A communication system may include a reconfigurable intelligent surface (RIS) that reflects a radio-frequency signal between first and second devices. The RIS may include an array of antenna elements coupled to adjustable devices. The adjustable devices may configure phase shifts imparted to the radio-frequency signal upon reflection off the RIS. The adjustable devices may include switch modules or may include PIN diodes that are controlled using programmable current sources. The programmable current sources may be disposed within control integrated circuits (ICs) mounted to the periphery of the RIS. Each control IC may control the PIN diodes of a different respective set of the antenna elements. The control ICs may have serial interfaces and may be daisy chained together. The antenna element may be a dual-polarization element with five patches and four diodes in some implementations.

A phase encoding method includes: determining, based on a plurality of to-be-encoded phases, a quantity of a plurality of bits needed for encoding the plurality of phases; generating first-order terms and higher-order terms of the plurality of bits; constructing a bit matrix based on the plurality of phases, the first-order terms, and the higher-order terms, where the bit matrix includes a plurality of value combinations of the plurality of bits; calculating a plurality of encoding coefficients based on the bit matrix and the plurality of phases; and encoding the plurality of phases by using the plurality of encoding coefficients. This method may be performed by any encoding process in which an encoding object is a discrete value.

Disclosed is a method and device for beam training for an IRS assisted cellular system. The method performed by BS in the IRS assisted cellular system includes configuring the IRS in a retro-reflection mode to reflect a received beam in same direction of reception of the beam and determining a BS optimal Tx-Rx beam pair for a BS-IRS link. The method includes: configuring the IRS to receive a beam from the UE; configuring the IRS to determine an IRS optimal Tx-Rx beam pair for an IRS-UE link and receiving signalling information from the UE indicating the IRS optimal Tx-Rx beam pair; and transmitting to the UE, a beam through the BS optimal Tx-Rx beam pair which is received at the UE through the UE optimal Tx-Rx beam pair, wherein the IRS reflects the beam transmitted by the BS to the UE through the IRS optimal Tx-Rx beam pair.

A transmission control method, a device and a reconfigure intelligent surface are provided. The method in the present disclosure is performed by a reconfigure intelligent surface (RIS), the RIS includes a plurality of RIS atoms and a plurality of connectors, where each of the plurality of connectors is configured to control a connection state of the plurality of RIS atoms around the connector; the method includes: determining a setting parameter of a RIS unit; determining the connection state of the plurality of RIS atoms around the connector according to the setting parameter, and determining the RIS unit according to the connection state; where at least one of the RIS atoms constitutes one RIS unit, the setting parameter includes a center distance between multiple RIS units.

Aspects provided herein provide methods and systems for utilizing an adaptable Van Atta reflective array (A-VARA) system. The system comprises an A-VARA panel comprising variable phase shifters incorporated into transmission lines linking a set of radiating elements. The system also comprises a control that modifies a reflection direction of the A-VARA panel and provides aggregate adjustment to each of the variable phase shifters to steer reflected coverage around an obstacle.

Disclosed is an apparatus and method for beam searching using an active reconfigurable intelligent surface in wireless communication systems. An Active Reconfigurable Intelligent Surface (Active RIS) operating method includes: receiving a control command for beam searching from a base station; determining a target RIS beam area according to the control command; setting differential amplification gain for each beam in the target area; processing a search signal received from the base station according to the set differential amplification gain and transmitting to a corresponding beam area; receiving measurement results from the base station; analyzing the measurement results to estimate terminal position and setting a next search target area when additional searching is needed; and relaying communication signals through an RIS beam corresponding to the estimated terminal position. The differential amplification gain includes basic reference gain and differential contrast gain, enabling efficient beam searching with reduced sweeping cycles.

The technology described herein is directed towards subdividing a reconfigurable intelligent surface into subarrays, or rectangular segments of unit cells, for different functions/operations. The subdividing can be dynamic, such as based on different performance-based allocations, and each segment can have a separate directivity or array gain. Control signal data from a base station or user equipment instructs a controller of the reconfigurable intelligent surface to change the respective numbers of unit cells for the various respective functions/operations, which can include a receive-and-forward function from the base station via the reconfigurable intelligent surface to user equipment, and a receive-and-forward function from the user equipment via the reconfigurable intelligent surface to the base station. There can be one subarray for receiving control information at the reconfigurable intelligent surface from the base station, and one subarray for transmitting control information back to the base station.

Wireless communications systems, apparatuses, and methods are provided. A method of wireless communication performed by a network unit includes transmitting, to one or more user equipment (UEs), one or more first reference signals, transmitting, to the one or more UEs, one or more second reference signals, and detecting an unintended signal reflection associated with a reconfigurable intelligent surface (RIS) based on a comparison of first measurements associated with the one or more first reference signals with second measurements associated with the one or more second reference signals.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a reconfigurable intelligent surface (RIS) may select a weight vector, from a plurality of stored weight vectors, for enabling a spatially multiplexed communication, between a transmitter and a receiver, that includes two or more layers for each polarization of a plurality of polarizations for the spatially multiplexed communication. The RIS may receive the spatially multiplexed communication from the transmitter. The RIS may transmit the spatially multiplexed communication to the receiver in accordance with the weight vector. Numerous other aspects are described.

A method includes: transmitting, from a UE, a first on-demand request for first PRS resources of a first signal type based on reception by the UE of a first DL-RS of the first signal type with at least a first threshold quality and lack of reception of a second DL-RS of a second signal type with at least a second threshold quality, one of the first and second signal types being for non-RIS-reflected signal transfer and the other signal type being for RIS-reflected signal transfer, or transmitting, from the UE, a second on-demand request for second PRS resources for RIS-reflected signal transfer, the second on-demand request specifying a first RIS of a plurality of RISes associated with a common base station; or transmitting, from the UE, a capability message indicating that the UE supports different PRS symbol durations for RIS-reflected PRS and non-RIS-reflected PRS; or any combination thereof.