Reconfigurable intelligent metasurface information design and signaling

Abstract

Methods, apparatus, and systems related to the design and signaling of the type, capability, and other information of one or more reconfigurable intelligent metasurface (RIS) structures or nodes are disclosed. A method for wireless communication includes reporting information about a first RIS node to one or more base stations when a network changes. A reconfigurable smart metasurface includes a material having configurable electromagnetic properties.

Description

Technical Field

[0001] This patent document relates to wireless communications. Background Art

[0002] Mobile communication technology is changing the world to an increasingly connected and networked society. The rapid growth of mobile communications and the advancement of technology have placed greater demands on capacity and connectivity. Other aspects, such as energy consumption, equipment cost, spectrum efficiency and latency are also important to meet the needs of different communication scenarios. Different technologies are being discussed, including new ways to provide higher quality of service, longer battery life and improved performance. Summary of the invention

[0003] This invention document describes technologies related to the design and signaling of the type, capabilities, and other information of one or more reconfigurable smart metasurface RIS structures or nodes. A reconfigurable smart metasurface includes a material with configurable electromagnetic properties.

[0004] In one exemplary embodiment, a method for wireless communication includes reporting information about a first RIS node to one or more base stations when a network change occurs.

[0005] In another exemplary embodiment, a method for wireless communication includes receiving, by a base station, information about a first RIS node when a network change occurs.

[0006] In another exemplary embodiment, a communication device is disclosed, which includes a processor configured to implement the above method.

[0007] In yet another exemplary embodiment, a computer program storage medium is disclosed. The computer program storage medium includes code stored thereon. The code, when executed by a processor, causes the processor to implement the described method.

[0008] These and other aspects are described in this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A An example of a reflective RIS according to one or more embodiments of the present invention is shown.

[0010] Figure 1B An example of a transmissive RIS according to one or more embodiments of the present invention is shown.

[0011] Figure 1C An example of a RIS-based transmissor according to one or more embodiments of the present invention is shown.

[0012] Figure 1DAn example of a simultaneous transmission and reflection (STAR) RIS is shown in accordance with one or more embodiments of the present invention.

[0013] Figure 1E An example of a back-to-back RIS according to one or more embodiments of the present invention is shown.

[0014] Figure 2A Examples of RIS performance information according to one or more embodiments of the present invention are shown.

[0015] Figure 2B Examples of configuration information according to one or more embodiments of the present invention are shown.

[0016] Figure 2C Examples of impedance information according to one or more embodiments of the present invention are shown.

[0017] Figure 2D Examples of location information according to one or more embodiments of the present invention are shown.

[0018] Figure 3 An example flow chart of reporting RIS frequency capabilities in accordance with one or more embodiments of the invention is shown.

[0019] Figure 4 An example flow chart of reporting time-division capabilities in accordance with one or more implementations of the invention is shown.

[0020] Figure 5 An example flow chart for reporting phase modulation capabilities in accordance with one or more embodiments of the present invention is shown.

[0021] Figure 6 An example flow chart for reporting AM capabilities in accordance with one or more implementations of the invention is shown.

[0022] Fig. 7A An example of a RIS structure communicating with a single base station in accordance with one or more embodiments of the present invention is shown.

[0023] Figure 7B An example of multiple RIS structures communicating with a single base station is shown in accordance with one or more embodiments of the present invention.

[0024] Figure 7C An example of multiple base stations communicating with a single RIS structure is shown in accordance with one or more embodiments of the present invention.

[0025] Fig.7D An example of multiple base stations communicating with multiple RIS structures is shown in accordance with one or more embodiments of the present invention.

[0026] Fig. 8A is a flowchart representation of a method for wireless communication according to one or more embodiments of the present invention.

[0027] Figure 8B is a flowchart representation of a method for wireless communication according to one or more embodiments of the present invention.

[0028] Fig. 9 An example of a wireless communication system to which the technology according to one or more embodiments of the present invention can be applied is shown.

[0029] Fig.10 is a block diagram representing a portion of a radio station to which one or more embodiments of the present invention can be applied. DETAILED DESCRIPTION

[0030] The continuous development of mobile communication technology has brought about the challenge of scarce wireless spectrum resources. It is necessary to find innovative, efficient and energy-saving solutions for future wireless networks. Reconfigurable intelligent metasurface (RIS) technology is a revolutionary enhancement of mobile communications and an important application of information metamaterials in the field of mobile communications. The basic principle is to control the electromagnetic properties of metamaterials through digital programming, artificially control the scattering of electromagnetic waves in space, realize intelligent regulation of electromagnetic waves in space, and build an intelligent and controllable electromagnetic environment with low power consumption and low cost. By establishing an intelligent and controllable wireless environment, RIS technology can bring a new communication network paradigm to future generations of wireless technologies.

[0031] In traditional communications, the endpoints of the transceiver can be optimized, but the transmission on the channel depends on environmental conditions. The introduction of RIS makes the channel controllable, and the transceiver and the channel can be jointly optimized to control the propagation of electromagnetic waves. Specifically, RIS technology is an important technology in solving non-line-of-sight transmission problems, extending coverage, increasing transmission freedom, reducing electromagnetic pollution, ultra-large-scale terminal access, environmental sensing and positioning. In order to provide various functions, achieve better environmental control and low-cost architecture design, many different types of RIS have been designed. However, the design of information exchange of different types of RIS is still in the early stages. In addition, it is still a problem to define the relevant types, capability information and networking information of RIS, and to notify the base station of this information accordingly.

[0032] This patent document discloses techniques that can be implemented in various embodiments for the design and signaling of RIS type, capability information, and other characteristics of the RIS to allow a base station to determine appropriate control information to enable effective subsequent communications using the RIS.

[0033] RIS type information

[0034] Figures 1A to 1EVarious RIS types are shown in accordance with one or more embodiments. Figure 1A An example of a reflective RIS according to one or more embodiments of the present invention is shown. Reflective RIS refers to a RIS structure that has only reflection capability. Signal 101 is emitted from one side and emitted from the same side, and the structure achieves 180° coverage on one side. This type of RIS structure is suitable for deployment in space, and can achieve blind spot coverage, coverage extension, and support multi-stream transmission through reflected signals.

[0035] Figure 1B An example of a transmissive RIS according to one or more embodiments of the present invention is shown. Transmissive RIS refers to a RIS structure that has only transmissive capabilities. Signal 102 enters from one side of the structure and exits from the other side, and the area on both sides of the structure achieves 180 coverage. This type of RIS structure is suitable for deployment in space, and usually needs to be deployed on a transparent medium such as a glass surface to achieve outdoor-to-indoor and indoor-to-outdoor transmission.

[0036] Figure 1C An example of a RIS-based transmitter according to one or more embodiments of the present invention is shown. A RIS-based transmitter is connected to the radio frequency structure (e.g., baseband, digital-to-analog converter (DAC)) of a base station to achieve high-precision transmission signal generation in a low-cost manner. The RIS-based transmitter can generate a signal 103 to achieve a transmission signal coverage range of 180°. This type of RIS is suitable for deployment on a base station and can replace traditional antennas and phase shifters at a lower cost.

[0037] Figure 1D An example of a simultaneous transmission and reflection (STAR)-RIS according to one or more embodiments of the present invention is shown. STAR-RIS represents a RIS with both reflection and transmission capabilities. Signal 104 can be injected from one side and can be emitted from both sides to achieve 360° or omnidirectional coverage. This type of RIS is suitable for deployment in a space that supports reflection and transmission, such as on a window glass to enhance indoor and outdoor signals simultaneously.

[0038] Figure 1E An example of a back-to-back RIS according to one or more embodiments of the present invention is shown. The back-to-back RIS is an extension of the reflective RIS. That is, two reflective RIS are deployed in a back-to-back manner to allow the signal 105 to enter from one side and exit from both sides, thereby achieving 360° coverage. Some reflective RIS are designed to include active amplification units to solve the problem of multiplication attenuation. This type of RIS structure can be deployed in spaces such as columns and glass to provide coverage and capacity.

[0039] In RIS system design, the elements in RIS are often modeled as array-based elements. In some embodiments, array-based elements (e.g., array-based reflectors) are configured to operate independently of each other. When the RIS structure accesses the network, the RIS can send its identifier (e.g., RIS ID) and type information to the base station so that the base station can adaptively determine the processing algorithm and subsequent signaling exchange for different types of RIS structures deployed in different locations. Information from different RIS structures may include some common information fields and some specific information fields for a certain type. For example, common information fields may include, but are not limited to, RIS element composition, quantitative performance, configuration information (e.g., topology, RIS elements, adjustment methods), etc. Each type of specific information field may include at least the following:

[0040] 1. Reflective RIS: Reflective RIS usually needs to obtain segment channel state information and / or RIS location information from the base station. When RIS acts as a relay node, this information can be transmitted from RIS to UE.

[0041] 2. Transmitted RIS: Transmitted RIS also needs to obtain segmented channel state information from the base station. When RIS acts as a relay node, RIS can transmit its capability information and / or location information to the UE.

[0042] 3. RIS-based transmitter: RIS-based transmitter needs to obtain channel state information from the base station.

[0043] 4. STAR-RIS: STAR-RIS can report its transmission and reflection capabilities to the base station, including whether the reflection and transmission are controllable and constrained. In some embodiments, STAR-RIS can also indicate the achievable reflection-transmission ratio to the base station.

[0044] 5. Back-to-back RIS: Back-to-back RIS can exchange channel status information of two RIS structures. Back-to-back RIS can also inform the base station of the information transmission method between the two RIS and whether they are equipped with active power supply units.

[0045] like Figures 1A to 1E The RIS type shown is determined based on the functionality of the RIS structure. An alternative and / or additional way to classify the RIS structure is based on the energy consumption of the RIS structure. For example, a RIS configured to amplify a signal may be classified as an active RIS, while a RIS configured without any signal amplification features may be considered a passive RIS. Similar to the above discussion, the type information may be transmitted to the base station accordingly.

[0046] The exchange of RIS type information enables the base station to determine the control signal phase shift matrix of the RIS, thereby making full use of different types of RIS and avoiding waste of network resources.

[0047] RIS Capability Information

[0048] RIS capability information may include various categories of information including, but not limited to: RIS performance information, frequency capability, time division capability, phase modulation capability, amplitude modulation capability, precoding capability, baseband measurement capability, and / or reflection and transmission capability. The categories are discussed in detail below.

[0049] Category 1: Performance Information

[0050] Figure 2A An example of RIS performance information according to one or more embodiments of the present invention is shown. RIS performance information may include different subcategories of information, including but not limited to configuration information, sensing capabilities, energy transfer information, impedance information, and location information.

[0051] In some implementations, the RIS may inform the base station of its configuration information. Figure 2B An example of configuration information according to one or more embodiments of the present invention is shown. The configuration information includes RIS topology, type of RIS element, number of RIS elements, and control method. The topology of RIS includes square plane, spherical plane, elliptical plane, triangular plane, hexagonal plane, square curve, spherical curve, etc. With this information, the base station can determine the type, topology, and size of RIS, thereby achieving effective channel estimation and beamforming algorithm design.

[0052] In some embodiments, the RIS may inform the base station whether it has sensing capability. If the RIS has sensing capability, the RIS may report information about the sensing accuracy to the base station.

[0053] In some embodiments, the RIS may inform the base station whether it has energy transfer capability. If the RIS supports energy transfer capability, the RIS may report the energy transfer energy detection threshold to the base station.

[0054] In some embodiments, the RIS can determine impedance information based on its structure and transmit this information to the base station. Figure 2CAn example of impedance information according to one or more embodiments of the present invention is shown. For a RIS with half-wavelength element spacing, it is generally considered that the mutual impedance of the half-wavelength RIS can be ignored. Therefore, the half-wavelength element spacing information can be sent to the base station, and the impedance information can be sent only when needed. For a RIS with an element spacing less than half a wavelength, both the element spacing information and the impedance information can be transmitted to the BS. In some embodiments, due to the symmetry of the RIS structure, the impedance information can be compressed according to an agreed rule before being transmitted to the base station to reduce signaling overhead. The base station can decompress the information when receiving.

[0055] In some embodiments, the RIS reports its location information to the base station. If the RIS location is fixed, the RIS only needs to report such information once. Figure 2D An example of location information according to one or more embodiments of the present invention is shown. The location information may include distance relative to a base station, angle information, and / or information about the surrounding environment. Based on the location information, the base station may determine whether the RIS is in the near field or far field of the base station, and determine the angle between the RIS and the base station. In some embodiments, the RIS may perform measurements of its surroundings to determine environmental information, such as weather information, occlusion information, etc. The environmental information may also be transmitted to the base station.

[0056] The exchange of RIS performance information helps the base station determine the shape of the RIS, obtain the functional capabilities, energy transfer capabilities, and impedance information of the RIS to better design the transmission scheme and the RIS phase shift matrix, and provide position and angle information to assist signal transmission. For example, if the RIS is dynamically deployed, the base station can calculate its expected deployment location. After the RIS notifies its performance information (e.g., configuration information, location information, etc.), the base station can further adjust the location. After the adjustment is completed, the RIS can notify the base station of the updated RIS performance information.

[0057] Category 2: Frequency capability.

[0058] The RIS may have different amplitude and phase responses to different frequency points. When a new RIS gains access to the network, it needs to inform the base station of the frequencies and bandwidths supported by the RIS.

[0059] Figure 3 An example flow chart 300 of reporting RIS frequency capabilities according to one or more embodiments of the present invention is shown. In operation 310, the RIS transmits the supported frequencies and / or bandwidths to the base station. In operation 320, the base station determines the operating frequency and bandwidth information accordingly and notifies the RIS of the operating frequency and bandwidth. In operation 330, the base station calculates the beamforming matrix and the RIS phase shift matrix. In operation 340, the base station may send the phase shift matrix information to the RIS.

[0060] The base station performs channel state information acquisition and beamforming design for different frequencies and bandwidths. Obtaining the RIS frequency capability can provide frequency-related information and avoid mismatches in system design, which may affect system performance. Specifically, the response of RIS at different frequencies and bandwidths may be different. If the frequency capability of RIS is not predicted in advance, it may have a serious impact on system performance. Due to different amplitude-frequency responses, it is desirable to design different phase sets for different frequency points to achieve target system performance. For example, RIS supports 28 GHz as its operating frequency, but the base station is unknown to this capability of RIS. In this case, RIS may use the electrical adjustment parameters of the 26 GHz frequency configured by the station, which may cause beam pointing deviation or beam shape change, thereby seriously reducing system performance. Therefore, accurately determining the frequency capability of RIS can enable the base station to achieve the desired system performance.

[0061] Category 3: Time-sharing capability

[0062] The RIS structure needs to switch dynamically to adapt to different channels. For example, in high frequency bands, channel state information changes more frequently, which places stricter requirements on the time division capability of RIS.

[0063] Figure 4 An example flow chart 400 of reporting time division capabilities according to one or more embodiments of the present invention is shown. In operation 410, the RIS sends the time division capabilities (e.g., switching speed capabilities) to the base station. In operation 420, the base station determines the switching speed based on channel state information (CSI) and other requirements. In operation 430, the base station may send the actual time switching speed to the RIS. Then, in operation 440, the base station and the RIS each synchronize their respective designs.

[0064] Informing the base station of the time division capability of the RIS can enable the base station to determine the time division granularity supported by the RIS, thereby effectively determining the timing and frequency of signaling interaction. For example, after the base station obtains the RIS time switching speed and other capabilities, the base station can determine the timing and phase set of the RIS based on the RIS time switching speed and other capabilities. The base station can make full use of the time switching capability of the RIS to adapt to the time-varying channel, thereby avoiding the situation where the speed of the base station's transmission phase setting exceeds the time switching speed of the RIS, and ensuring the synchronization between the base station and the RIS.

[0065] Category 4: Phase modulation capability

[0066] The phase modulation capability of RIS is related to its hardware structure. The achievable phase modulation capabilities include N-bit (N=1, 2, ...) quantized phase modulation and continuous phase modulation. For N-bit phase quantization, the phase difference of RIS elements can be expressed as Taking 1-bit RIS as an example, the phase of the RIS element includes two cases: 0° and 180°.

[0067] The RIS needs to inform the base station of its phase modulation capabilities, such as the accuracy and / or number of bits of phase modulation. Figure 5 An example flow chart for reporting phase modulation capabilities according to one or more embodiments of the present invention is shown. In operation 510, the RIS sends the phase modulation accuracy to the base station. In operation 520, the RIS also informs the base station whether the phase is continuous or discrete. If the phase is discrete, then in operation 530, the RIS can send quantization information to the base station. In operation 540, the base station determines the phase matrix. Given the RIS phase modulation capability, the base station can design different phase sets for different frequencies in combination with the RIS frequency capability to achieve phase control at the corresponding frequency.

[0068] Category 5: Amplitude modulation capability

[0069] Different types of RIS have different amplitude modulation capabilities. As discussed above, these RIS structures can be classified based on the corresponding energy consumption. For example, active RIS has the ability to amplify signals, while passive RIS cannot amplify amplitude. The amplitude modulation capability of passive RIS can include two types: constant amplitude and reduced amplitude. Assuming that the ratio of the amplitude of the signal passing through the RIS element to the amplitude of the signal incident on the RIS element is A, the assumption of reduced amplitude (A<1) is closer to the actual performance of the RIS device. Reduced amplitude RIS includes phase-dependent amplitude modulation model and phase-independent amplitude modulation model. Phase-dependent amplitude modulation capability means that the amplitude and phase of the RIS element meet a certain constraint relationship, while phase-dependent amplitude modulation capability means that the amplitude and phase of the RIS element are independent. On the other hand, active RIS can achieve an amplitude modulation ratio of A>1.

[0070] The exchange of amplitude modulation capabilities allows for the proper correlation of phase and amplitude information. The RIS may report its amplitude modulation capabilities, including but not limited to the ratio of the amplitude of the signal after passing through the RIS element to the amplitude of the signal incident to the RIS element, the range of the ratio, and / or whether the amplitude and phase are correlated. If the amplitude and phase are correlated, the RIS may also inform the base station of the correlation between the amplitude and phase. Figure 6An example flow chart for reporting amplitude modulation capabilities according to one or more embodiments of the present invention is shown. In operation 610, the RIS may send an amplitude control mode to the base station. In operation 620, the RIS may also send an amplitude control range to the base station. In operation 630, the RIS may determine whether the amplitude and phase are correlated. If they are correlated, the RIS may notify the base station of the correlation in operation 640.

[0071] Category 6: Precoding Capabilities

[0072] The precoding capabilities of the RIS include at least one of precoding granularity, supported precoding models, codebooks and quantization, RIS group precoding capabilities, and / or the ability to support pilot, data, control, etc. using different precoding.

[0073] The granularity of precoding can be determined based on statistical channel characteristics, including frequency selectivity level, angular spread, user distribution, frequency selective fading and / or spatial selective fading. In the case of high frequency bands, the frequency domain channel changes rapidly, so small granularity precoding becomes appropriate. Small granularity precoding is suitable for situations with large angular spread, dispersed user distribution, and / or frequency domain selective fading and spatial selective fading.

[0074] The supported precoding models may include discrete Fourier transform (DFT) precoding, Hankel precoding, Kroneck precoding, Gaussian precoding, Bessel precoding, gradient descent precoding, beam focusing precoding, lens precoding, chirp precoding, orbital angular momentum (OAM) precoding, etc. The selection basis of the precoding model may include UE position / distribution, distance, target signal shape (wide beam, narrow beam, etc.), target beam shape, etc. In order to achieve a narrow beam in the far field, DFT precoding, Kroneck precoding or gradient descent precoding may be selected. In order to achieve a wide beam in the far field, Hankel precoding, Gaussian precoding or chirp precoding may be selected. In order to achieve a narrow beam in the near field, beam focusing precoding or lens precoding may be selected. In order to achieve a wide beam in the near field, chirp precoding or Hankel precoding may be selected. In order to achieve an orbital angular momentum beam, OAM precoding may be selected. The RIS or base station may select a suitable precoding model according to user requirements, road conditions, etc.

[0075] The selection of the RIS codebook is related to the predetermined codebook design. A specific codebook can be implemented based on the quantization restrictions of the RIS elements. The base station or RIS can select a codebook from a preset codebook. The RIS can notify the base station of the codebooks it supports, and the base station or RIS can determine the appropriate codebook to match different transmission targets.

[0076] The RIS element group precoding capability is an effective means for RIS to support multi-user transmission. Through RIS element group precoding, multiple users of the same frequency can be supported simultaneously, multi-directional beams or multi-focused beams can be realized, and the equipment cost can be effectively reduced. The granularity of RIS element group precoding is determined by factors such as the number of users, user angle distribution, channel state information, cost constraints, etc. If the number of users is large, the number of RIS element groups can be increased. If the user angle distribution is concentrated or the channel state information changes rapidly, the number of RIS element groups can be reduced.

[0077] In addition, the information about whether the RIS can support the use of different precoding methods to support pilot, data, and control capabilities can be reported to the base station to determine the appropriate precoding scheme at different stages. The exchange of RIS precoding capabilities can help the base station determine the selection range of the RIS phase shift matrix and the design criteria of the phase shift matrix, simplify the design process of the RIS phase shift matrix, and convert high-dimensional optimization problems into low-complexity selection or parameter design problems. The design of subarray precoding can further support the generation of multiple beams and reduce control complexity.

[0078] Category 7: Baseband measurement capabilities

[0079] When the RIS has baseband measurement capability, the original concatenated channel estimate can be divided into segmented channel estimates, which can significantly reduce the complexity of channel estimation. Such capability information (e.g., baseband measurement, port number and / or array element location information) can be sent to the base station to avoid the difficulty of channel estimation caused by the limited number of antennas.

[0080] On the other hand, if the RIS does not have baseband measurement capability, the base station can be informed of corresponding information to have appropriate channel estimation design and beamforming design.

[0081] Category 8: Transmission and reflection capabilities

[0082] Different types of RIS may have different transmission and reflection capabilities. Specific transmission and reflection capabilities include whether there is energy loss in the RIS, whether the transmission and reflection of the RIS are controllable, the range of transmittance and reflectance that the RIS can achieve, the constraint relationship between the transmission phase and the reflection phase, and / or the constraint relationship between the transmission amplitude and the reflection amplitude. Such information is important for the base station to determine the characteristics of the RIS in combination with the type (e.g., reflection only, transmission only, or both reflection and transmission).

[0083] Obtaining the transmission and reflection capabilities of the RIS helps the base station determine the reflection and reflection capabilities supported by the RIS, determine its capability limits and constraints, and properly design reflection and transmission beams to better support multi-user transmission.

[0084] RIS network configuration information

[0085] In a communication system, a RIS structure can be controlled by one or more base stations. A base station can control one or more RIS structures. Fig. 7A -D shows different network configurations of the RIS structure and the base station according to one or more embodiments of the present invention. It is necessary for the base station and the RIS to exchange network configuration information and / or control information.

[0086] Fig. 7A An example of a RIS structure communicating with a single base station according to one or more embodiments of the present invention is shown. The RIS notifies the base station of its identifier (e.g., RIS ID). The RIS also sends type information and capability information to the base station when it accesses the network so that the base station can determine the corresponding control information for subsequent transmission.

[0087] Figure 7B An example of multiple RIS structures communicating with a single base station according to one or more embodiments of the present invention is shown. In this example, each RIS notifies the base station of its RIS ID, type information, and capability information when accessing the system. Upon receiving information from multiple RIS structures, the base station can design a multi-RIS control strategy and determine control information accordingly. In addition, the synchronous design of multiple RISs is important for ensuring the effective operation of the RIS structure.

[0088] Figure 7C An example of multiple base stations communicating with a single RIS structure according to one or more embodiments of the present invention is shown. In this example, the RIS can broadcast its RIS ID, type information, and capability information to the base stations communicating with it. When receiving the broadcasted information, the base station can determine the corresponding control information. In this scenario, synchronization between multiple base stations is important to avoid performance loss.

[0089] Fig.7D An example of multiple base stations communicating with multiple RIS structures according to one or more embodiments of the present invention is shown. In this example, each RIS can broadcast its respective RIS ID, type information, and capability information to the base stations communicating therewith. Upon receiving the broadcasted information, the base station can determine the corresponding control information. Synchronization between base stations and synchronization of RIS structures are important in these scenarios. For each RIS, the base station controlling the RIS needs to exchange signaling to determine the control channel to implement multi-BS cooperative control of the RIS.

[0090] Fig. 8A8 is a flowchart representation of a method 800 for wireless communication according to one or more embodiments of the present invention. The method 800 includes: in operation 810, when a change occurs in the network, reporting information about a first reconfigurable intelligent super surface (RIS) node to one or more base stations. A reconfigurable intelligent super surface includes a material having configurable electromagnetic properties. In the present invention, RIS, RIS node and RIS structure are used interchangeably to refer to RIS network components.

[0091] Changes in the network include various scenarios, including but not limited to: initial connection of a first RIS node to the network, configuration update of the first RIS node, or update of at least one base station, such as addition of a base station or deletion of a base station from a plurality of base stations in communication with the first RIS.

[0092] In some embodiments, the information is broadcast from the first RIS node, such as Figure 7B and / or Fig.7D In some embodiments, the first RIS node may transmit information at the radio resource control (RRC) layer in a manner similar to a user equipment (UE) capability report (e.g., Fig. 7A and / or Figure 7C shown).

[0093] In some embodiments, the first RIS transmits its RIS ID to the base station. Then, before receiving the base station control information, it transmits information to the base station. The information of the first RIS node includes at least one of type information of the first RIS node or capability information of the first RIS node. The type information includes at least one of the following: reflective RIS type, transmissive RIS type, RIS-based transmissive type, simultaneous transmissive and reflective RIS type, or back-to-back RIS type (e.g., Figures 1A to 1E ).

[0094] In some embodiments, the capability information includes at least one of: performance capability information, frequency capability information, time division capability information, phase modulation capability information, amplitude modulation capability information, precoding capability information, measurement capability information, or transmission and reflection capability information. In some embodiments, the performance capability information includes at least one of: topology information of the first RIS node, type and / or number of RIS elements of the first RIS node, sensing capability of the first RIS node, energy transmission information of the first RIS node, impedance information of the first RIS node, or location information of the first RIS node (e.g., FIG. 2A to FIG. 2B). The frequency capability information includes the frequency and / or bandwidth supported by the first RIS node. In some embodiments, the time division capability information includes the response time or time switching speed of the first RIS node. In some embodiments, the phase modulation capability information includes the accuracy and / or number of bits of phase modulation supported by the first RIS node. In some embodiments, the amplitude modulation capability information includes at least the signal amplitude ratio, ratio range, or correlation between amplitude and phase supported by the first RIS node. In some embodiments, the precoding capability information includes at least the precoding granularity, the precoding model supported by the first RIS node, the codebook and / or quantization, or the grouping of precoding capabilities. In some embodiments, the measurement capability information includes at least multiple ports and / or location information of the RIS unit of the first RIS node. In some embodiments, the transmission and reflection capability information includes at least the energy loss in the first RIS, the controllability of transmission and reflection, the range of transmittance and / or reflectance, the correlation between the transmission phase and the reflection phase, or the correlation between the transmission amplitude and the reflection amplitude.

[0095] In some embodiments, the method includes receiving, by a first RIS node, control information from one or more base stations. The control information indicates that the one or more base stations communicate with a plurality of RIS nodes including the first RIS node. In some embodiments, the control information from the base station to the first RIS node includes at least information about a control channel, a channel measurement, or a precoding scheme. The method also includes: sending, by the first RIS node, information to the one or more base stations to enable the one or more base stations to coordinate the plurality of RIS nodes.

[0096] Figure 8B is a flowchart representation of a method for wireless communication according to one or more embodiments of the present invention. Method 850 includes: in operation 860, when a change occurs in the network, receiving information about a first reconfigurable smart metasurface (RIS) node by a base station. A reconfigurable smart metasurface includes a material having configurable electromagnetic properties.

[0097] Return to reference Figure 7BIn some embodiments, a base station communicates with a plurality of RIS nodes including a first RIS node. The base station may determine control information (e.g., network configuration information) based on the reported type and capability information from the plurality of RIS nodes. The method includes transmitting, by the base station, control information to the first RIS node based on information from the plurality of RIS nodes. In some embodiments, the method includes re-evaluating control information when the plurality of RIS nodes change, and transmitting the re-evaluated control information to a RIS node in communication with the base station. Here, the change of the plurality of RIS nodes includes the addition of a RIS node, the deletion of a RIS node, or any configuration change performed on a RIS node. For example, if the capability information of a RIS node is adjusted or a new RIS obtains access to a network, the adjusted RIS or the newly added RIS needs to notify the base station of its RIS ID and related information. The base station also needs to adjust the control information to achieve dynamic exchange of RIS information.

[0098] In some embodiments, the base station may collect RIS type information from one or more RIS nodes and first determine control information or network configuration information based on the type information. The base station then receives capability information from the RIS nodes. The network configuration information may be optionally updated based on the RIS capability information.

[0099] In some embodiments, the base station may collect RIS capability information from one or more RIS nodes and first determine control information or network configuration information based on the capability information. The base station then receives type information from the RIS node. The network configuration information may be optionally updated based on the RIS type information.

[0100] In some embodiments, the base station may first determine network configuration information (e.g., based on pre-configuration information or a predefined set of rules of a RIS node). The base station then receives RIS type and / or capability information from the RIS node. The network configuration information may be optionally updated based on the type and / or capability information.

[0101] Fig. 9An example of a wireless communication system 900 to which the technology according to one or more embodiments of the present invention can be applied is shown. The wireless communication system 900 may include one or more base stations (BS) 905a, 905b, one or more wireless devices (or UEs) 910a, 910b, 910c, 910d, and a core network 925. The base stations 905a, 905b may provide wireless services to user devices 910a, 910b, 910c, and 910d in one or more wireless sectors. In some implementations, the base stations 905a, 905b include directional antennas to generate two or more directional beams to provide wireless coverage in different sectors. The core network 925 may communicate with one or more base stations 905a, 905b. The core network 925 provides connections with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information about subscription user devices 910a, 910b, 910c, and 910d. The first base station 905a can provide wireless services based on a first radio access technology, and the second base station 905b can provide wireless services based on a second radio access technology. Depending on the deployment scenario, the base stations 905a and 905b can be co-located or can be installed separately on site. User equipment 910a, 910b, 910c and 910d can support multiple different radio access technologies. The techniques and embodiments described in the present invention can be implemented by the base station of the wireless device described in the present invention.

[0102] Fig.10 1 is a block diagram representing a portion of a radio station capable of applying one or more embodiments of the present invention. A radio station 1005 such as a network node, a base station or a wireless device (or a user equipment UE) may include a processor electronic device 1010 such as a microprocessor, which implements one or more of the wireless technologies presented in this document. The radio station 1005 may include a transceiver electronic device 1015 to send and / or receive wireless signals through one or more communication interfaces such as an antenna 1020. The radio station 1005 may include other communication interfaces for sending and receiving data. The radio station 1005 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some implementations, the processor electronic device 1010 may include at least a portion of the transceiver electronic device 1015. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the radio station 1005. In some embodiments, the radio station 1005 may be configured to perform the methods described herein.

[0103] The disclosed and other embodiments, modules and functional operations described in this document may be implemented in digital electronic circuits, or in computer software, firmware or hardware (including the structures disclosed in this document and their structural equivalents), or in a combination of one or more of them. The disclosed and other embodiments may be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer-readable medium for execution by a data processing device or for controlling the operation of the data processing device. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a material component that affects a machine-readable propagation signal, or a combination of one or more of them. The term "data processing device" includes all devices, equipment and machines for processing data, including, for example, a programmable processor, a computer or multiple processors or computers. In addition to hardware, the device may include code that creates an execution environment for the computer program in question, for example, code that constitutes a processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagation signal is an artificially generated signal, for example, a machine-generated electrical, optical or electromagnetic signal, which is generated to encode information for transmission to a suitable receiver device.

[0104] A computer program (also referred to as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, in one or more coordinated files (e.g., files storing one or more modules, subroutines, or multiple portions of code). A computer program may be deployed to execute on a computer or multiple computers located at a site or distributed across multiple sites and interconnected by a communication network.

[0105] The process and logic flow described in this article can be performed by one or more programmable processors, and the one or more programmable processors execute one or more computer programs to perform functions by operating input data and generating output. The process and logic flow can also be performed by a special logic circuit (for example, FPGA (field programmable gate array) or ASIC (application-specific integrated circuit)), and the device can also be implemented as a special logic circuit. For example, a processor suitable for executing a computer program includes any one or more processors of a general and special microprocessor and a digital computer of any kind. Usually, the processor will receive instructions and data from a read-only memory or a random access memory or both. The basic element of a computer is a processor for executing instructions and one or more memory devices for storing instructions and data. Usually, a computer will also include one or more large-capacity storage devices (for example, a disk, a magneto-optical disk, or an optical disk) for storing data or be operably coupled to receive data from it or transmit data to it or both. However, a computer does not need to have such a device. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated in special purpose logic circuitry.

[0106] Although the present invention document contains many details, these details should not be interpreted as limitations on the scope of any invention or the scope of what may be claimed, but rather as descriptions of features that may be specific to a particular embodiment of a particular invention. Certain features described in the present invention document in the context of a separate embodiment may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although features may be described above as working in certain combinations and even initially claimed as such, in some cases, one or more features from the claimed combination may be removed from the combination, and the claimed combination may involve a sub-combination or a variant of a sub-combination.

[0107] Although operations are depicted in a particular order in the drawings, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed, in order to achieve the desired results. In addition, the separation of various system components in the embodiments described in this invention document should not be understood as requiring such separation in all embodiments.

[0108] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and shown in this invention document.

Claims

1. A wireless communication method, characterized in that: include: When a change occurs in the network, information about a first reconfigurable smart metasurface RIS node is reported to one or more base stations, wherein the reconfigurable smart metasurface includes a material with configurable electromagnetic properties.

2. The method according to claim 1, comprising: The first RIS node receives control information from the one or more base stations, wherein the control information indicates that the one or more base stations communicate with a plurality of RIS nodes, and the plurality of RIS nodes communicate include the first RIS node; The first RIS node sends information to the one or more base stations to enable the one or more base stations to coordinate the plurality of RIS nodes.

3. A wireless communication method, characterized in that: include: When a network changes, the base station receives information of a first reconfigurable smart metasurface RIS node, wherein the reconfigurable smart metasurface includes a material with configurable electromagnetic properties.

4. The method according to claim 3, wherein: The base station communicates with a plurality of RIS nodes including the first RIS node, and the method comprises: Based on the information from the plurality of RIS nodes, the base station transmits control information to the first RIS node.

5. The method according to claim 4, comprising: re-evaluating the control information when the plurality of RIS nodes change; The re-evaluated control information is transmitted to a RIS node in communication with the base station.

6. The method according to any one of claims 1 to 5, wherein: The change in the network includes at least one of the following: initial attachment of the first RIS node to the network; a configuration update of the first RIS node; or The updating of at least one base station includes adding a base station or deleting a base station.

7. The method according to any one of claims 1 to 6, wherein: The information is broadcast from the first RIS node.

8. The method according to any one of claims 1 to 6, wherein: The information is transmitted by the first RIS node at the radio resource control RRC layer.

9. The method according to any one of claims 1 to 8, wherein: The information of the first RIS node includes at least one of type information of the first RIS node or capability information of the first RIS node.

10. The method according to claim 9, wherein: The type information includes at least one of the following: Reflective RIS type, Transmission RIS type, Based on the type of RIS transmitter, RIS type that is both transmissive and reflective, or Back-to-back RIS type.

11. The method according to claim 9, wherein: The capability information includes at least one of the following: Performance capability information, Frequency capability information, Time-sharing capability information, Phase modulation capability information, AM capability information, Precoding capability information, Measurement capability information, or Transmission and reflection capability information.

12. The method according to claim 11, wherein: The performance capability information includes at least one of the following: topology information of the first RIS node, type and / or number of RIS elements of the first RIS node, sensing capability of the first RIS node, energy transfer information of the first RIS node, impedance information of the first RIS node, or location information of the first RIS node.

13. The method according to claim 11, wherein: The frequency capability information includes frequencies and / or bandwidths supported by the first RIS node.

14. The method according to claim 11, wherein: The time-division capability information includes a response time or a switching speed of the first RIS node.

15. The method according to claim 11, wherein: The phase modulation capability information includes phase modulation accuracy and / or number of bits supported by the first RIS node.

16. The method according to claim 11, wherein: The amplitude modulation capability information includes at least a signal amplitude ratio, a magnitude range, or a corresponding relationship between amplitude and phase supported by the first RIS node.

17. The method according to claim 11, wherein: The precoding capability information includes at least precoding granularity, precoding models supported by the first RIS node, codebooks and / or quantization, or grouping of precoding capabilities.

18. The method according to claim 11, wherein: The measurement capability information includes at least a plurality of ports and / or location information of the RIS unit of the first RIS node.

19. The method according to claim 11, wherein: The transmission and reflection capability information includes at least energy loss in the first RIS, controllability of transmission and reflection, range of transmittance and / or reflectance, correlation between transmission phase and reflection phase, or correlation between transmission amplitude and reflection amplitude.

20. The method according to any one of claims 2, 4 or 5, wherein: The control information to the first RIS node includes at least information about a control channel, channel measurement, or a precoding scheme.

21. A communication device comprising a processor configured to implement the method according to any one or more of claims 1 to 20.

22. A computer program product having stored thereon code which, when executed by a processor, causes the processor to carry out the method according to any one or more of claims 1 to 20.

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