Existing approaches for channel estimation in Reconfigurable Intelligent Surface (RIS) assisted communication systems have the disadvantage that they require separate estimation of Angle of Arrival (AoA) and Angle of Departure (AoD), requiring additional step of computationally demanding data association. Embodiments disclosed herein provide a method and system for channel estimation in RIS assisted communication systems. In this approach, the system jointly visualizes the plurality of RIS elements and the plurality of multi-antenna receiver array elements as a RIS-SIMO virtual array, thereby eliminating need to separately estimate the AoA and AoD.

Provided are a signal detection circuit and a detection method using the signal detection circuit. The signal detection circuit includes a reconfigurable intelligent surface, a multiple input/output circuit connected to the reconfigurable intelligent surface, a magnitude detection circuit connected to the multiple input/output circuit, and a processor connected to the magnitude detection circuit, wherein the reconfigurable intelligent surface includes a sampling area arranged to intersect in a first direction and a second direction, the multiple input/output circuit is configured to receive and process a signal from the sampling area, the magnitude detection circuit is configured to receive the signal from the multiple input/output circuit and detect a magnitude of the received signal, and the processor is configured to identify an incidence direction of the signal based on a detection result of the magnitude detection circuit.

An electronic device and method for wireless communication, and a computer-readable storage medium. The electronic device for wireless communication may comprise a processing circuit, and the processing circuit may be configured to: when a current serving base station of a user equipment is overloaded, obtain a measurement result of a communication link, between the user equipment and an alternative base station, assisted by an intelligent reflecting surface; and when the measurement result of the communication link is higher than a threshold value, enable the user equipment to access the alternative base station and perform communication between the user equipment and the alternative base station under the assistance of the intelligent reflecting surface.

In order to estimate a channel in a wireless communication system, a method of operating a base station may comprise transmitting configuration information for at least one downlink reference signal, transmitting the at least one downlink reference signal, transmitting configuration information for an uplink reference signal to at least one user equipment (UE), receiving channel information from a reflecting intelligent surface (RIS), transmitting control information indicating a scheduling result for transmitting downlink data to the at least one UE, and transmitting the downlink data to the at least one UE according to the scheduling result.

A precoding method, performed by a reconfigurable intelligent surface (RIS) array, includes determining a phase shift list corresponding to the RIS array, in which the phase shift list includes at least one row of phase shift sequence, the phase shift sequence includes a phase shift of each RIS array element in the RIS array, each row of phase shift sequence is configured to cause the RIS array to reflect an incident signal along a pair of reflection angles, and each row of phase shift sequence corresponds to one index value; acquiring a first index value from a user equipment (UE); determining a first phase shift sequence corresponding to the first index value from the phase shift list; and precoding the RIS array by configuring the phase shift of each RIS array element in the RIS array according to the first phase shift sequence.

A communication system includes one or more transmitters, each transmitter to: transmit communication signals using a defined signaling protocol with multiple antenna elements to a target receiver, the communication signals containing known specific transmit sequences spread across a frequency spectrum of the communication signals to be detectable only by receivers having the known specific transmit sequences, and receive feedback from the target receiver indicating any errors in reception of the communication signals based upon the known specific transmit sequences, and a machine learning system to use configuration of the multiple antenna elements when the communication signal was sent and the feedback to predict preconfigured settings for transmitters. A test and measurement system located at a base station, a signal generator to generate one or more signals having a predetermined modulation format, a receiver to receive the one or more signals, and a machine learning system to develop a calibration matrix.

Methods, systems, and devices for wireless communications are described. Generally, the described techniques provide for performing initial access procedures including transmitting or receiving synchronization signal blocks (SSBs) based on a capability of a user equipment (UE) to use reconfigurable intelligent surfaces (RISs). In some examples, a base station may transmit SSBs using two synchronization raster grids. For example, the base station may transmit SSBs on a first synchronization raster grid for UEs that do not support RISs and on a second synchronization raster grid for UEs that support RISs. In some examples, a base station may transmit different types of SSBs. For example, a base station may transmit a first type of SSB for UEs that do not support RISs and a second type of SSB for UEs that support RISs. A UE may search for and receive SSBs according to a capability of the UE.

A beam management method and apparatus to optimize a beam management procedure between a reconfigurable intelligent meta-surface (RIS) and a terminal device, so that beam management efficiency may be improved, and system overheads may be reduced. The method includes: determining first measurement information based on information of a beam set, sending the first measurement information, and communicating with a RIS through a first beam, where the beam set is determined based on first location information of a terminal device, the beam set includes one or more beams between the RIS and the terminal device, the first measurement information includes information determined by the terminal device based on a beam corresponding to a downlink reference signal, and the first beam is a beam in the beam set.

Aspects of the disclosure related to devices, wireless communication apparatuses, methods, and other aspects of passive multiple input multiple output. In some aspects, an apparatus is provided that includes a first radio frequency (RF) transmission line having a first terminated with a quarter wavelength grounded transmission line, and a first array of antennas including a plurality of antenna elements. The apparatus also includes a switch array including a corresponding switch for each antenna element of the plurality of antenna elements of the first array of antennas, to selectively connect each antenna element to the first RF transmission line, and path lengths selectable by the switches at half wavelength distances for passive transmission. The apparatus also includes or more lens elements configured to modify wireless inputs signals to the first array of antennas and to modify wireless output signals from the first array of antennas.

A method for controlling a reconfigurable intelligence surface (RIS) to transmit a reference signal, performed by the RIS, includes: sending indication information to a network device, wherein the indication information is used to indicate capability information of transmitting the reference signal of the RIS; receiving control information sent by the network device, wherein the control information is used to control the RIS to transmit the reference signal; and transmitting the reference signal according to the control information sent by the network device.