Systems and methods using configurable surfaces for wireless communication

Patent metadata

Field	Value
Publication number	US-2022014935-A1
Application number	US-202016926176-A
Country	US
Kind code	A1
Filing date	Jul 10, 2020
Priority date	Jul 10, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

Aspects of the present disclosure take advantage of a prism-like effect that occurs in a Reconfigurable Intelligent Surface (RIS), where the RIS reflects incident signals of different frequencies in different directions. for determining characteristics of a channel between a transmitter and a receiver wherein the channel includes the RIS. In particular, this may include estimating an angle of arrival (AoA) to the RIS in uplink transmission or the angle of departure (AoD) from the RIS in downlink transmission. Aspects of the present disclosure also provide solutions to compensate the prism effect for wideband transmission, especially at high frequencies (e.g. mmWave and THz).

First claim

What is claimed is:

1 . A method comprising:
transmitting first configuration information to a user equipment (UE), the first configuration information identifying both a reference signal and a carrier frequency of the reference signal, the reference signal and carrier frequency being used to determine channel information about a channel between a base station and the UE via a reconfigurable intelligent surface (RIS); transmitting a reference signal that is redirected by the RIS based on second configuration information that configures the RIS to redirect different frequency components of the reference signal in different directions; receiving measurement information from the UE pertaining to measurement of the reference signal redirected by the RIS; and determining the channel information based on the transmitted reference signal and the received measurement information.

2 . The method of claim 1 further comprising at least one of:
transmitting a data transmission in a direction toward the RIS, the data transmission redirected by the RIS to the UE; or
receiving a data transmission from the UE, the data transmission redirected by the RIS before being received.

3 . The method of claim 1 , wherein transmitting a reference signal comprises transmitting at least one of:
one or more narrow frequency band reference signals that are redirected by the RIS in different directions such that reflected beams from the RIS are substantially non-overlapping; one or more narrow frequency band reference signals that are redirected by the RIS in different directions such that reflected beams from the RIS are overlapping; or a wide frequency band reference signal wherein frequency components of the wide frequency band reference signal are redirected by the RIS in different directions due to the prism-like effect of the RIS.

4 . The method of claim 2 further comprising:
compensating for a multipath fading effect resulting from frequency components in a wide frequency band data signal occupying a range of frequencies being redirected in different directions by the RIS, the compensating by at least one of
using orthogonal frequency division multiplexing (OFDM) for the data transmission with a subcarrier spacing depending on a measured frequency response of the wide frequency band data signal interacting with the RIS;
configuring the RIS to reduce a deviation from a main desired direction; or
transmitting an indication that the UE is to perform channel equalization.

5 . The method of claim 4 , wherein configuring the RIS to reduce the deviation from the main desired direction comprises configuring the RIS with third configuration information comprising configuration information for at least one of:
configuring the RIS to redirect with a wide frequency band data signal transmitted in a wide beam that is larger than a deviation caused by a prism-like effect; configuring the RIS to divide the RIS into separate portions, each portion redirecting a subset of the wide frequency band data signal incident on the RIS; or configuring the RIS so that different sets of one or more configurable elements of the RIS redirect the wide frequency band data signal incident on the RIS in a desired direction by having the configurable elements on one end of the RIS configured to redirect a lowest frequency component of the wide frequency band data signal in the desired direction and then configuration of other configurable elements of the RIS gradually changes such that at the other end of the RIS, the configurable elements are configured to redirect a highest frequency of the wide frequency band data signal in the desired direction.

6 . The method of claim 1 , wherein receiving measurement information from the UE comprises receiving at least one of:
an identification of one or more reference signals with a received reference signal strength that satisfies a minimum threshold, wherein the received reference signal strength is one of:
a reference signal received power (RSRP) for one or more reference signals;
a reference signal strength indicator (RSSI) for one or more reference signals;
a reference signal received quality (RSRQ) for one or more reference signals; and
a signal-to-noise ratio (SNR) for one or more reference signals; or
a frequency response of a received wideband frequency band reference signal.

7 . The method of claim 1 , wherein transmitting the first configuration information comprises transmitting one or more of:
an indication that the RIS is being used to redirect signaling to the UE; an indication of a type of RIS being used to redirect signaling to the UE; an identification of carrier frequencies that the reference signals are transmitted on; or an identification of bandwidth of the reference signals.

8 . The method of claim 1 further comprises transmitting third configuration information to the RIS to configure the RIS to redirect a data transmission in an appropriate direction when the data transmission interacts with the RIS.

9 . The method of claim 1 further comprising transmitting the second configuration information to the RIS.

10 . The method of claim 1 , wherein transmitting the second configuration information comprises transmitting one or more of:
carrier frequencies that the reference signals are transmitted on; an angle of arrival (AoA) of the reference signal at the RIS; an assumed one or more angle of departure (AoDs) of the reference signal from the RIS when the reference signal is redirected; beam-width of the redirected signal; or partitioning of the RIS to redirect reference signals of different frequencies.

11 . An apparatus comprising:
a processor; and a computer-readable medium having stored thereon computer executable instructions that when executed cause the processor to:
transmit first configuration information to a user equipment (UE), the first configuration information identifying both a reference signal and a carrier frequency of the reference signal, the reference signal and carrier frequency being used to determine channel information about a channel between a base station and the UE via a reconfigurable intelligent surface (RIS);
transmit a reference signal that is redirected by the RIS based on second configuration information that configures the RIS to redirect different frequency components of the reference signal in different directions;
receive measurement information from the UE pertaining to measurement of the reference signal redirected by the RIS; and
determine the channel information based on the transmitted reference signals and the received measurement information.

12 . The apparatus of claim 11 , wherein the processor is further caused to perform at least one of:
transmitting a data transmission in a direction toward the RIS, the data transmission redirected by the RIS to the UE; or receiving a data transmission from the UE, the data transmission redirected by the RIS before being received.

13 . The apparatus of claim 11 , wherein the processor is caused to transmit at least one of:
one or more narrow frequency band reference signals that are redirected by the RIS in different directions such that reflected beams from the RIS are substantially non-overlapping; one or more narrow frequency band reference signals that are redirected by the RIS in different directions such that reflected beams from the RIS are overlapping; or a wide frequency band reference signal wherein frequency components of the wide frequency band reference signal are redirected by the RIS in different directions due to the prism-like effect of the RIS.

Assignees

• Haija Ahmad Abu Al
• Baligh Mohammadhadi
• Huawei Tech Co Ltd

Inventors

• Haija Ahmad Abu Al
• Baligh Mohammadhadi

Classifications

• H04B17/328

  Reference signal received power [RSRP]; Reference signal received quality [RSRQ] · CPC title

• H04B17/336

  Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] · CPC title

• H04W16/26

  Cell enhancers {or enhancement}, e.g. for tunnels, building shadow · CPC title

• H04L5/0094

  Indication of how sub-channels of the path are allocated · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title