Various aspects to reduce interferences in presence of a reconfigurable intelligent surface (RIS) are provided. In an aspect, a first device perform a first transmission using a first set of beams of the first device in response to an activated RIS for serving a second device to facilitate communication between the first device and the second device not being present. The first device may further perform a second transmission using a second set of beams of the first device in response to the activated RIS being present, the second set of beams being a subset of the first set of beams that excludes one or more beams of the first set of beams.

The disclosure relates to a 5th generation (5G) or 6th generation (6G) communication system for supporting higher data transmission rates than 4th generation (4G) communication systems, such as long-term evolution (LTE) systems. A method and a device are provided. The method includes, by a user equipment (UE) in a wireless communication system, receiving RIS information from an RIS controller (RC), identifying an incident beam incident on the UE, providing information about the identified incident beam to the RC and requesting information about candidate RIS modes, receiving the information about the candidate RIS modes, performing probing on the candidate RIS modes, deriving a final RIS mode among the candidate RIS modes using a result of the probing, and transmitting information about the final RIS mode to an RIS through the RC.

Aspects of the present disclosure relate to utilizing an intelligent reflecting surface (IRS), a tracking algorithm, or both, to receive, calibrate, and maintain orbital angular momentum (OAM) signaling between wireless devices. The present disclosure describes a first wireless device transmitting spatial-multiple input-multiple output (MIMO) beams to the IRS such that reflected waves from the IRS form a spatial mixture of OAM modes. The IRS may reflect such OAM modes to a second wireless device for subsequent reflection (e.g., a second IRS), reception, calibration, and optimization. For example, the second wireless device may perform pattern recognition of the concentric OAM modes (e.g., by estimating ellipse geometry) to determine the modes of the OAM signaling. The second wireless device may also perform decorrelation, where small perturbations to the elliptical OAM geometry allow the second wireless device to perform one or more optimization techniques related to the OAM signaling.

A method of a transmitting node may comprise: modulating a codeword corresponding to data to be transmitted; generating sparse space-frequency block code (SSFBC)-coded symbols by encoding the modulated codeword in an SSFBC scheme; performing precoding on the SSFBC-coded symbols for each of subbands respectively corresponding to transmit antenna groups; and transmit the precoded SSFBC-coded symbols by performing beamforming on the precoded SSFBC-coded symbols using at least one array antenna group among two or more array antenna groups.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a network node may determine a reference location associated with a virtual image corresponding to a target area. The network node may transmit a radio frequency signal, wherein the radio frequency signal is beamformed based at least in part on the reference location to direct the radio frequency signal to the target area. Numerous other aspects are described.

A method includes acquiring multiple pieces of first received signal quality information at a receiver, where the multiple pieces of first received signal quality information represent qualities of signals received at the receiver, generating first conditional sample statistical values based on the multiple pieces of first received signal quality information and phase shift arrays corresponding to the signals, determining the first phase shift array that meets a communication requirement according to the first conditional sample statistical values, where the first phase shift array includes the phase shift value for at least one reflective element of an IRS, and configuring the IRS based on the first phase shift array.

A wireless access point, AP, (110a) is disclosed, which is configured to share a transmission opportunity with at least one further wireless access point (110b) within a Multi-AP set using a Coordinated Beamforming, C-BF, scheme. The wireless AP (110a) comprises a processing circuitry (111) configured to generate a C-BF Null Data PPDU Announcement, C-BF NDPA, frame, wherein the C-BF NDPA frame comprises a Multi-AP set identifier. Moreover, the wireless AP (110a) comprises a communication interface (113) configured to transmit the C-BF NDPA frame to one or more wireless stations (120a) associated with the wireless AP (110a) and/or to one or more further wireless stations (120b) associated with the at least one further wireless AP (110b) within the Multi-AP set.

Various techniques are provided for determining, by a base station, a beam coverage in a cell, the beam coverage including angle range for an azimuth and an angle range for an elevation, determining, by the base station, an angle quantization step, generating, by the base station, a grid of narrow beams based on the angle range and the angle quantization step, computing, by the base station, a beam index matrix based on the grid of narrow beams, generating, by the base station, a wide beam codebook based on the grid of narrow beams, and transmitting, by the base station, at least one of a CSI-RS resource and a SSB resource using multiple-TX-directions wide beams based on the wide beam codebook.

Aspects of the present disclosure relate to techniques, methods, devices, systems, and non-transitory computer readable medium for generating codebooks for reconfigurable intelligent surfaces (RIS) s. For example, a RIS controller generates a codebook for a RIS by computing weights using a discrete Fourier transform (DFT) function or a fractional Fourier transform (FrFT) function, based on reference signals (RSs) transmitted by a transmitter. The weights correspond to the RIS elements or a subset of the RIS elements. In some aspects, the computation of the weights may include oversampling factors that allow for a higher resolution of the weights and improved search for an optimal precoding setting. Different sets of weights may be used for different incoming beams. The RIS controller may be trained with a pair of transmitter and a receiver to identify/generate the codebook for an optimized set of weights under specific situations.

According to an aspect, there is provided an apparatus for performing the following. The apparatus maintains, in at least one memory, information on a reference incidence direction and reference configuration information defining a plurality of configurations of a plurality of tunable load impedance circuits of a tunable reflective array of a reconfigurable intelligent surface or a subpanel thereof for the reference incidence direction. The apparatus measures an incidence direction from which electromagnetic waves are received by the reconfigurable intelligent surface. The apparatus calculates, based on the reference incidence direction, the measured incidence direction and the reference configuration information, corrected configuration information defining a plurality of corrected configurations for the measured incidence direction. Finally, the apparatus configures the plurality of tunable load impedance circuits according to a corrected configuration.