There is provided mechanisms for directional beam determination towards a user equipment. A method is performed by a network node. The network node determines that the user equipment is served a the reflector node. The network node selects the directional beam to be used by the reflector node for subsequent communication between the network node and the user equipment via the reflector node. The network node configures the reflector node such that the selected directional beam is used. The network node communicates with the user equipment via the reflector node once the reflector node has been configured.

In order to estimate a channel in a wireless communication system, a method of operating a base station may comprise receiving reference signals from at least one user equipment (UE), estimating a channel based on the reference signals, performing scheduling for uplink communication, transmitting an uplink grant to the at least one UE based on a result of scheduling, and receiving uplink data from the at least one UE according to the uplink grant,

Reconfigurable Intelligent Surface devices, RIS, may be used to improve receipt of radio signals received by wireless transmit-receive units, WTRUs, in a given area. In such area, WTRUs may receive radio signals directly from the transmitter, and indirectly, via reflection of the radio signals from the transmitter by the RIS device. A RIS may consist of programmable sub-wavelength sized unit cells placed in close proximity. Each unit cell behaves like a scatterer. Embodiments of a new RIS structure are described here, being based on a nearly passive reflecting platform. In a Nearly-Passive RIS structure according to embodiments, NP-RIS, each unit cell is programmed to have a constant invariable phase-shift. Embodiments of a unit cell selection method are described, to control the reflected wave by selecting a subset of unit cells whose reflection could assist coherent alignment of the reflected wave with the main direct signal at the WTRU.

A user equipment (UE) for communication with a base station over a communication channel via an intelligent reflective surface (IRS. The UE is configured to control the IRS to operate with a plurality of reflection configurations for reflecting a plurality of pilot signals sent from the base station to the UE for probing the channel between the base station, IRS, and the UE. The plurality of reflection configurations of the IRS includes a first plurality of reflection configurations for estimating, by the UE, a channel covariance matrix, (CCM) of the communication channel between the base station and the UE via the IRS, and a second plurality of reflection configurations for estimating, by the UE, the communication channel between the base station and the UE via the IRS.

Methods, systems, and devices for wireless communications are described. A network entity may transmit a control signal indicating a configuration of radio resources for communicating signals to a controller of a reconfigurable intelligent surface (RIS). The network entity may exchange the signals with one or more wireless devices via a set of reflective elements of the RIS. The network entity may determine a set of restricted locations (e.g., angles, positions, or both) for the signals reflected by the RIS and corresponding restriction types. The network entity may transmit the set of restricted locations and restriction types to a controller of the RIS. The controller of the RIS may generate a weighting matrix to control the set of reflective elements of the RIS to reflect the signals according to the radio resources and based on the set of restricted locations and corresponding restriction types.

Various aspects of the present disclosure relate to network device (e.g., a base station) that transmits a first signaling indicating a first configuration to a reconfigurable intelligent surface (RIS) for an orbital angular momentum (OAM) mode for a reflected signal transmission from the RIS. The network device can also transmit a second signaling to a user equipment (UE) indicating a mapping of a transmission configuration indicator (TCI) to the OAM mode. Additionally, the network device can transmit a third signaling indicating a second configuration to the RIS for multiple OAM modes, and transmit the second signaling to the UE indicating the mapping of the TCI to the multiple OAM modes.

A method of controlling signal exchange includes: receiving at least one of: (1) a measurement indication indicating a first measurement of a first signal type and/or a second measurement of a second signal type, the first signal type being for non-RIS-reflected signal transfer and the second signal type being for RIS-reflected signal transfer; or (2) a first UL-PRS of the first signal type and/or a second UL-PRS of the second signal type; or (3) an indication of a power-saving mode of a UE; and transmitting a message in response to the at least one signal, the message indicating for the UE to report measurement of DL-PRS of only one type of the first signal type or the second signal type and/or indicating for the UE to transmit UL-PRS of only one type of the first signal type or the second signal type.

Reconfigurable surfaces and methods for configuring surfaces include measuring properties of one or more incident signals at a configurable cell of a surface. A beam forming pattern for the surface is determined based on the measured properties of the one or more incident signals. Parameters of the configurable cell are set to implement the beam forming pattern in the surface.

In an aspect, a user equipment (UE) may obtain an indication of one or more reconfigurable intelligent surfaces (RIS) for use during a self-localization positioning session. The UE may receive a reference signal (RS) configuration for transmitting one or more RS for the self-localization positioning session. The UE may receive a reflection schedule for at least one RIS of the one or more RIS, wherein the reflection schedule indicates one or more reflection phases of the at least one RIS for reflecting the one or more RS transmitted by the UE and corresponding times at which each reflection phase of the one or more reflection phases is activated at the at least one RIS.

Aspects presented herein may improve the performance and accuracy of a UE positioning based on RIS, such as when the RIS has a limited number of control voltage sets available. In one aspect, a UE obtains an indication of beam pattern information for a set of DL beams for a network entity, where the set of DL beams is associated with an RIS. The UE adjusts a first transmission angle for a set of UL beams based on the beam pattern information and measurement for the set of DL beams, where the first transmission angle for the set of UL beams is adjusted to proximately align with a second transmission angle of the set of DL beams from the RIS. The UE transmits, via the RIS, the set of UL beams to the network entity based on the adjusted first transmission angle.