-size RIS, a beamforming technique suitable for communication is required. For example, a coherent BF technique can be used for beamforming. In the coherent BF technique, by independently compensating the phases of the channels of each element of the RIS, the reflected / transmitted signals are in-phase superimposed at the user. However, the coherent BF technique requires complete channel state information (CSI), and it is extremely difficult to obtain complete channel state information in the RIS scenario, and lacks practicality.

[0007] For example, a focusing BF technique can also be used for beamforming. In the focusing BF technique, the phase of each RIS element is adjusted one by one based on the accurate position of the user, so as to focus the reflected signal or the transmitted signal at the user. However, this technique requires the RIS to accurately control each element, which is complex. SUMMARY

[0008] It is desirable to provide a new reconfigurable surface device to improve the problem of a large near-field range and low gain in the near-field range of a large-size RIS.

[0009] According to an aspect of the present disclosure, a reconfigurable surface device is provided, comprising: a receiving unit configured to receive subarray division setting information sent from a base station; a reconfigurable panel; and a processing unit configured to divide the reconfigurable panel into M subarrays based on the subarray division setting information, M being a positive integer greater than 1, wherein the subarray division setting information is determined based on the distance between a target device and the reconfigurable panel, and N subarrays of the M subarrays serve one target device, N being a positive integer greater than 1 and less than or equal to M.

[0010] According to an aspect of the present disclosure, each of the M subarrays corresponds to a specific beam.

[0011] According to an aspect of the present disclosure, the specific beams of the N subarrays of the M subarrays converge on one target device.

[0012] According to an aspect of the present disclosure, the specific beams of the N subarrays of the M subarrays diverge within a specific range with respect to one target device.

[0013] According to an aspect of the present disclosure, the M subarrays serve a plurality of target devices, the number of subarrays serving each target device is a positive integer, and the number of subarrays is greater than 1 and less than or equal to M.

[0014] According to an aspect of the present disclosure, a reconfigurable surface device is provided, comprising: a receiving unit configured to receive position information of a target device; a reconfigurable panel; and a processing unit configured to determine a first codebook based on the direction of the reconfigurable panel with respect to the target device, and to calculate the first codebook based on the distance between the reconfigurable panel and the target device and the position of each subarray of M subarrays included in the reconfigurable panel to determine a second codebook, wherein M is a positive integer greater than 1.

[0015] According to one aspect of the present disclosure, each of the sub-arrays includes a plurality of array elements, the second codebook includes an array element steering sub-codebook and a phase compensation sub-codebook, the array element steering sub-codebook steers each array element in the sub-array respectively, and the phase compensation sub-codebook compensates the phase of the sub-array.

[0016] According to one aspect of the present disclosure, the reconfigurable surface device determines the first beam of each sub-array through the first codebook, and performs the steering and the phase compensation on the first beam through the second codebook.

[0017] According to one aspect of the present disclosure, the target device includes at least one of a terminal and a base station.

[0018] According to one aspect of the present disclosure, the reconfigurable surface device oversamples the first codebook and the second codebook. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description thereof taken in conjunction with the accompanying drawings, in which: The drawings provided in the disclosure and their accompanying descriptive text are intended to convey a working understanding of embodiments of the disclosure. They include schematic illustrations of embodiments of the disclosure. They are included to provide a

[0020] Figure 1 is a schematic diagram showing a reconfigurable surface device involved in an embodiment of the present disclosure.

[0021] Figure 2A and Figure 2B is a schematic diagram showing the relationship between sub-array partitioning and near-field influence of a reconfigurable panel involved in an embodiment of the present disclosure.

[0022] Figure 3 is a diagram showing an example of sub-array size and distance from a target device to a reconfigurable panel involved in an embodiment of the present disclosure.

[0023] Figure 4 is a schematic diagram showing a reconfigurable surface device involved in another embodiment of the present disclosure.

[0024] Figure 5 is a diagram showing a double-layer codebook calculation formula involved in an embodiment of the present disclosure.

[0025] Figure 6 is a schematic diagram showing the determination of a beam based on a double-layer codebook, and the steering and phase compensation of the beam involved in an embodiment of the present disclosure.

[0026] Figure 7is a flowchart representing a control method performed by a reconfigurable surface device according to an embodiment of the present disclosure.

[0027] Figure 8 is a flowchart representing a control method performed by a reconfigurable surface device according to another embodiment of the present disclosure.

[0028] Figure 9 is a schematic diagram representing a hardware structure of an apparatus according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions, and advantages of the present disclosure more obvious, the following will describe the example embodiments according to the present disclosure in detail with reference to the drawings. In the drawings, the same reference numerals represent the same elements throughout. It should be understood that the embodiments described in the present disclosure are merely illustrative, and should not be interpreted as limiting the scope of the present disclosure. In addition, the terminal described in the present disclosure can include various types of terminals, such as a vehicle terminal, a user equipment (UE), a mobile terminal (or mobile station), or a fixed terminal, etc. The base station (BS) described in the present disclosure includes various types of base stations, such as a wireless base station, a fixed station, a NodeB, an eNodeB (eNB), a gNodeB (gNB), an access point, a transmission point (TP), a reception point (RP), a transmission / reception point (TRP), etc. In the present disclosure, the reconfigurable intelligent surface (RIS) can also be referred to as a reconfigurable panel, an RIS panel, a large intelligent surface, an intelligent reflecting surface, a reconfigurable intelligent surface, a passive intelligent surface, a reconfigurable metasurface, a software defined surface, a software defined metasurface, a large intelligent metasurface, a smart reflect array, etc. according to specific circumstances.

[0030] Referring to Figure 1 to explain the reconfigurable intelligent surface device 100 related to one embodiment of the present disclosure. Figure 1 is a schematic diagram of the reconfigurable intelligent surface device related to the embodiments of the present disclosure. As Figure 1As shown, the reconfigurable surface device 100 comprises a receiving unit 110, a reconfigurable panel 120, and a processing unit 130. In embodiments according to the present disclosure, the reconfigurable panel 120 can be located in the same housing as the processing unit 130. Alternatively, the reconfigurable panel 120 can be located independently of the processing unit 130.

[0031] In particular, in the example described above, the receiving unit 110 receives the subarray partitioning setting information from the base station. The subarray partitioning setting information can be determined based on the distance between the target device and the reconfigurable panel 120. In addition, the specific target device can be determined as needed. For example, the target device can include one of the terminal and the base station. The target device can be one device or a plurality of devices. For example, when the target device is a terminal device, the target device can be one terminal device that is closer to the reconfigurable surface device 100, or the target device can be a plurality of terminal devices that are closer to the reconfigurable surface device 100. Figure 1

[0032] The processing unit 130 partitions the reconfigurable panel 120 into M subarrays based on the subarray partitioning setting information, where M is a positive integer greater than 1. In examples according to the present disclosure, N subarrays of the M subarrays serve one of the target devices, where N is a positive integer greater than 1 and less than or equal to M. In other words, when it is desired to use the reconfigurable surface device 100, the reconfigurable panel 120 can be partitioned into a plurality of subarrays based on the subarray partitioning setting information indicating the distance between the target device and the reconfigurable panel 120. In addition, in embodiments according to the present disclosure, other factors, such as hardware limitation conditions, can also be considered when partitioning the reconfigurable panel 120 into a plurality of subarrays. Since the area of the reconfigurable panel is related to its gain. As the area of the reconfigurable panel increases, the gain of the reconfigurable panel also increases, and accordingly, the near-field range of the reconfigurable panel also increases due to the increase in area, and the near-field effect on the target device is more significant. Conversely, as the area of the reconfigurable panel decreases, the gain of the reconfigurable panel also decreases, and accordingly, the near-field range of the reconfigurable panel also decreases due to the decrease in area, and the near-field effect on the target device is alleviated.

[0033] ​Therefore, according to one example of the present disclosure, for a target device indicated by the subarray division setting information to have a larger distance from the reconfigurable panel 120, the processing unit 130 can divide the reconfigurable panel 120 into fewer subarrays, so that each subarray can have a larger area. Since the target device has a larger distance from the reconfigurable panel 120, even the subarray with a larger area will not cause a significant near-field effect on the target device. For a target device indicated by the subarray division setting information to have a smaller distance from the reconfigurable panel 120, the processing unit 130 can divide the reconfigurable panel 120 into more subarrays, so that each subarray can have a smaller area. Since the target device has a smaller distance from the reconfigurable panel 120, the subarray with a smaller area can reduce the near-field effect on the target device.

[0034] Figure 2A and Figure 2B are schematic diagrams representing the subarray division of the reconfigurable panel 120 and the near-field effect according to an embodiment of the present disclosure. In Figure 2A and Figure 2B , since the total area of the reconfigurable panel is the same, the near-field range of the reconfigurable panel itself is the same under the same load rate.

[0035] In Figure 2A , the reconfigurable panel 230A is divided into 4x4 subarrays in total, so that each subarray has a smaller area and the near-field range formed by each subarray is also smaller. In this case, the target device 240A needs to be located at a position farther from the reconfigurable panel 230A than the target device 240A in

[0036] In Figure 2B , the reconfigurable panel 230B is divided into 2x2 subarrays in total, so that each subarray has a larger area and the near-field range formed by each subarray is also larger. In this case, the target device 240B needs to be located at a position farther from the reconfigurable panel than the target device 240A in Figure 2A . In other words, for a target device indicated by the subarray division setting information to have a larger distance from the reconfigurable panel, the processing unit 130 can divide the reconfigurable panel 230B into fewer subarrays, so that each subarray can have a larger area. Since the target device has a larger distance from the reconfigurable panel 120, even the subarray with a larger area will not cause a significant near-field effect on the target device.

[0037] The "near field" and "far field" of the reconfigurable panel 120 can be determined according to the specific configuration of the communication system.

[0038] Therefore, the processing unit 130 reasonably selects the size of the subarray according to the distance between the target device and the reconfigurable panel, divides the M subarrays, and makes the target device in the far field of a single subarray to solve the problem of large near-field range and low near-field gain of the large-size RIS based on DFT beamforming.

[0039] According to one example of the present disclosure, the processing unit 130 can divide the reconfigurable panel 120 based on the subarray division setting information so that the target device is located in the far field of a single subarray after division. For example, the value range of the corresponding subarray aperture can be calculated according to the position information of the target device using formula (1).

[0040] D 2 <2λ·α·d RIS-Target (1)

[0041] where D is the subarray aperture, and in the case of a square subarray, D is equal to the length of the square diagonal. λ is the wavelength of the carrier for communication transmission. d RIS-Target is the distance between the reconfigurable panel and the target device. α is the scaling coefficient, and the typical value is 1, and α>0.4 can also be considered.

[0042] For example, in the case where the subarray division setting information includes the position information of the target device, the processing unit 130 can determine the distance d RIS-Target between the target device and the reconfigurable panel 120 according to the received subarray division setting information. Then the processing unit 130 can divide the subarray of the reconfigurable panel 120 according to the above formula (1) so that the target device is in the far field of a single subarray. Alternatively, the processing unit 130 can also consider the overall size of the reconfigurable panel, the limitation of hardware capability, and other actual situations when dividing the reconfigurable panel 120.

[0043] Alternatively, the base station can determine the distance d RIS-Target between the target device and the reconfigurable panel 120 according to the position information of the target device, and send information indicating the determined distance d RIS-Target to the reconfigurable surface device as subarray division setting information, so that the processing unit 130 performs subarray division based on the subarray division setting information. In addition, the base station can also determine the division mode of the reconfigurable panel 120 according to the distance d RIS-Target between the target device and the reconfigurable panel 120, and send information indicating the determined division mode to the reconfigurable surface device as subarray division setting information, so that the processing unit 130 performs subarray division based on the subarray division setting information.

[0044] According to examples in this disclosure, when dividing the subarray, the distance between the target device and the reconfigurable panel can also be logarithmically quantized to determine the subarray size.

[0045] Figure 3 Examples of values ​​for the subarray size and the distance from the target device to the reconfigurable panel involved in embodiments of this disclosure.

[0046] like Figure 3 As shown, with a carrier frequency of 30GHz and a scaling factor α set to 1, when the distance between the target device and the reconfigurable panel is greater than or equal to 2.5m, a subarray size of less than or equal to 16cm x 16cm is selected, and the maximum number of array elements contained in this subarray is 32x32. When the distance between the target device and the reconfigurable panel is greater than or equal to 10m, a subarray size of less than or equal to 32cm x 32cm is selected, and the maximum number of array elements contained in this subarray is 64x64. When the distance between the target device and the reconfigurable panel is greater than or equal to 40m, a subarray size of less than or equal to 64cm x 64cm is selected, and the maximum number of array elements contained in this subarray is 128x128. When the distance between the target device and the reconfigurable panel is greater than or equal to 160m, a subarray size of less than or equal to 1.3m x 1.3m is selected, and the maximum number of array elements contained in this subarray is 256x256.

[0047] In addition, according to another example of this disclosure, other factors, such as the processing power of the reconfigurable surface device, the complexity of the system implementation, power consumption, etc., may also be considered when determining the size and number of subarrays.

[0048] Furthermore, while the above explanation used a square subarray as an example, the subarray can also be of other shapes. Additionally, the shape of the reconfigurable panel can be arbitrary and not limited to a square.

[0049] As described above, N subarrays out of the M subarrays divided by the reconfigurable panel serve a target device, where N is a positive integer greater than 1 and less than or equal to M.

[0050] According to another example of this disclosure, the reconfigurable surface device can also serve multiple target devices.

[0051] Specifically, when the M subarrays divided by the reconfigurable panel serve multiple target devices, if the multiple subarrays serving target device A are set as N1 subarrays and the multiple subarrays serving target device B are set as N2 subarrays, N1 and N2 are both positive integers greater than 1 and less than or equal to M.

[0052] In this case, the N1 sub-arrays providing services to the target device A and the N2 sub-arrays providing services to the target device B can be completely different, completely the same, or partially the same. In the case of the N1 sub-arrays providing services to the target device A and the N2 sub-arrays providing services to the target device B being completely the same or partially the same, multiplexing can also be achieved by time division, frequency division, or the like.

[0053] Although the above describes the case that the M sub-arrays divided by the reconfigurable panel serve two target devices, the M sub-arrays can also serve more than two target devices.

[0054] As described above, the target device can also include one of a terminal and a base station. The above has been described in combination with the terminal as the target device. Figure 2A and Figure 2B The terminal is described as the target device. Alternatively, the base station can also be the target device, in which case, the sub-array division can be based on the distance between the base station and the reconfigurable panel.

[0055] In particular, when the base station is located in the near field of the reconfigurable panel, the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel needs to be considered. The reconfigurable surface device can also take the base station as the target device in this case, so as to compensate for the phase difference when the spherical incident wave reaches the reconfigurable panel. This part will be described later.

[0056] Therefore, the above sub-array division can be based on the distance between the terminal and the reconfigurable panel, or based on the distance between the base station and the reconfigurable panel.

[0057] The "base station" as the target device can also refer to the "beam emitting device in the base station", that is, the "distance between the base station and the reconfigurable panel" can also refer to the "distance between the beam emitting device in the base station and the reconfigurable panel". For example, in the case that the reconfigurable panel is located inside the base station, the sub-array division can also be based on the distance between the beam emitting device in the base station and the reconfigurable panel.

[0058] By dividing the reconfigurable panel into M sub-arrays based on the distance between the target device and the reconfigurable panel, so that the target device is in the far field range of a single sub-array, the problem of large near field range and low near field gain of the large size RIS based on DFT beamforming can be improved, and further, by making multiple sub-arrays serve the same target device, the problem of low gain provided by a single sub-array can be solved.

[0059] Thus, even if the target device is in the near-field range of the large-size RIS based on DFT beamforming, the signal-to-noise ratio of the target device can be improved, and the transmission rate of the target device can be improved by placing the target device in the far-field range of a single subarray and serving the target device by multiple subarrays.

[0060] According to one example of the present disclosure, each of the M subarrays divided by the reconfigurable panel corresponds to a specific beam. The specific beam can also be a beam emitted from the corresponding subarray.

[0061] According to one example of the present disclosure, the specific beams of the N subarrays of the M subarrays divided by the reconfigurable panel converge on a target device.

[0062] Thus, by converging the specific beams of the N subarrays of the M subarrays divided by the reconfigurable panel on a target device, compared with the scheme of irradiating the target device with the specific beam of a single subarray, higher gain can be provided to the specific target device, the signal-to-noise ratio can be improved, and the transmission rate can be improved.

[0063] According to another example of the present disclosure, in the case where the M subarrays divided by the reconfigurable panel serve multiple target devices, if the multiple subarrays that provide services to the target device A are set as N1 subarrays, and the multiple subarrays that provide services to the target device B are set as N2 subarrays, N1 and N2 are positive integers greater than 1 and less than or equal to M.

[0064] In this case, the specific beams of the N1 subarrays that provide services to the target device A converge on a target device, and the specific beams of the N2 subarrays that provide services to the target device B converge on another target device.

[0065] Although the above describes the case where the M subarrays divided by the reconfigurable panel serve two target devices, it can also serve more than two target devices.

[0066] Moreover, although the beam convergence to a specific target device can improve the gain, the covered area is relatively small after the beam convergence, and thus, once the target device moves out of the covered area, a large performance loss can occur. In view of this, according to another embodiment of the present disclosure, the specific beams of the N sub-arrays among the M sub-arrays can be diverged within a specific range with respect to a target device. The specific range can be determined according to the signal-to-noise ratio required when the target device communicates. For example, when the target device performs high-rate transmission and requires a high signal-to-noise ratio, the range of divergence is reduced, or the beams are not diverged but converged to the target device to improve the gain. On the other hand, when the target device performs low-rate transmission and does not require a high signal-to-noise ratio, the specific range of divergence of the beams of the sub-arrays providing service to the target device with respect to the target device is increased, thereby covering a larger range and improving the robustness.

[0067] According to another example of the present disclosure, when the reconfigurable panel is relatively close to the base station, the total path loss composed of the path loss between the base station and the reconfigurable panel and the path loss between the target device and the reconfigurable panel is relatively small, and thus, the signal-to-noise ratio of the target device is already sufficient to support high-rate transmission, and it is not necessary to converge the beams of the sub-arrays providing service to the target device to the target device to improve the gain. In this case, the beams of the sub-arrays can also be appropriately diverged to cover a larger range as described above.

[0068] According to another example of the present disclosure, the beams of a part of the sub-arrays providing service to the target device can also be converged to the target device, and the beams of another part of the sub-arrays providing service to the target device can be diverged with respect to the target device, thereby flexibly adjusting the gain to the target device according to different transmission rates required.

[0069] According to another example of the present disclosure, the communication system with the reconfigurable surface device can also implement multi-stream transmission. For example, the communication system includes a base station, a reconfigurable surface device, and a terminal. While the base station directly communicates with the terminal, the base station also communicates with the terminal via the reconfigurable surface device, thereby implementing multi-stream transmission.

[0070] In the process of multi-stream transmission, in order to improve the efficiency of multi-stream transmission, it is necessary to balance the gain of the direct path of the base station directly communicating with the terminal and the gain of the path of the base station communicating with the terminal via the reconfigurable surface device, and thus, the gain of the base station-terminal direct path and the base station-reconfigurable surface device-terminal path can also be balanced by selecting the inter-sub-array codewords of the reconfigurable panel in the reconfigurable surface device, thereby maximizing the efficiency of multi-stream transmission.

[0071] In addition, in the case where the reconfigurable panel serves multiple target devices, the channel quality of different target devices can also be different, and therefore, in order to match the transmission rate of target devices with different channel qualities, the gain for different target devices can also be adjusted by configuring different subarray sizes and subarray numbers for different target devices.

[0072] The fact that the reconfigurable panel serves multiple target devices can also be implemented by orthogonal time division multiplexing, orthogonal frequency division multiplexing, or non-orthogonal (NOMA) waveform.

[0073] In this way, by configuring different subarray sizes and subarray numbers for different target devices to adjust the gain for different target devices, the transmission rate of target devices with different channel qualities can be matched in the case where the reconfigurable panel serves multiple target devices.

[0074] In summary, even if the target device is in the near-field range of a large-size RIS based on DFT beamforming, the signal-to-noise ratio of the target device can be improved and the transmission rate of the target device can be improved by placing the target device in the far-field range of a single subarray and serving the target device by multiple subarrays.

[0075] In the following, the codebook implementation method for implementing multiple subarrays to serve one target device will be described in detail.

[0076] At present, the DFT-based beamforming method has the advantages of simple implementation and less signaling consumption. Further, in order to solve the problem of small beam gain of a single subarray, the following double-layer codebook implementation method is used, i.e., first, a reference DFT beam is determined by a first layer codebook (i.e., a first codebook), and then the reference DFT beam is deflected and the phase is compensated by a second layer codebook (i.e., a second codebook) to make multiple subarrays serve one target device, so as to improve the gain and further improve the transmission rate.

[0077] According to one example of the present disclosure, a reconfigurable surface device 400 is provided. As shown in Figure 4 The reconfigurable surface device 400 includes a receiving unit 410 configured to receive position information of a target device, a reconfigurable panel 420, and a processing unit 430 configured to determine a first codebook based on the direction of the reconfigurable panel relative to the target device, and calculate the first codebook based on the distance between the reconfigurable panel and the target device and the position of each subarray in the M subarrays contained in the reconfigurable panel to determine a second codebook.

[0078] The location information may include the orientation of the reconfigurable panel relative to the target device and the distance between the reconfigurable panel and the target device. On the other hand, the positions of each of the M subarrays contained in the reconfigurable panel may not be included in the location information of the target device received by the receiving unit 410.

[0079] The orientation of the reconfigurable panel relative to the target device can also be represented by azimuth and elevation.

[0080] In addition, the orientation of the reconfigurable panel relative to the target device and the distance between the reconfigurable panel and the target device can also be represented by three-dimensional coordinates.

[0081] For example, the reconfigurable panel can be used as a reference point, and the position of the target device can be represented in three-dimensional coordinates. Alternatively, the reference point does not necessarily have to be the reconfigurable panel; other locations can also be used as reference points, as long as the positional relationship between the reconfigurable panel and the target device is clearly represented.

[0082] The position of each subarray in the M subarrays divided by the reconfigurable panel can refer to the position of each subarray in the M subarrays, or it can refer to the position of each subarray in the multiple subarrays serving a certain target device in the M subarrays.

[0083] According to another example of this disclosure, the location information of the target device, the reconfigurable panel, its contained subarrays, etc., can also be represented in other ways, such as in a vector manner.

[0084] According to one example of this disclosure, each subarray contains multiple array elements, and the second codebook includes an array element deflection subcodebook and a phase compensation subcodebook. The array element deflection subcodebook deflects each array element in the subarray, and the phase compensation subcodebook compensates the phase of the subarray.

[0085] Figure 5 This represents the calculation formula for the double-layer codebook involved in the embodiments of this disclosure. In Figure 5 For ease of explanation, the calculation formula for the two-layer codebook is explained using the terminal as the target device. However, the target device can also be set as the base station. In this case, Figure 5 The position vector r of the terminal in UE Replace with the base station's location vector r BS That's all.

[0086] like Figure 5 As shown, the BF emission coefficients of the RIS-UE of the (m, n)th element of the (k, l)th subarray are determined by the calculation formula of the double-layer codebook. Figure 5 The calculation formula for the dual-layer codebook includes a calculation formula for determining the first-layer codebook and a calculation formula for determining the second-layer codebook.

[0087] based on the direction of the reconfigurable panel with respect to the target device, determine Figure 5 a first layer codebook, i.e., select a reference DFT beam.

[0088] based on the distance between the reconfigurable panel and the target device, and the position of each subarray in the M subarrays included in the reconfigurable panel, calculate the first layer codebook to determine Figure 5 a second layer codebook.

[0089] As shown in Figure 5 , the calculation formula for determining the first layer codebook is related to the position vector of the terminal and the position vector of the (m, n)th array element, and the calculation formula for determining the second layer codebook further includes a calculation formula for determining an array element deflection sub-codebook and a calculation formula for determining a phase compensation sub-codebook. The calculation formula for determining the array element deflection sub-codebook contains the vector of the terminal, the position vector of the (k, l)th subarray, and the position vector of the (m, n)th array element, and through the array element deflection sub-codebook, each array element in each subarray is deflected respectively. The calculation formula for determining the phase compensation sub-codebook contains the vector of the terminal and the position vector of the (k, l)th subarray, and through the phase compensation sub-codebook, each subarray is phase compensated.

[0090] According to one example of the present disclosure, the reconfigurable surface device determines the first beam of each subarray through the first codebook, and deflection and phase compensation of the first beam through the second codebook.

[0091] Figure 6 is a flowchart representing the process of determining the beam based on the double-layer codebook and deflection and phase compensation of the beam according to the embodiments of the present disclosure.

[0092] Figure 6 Step S610 of Figure 5 corresponds to the determination of the first layer codebook in the codebook calculation formula of Figure 6 , i.e., the determination of the reference DFT beam. Figure 5 Step S620 of Figure 5 corresponds to the determination of the second layer codebook in the codebook calculation formula of , i.e., the deflection and phase compensation of the reference DFT beam through the determination of the array element deflection sub-codebook and the phase compensation sub-codebook in the second layer codebook as shown in

[0093] Figure 5The position vector of the subarray is not included in the calculation formula of the first layer codebook of the target device, only the position vector of the target device and the position vector of the array element, so the directions of the first beams emitted by each subarray are the same.

[0094] In S620, each array element in the subarray is deflected by the array element deflection subcodebook in the second layer codebook, so that the beams emitted by each subarray converge on the target device. Since the distance from each subarray to the target device is different, in order to offset the phase deviation caused by the difference in distance, each subarray is phase compensated by the phase compensation subcodebook in the second layer codebook to offset the phase deviation of the beams of each subarray when they reach the target device.

[0095] Here, each array element in the subarray is deflected by the array element deflection subcodebook in the second layer codebook, so that the first beams emitted by each subarray converge on the target device. Compared with the scheme that the beam of a single subarray irradiates a specific target device, higher gain can be provided to the specific target device, the signal-to-noise ratio is improved, and the transmission rate is further improved.

[0096] Alternatively, each array element in the subarray can also be deflected by the array element deflection subcodebook in the second layer codebook, and diverge within a specific range with respect to a specific target device. In this way, a larger range can be covered, and the robustness is improved.

[0097] According to one example of the present disclosure, the first layer codebook and the second layer codebook described above can also be oversampled to improve the beam convergence accuracy. Here, oversampling the codebook can also be interpreted as selecting beams with better convergence capability from multiple beam candidates to improve the beam convergence accuracy. Alternatively, based on the hardware conditions of the reconfigurable surface device or other factors, a beam can be selected from multiple beam candidates.

[0098] The oversampling multiple can also be selected to be greater than or equal to 2. For example, there are 4 beam candidates, and 2 beams are selected with an oversampling multiple of 2.

[0099] The reconfigurable surface device can improve the problem of large near-field range and low gain in the near-field range of a large-size RIS based on DFT beamforming by the above-mentioned subarray division when communicating with the terminal. Moreover, by using the double-layer codebook, multiple subarrays can serve the same target device, which can solve the problem of low gain provided by a single subarray.

[0100] According to one example of the present disclosure, the reconfigurable surface device can also perform the above-mentioned similar processing when communicating with the base station.

[0101] For example, when the base station is located in the near field of the reconfigurable panel, the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel needs to be considered.

[0102] Therefore, the reconfigurable surface device can also perform the same processing of subarray partitioning and double-layer codebook as described above when communicating with the terminal to compensate for the phase difference caused by the spherical wave effect when the beam emitted by the base station reaches the reconfigurable panel. In this case, the target device is the base station. Therefore, when calculating the subarray partitioning and the double-layer codebook, the position of the terminal needs to be replaced by the position of the base station.

[0103] In addition, since the position of the base station and the position of the reconfigurable panel are generally fixed when the target device is the base station, the coefficient formula for compensating the phase difference can be determined by prior calibration when deploying the reconfigurable panel.

[0104] Alternatively, the base station can communicate with the reconfigurable surface device before the terminal accesses, and the reconfigurable surface device reports the parameter information of the reconfigurable panel, such as position, height, angle, size, etc. to the base station. Then, based on this information, the base station informs the reconfigurable surface device of the compensation required by the reconfigurable surface device in the form of a codebook. This codebook form can be the same as the calculation formula of the double-layer codebook shown in Figure 5 .

[0105] Further, in a communication system with a base station, a reconfigurable surface device, and a terminal, the processing of subarray partitioning and double-layer codebook can also be performed for the base station and the terminal respectively. That is, taking the target device as the base station, using the codebook calculation formula in Figure 5 , the processing of subarray partitioning and double-layer codebook is performed to obtain the receiving coefficient for RIS-BS end BF, and then taking the target device as the terminal, using the codebook calculation formula in Figure 5 , the processing of subarray partitioning and double-layer codebook is performed to obtain the transmitting coefficient for RIS-UE end BF. Finally, the receiving coefficient for RIS-BS end BF and the transmitting coefficient for RIS-UE end BF are multiplied to obtain the final reflection / transmission coefficient of RIS.

[0106] In addition, the "base station" as the target device can also refer to "beam transmitting device in the base station", that is, the "distance between the base station and the reconfigurable panel" can also refer to "distance between the beam transmitting device in the base station and the reconfigurable panel". For example, in the case where the reconfigurable panel is located inside the base station, the above-mentioned subarray partitioning, deflection, and phase compensation can also be performed based on the distance between the beam transmitting device in the base station and the reconfigurable panel.

[0107] Thus, while improving the problems of large near-field range of large-size RIS based on DFT beamforming and low gain in the near-field range, when the base station is located in the near field of the reconfigurable panel, the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel can also be compensated for when the base station is located in the near field of the reconfigurable panel.

[0108] Thus, based on the positions of each of the M sub-arrays divided by the reconfigurable panel, and the direction of the reconfigurable panel relative to the target device and the distance between the reconfigurable panel and the target device contained in the position information of the target device, a double-layer codebook can be determined, thereby providing a new solution to improve the problems of large near-field range of large-size RIS based on DFT beamforming and low gain in the near-field range.

[0109] The above describes the reconfigurable surface device according to the embodiments of the present disclosure, and in the above description, the description is made in a manner of dividing into individual units, such as a receiving unit, a processing unit, etc., but the description can also be made in a manner of dividing into individual steps, i.e., in a manner of receiving steps, processing steps to describe the control method performed by the reconfigurable surface device. Figures 1-6 The control method performed by the reconfigurable surface device is described below.

[0110] The control method performed by the reconfigurable surface device is described below.

[0111] Next, referring to Figure 7 , a control method 700 performed by a reconfigurable surface device according to an embodiment of the present disclosure is described. Figure 7 is a flowchart showing the control method 700 performed by the reconfigurable surface device according to the embodiment of the present disclosure.

[0112] As Figure 7 indicated, the control method 700 performed by the reconfigurable surface device includes a receiving step 710 and a processing step 720.

[0113] Specifically, in the example described in Figure 7 , in the receiving step 710 (S710), sub-array division setting information transmitted from the base station is received. For example, the sub-array division setting information can also be determined based on the distance between the target device and the reconfigurable panel of the reconfigurable surface device. In addition, the specific target device can be determined as needed. For example, the target device can include one of the terminal and the base station. The target device can be one device or multiple devices. For example, when the target device is a terminal device, the target device can be one terminal device close to the reconfigurable surface device, or the target device can be multiple terminal devices close to the reconfigurable surface device.

[0114] In the processing step 720 (S720), the reconfigurable panel is divided into M sub-arrays based on the sub-array division setting information, where M is a positive integer greater than 1. In examples according to the present disclosure, N sub-arrays of the M sub-arrays serve one of the target devices, where N is a positive integer greater than 1 and less than or equal to M. In other words, when the reconfigurable surface device is desired to be used, the reconfigurable panel can be divided into a plurality of sub-arrays based on the sub-array division setting information indicating the distance between the target device and the reconfigurable panel. In addition, in embodiments according to the present disclosure, other factors such as hardware limitation conditions can also be considered when dividing the reconfigurable panel into a plurality of sub-arrays. Since the area of the reconfigurable panel is related to its gain. As the area of the reconfigurable panel increases, the gain of the reconfigurable panel also increases, and accordingly, the near field range of the reconfigurable panel due to the increase in area also becomes larger, and the near field impact on the target device is more significant. Conversely, as the area of the reconfigurable panel decreases, the gain of the reconfigurable panel also decreases, and accordingly, the near field range of the reconfigurable panel due to the decrease in area also becomes smaller, and the near field impact on the target device is alleviated.

[0115] Therefore, according to one example of the present disclosure, for the target device indicated by the sub-array division setting information to have a larger distance from the reconfigurable panel, in the processing step 720, the reconfigurable panel can be divided into fewer sub-arrays, so that each sub-array can have a larger area. Since the distance between the target device and the reconfigurable panel is larger, even if the sub-array with a larger area, it will not cause significant near field impact on the target device.

[0116] As described above, according to one example of the present disclosure, in the processing step 720, for the case that the target device is closer to the reconfigurable panel, the reconfigurable panel can be divided into more sub-arrays, so that each sub-array can have a smaller area, and the sub-array with a smaller area can reduce the near field impact on the target device.

[0117] As described above, according to one example of the present disclosure, in the processing step 720, for the target device indicated by the sub-array division setting information to have a larger distance from the reconfigurable panel, the reconfigurable panel can be divided into fewer sub-arrays, so that each sub-array can have a larger area. Since the distance between the target device and the reconfigurable panel is larger, even if the sub-array with a larger area, it will not cause significant near field impact on the target device.

[0118] Therefore, according to one example of the present disclosure, in the processing step 720, the size of the subarray is reasonably selected according to the distance between the target device and the reconfigurable panel, and M subarrays are divided so that the target device is in the far field of a single subarray, to solve the problem of large near-field range and low near-field gain of the large-size RIS based on DFT beamforming.

[0119] According to one example of the present disclosure, in the processing step 720, the reconfigurable panel can be divided based on the subarray division setting information so that the target device is located in the far field of a single divided subarray.

[0120] According to an example of the present disclosure, when dividing the subarray, the distance between the target device and the reconfigurable panel can also be quantified to determine the size of the subarray.

[0121] In addition, according to another example of the present disclosure, when determining the size and number of subarrays, other factors such as the processing capability of the reconfigurable surface device, and the complexity, power consumption, etc. of the system implementation can also be considered.

[0122] In addition, in the above description, the example of the divided subarray being a square subarray is described, but the divided subarray can also be a subarray of other shapes. In addition, the shape of the reconfigurable panel can also be any shape, and is not limited to a square.

[0123] As described above, N subarrays of the M subarrays divided by the reconfigurable panel serve one target device, where N is a positive integer greater than 1 and less than or equal to M.

[0124] According to another example of the present disclosure, the reconfigurable surface device can also serve multiple target devices.

[0125] Alternatively, the base station can also be taken as a target device, in which case the subarray division can be performed based on the distance between the base station and the reconfigurable panel.

[0126] By dividing the reconfigurable panel into M subarrays based on the distance between the target device and the reconfigurable panel, so that the target device is in the far field range of a single subarray, the problem of large near-field range and low near-field gain of the large-size RIS based on DFT beamforming can be improved, and further, by having multiple subarrays serve the same target device, the problem of low gain provided by a single subarray can be solved.

[0127] Therefore, even if the target device is in the near-field range of the large-size RIS based on DFT beamforming, by having the target device in the far-field range of a single subarray and by having multiple subarrays serve the target device, the signal-to-noise ratio of the target device can be improved, and the transmission rate of the target device can be improved.

[0128] According to one example of the present disclosure, each of the M sub-arrays divided by the reconfigurable panel corresponds to a specific beam. The specific beam can also be a beam emitted from the corresponding sub-array.

[0129] According to one example of the present disclosure, the specific beams of the N sub-arrays of the M sub-arrays divided by the reconfigurable panel converge on one target device.

[0130] In this way, by converging the specific beams of the N sub-arrays of the M sub-arrays divided by the reconfigurable panel on one target device, compared with the scheme that the specific beam of a single sub-array irradiates the target device, a higher gain can be provided to the specific target device, the signal-to-noise ratio is improved, and the transmission rate is further improved.

[0131] According to another example of the present disclosure, in the case that the M sub-arrays divided by the reconfigurable panel serve multiple target devices, if the multiple sub-arrays that provide services to target device A are set as N1 sub-arrays, and the multiple sub-arrays that provide services to target device B are set as N2 sub-arrays, N1 and N2 are positive integers greater than 1 and less than or equal to M.

[0132] In this case, the specific beams of the N1 sub-arrays that provide services to target device A converge on one target device, and the specific beams of the N2 sub-arrays that provide services to target device B converge on another target device.

[0133] Although the above describes the case that the M sub-arrays divided by the reconfigurable panel serve two target devices, it can also serve more than two target devices.

[0134] In addition, although converging the beams on the specific target device can improve the gain, since the covered area is relatively small after the beams are converged, once the target device moves, it can leave the covered area, which can cause a large performance loss. In view of this, according to another embodiment of the present disclosure, the specific beams of the N sub-arrays of the M sub-arrays can be diverged within a specific range with respect to one target device. The specific range can be determined according to the signal-to-noise ratio required when the target device communicates. For example, when the target device performs high-rate transmission and requires a higher signal-to-noise ratio, the range of divergence is reduced, or the beams are not diverged but converge on the target device to improve the gain. On the other hand, when the target device performs low-rate transmission and does not require a higher signal-to-noise ratio, the specific range in which the beams of the multiple sub-arrays that provide services to the target device are diverged with respect to the target device is increased, thereby being able to cover a larger range and improve robustness.

[0135] According to another example of the present disclosure, when the reconfigurable panel is relatively close to the base station, the total path loss constituted by the path loss between the base station and the reconfigurable panel and the path loss between the target device and the reconfigurable panel is relatively small, and thus the signal-to-noise ratio of the target device is already sufficient to support high-rate transmission, and there is no need to converge the beams of the multiple subarrays serving the target device to the target device to increase the gain. In this case, the beams of the multiple subarrays can also be appropriately diverged to cover a larger range as described above.

[0136] According to another example of the present disclosure, the beams of part of the multiple subarrays serving the target device can be converged to the target device, while the beams of another part of the multiple subarrays serving the target device are diverged with respect to the target device, so that the gain to the target device can be flexibly adjusted according to the different transmission rates required.

[0137] According to another example of the present disclosure, the communication system with the reconfigurable surface device can also implement multi-stream transmission. For example, the communication system includes a base station, a reconfigurable surface device, and a terminal. While the base station communicates directly with the terminal, the base station also communicates with the terminal via the reconfigurable surface device, thereby implementing multi-stream transmission.

[0138] In the process of multi-stream transmission, in order to improve the efficiency of multi-stream transmission, it is necessary to balance the gain of the direct path of the base station communicating directly with the terminal and the gain of the path of the base station communicating with the terminal via the reconfigurable surface device, and thus the gain of the base station-terminal direct path and the base station-reconfigurable panel-terminal path can also be balanced by selecting inter-subarray codewords for the reconfigurable panels in the reconfigurable surface device, so as to maximize the efficiency of multi-stream transmission.

[0139] In addition, when the reconfigurable panel serves multiple target devices, the channel qualities of different target devices can also be different, and thus in order to match the transmission rates of target devices with different channel qualities, the gain to different target devices can also be adjusted by configuring different subarray sizes and numbers of subarrays for different target devices.

[0140] The fact that the reconfigurable panel serves multiple target devices can also be implemented by orthogonal time division multiplexing, orthogonal frequency division multiplexing, or non-orthogonal (NOMA) waveform.

[0141] Thus, by configuring different subarray sizes and numbers of subarrays for different target devices, the gain to different target devices can be adjusted, so that when the reconfigurable panel serves multiple target devices, target devices with different channel qualities can be matched to transmission rates.

[0142] In summary, even if the target device is in the near-field range of the large-size RIS based on DFT beamforming, the signal-to-noise ratio of the target device can be improved by placing the target device in the far-field range of a single subarray and serving the target device by multiple subarrays, and the transmission rate of the target device can be improved.

[0143] In the following, the codebook implementation method for implementing multiple subarrays to serve one target device will be specifically described.

[0144] At present, the DFT-based beamforming method has the advantages of simple implementation and less signaling consumption. Further, in order to solve the problem of small beam gain of a single subarray, the following double-layer codebook implementation method is used, that is, first, a reference DFT beam is determined by a first-layer codebook (i.e., a first codebook), and then the reference DFT beam is deflected and the phase is compensated by a second-layer codebook (i.e., a second codebook) to make multiple subarrays serve one target device, so as to improve the gain and further improve the transmission rate.

[0145] According to another embodiment of the present disclosure, a control method 800 performed by a reconfigurable surface device is provided. Figure 8 is a flowchart representing the control method 800 performed by the reconfigurable surface device according to another embodiment of the present disclosure.

[0146] As shown in Figure 8 The control method 800 performed by the reconfigurable surface device includes a receiving step 810 configured to receive position information of a target device, and a processing step 820 configured to determine a first codebook based on a direction of a reconfigurable panel of the reconfigurable surface device relative to the target device, and calculate the first codebook based on a distance between the reconfigurable panel and the target device and positions of each of M subarrays included in the reconfigurable panel to determine a second codebook.

[0147] The position information can include the direction of the reconfigurable panel relative to the target device, and the distance between the reconfigurable panel and the target device. On the other hand, the positions of each of the M subarrays included in the reconfigurable panel can also not be included in the position information of the target device received in the receiving step 810.

[0148] The direction of the reconfigurable panel relative to the target device can also be represented by an azimuth and an elevation.

[0149] In addition, the direction of the reconfigurable panel relative to the target device and the distance between the reconfigurable panel and the target device can also be represented by three-dimensional coordinates.

[0150] For example, the position of the target device is expressed in the form of three-dimensional coordinates with the reconfigurable panel as the reference point. For another example, the reference point does not necessarily have to be the reconfigurable panel, but can be another position as long as the position relationship between the reconfigurable panel and the target device can be clearly expressed.

[0151] The position of each of the M sub-arrays divided by the reconfigurable panel can refer to the position of each of the M sub-arrays, or can refer to the position of each of the sub-arrays serving the target device in the M sub-arrays.

[0152] According to another example of the present disclosure, the position information of the target device, the reconfigurable panel, and the sub-arrays contained therein can also be expressed in other ways, such as a vector.

[0153] According to one example of the present disclosure, each sub-array contains a plurality of elements, the second codebook includes an element deflection sub-codebook and a phase compensation sub-codebook, the element deflection sub-codebook deflection each element in the sub-array, and the phase compensation sub-codebook compensates the phase of the sub-array.

[0154] According to one example of the present disclosure, the reconfigurable surface device determines the first beam of each sub-array through the first codebook, and deflection and phase compensation of the first beam through the second codebook.

[0155] As described above, the reconfigurable surface device determines the first beam of each sub-array through the first codebook, i.e., according to the direction of the reconfigurable panel relative to the target device, which can also be referred to as a reference beam. Since the calculation formula of the first layer codebook does not contain the position vector of the sub-array, only the position vector of the target device and the position vector of the element, the direction of the first beam emitted by each sub-array is the same. Figure 5

[0156] Each element in the sub-array is deflected by the element deflection sub-codebook in the second layer codebook, so that the beams emitted by each sub-array converge on the target device. Since the distance from each sub-array to the target device is different, in order to offset the phase deviation caused by the different distances, the phase of each sub-array is compensated by the phase compensation sub-codebook in the second layer codebook to offset the phase deviation of the beam of each sub-array when it reaches the target device.

[0157] Here, each element in the sub-array is deflected by the element deflection sub-codebook in the second layer codebook, so that the first beam emitted by each sub-array converges on the target device, which can provide higher gain to the specific target device compared to the scheme in which the beam of a single sub-array irradiates the specific target device, improve the signal-to-noise ratio, and further improve the transmission rate.

[0158] ​Alternatively, each array element in the sub-array can also be deflected respectively by the array element deflection sub-codebook in the second layer codebook, and diverge within a certain range relative to a specific target device. In this way, a larger range can be covered, and the robustness can be improved.

[0159] According to one example of the present disclosure, the first layer codebook and the second layer codebook described above can also be oversampled to improve beam convergence accuracy. Here, oversampling the codebook can also be interpreted as selecting a beam with better convergence capability from multiple beam candidates to improve beam convergence accuracy. It can also be that a beam is selected from multiple beam candidates based on the hardware conditions of the reconfigurable surface device or other factors.

[0160] The oversampling multiple can also be selected to be greater than or equal to 2. For example, there are 4 beam candidates, and with an oversampling multiple of 2, 2 beams are selected.

[0161] The reconfigurable surface device can improve the problem of large near-field range and low gain in the near-field range of the large-size RIS based on DFT beamforming by the sub-array division described above when communicating with the terminal. And by the double-layer codebook, multiple sub-arrays can serve the same target device, which can solve the problem of low gain provided by a single sub-array.

[0162] According to one example of the present disclosure, the reconfigurable surface device can also perform similar processing described above when communicating with the base station.

[0163] For example, when the base station is located in the near field of the reconfigurable panel, the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel needs to be considered.

[0164] Therefore, the reconfigurable surface device can also perform the same processing as the sub-array division and double-layer codebook when communicating with the terminal when communicating with the base station to compensate for the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel. In this case, the target device is the base station. Therefore, when calculating the sub-array division and the double-layer codebook, the position of the terminal needs to be replaced by the position of the base station.

[0165] In addition, since the position of the base station and the position of the reconfigurable panel are usually fixed when the target device is the base station, the coefficient formula when compensating for the phase difference can be determined by pre-calibration when deploying the reconfigurable panel.

[0166] Alternatively, the base station can also communicate with the reconfigurable surface device before the terminal accesses, and the reconfigurable surface device reports the parameter information of the reconfigurable panel to the base station, such as position, height, angle, size, etc. Then, based on these information, the base station informs the reconfigurable surface device of the compensation required by the reconfigurable surface device in the form of a codebook. The codebook form can be the same as the calculation formula of the double-layer codebook shown in Figure 5 .

[0167] Further, in a communication system with a base station, a reconfigurable surface device and a terminal, the base station and the terminal can also perform subarray partitioning and double-layer codebook processing respectively. That is, taking the target device as the base station, using the codebook calculation formula in Figure 5 , the subarray partitioning and double-layer codebook processing are performed to obtain the receiving coefficients for RIS-BS end BF, and then taking the target device as the terminal, using the codebook calculation formula in Figure 5 , the subarray partitioning and double-layer codebook processing are performed to obtain the transmitting coefficients for RIS-UE end BF. Finally, the receiving coefficients for RIS-BS end BF and the transmitting coefficients for RIS-UE end BF are multiplied to obtain the final reflection / transmission coefficients of the RIS.

[0168] In addition, the "base station" as the target device can also refer to "beam transmitting device in the base station", that is, the "distance between the base station and the reconfigurable panel" can also refer to "distance between the beam transmitting device in the base station and the reconfigurable panel". For example, in the case where the reconfigurable panel is located inside the base station, the above-mentioned subarray partitioning, deflection and phase compensation can also be performed based on the distance between the beam transmitting device in the base station and the reconfigurable panel.

[0169] Thus, while improving the problem of large near-field range of large-size RIS based on DFT beamforming and low gain of terminals in the near-field range, when the base station is located in the near-field of the reconfigurable panel, the phase difference caused by the spherical wave effect when the beam emitted from the base station reaches the reconfigurable panel can also be compensated for when the base station is located in the near-field of the reconfigurable panel.

[0170] Thus, based on the position of each subarray in the M subarrays partitioned by the reconfigurable panel, and the direction of the reconfigurable panel relative to the target device, the distance between the reconfigurable panel and the target device contained in the position information of the target device, the double-layer codebook can be determined, thereby providing a new solution to improve the problem of large near-field range of large-size RIS based on DFT beamforming and low gain in the near-field range.

[0171] <Hardware structure>

[0172] In addition, the block diagrams used in the description of the above-described embodiments show blocks functionally. These functional blocks (constructional units) are realized by any combination of hardware and / or software. Furthermore, the means of realization of each functional block are not particularly limited. That is, each functional block can be realized by one device physically and / or logically integrated, or two or more devices physically and / or logically separated can be directly and / or indirectly (for example, through wired and / or wireless) connected to realize the above-described multiple devices.

[0173] For example, the device (such as a terminal, a base station, or the like) of one embodiment of the present disclosure can function as a computer that executes processing of the wireless communication method of the present disclosure. Figure 9 is a schematic diagram of a hardware structure of the device 900 according to the embodiment of the present disclosure. The device 900 described above can be configured as a computer device that physically includes a processor 910, a memory 920, a storage 930, a communication device 940, an input device 950, an output device 960, a bus 970, and the like.

[0174] In addition, in the following description, the word "device" can be replaced with circuit, apparatus, unit, or the like. The hardware structure of the terminal can include one or more of each device shown in the drawing, or can not include part of the devices.

[0175] For example, the processor 910 is illustrated as one, but can be multiple processors. Furthermore, the processing can be executed by one processor, or can be executed by one or more processors simultaneously, sequentially, or by other methods. In addition, the processor 910 can be mounted by one or more chips.

[0176] Each function of the device 900 is realized, for example, by reading a prescribed software (program) into the processor 910, the memory 920, or the like hardware, and causing the processor 910 to perform an operation, to control communication by the communication device 940, and to control reading and / or writing of data in the memory 920 and the storage 930.

[0177] The processor 910 causes, for example, an operating system to operate to control the entire computer. The processor 910 can be constituted by a central processing unit (CPU) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like. For example, the above-described processing unit or the like can be realized by the processor 910.

[0178] Further, the processor 910 reads out programs (program codes), software modules, data, etc., from the storage 930 and / or the communication device 940 into the memory 920 and executes various processes according to them. For example, a functional block of the terminal can be realized by a control program of the processor 910 operating in cooperation with the memory 920. Similarly, other functional blocks can also be realized in this way.

[0179] The memory 920 is a computer-readable recording medium, and can be configured with at least one of, for example, a read only memory (ROM), an erasable programmable ROM (EPROM), an electrically EPROM (EEPROM), a random access memory (RAM), other appropriate storage media. The memory 920 can also be referred to as a register, a cache, a main memory, and the like. The memory 920 can store an executable program (program code), a software module, and the like for implementing a method related to an embodiment of the present disclosure.

[0180] The storage 930 is a computer-readable recording medium, and can be configured with at least one of, for example, a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disc ROM (CD-ROM), a digital versatile disk, a Blu-ray (registered trademark) disk), a removable magnetic disk, a hard disk drive, an intelligent media card, a flash memory device (for example, a card, a stick, a key driver), a magnetic stripe, a database, a server, other appropriate storage media. The storage 930 can also be referred to as an auxiliary storage device.

[0181] The communication device 940 is hardware (transmission-reception device) for communication between computers via wired and / or wireless networks, and is also referred to as a network device, a network controller, a network card, a communication module, and the like. The communication device 940 can include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize, for example, frequency division duplex (FDD) and / or time division duplex (TDD). For example, the above-described transmission unit, reception unit, and the like can be realized by the communication device 940.

[0182] The input device 950 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 960 is an output device (e.g., a display, a speaker, a Light Emitting Diode (LED) lamp, etc.) that implements output to the outside. In addition, the input device 950 and the output device 960 can also be a structure integrated with each other (e.g., a touch panel).

[0183] Further, the processor 910, the memory 920, and the like are connected through a bus 970 for communication of information. The bus 970 can be constituted by a single bus, or can be constituted by different buses between devices.

[0184] Further, the terminal can include a microprocessor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), and the like hardware, and part or all of the functional blocks can be implemented by the hardware. For example, the processor 910 can be mounted by at least one of these hardware.

[0185] (Modified example)

[0186] In addition, as for the terms described in the present specification and / or the terms required for understanding the present specification, terms having the same or similar meanings can be replaced with each other. For example, a channel and / or a symbol can also be a signal (signaling). Further, a signal can also be a message. A reference signal can also be simply referred to as RS (Reference Signal), and can also be referred to as a pilot, a pilot signal, and the like according to the applied standard. Further, a Component Carrier (CC) can also be referred to as a cell, a frequency carrier, a carrier frequency, and the like.

[0187] Further, the information, the parameters, and the like described in the present specification can be expressed by absolute values, can be expressed by relative values to the prescribed values, and can also be expressed by corresponding other information. For example, a radio resource can be indicated by a prescribed index. Further, a formula and the like using these parameters can also be different from those explicitly disclosed in the present specification.

[0188] Names used for parameters and the like in the present specification are not limiting in any respect. For example, various channels (Physical Uplink Control Channel (PUCCH), Physical Downlink Control Channel (PDCCH), and the like) and information units can be identified by any appropriate names, and thus various names assigned to these various channels and information units are not limiting in any respect.

[0189] Information, signals, and the like described in the present specification can be represented using any of a wide variety of different technologies. For example, data, commands, instructions, information, signals, bits, symbols, chips, and the like that can be mentioned throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0190] Further, information, signals, and the like can be outputted from a higher layer to a lower layer, and / or from a lower layer to a higher layer. Information, signals, and the like can be inputted or outputted to or from a plurality of network nodes.

[0191] Information, signals, and the like that are inputted or outputted can be stored in a specific place (for example, a memory) and can be managed by a management table. Information, signals, and the like that are inputted or outputted can be overwritten, updated, or supplemented. Information, signals, and the like that are outputted can be deleted. Information, signals, and the like that are inputted can be transmitted to other devices.

[0192] Notification of information is not limited to the manners / embodiments described in the present specification, and can be performed by other methods. For example, notification of information can be implemented by physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (for example, Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), and the like), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0193] In addition, the physical layer signaling can also be referred to as L1 / L2 (Layer 1 / Layer 2) control information (L1 / L2 control signal), L1 control information (L1 control signal), and so on. Furthermore, the RRC signaling can also be referred to as an RRC message, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, and so on. Furthermore, the MAC signaling can be notified, for example, by a MAC control element (MAC CE).

[0194] Furthermore, the notification of the prescribed information (for example, the notification of "X") is not limited to being explicitly performed, but can also be implicitly performed (for example, by not performing the notification of the prescribed information, or by the notification of other information).

[0195] As for the determination, it can be performed by a value represented by 1 bit (0 or 1), can be performed by a true / false value (Boolean value) represented by true or false, or can be performed by a comparison of numerical values (for example, a comparison with a prescribed value).

[0196] Software, regardless of the term by which it is denoted, such as software, firmware, middleware, microcode, hardware description language, or by other names, should be broadly interpreted as referring to a command, a set of commands, code, a code segment, a program code, a program, a subprogram, software modules, an application, a software application, a software package, a routine, a subroutine, an object, an executable file, an execution thread, a procedure, a function, and so on.

[0197] Furthermore, software, commands, information, and so on can be transmitted or received via a transmission medium. For example, when software is transmitted from a website, a server, or other remote source using wired technology (coaxial cables, optical cables, twisted pair cables, digital subscriber line (DSL), and so on) and / or wireless technology (infrared, microwave, and so on), these wired and / or wireless technologies are included within the definition of transmission medium.

[0198] The terms "system" and "network" used in this specification can be used interchangeably.

[0199] In this specification, the terms "base station (BS)", "wireless base station", "eNB", "gNB", "cell", "sector", "cell group", "carrier", and "component carrier" can be used interchangeably. The base station is also sometimes referred to as a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmission point, a reception point, a femto cell, a small cell, and so on.

[0200] A base station can accommodate one or more (e.g., three) cells (also referred to as sectors). When a base station accommodates multiple cells, the entire coverage of the base station can be divided into multiple smaller areas, each of which can also be provided with communication services by a base station subsystem (e.g., a small-sized base station (Remote Radio Head (RRH)) for indoor use). The term "cell" or "sector" refers to a part or the entirety of the coverage area of a base station and / or a base station subsystem that provides communication services in the coverage.

[0201] In the present specification, the terms "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" can be used interchangeably. A mobile station is also sometimes referred to by those skilled in the art as a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or several other suitable terms.

[0202] Furthermore, a wireless base station in the present specification can also be replaced with a user terminal. For example, for a structure in which communication between a wireless base station and a user terminal is replaced with communication between a plurality of user terminals (D2D: Device-to-Device), each of the modes / embodiments of the present disclosure can also be applied. At this time, the functions possessed by the first communication device or the second communication device in the device 900 described above can be regarded as functions possessed by a user terminal. Furthermore, the words "uplink" and "downlink" and the like can be replaced with "side". For example, an uplink channel can be replaced with a side channel.

[0203] Similarly, a user terminal in the present specification can also be replaced with a wireless base station. At this time, the functions possessed by the user terminal described above can be regarded as functions possessed by the first communication device or the second communication device.

[0204] In the present specification, a certain action performed through a base station is sometimes performed through an upper node thereof according to the situation. Obviously, in a network constituted by one or a plurality of network nodes having a base station, various actions performed for communication with a terminal can be performed through the base station, one or a plurality of network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), and the like can be considered, but are not limited thereto), or a combination thereof.

[0205] Each of the modes / embodiments described in the present specification can be used alone or in combination, and can also be used in switching during execution. Furthermore, the processing steps, sequences, flowcharts, and the like of each of the modes / embodiments described in the present specification can be changed in order as long as there is no contradiction. For example, with respect to the methods described in the present specification, various step units are given in an exemplary order, and are not limited to the specific order given.

[0206] The modes / embodiments described in this specification can be applied to systems utilizing Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New-RAT (Radio Access Technology), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile Communications (GSM (registered trademark)), Code Division Multiple Access 3000 (CDMA3000), Ultra Mobile Broadband (UMB), IEEE 920.11 (Wi-Fi (registered trademark)), IEEE 920.16 (WiMAX (registered trademark)), IEEE 920.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), other appropriate wireless communication methods, and / or next-generation systems expanded based on them.

[0207] The description "according to" used in this specification, unless explicitly described in other paragraphs, does not mean "only according to". In other words, the description "according to" means both "only according to" and "at least according to".

[0208] Any reference to units using the names "first", "second", and the like used in this specification does not limit the number or order of the units. The names can be used in this specification as a convenient method of distinguishing two or more units. Therefore, reference to a first unit and a second unit does not mean that only two units are employed or that the first unit must precede the second unit in some form.

[0209] As used in the specification, the phrase "determining" encompasses a wide variety of actions. For example, "determining" can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, "determining" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, "determining" can include resolving, selecting, choosing, establishing and the like.

[0210] As used in the specification and in the claims, the terms "connected", "coupled", or any variant thereof, are intended to mean any connection or coupling, either direct or indirect, between two or more elements. Such connection or coupling can be physical, logical, or a combination thereof. For example, a connection can be an access. As used in the specification, two elements are considered to be "connected" or "coupled" to each other when they are either in direct physical or logical contact or there is an element or elements between them that allows for the direct or indirect contact between the two elements.

[0211] As used in the specification and in the claims, the term "comprising" and its variants are meant to be open-ended terms that do not preclude the possibility of additional elements or steps. Further, as used in the specification and in the claims, the term "or" is meant to be inclusive, not exclusive.

[0212] The present disclosure has been described in detail, but it will be obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the specification. The present disclosure can be implemented as modifications and changes without departing from the spirit and scope of the present disclosure defined by the recitations of the claims. Therefore, the recitations of the specification are intended to serve as illustrative purposes only and are not intended to have any limiting meaning on the present disclosure.

Claims

1.A reconfigurable surface device comprising: a receiving unit configured to receive subarray partitioning information transmitted from a base station; a reconfigurable panel; and a processing unit configured to partition the reconfigurable panel into M subarrays based on the subarray partitioning information, M being a positive integer greater than 1, wherein the subarray partitioning information is determined based on a distance between a target device and the reconfigurable panel, and wherein the reconfigurable panel is partitioned into M subarrays based on the distance between the target device and the reconfigurable panel such that the target device is within a far field range of a single subarray, N subarrays of the M subarrays serve one target device, N being a positive integer greater than 1 and less than or equal to M. 2.The reconfigurable surface device of claim 1, wherein each of the M subarrays corresponds to a specific beam, respectively. 3.The reconfigurable surface device of claim 2, wherein the specific beams of the N subarrays of the M subarrays converge on one target device, respectively. 4.The reconfigurable surface device of claim 2, wherein the specific beams of the N subarrays of the M subarrays diverge within a specific range with respect to one target device, respectively. 5.The reconfigurable surface device of any one of claims 1-4, wherein the M subarrays serve a plurality of target devices, a number of subarrays serving each target device is a positive integer, and the number of subarrays is greater than 1 and less than or equal to M. 6.A reconfigurable surface device comprising: a receiving unit configured to receive position information of a target device; a reconfigurable panel; and a processing unit configured to determine a first codebook based on a direction of the reconfigurable panel with respect to the target device, and to calculate the first codebook based on a distance between the reconfigurable panel and the target device and a position of each of M subarrays included in the reconfigurable panel to determine a second codebook, wherein M is a positive integer greater than 1. 7.The reconfigurable surface device of claim 6, wherein each of the subarrays includes a plurality of elements, the second codebook includes an element deflection subcodebook and a phase compensation subcodebook, the element deflection subcodebook deflection is performed on each element in the subarrays, respectively, and the phase compensation subcodebook performs phase compensation on the subarrays. 8.The reconfigurable surface device of claim 7, wherein the reconfigurable surface device determines a first beam of the subarrays through the first codebook, and performs the deflection and the phase compensation on the first beam through the second codebook. 9.The reconfigurable surface device of claim 6, wherein the target device includes at least one of a terminal and a base station. 10.The reconfigurable surface device of claim 6, wherein the reconfigurable surface device oversamples the first codebook and the second codebook. ​ ​

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