US-12627361-B2 - Decoupled uplink and downlink communications via reconfigurable intelligent surfaces

US12627361B2US 12627361 B2US12627361 B2US 12627361B2US-12627361-B2

Abstract

Methods, systems, and devices for wireless communications are described. The described techniques support decoupled uplink and downlink communications via reconfigurable intelligent surfaces. Generally, the described techniques provide for using different passive network nodes for uplink and downlink communications. A user equipment (UE) may receive, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station. The UE may receive, from the base station via a first passive device (e.g., a first reconfigurable intelligent surface (RIS)) associated with the first transmission configuration indicator state, a downlink message in a radio frame. The UE may transmit, to the base station via a second passive device (e.g., a second RIS) associated with the second transmission configuration indicator state, an uplink message in the radio frame.

Inventors

Hung Dinh Ly
Yu Zhang
Saeid SAHRAEI
Krishna Kiran Mukkavilli

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260512
Application Date: 20210310

Claims (20)

1 . A method for wireless communications at a user equipment (UE), comprising: receiving, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station, wherein the indication configures uplink communications to be routed from the UE to the base station via a first passive device that is different than a second passive device used to route downlink communications from the base station to the UE; receiving, from the base station via the first passive device associated with the first transmission configuration indicator state, a downlink message in a radio frame; and transmitting, to the base station via the second passive device associated with the second transmission configuration indicator state, an uplink message in the radio frame.
2 . The method of claim 1 , further comprising: receiving, from the base station and via the first passive device, a source reference signal that is associated with the first passive device; and receiving the downlink message from the base station via the first passive device according to a quasi co-location relationship identified by the UE based at least in part on the received source reference signal and the first transmission configuration indicator state.
3 . The method of claim 1 , further comprising: receiving, from the base station and via the second passive device, a source reference signal that is associated with the second passive device; and transmitting the uplink message to the base station via the second passive device according to a quasi co-location relationship identified by the UE based at least in part on the received source reference signal and the second transmission configuration indicator state.
4 . The method of claim 1 , further comprising: receiving, from the base station, an indication that the UE is to switch to using the first transmission configuration indicator state for transmitting a second uplink message and using the second transmission configuration indicator state for receiving a second downlink message; receiving, based at least in part on receiving the indication that the UE is to switch, the second downlink message from the base station in a second radio frame via the second passive device according to the second transmission configuration indicator state; and transmitting, based at least in part on receiving the indication that the UE is to switch, the second uplink message to the base station in the second radio frame via the first passive device according to the first transmission configuration indicator state.
5 . The method of claim 4 , wherein receiving the indication that the UE is to switch comprises: receiving a downlink control information message or a medium access control layer control element message comprising the indication that the UE is to switch.
6 . The method of claim 4 , wherein receiving the indication that the UE is to switch comprises: receiving an indication of a first source reference signal corresponding to the first transmission configuration indicator state and an indication of a second source reference signal corresponding to the second transmission configuration indicator state.
7 . The method of claim 1 , wherein the first passive device is a first reconfigurable intelligent surface and the second passive device is a second reconfigurable intelligent surface.
8 . The method of claim 1 , further comprising: generating feedback associated with receipt of the downlink message according to the first transmission configuration indicator state; and transmitting the feedback in the uplink message according to the second transmission configuration indicator state.
9 . The method of claim 1 , further comprising: receiving, in the downlink message, feedback associated with transmission of the uplink message according to the second transmission configuration indicator state.
10 . A method for wireless communications at a base station, comprising: transmitting, to a user equipment (UE), an indication of a first transmission configuration indicator state for downlink communications and a second transmission configuration indicator state for uplink communications, wherein the indication configures uplink communications to be routed from the UE to the base station via a first passive device that is different than a second passive device used to route downlink communications from the base station to the UE; transmitting, to the UE via the first passive device according to the first transmission configuration indicator state, a downlink message in a radio frame; and receiving, from the UE via the second passive device according to the second transmission configuration indicator state, an uplink message in the radio frame.
11 . The method of claim 10 , further comprising: transmitting, to the UE via the first passive device, a source reference signal that is associated with the first passive device; and transmitting, to the UE via the first passive device, the downlink message based at least in part on a quasi co-location relationship associated with the transmitted source reference signal and defined by the first transmission configuration indicator state.
12 . The method of claim 10 , further comprising: transmitting, to the UE via the second passive device, a source reference signal that is associated with the second passive device; and receiving, from the UE via the second passive device, the uplink message based at least in part on a quasi co-location relationship associated with the transmitted source reference signal and defined by the second transmission configuration indicator state.
13 . The method of claim 10 , further comprising: transmitting, to the UE, an indication that the UE is to switch to using the first transmission configuration indicator state for transmitting a second uplink message and the second transmission configuration indicator state for receiving a second downlink message; transmitting, based at least in part on transmitting the indication that the UE is to switch, the second downlink message in a second radio frame via the second passive device according to the second transmission configuration indicator state; and receiving, based at least in part on transmitting the indication that the UE is to switch, the second uplink message in the second radio frame via the first passive device according to the first transmission configuration indicator state.
14 . The method of claim 13 , wherein transmitting the indication that the UE is to switch comprises: transmitting a downlink control information message or a medium access control layer control element message comprising the indication that the UE is to switch.
15 . The method of claim 13 , wherein transmitting the indication that the UE is to switch comprises: transmitting an indication of a first source reference signal corresponding to the first transmission configuration indicator state and an indication of a second source reference signal corresponding to the second transmission configuration indicator state.
16 . The method of claim 10 , wherein the first passive device is a first reconfigurable intelligent surface and the second passive device is a second reconfigurable intelligent surface.
17 . The method of claim 10 , wherein receiving the uplink message comprises: receiving, from the UE, feedback associated with the transmitted downlink message.
18 . The method of claim 10 , further comprising: generating feedback associated with receipt of the uplink message that is transmitted by the UE via the second transmission configuration indicator state; and transmitting the feedback in the downlink message via the first transmission configuration indicator state.
19 . An apparatus for wireless communications at a user equipment (UE), comprising: a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receive, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station, wherein the indication configures uplink communications to be routed from the UE to the base station via a first passive device that is different than a second passive device used to route downlink communications from the base station to the UE; receive, from the base station via the first passive device associated with the first transmission configuration indicator state, a downlink message in a radio frame; and transmit, to the base station via the second passive device associated with the second transmission configuration indicator state, an uplink message in the radio frame.
20 . The apparatus of claim 19 , wherein the instructions are further executable by the processor to cause the apparatus to: receive, from the base station and via the first passive device, a source reference signal that is associated with the first passive device; and receive the downlink message from the base station via the first passive device according to a quasi co-location relationship identified by the UE based at least in part on the received source reference signal and the first transmission configuration indicator state.

Description

CROSS REFERENCE The present Application is a 371 national stage filing of International PCT Application No. PCT/CN2021/079892 by L Y et al. entitled “DECOUPLED UPLINK AND DOWNLINK COMMUNICATIONS VIA RECONFIGURABLE INTELLIGENT SURFACES,” filed Mar. 10, 2021, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. FIELD OF TECHNOLOGY The present disclosure relates to wireless communications, including decoupled uplink and downlink communications via reconfigurable intelligent surfaces. BACKGROUND Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). In some wireless communications systems, a UE may transmit uplink data and control information directly to a base station (e.g., using beamforming). In some cases, however, the path between the UE and the base station may be obstructed or blocked, and the likelihood that the base station receives an uplink transmission from the UE may be low. SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support decoupled uplink and downlink communications via reconfigurable intelligent surfaces. Generally, the described techniques provide for using different passive devices for uplink and downlink communications. A user equipment (UE) may receive, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station. The UE may receive, the base station via a first passive device (e.g., a first reconfigurable intelligent surface (RIS)) associated with the first transmission configuration indicator state, a downlink message in a radio frame. The UE may transmit, to the base station via a second passive device (e.g., a second RIS) associated with the second transmission configuration indicator state, an uplink message in the radio frame. A method for wireless communications at a user equipment (UE) is described. The method may include receiving, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station, receiving, from the base station via a first passive device associated with the first transmission configuration indicator state, a downlink message in a radio frame, and transmitting, to the base station via a second passive device associated with the second transmission configuration indicator state, an uplink message in the radio frame. An apparatus for wireless communications at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, an indication of a first transmission configuration indicator state for downlink communications with the base station and a second transmission configuration indicator state for uplink communications with the base station, receive, from the base station via a first passive device associated with the first transmission configuration indicator state, a downlink message in a radio frame, and transmit, to the base station via a second passive device associated with the second transmission configuration indicator state, an uplink message in the radio frame. Another apparatus for wireless communications at a UE is described. The apparatus may include means for receiving, from a base station, an indication o