WO2022187801A1

WO2022187801A1 - Phase vector training for adaptive phase-changing device-enabled communication

Info

Publication number: WO2022187801A1
Application number: PCT/US2022/070871
Authority: WO
Inventors: Jibing Wang; Erik Richard Stauffer
Original assignee: Google Llc
Priority date: 2021-03-01
Filing date: 2022-02-28
Publication date: 2022-09-09

Abstract

Techniques and apparatuses are described for phase vector training for adaptive phase- changing device-enabled (APD-enabled) communication. In aspects, a base station (120) configures an APD (180) with a beam sweeping pattern of multiple phase vectors. The base station (120) then directs the APD (180) to perform the phase sweeping pattern in coordination with the base station transmitting downlink reference signals or a user equipment (UE, 110) transmitting uplink sounding signals through a wireless channel that includes the APD (180). Based on respective identifiers of reflections of the downlink reference signals that reach the UE (110) or reflections of the uplink sounding signals that reach the base station (120), the base station selects a phase vector for the APD to enable or improve communication between the base station (120) and the UE (110). The base station (120) then configures the APD (180) to use the selected phase vector for reflecting downlink communications or uplink communications between the base station (120) and the UE (110).

Description

PHASE VECTOR TRAINING FOR ADAPTIVE PHASE-CHANGING DEVICE-ENABLED COMMUNICATION

BACKGROUND

[0001] Evolving wireless communication systems, such as fifth generation (5G) technologies and sixth generation (6G) technologies, use various techniques to increase data capacity relative to preceding wireless networks. As one example, 5G technologies transmit data using higher frequency ranges, such as in an above-6 gigahertz (GHz) band.

[0002] The higher frequency ranges for 5G wireless systems provide bandwidth to support increased data rates for New Radio communications between 5G base stations and user equipment of a wireless network. While these techniques are capable of increasing data rates, transmitting and recovering information using these higher frequency ranges also poses challenges. The higher frequency signals are more susceptible to obstructions, atmospheric conditions, multipath fading, and other types of path loss, which lead to recovery errors, reduced throughput, or wireless link degradation at a receiver. To provide a reliable and flexible data link at higher frequencies, it becomes desirable to compensate for or avoid signal distortions throughout the wireless channel to obtain the performance benefits, such as increased data capacity, provided by these approaches.

SUMMARY

[0003] This document describes techniques and apparatuses that enable phase vector training for adaptive phase-changing device-enabled communication between entities of a wireless network. In aspects, a base station configures an adaptive phase-changing device (APD) with a beam sweeping pattern of multiple phase vectors. The base station then directs the APD to implement the phase sweeping pattern in coordination with the base station transmitting downlink reference signals or a user equipment (UE) transmitting uplink sounding signals through a wireless channel that includes the APD. Based on respective identifiers of reflections of the downlink reference signals that reach the UE or reflections of the uplink sounding signals that reach the base station, the base station selects a phase vector for the APD to enable or improve communication between the base station and the UE (e.g., in an above-6 GHz band). The base station can then configure the APD to use the selected phase vector for reflecting downlink communications or uplink communications between the base station and the UE.

[0004] In various aspects, a base station implements a method for phase vector training for adaptive phase-changing device-enabled communication that includes configuring an APD with a phase sweeping pattern of multiple phase vectors and configuring a UE to implement an uplink sounding process through a wireless channel that includes the APD. The base station directs the APD to implement the phase sweeping pattern while the UE transmits uplink sounding signals that correspond to the uplink sounding process. The method includes receiving, from the APD and based on the phase sweeping pattern, reflections of at least one of the uplink sounding signals transmitted by the UE. Each of the reflections may have a respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern. In aspects, the base station demodulates the reflections of the at least one uplink sounding signal to obtain the respective identifiers. Based on the respective identifiers of the reflections of the at least one uplink sounding signal, the base station selects a phase vector for the APD and configures the APD to use the selected phase vector for reflecting subsequent communications between the base station and the UE. Alternatively or additionally, the base station may select a beam configuration for antennas of the base station to receive reflections of uplink communications and/or select a phase steering vector for the UE to transmit uplink communications to the base station. By so doing, the base station may enable or improve APD-enabled communications between the base station and the UE.

[0005] The details of one or more implementations of phase vector training for APD- enabled communication between a base station and user equipment are set forth in the accompanying drawings and the following description. Other features and advantages will be apparent from the description and drawings, and from the appended claims. This summary introduces subject matter that is further described in the Detailed Description and Drawings. Accordingly, this summary should not be considered to describe essential features nor used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The details of one or more aspects of phase vector training for adaptive phase changing device-enabled communication are described with reference to the following drawings. The same numbers are used throughout the drawings to reference like features and components:

FIG. 1 illustrates an example operating environment in which various aspects of phase vector training for adaptive phase-changing device-enabled (APD-enabled) communication can be implemented;

FIG. 2 illustrates an example device diagram of entities that can implement various aspects of phase vector training for APD-enabled communication;

FIG. 3 illustrates an example device diagram of an APD that can be used to implement phase vector training for a communication channel that includes the APD;

FIG. 4 illustrates an example of a base station configuring an APD in accordance with various aspects; FIG. 5 illustrates an example of a base station using an APD to communicate with a user equipment in accordance with one or more aspects;

FIGs. 6A and 6B illustrate examples of using an APD to reflect uplink signals for phase vector training in accordance with one or more aspects;

FIGs. 7A and 7B illustrate examples of modulating uplink signals with beam identifiers or reflection identifiers in accordance with one or more aspects;

FIG. 8 illustrates an example of a base station using an APD to beam sweep reflections of uplink signals in accordance with various aspects;

FIG. 9 illustrates an example of a base station configuring antenna panels to receive a reflection of an uplink signal and a direct uplink signal in accordance with one or more aspects;

FIG. 10 illustrates an example of using an APD to reflect downlink signals for phase vector training in accordance with one or more aspects;

FIGs. 11 A and 11B illustrate examples of modulating downlink signal with beam identifiers or reflection identifiers in accordance with one or more aspects;

FIG. 12 illustrates an example of a base station using an APD to beam sweep reflections of downlink signals in accordance with various aspects;

FIG. 13 illustrates example details of signaling and control transactions for configuring and using an APD for phase vector training with uplink signals in accordance with one or more aspects;

FIG. 14 illustrates example details of signaling and control transactions for configuring and using an APD to beam sweep reflected uplink beams in accordance with one or more aspects;

FIG. 15 illustrates example details of signaling and control transactions for configuring and using an APD for phase vector training with downlink signals in accordance with one or more aspects;

FIG. 16 illustrates an example method for phase vector training based on uplink signals reflected by an APD in accordance with one or more aspects;

FIG. 17 illustrates an example method for directing an APD to beam sweep reflections of uplink beams in accordance with one or more aspects; and

FIG. 18 illustrates an example method for phase vector training based on downlink signals reflected by an APD in accordance with one or more aspects. DETAILED DESCRIPTION

[0007] Evolving wireless communication systems use various techniques to determine information relating to a wireless channel between a base station and user equipment of a wireless network, which can be leveraged to improve communications with the user equipment. While signals transmitted in low-frequency bands (e.g., sub-6 GHz) may enable non-line-of-sight (non- LoS) communication between base stations of the wireless network and the user equipment, the non-LoS signals are susceptible to multipath and other types of fading due to structures, obstructions, or other line-of-sight (LoS) impairments between the base station and the user equipment. Additionally, channel information determined using these low-frequency signals may not accurately indicate how conditions of the wireless channel will affect communications between a base station and user equipment at higher frequencies (e.g., 6 GHz and above). Thus, the techniques implemented by pre-existing network technologies to determine channel information for managing communications between base stations and user equipment are often inaccurate and not useful to configure transceivers for communicating through newer approaches enabled by fifth generation (5G) technologies or sixth generation (6G) technologies.

[0008] This disclosure describes improvements in channel characterization processes and phase vector training for adaptive phase-changing device-enabled communication, which may be used with adaptive phase-changing devices implemented in fifth generation new radio (5G NR) and future wireless networks. To improve wireless network system performance and deliver larger quantities of user data, evolving wireless communication systems (e.g., 5G, 6G) can transmit at higher frequencies (e.g., millimeter wave range), sometimes through LoS communication between user equipment and a base station of the next generation wireless network systems. While this high-frequency LoS communication enables higher data rates and lower latencies, obstructions within or near the LoS communication path (e.g., buildings, utility poles, atmospheric conditions, or foliage) may block or absorb the high-frequency signals; or the user equipment may not always have a LoS communication channel with a base station. As an example, mmWave signals have high throughput and low latency under LoS conditions but a user equipment (e.g., a non-stationary user equipment) may not have consistent, unobstructed LoS conditions with any current base station or handover target base station.

[0009] As described herein, adaptive phase-changing devices (APDs) can be used to address these or other issues by reflecting radio frequency (RF) waves or signal rays in a controlled manner to enhance wireless communications. In aspects, APDs can be configured to reflect wireless signals communicated between a base station and a user equipment that may not have a direct LoS communication channel to provide an additional communication path for control and data signals. Thus, an APD enables a base station to communicate high-frequency signals with the user equipment using respective reflections of downlink signals or uplink signals that can be steered toward a receiver around obstructions or through different angles. In the context of phase vector training, a base station may need to properly train phase adjustment of an APD to enable the base station to configure the phase vectors of the APD for reflecting uplink signals or downlink signals between the base station and a UE. Without such phase training or with sub-optimal phase vector selection at an APD, APD-enabled communication links between the base station and UE may fail (e.g., connection drop/link loss) or suffer degraded communication (e.g., reduced throughput, dropped packets, low data rates, increased latency, etc.). As such, to implement phase training, the base station may align phase vectors of the APD with sounding signals sent at the UE on the uplink or with reference signals sent by the base station on the downlink.

[0010] In various aspects of phase training for APD-enabled communication, the base station may bind or associate phase sweeping of the APD with an uplink sounding process or a downlink channel state information (CSI) process to coordinate the phase vectors of the APD with transmission of uplink sounding signals by the UE or downlink reference signals by the base station. By so doing, the base station can use the APD to provide reflections of the uplink sounding signals that reach the base station or provide reflections of the downlink reference signals that reach the UE. Based on respective identifiers and/or signal quality parameters of the reflections that the UE or base station receive, the base station can select a phase vector for the APD to reflect subsequent communications between the base station and the UE. Alternatively or additionally, the base station may select a phase steering vector for the base station to use for downlink communications to the UE, a phase steering vector for the UE to use for uplink communications to the base station, or receive beam configurations for the base station to use for receiving reflected or direct uplink communications from the UE. These are but a few example aspects of phase vector training for adaptive phase-changing device-enabled communication, others of which are described throughout this disclosure.

[0011] In aspects of phase vector training for APD-enabled communication, a base station configures an APD with a beam sweeping pattern of multiple phase vectors. The base station then directs the APD to implement the phase sweeping pattern in coordination with the base station transmitting reference signals on the downlink or a UE transmitting sounding signals on the uplink. Based on respective identifiers of reflections of the downlink reference signals that reach the UE or reflections of the uplink sounding signals that reach the base station, the base station selects a phase vector for the APD to enable or improve communication between the base station and the UE. The base station can then configure the APD to use the selected phase vector for reflecting downlink communications to the UE or for reflecting uplink communications to the base station. [0012] For example, a method implemented by a base station for phase vector training includes configuring an APD with a phase sweeping pattern of multiple phase vectors and configuring a UE to implement an uplink sounding process through a wireless channel that includes the APD. The base station directs the APD to implement the phase sweeping pattern while the UE transmits uplink sounding signals that correspond to the uplink sounding process. The method includes the base station receiving, from the APD and based on the phase sweeping pattern, reflections of at least one of the uplink sounding signals transmitted by the UE. Each of the reflections may have a respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern. In some cases, the base station also measures signal quality parameters of the reflections of the uplink sounding signals. The base station selects a phase vector for the APD based on the respective identifiers and/or signal quality parameters of the reflections of the at least one uplink sounding signal and configures the APD to use the selected phase vector for reflecting communications between the base station and the UE. Alternatively or additionally, the base station may select a beam configuration for antennas of the base station to receive reflections of uplink communications or select a phase steering vector for the UE to transmit uplink communications. By so doing, the base station may enable or improve APD- enabled communications between the base station and the UE.

[0013] While features and concepts of the described systems and methods for phase vector training for adaptive phase-changing device-enabled communication can be implemented in any number of different environments, systems, devices, and/or various configurations, various aspects of phase vector training for adaptive phase-changing device-enabled communication are described in the context of the following example environments, devices, systems, and configurations.

Example Environment

[0014] FIG. 1 illustrates an example environment 100, which includes a user equipment 110 (UE 110) that can communicate with base stations 120 (illustrated as base stations 121 and 122) through one or more wireless communication links 130 (wireless link 130), illustrated as wireless links 131 and 132. To illustrate, the UE 110 communicates with the base station 121 and base station 122 contemporaneously using the wireless links 131 and 132, respectively. Alternatively or additionally, the wireless links 130 include a wireless link 133 between at least one of the base stations 120 (e.g., base station 121) and an adaptive phase-changing device 180 (APD 180) to control a surface configuration of the APD 180. In other implementations, the base stations 120 include a wireline interface for communicating control information with the APD 180. For simplicity, the UE 110 is implemented as a smartphone but may be implemented as any suitable computing or electronic device, such as a mobile communication device, modem, cellular phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, smart appliance, vehicle-based communication system, or an Intemet-of-Things (IoT) device, such as a sensor, relay, or actuator. The base stations 120 (e.g., an Evolved Universal Terrestrial Radio Access Network Node B, E-UTRAN Node B, evolved Node B, eNodeB, eNB, Next Generation Node B, gNode B, gNB, ng-eNB, or the like) may be implemented in a macrocell, microcell, small cell, picocell, distributed base stations, or the like, or any combination thereof.

[0015] One or more base stations 120 communicate with the user equipment 110 using the wireless links 131 and 132, which may be implemented as any suitable type of wireless link and can include multiple links (e.g., a sub-6 gigahertz (GHz) low-band link (anchor link), an above-6 GHz high-band link). The wireless links 131 and 132 include control-plane information and/or user-plane data, such as downlink user-plane data and control-plane information communicated from the base stations 120 to the user equipment 110, uplink user-plane data and control-plane information communicated from the user equipment 110 to the base stations 120, or both. The wireless links 130 may include one or more wireless links (e.g., radio links) or bearers implemented using any suitable communication protocol, communication standard, or combination of communication protocols or standards, such as 3rd Generation Partnership Project Long-Term Evolution (3GPP LTE), fifth generation New Radio (5GNR), sixth generation (6G), and so forth. Multiple wireless links 130 may be aggregated in a carrier aggregation or multi connectivity technology to provide a higher data rate for the UE 110. Multiple wireless links 130 from multiple base stations 120 may be configured for Coordinated Multipoint (CoMP) or dual connectivity (DC) communication with the UE 110.

[0016] In some implementations, the wireless links (e.g., wireless link 131 and/or wireless link 132) utilize wireless signals, where an intermediate device (e.g., APD 180) reflects or transforms ray(s) of the wireless signals. To illustrate, signal ray 190 and signal ray 191 correspond to rays of a wireless signal used to implement the wireless link 131. In the environment 100, the signal rays 190 and 191 correspond to rays of a downlink wireless signal from the base station 121 to the UE 110, but the rays can alternatively or additionally correspond to an uplink wireless signal from the UE 110 to the base station 121. As part of communicating with the UE 110 through wireless link 131, the base station 121 beamforms a downlink wireless signal intended for the UE 110. A first ray of the downlink wireless signal (e.g. , signal ray 190) propagates toward the UE 110 in a line-of-sight (LoS) manner and a second ray of the downlink wireless signal (e.g., signal ray 191) propagates toward the APD 180. The signal ray 191 strikes the surface of the APD 180 and transforms into signal ray 192 (e.g., a reflection of wireless signal 191) that propagates toward the UE 110. In aspects, the signal ray 191 strikes the surface of a reconfigurable intelligent surface (RIS) of the APD 180, which steers its reflected signal ray 192 toward the UE 110. Note, that the LoS signal ray 190 may be dynamically blocked or attenuated by foliage, human bodies, atmospheric conditions (e.g., water vapor), or other materials (not shown). Although illustrated as stationary entities, a base station 120 or an APD 180 may also include non-stationary or non terrestrial implementations, examples of which include satellite-based base stations, vehicle-based base stations, aerial-drone APDs, or the like.

[0017] Generally, the base station 121 configures an RIS of the APD 180 to direct how the RIS alters signal properties (e.g., direction, phase, amplitude, polarization) of a wireless signal. In aspects, the base station 121 communicates RIS surface-configuration information to the APD 180 using the wireless link 133, which may include an adaptive phase-changing device slow- control channel (APD-slow-control channel) or an adaptive phase-changing device fast-control channel (APD-fast-control channel). In various implementations of phase vector training for APD-enabled communication, the base station 121 determines a surface configuration for the APD 180 to reflect downlink communications or uplink communications between the base stations 120 and the UE 110. Alternatively or additionally, the base station 121 determines a configuration for the APD 180 based on identifiers and/or signal quality of reflections of wireless signals received by the UE 110 on the downlink (e.g. , UE reported information) or the base station 121 on the uplink (e.g., information determined by the base station 121). The base station 121 may also communicate time information to the APD 180 that indicates when to apply the surface configuration to the RIS, such as a time slot, a start time, a time-duration, periodic time information (e.g., for applying the surface configuration periodically), or dynamic time information (e.g., for applying the surface configuration once). As described herein, the base station 121 may configure an APD 180 with multiple surface configurations and timing information to direct the APD 180 to implement a phase sweeping pattern of reflections synchronized with an incident uplink or downlink signal. In some cases, the base station 121 communicates direction information (e.g., a UE-to-BS communication direction or a BS-to-UE communication direction) with the surface configuration such that the APD 180 configures the RIS to reflect a wireless signal in the indicated direction (e.g., by determining or using reciprocal reflection angles). The base station 121 can also determine surface configuration(s) for the APD 180 based on signal-quality measurements, link-quality measurements, location information, historical records, beam-sweeping procedures, and so forth.

[0018] The base stations 120 of FIG. 1 collectively form part of a Radio Access Network 140 (e.g., RAN, Evolved Universal Terrestrial Radio Access Network, E-UTRAN, 5GNR RAN or NR RAN). The base stations 121 and 122 in the RAN 140 are connected to a core network 150. The base stations 121 and 122 connect, at 102 and 104 respectively, to the core network 150 through an NG2 interface for control-plane signaling and using an NG3 interface for user-plane data communications when connecting to a 5G core network, or using an SI interface for control- plane signaling and user-plane data communications when connecting to an Evolved Packet Core (EPC) network. The base stations 121 and 122 can communicate using an Xn Application Protocol (XnAP) through an Xn interface or using an X2 Application Protocol (X2AP) through an X2 interface, at 106, to exchange user-plane and control -plane data. The user equipment 110 may connect, via the core network 150, to public networks (e.g., the Internet) to interact with a remote service (not shown).

Example Devices

[0019] FIG. 2 illustrates an example device diagram 200 of the user equipment 110 and base stations 120. Generally, the device diagram 200 describes network entities that can implement various aspects of phase vector training for adaptive phase-changing device-enabled communication. FIG. 2 shows respective instances of the UE 110 and the base stations 120. The UE 110 or the base stations 120 may include additional functions and interfaces that are omitted from FIG. 2 for the sake visual brevity. The UE 110 includes antennas 202, a radio frequency front end 204 (RF front end 204), and one or more wireless transceivers 206 (e.g., radio frequency transceivers), such as any combination of an LTE transceiver, a 5GNR transceiver, and/or a 6G transceiver for communicating with base stations 120 in the RAN 140. In aspects, an antenna 202 (e.g., antenna array), RF front end 204, and a wireless transceiver 206 may be implemented as a radio module of the UE 110. For example, the UE 110 may include one or more radio modules (e.g., 5G NR or mmWave modules) capable of implementing respective transmit and/or receive functionalities. The RF front end 204 of the UE 110 can couple or connect the wireless transceivers 206 to the antennas 202 to facilitate various types of wireless communication.

[0020] The antennas 202 of the UE 110 may include an array of multiple antennas that are configured in a manner similar to or different from each other. The antennas 202 and the RF front end 204 can be tuned to, and/or be tunable to, one or more frequency bands defined by various communication standards (e.g., 3GPP LTE, 5G NR, 6G) and implemented by the wireless transceivers 206. Additionally, the antennas 202, the RF front end 204, and/or the wireless transceiver(s) 206 may be configured to support beam-sweeping for the transmission and reception of communications with the base stations 120. By way of example and not limitation, the antennas 202 and the RF front end 204 can be implemented for operation in sub-gigahertz bands, sub-6 GHz bands, and/or above-6 GHz bands that are defined by the 3GPP LTE, 5GNR, or 6G communication standards (e.g., 57-64 GHz, 28 GHz, 38 GHz, 71 GHz, 81 GHz, or 92 GHz bands). [0021] The UE 110 also includes processor(s) 208 and computer-readable storage media 210 (CRM 210). The processor 208 may be a single-core processor or a multiple-core processor implemented with a homogenous or heterogeneous core structure. The computer-readable storage media described herein excludes propagating signals. CRM 210 may include any suitable memory or storage device such as random-access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or Flash memory useable to store device data 212 of the UE 110. The device data 212 includes any combination of user data, multimedia data, applications, and/or an operating system of the UE 110. In implementations, the device data 212 stores processor-executable instructions that are executable by the processor(s) 208 to enable the UE 110 to communicate user-plane data and/or control-plane information, as well as enable various user interactions (e.g., an application or user interface).

[0022] In this example, the CRM 210 of the UE 110 also includes a user equipment adaptive phase-changing device manager 214 (UE APD manager 214) for managing APD usage in an access link with the base station 120. The UE APD manager 214 may be implemented in whole or in part as hardware logic or circuitry integrated with or separate from other components (e.g., wireless transceivers 206) of the UE 110. In aspects, the UE APD manager 214 receives APD-access information for using a surface of an APD, such as reflection-access information that indicates time information on when to use the APD surface and/or configurable surface element information that indicates portions of the APD surface available to the UE 110. In aspects, the UE APD manager 214 of the UE 110 decodes reflection or beam identifiers (e.g., a CSI reference signal (CSI-RS) resource or a synchronization signal block (SSB) index), analyzes link quality parameters, and generates various APD or channel feedback messages for a base station 120. The UE APD manager 214 may also maintain a low-band connection (e.g., anchor connection) with a base station 120 over a low-frequency band (e.g., sub-6 GHz) to provide signal reflection or beam information for high-frequency signals (e.g., above-6 GHz) used to implement aspects of phase vector training for APD-enabled communication. The UE 110 may also receive beam sweeping information or phase steering configurations from the base station 120 over the low-band connection. As such, the UE 110 may implement carrier aggregation (CA) to communicate in two frequency bands when communicating with the base station 120 to implement aspects of phase vector training for APD-enabled communication. Alternatively or additionally, the UE APD manager 214 directs the UE 110 to transmit communications (e.g., uplink sounding signals) to the base station 120 through APD-enabled communication channels (e.g., based on the APD- access information) or through non- APD communication paths (e.g., direct UE-base station communication). [0023] The device diagram for the base station 120, shown in FIG. 2, includes a single network node (e.g., a gNode B). The functionality of the base station 120 may be distributed across multiple network nodes or devices and may be distributed in any fashion suitable to perform the functions described herein. The nomenclature for this distributed base station functionality varies and includes terms such as Central Unit (CU), Distributed Unit (DU), Baseband Unit (BBU), Remote Radio Head (RRH), and/or Remote Radio Unit (RRU). The base station 120 includes antennas 252, a radio-frequency front end 254 (RF front end 254), one or more wireless transceiver(s) 256 (e.g., LTE transceivers, 5G NR transceivers, and/or 6G transceivers) for communicating with the UE 110, other UEs (not shown), and/or another base station 120.

[0024] The RF front end 254 of the base station 120 can couple or connect the wireless transceivers 256 (e.g., radio frequency transceivers) to the antennas 252 to facilitate various types of wireless communication. The antennas 252 of the base station 120 may include an array of multiple antennas (e.g., antenna panels or antenna elements) that are configured in a manner similar to or different from each other. The antennas 252 and the RF front end 254 can be tuned to, and/or be tunable to, one or more frequency bands defined by communication standards (e.g., 3GPP LTE, 5G NR, and/or 6G) and implemented by the wireless transceivers 256. Additionally, the antennas 252, the RF front end 254, and/or the wireless transceivers 256 may be configured to support beamforming, such as Massive-MIMO, for the transmission and reception of communications with the UE 110, other UEs, and/or another base station 120.

[0025] The base station 120 also includes processor(s) 258 and computer-readable storage media 260 (CRM 260). The processor 258 may be a single-core processor or a multiple-core processor composed of a variety of materials, such as silicon, polysilicon, high-K dielectric, copper, and so on. The CRM 260 may include any suitable memory or storage device such as RAM, SRAM, DRAM, NVRAM, ROM, or Flash memory useable to store device data 262 of the base stations 120. The device data 262 includes network-scheduling data, radio resource- management data, applications, and/or an operating system of the base station 120, which are executable by processor(s) 258 to enable communication with another base station 120, core network entities, and/or the UE 110. The device data 262 also includes codebooks 264 and APD information 266 for APDs 180 associated with the base station 120. The codebooks 264 may include any suitable type or combination of codebooks, including surface-configuration codebooks that store surface-configuration information for a RIS of an APD and beam-sweeping codebooks that store patterns, sequences, or timing information for implementing multiple surface-configurations useful to direct an APD to perform a variety of reflective beamforming. In some aspects, the surface-configuration codebooks and beam-sweeping codebooks include phase- vector information, angular information (e.g., calibrated to respective phase vectors), and/or beam-configuration information. The APD information 266 can include respective identifiers, capabilities, command and control information, locations, orientations (e.g., static or last known) for the APDs 180 with which the base station 120 communicates. The base station 120 may generate or revise the APD information 266 to add new APDs 180 that are detected, update information of known APDs 180, or delete existing ADPs 180 that are deprecated.

[0026] In aspects, the CRM 260 includes a phase vector function 268 (PVF 268) that manages or implements aspects of phase vector training for APD-enabled communication. Alternatively or additionally, the PVF 268 may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the base station 120. Generally, the PVF 268 may characterize one or more wireless communication paths (e.g., communication channels) between a base station and a UE, and select a phase vector for an APD, a phase steering vector for the base station, or a phase steering vector for the UE based on the respective channel characterizations. In aspects, the PVF 268 of the base station 120 manages usage of the APDs 180 to direct or steer reflections of wireless signals (e.g., signal ray or beams) to the base station on the uplink or to the UE on the downlink. To manage the usage of the APDs 180 associated with the base station 120, the PVF 268 can identify an APD 180 near a UE 110, determine surface configurations for the APD 180 (e.g., RIS configurations), or select beam sweeping directions or pattens for the APD 180 or the UE 110. By so doing, the PVF 268 can direct the APD to reflect downlink wireless signals for reception by the UE 110 (e.g., BS-originated reference signals) or reflect uplink wireless signals for reception by the base station 120 (e.g., UE-originated sounding signals). Based on an analysis of identifiers and/or signal quality parameters for reflections of the wireless signals that reach the UE 110 or the base station 120, the PVF 268 can determine which surface configurations (e.g., phase vectors) are associated with those received reflections.

[0027] The surface configurations of the APD 180 may be calibrated or predetermined to correspond to respective angles of reflection, which the PVF 268 uses determine directional information (e.g., angular information) for the respective reflections of wireless signals that reach the UE 110 or the base station 120. Alternatively or additionally, the PVF 268 can use the signal quality parameters, such as reference signal received power (RSRP) of the reflections, in the determination of which combination of UL beam and APD phase vector or DL beam and APD phase vector provide reflections that reach the UE 110 or base station 120. Using the directional information and other channel information, the PVF 268 can select a phase vector for the APD to enable or improve communication between the base station 120 and the UE 110. Alternatively or additionally, the PVF 268 can select a phase steering vector for the base station to transmit downlink communications, select beam configurations for the base station to receive uplink communications (e.g., direct or APD-reflected uplinks), or select a phase steering vector for the UE to transmit uplink communications. In aspects, the PVF 268 may implement iterations of channel soundings and phase vector selections from omnidirectional or broad beam transmissions and APD-reflections to narrow beam transmissions and APD-reflections that the UE 110 and base station 120 use to communicate. These are but a few examples of phase vector training that the PVF 268 or base station 120 can implement, others of which are described throughout this disclosure.

[0028] The CRM 260 also includes a base station manager 270 for managing various functionalities and communication interfaces of the base stations 120. Alternatively or additionally, the base station manager 270 may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the base stations 120. In at least some aspects, the base station manager 270 configures the antennas 252, RF front end 254, and wireless transceiver(s) 256 for communication with the UE 110, the APDs 180, and/or communication with a core network. The base stations 120 include an inter-base station interface 272, such as an Xn and/or X2 interface, which the base station manager 270 configures to exchange user-plane data and control -plane information between another base station 120, to manage the communication of the base stations 120 with the UE 110. The base stations 120 also include a core network interface (not shown) that the base station manager 270 configures to exchange user-plane data and control-plane information with core network functions and/or entities.

[0029] FIG. 3 illustrates an example device diagram 300 of the APD 180. Generally, the device diagram 300 describes an example entity with which various aspects of phase vector training for APD-enabled communication can be implemented but may include additional functions and interfaces that are omitted from FIG. 3 for the sake of visual brevity. The adaptive phase-changing device (APD) 180 is an apparatus that includes a Reconfigurable Intelligent Surface (RIS) 322, and components for controlling the RIS 322 (e.g., by applying a surface configuration of the RIS), as further described below. In some implementations, the APD 180 may also include components for modifying the position of the APD 180 itself, which in turn modifies the position of the RIS 322. The APD 180 includes one or more antenna(s) 302, a radio frequency front end 304 (RF front end 304), and one or more radio-frequency transceivers 306 (e.g. , radio-frequency transceivers, LTE transceivers, 5G NR transceivers, or 6G transceivers) for wirelessly communicating with the base station 120 and/or the UE 110. The APD 180 can also include a position sensor, such as a Global Navigation Satellite System (GNSS) module, that provides position information based on a location of the APD 180.

[0030] The antenna(s) 302 of the APD 180 may include an array of multiple antennas that are configured in a manner similar to or different from each other. Additionally, the antennas 302, the RF front end 304, and the transceiver(s) 306 may be configured to support beamforming for the transmission and reception of communications with the base station 120 and/or UE 110. By way of example and not limitation, the antennas 302 and the RF front end 304 can be implemented for operation in sub-gigahertz bands, sub-6 GHz bands, and/or above-6 GHz bands. Thus, the antenna 302, the RF front end 304, and the transceiver(s) 306 provide the APD 180 with an ability to receive and/or transmit communications with the base station 120 and/or the UE 110, such as information transmitted using APD-control-channels (e.g., an APD-slow-control channel or APD- fast-control channel) as further described.

[0031] The APD 180 includes processor(s) 310 and computer-readable storage media 312

(CRM 312). The processor 310 may be a single core processor or a multiple-core processor implemented with a homogenous or heterogeneous core structure. The computer-readable storage media described herein excludes propagating signals. The CRM 312 of the APD 180 may include any suitable memory or storage device such as RAM, SRAM, DRAM, NVRAM, ROM, or Flash memory useable to store device data 314 of the APD 180. The device data 314 includes configuration data, RIS information, applications, and/or an operating system of the APD 180, which are executable by processor(s) 310 to enable dynamic configuration of the APD 180 as further described. The device data 314 also includes one or more codebooks 316 of any suitable type or combination, and position information 318 of the APD 180. The position information 318 may be obtained or configured using the position sensor 308 or programmed into the APD 180, such as during installation. The position information 318 indicates a position of the APD 180 and may include a location, geographic coordinates, orientation, elevation information, or the like. A base station 120, PVF 268, and/or UE 110 can use the position information 318 in computing angular or distance information, such as between the base station 120 and APD 180 and/or between the APD 180 and a UE 110 of interest. The codebooks 316 can include surface- configuration codebooks that store surface-configuration information for a RIS of an APD and beam sweeping codebooks that store patterns, sequences, or timing information (e.g., phase vectors and reflection identifiers) for implementing multiple surface configurations useful to direct an APD to perform a variety of reflective beamforming. In some aspects, the surface- configuration codebooks and beam sweeping codebooks include phase vector information, angular information (e.g., calibrated to respective phase vectors), identifier information, and/or beam configuration information.

[0032] In aspects of phase vector training for APD-enabled communication, the CRM 312 of the APD 180 includes an adaptive phase-changing device manager 320 (APD manager 320). Alternatively or additionally, the APD manager 320 may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the APD 180. Generally, the APD manager 320 manages a surface configuration of the APD 180, such as by processing information exchanged with a base station over wireless link(s) 133, then using the information to configure a reconfigurable intelligent surface 322 (RIS 322) of the APD 180. To illustrate, the APD manager 320 receives an indication of a surface configuration over the wireless links 133 (an APD control channel), extracts the surface configuration from the codebooks 316 using the indication, and applies the surface configuration to the RIS 322. Alternatively or additionally, the APD manager 320 initiates the transmission of uplink messages to the base station over the wireless links 133, such as acknowledgments/negative acknowledgments (ACKs/NACKs) for various APD configuration or management commands. In some aspects, the APD manager 320 receives an indication of a beam sweeping pattern ( e.g . , beam sweeping pattern index) over the wireless links 133, and applies a sequence of various surface configurations to the RIS based on the beam sweeping pattern and/or in accordance with a synchronization or pattern timing indicated by or received with the indication. Optionally, the beam sweeping pattern may include reflection identifier information by which the APD 180 modulates or applies (e.g., using the RIS) one or more reflection identifiers to a downlink reference signal or uplink sounding signal reflected by the APD 180.

[0033] In some aspects, the APD manager 320 receives timing information with the surface configuration communication, where the timing information indicates when to apply the surface configuration to the RIS 322 (e.g, start time, time duration, periodic time information, dynamic time information). Alternatively or additionally, the APD manager 320 receives direction information with the surface configuration that indicates to configure the surface to reflect signals of the RIS 322 based on the direction information. For example, when the direction information indicates a BS-to-UE communication direction, the APD manager 320 selects a first surface configuration with a first reflection angle that reflects wireless signals from the base station 120 to the UE 110. When the direction indicates a UE-to-BS communication direction, the APD 320 selects a second surface configuration with a second, reciprocal reflection angle that reflects wireless signals from the UE 110 to the base station 120.

[0034] The RIS 322 of the APD 180 includes one or more configurable surface element(s) 324, such as configurable electromagnetic elements, configurable resonator elements, or configurable reflectarray antenna elements. Generally, the configurable surface elements 324 can be selectively or programmatically configured to control how the RIS 322 reflects (e.g, directionality) and/or transforms incident waveforms. By way of example and not of limitation, configurable electromagnetic elements include scattering particles that are connected electronically (e.g, through PIN diodes). Implementations use the electronic connection to arrange the scattering particles, such as based on principles of reflection, to control a directionality, phase, amplitude, and/or polarization of the transformed waveform (from the incident waveform). The RIS 322 can include array(s) of independently configurable surface element(s) 324, where an array can include any number of elements having any size.

[0035] In some aspects, a position and/or orientation of the APD 180 is configurable and the APD 180 includes a motor controller 326 communicating with one or more motor(s) 328 that are operably coupled with a physical chassis of the APD 180. Based on command-and-control information, such as received from a base station 120, the motor controller 326 can send commands to the motors 328 that alter one or more kinematic behaviors of the motors 328, which may include any suitable type of stepper motor or servo. For example, the motor controller 326 may issue commands or control signals that specify a shaft rotation of a stepper motor in degrees, a shaft rotation rate of a stepper motor in revolutions per minute (RPM), a linear movement of a linear motor millimeters (mm), a linear velocity of a linear motor in meters/second (m/s)). The one or more motors 328, in turn, may be linked to mechanisms that mechanically position the physical chassis or a platform (e.g., avionics of a drone, a drive of a linear rail system, a gimble within a base station, a linear bearing within a base station) supporting the APD 180. Through the commands and signals that the motor controller 326 generates and sends sent to the motors 328, a physical position, location, or orientation of the APD 180 (and/or the platform supporting the APD 180) may be altered. In response to receiving a position configuration from a base station, the APD manager 320 communicates movement commands to the motor controller 326, such as through a software interface and/or hardware addresses, based on the position configuration. In aspects of phase vector training for APD-enabled communication, a base station 120 may reposition or reorient one or more APDs 180 to improve or enable the reflection of wireless signals (e.g., uplink and/or downlink signals) between the base station 120 and the UE 110

[0036] Generally, the APD 180 can include multiple motors, where each motor corresponds to a different rotational or linear direction of movement. Examples of motor(s) 328 that can be used to control orientation and location of the APD include linear servo motors that might be part of a (i) rail system mounting for the APD, (ii) motors controlling a direction and pitch, yaw, roll of a drone carrying the APD, (iii) radial servo or stepper motors that rotate an axis if the APD is in a fixed position or on a gimbal, and so on. For clarity, the motor controller 326 and the motors 328 are illustrated as being a part of the APD 180, but in alternative or additional implementations, the APD 180 communicates with motor controllers and/or motors external to the APD. To illustrate, the APD manager 320 communicates a position configuration to a motor controller that mechanically positions a platform or chassis that supports the APD 180. In aspects, the APD manager 320 communicates the position configuration to the motor controller using a local wireless link, such as Bluetooth™, Zigbee, IEEE 802.15.4, or a hardwire link. The motor controller then adjusts the platform based on the position configuration using one or more motors. The platform can correspond to, or be attached to, any suitable mechanism that supports rotational and/or linear adjustments, such as a drone, an aircraft, a non-stationary ground station (e.g., a vehicle-towable APD tower/module), a rail propulsion system, a hydraulic lift system, and so forth.

[0037] As shown in FIG. 3, a position of the APD 180 may be defined with respect to a three-dimensional coordinate system in which an X-axis 330, Y-axis 332, and Z-axis 334 define a spatial area and provide a framework for indicating a position configuration through rotational and/or linear adjustments. While these axes are generally labeled as the X-axis, Y-axis, and Z- axis, other frameworks can be utilized to indicate the position configuration (e.g., azimuth and elevation). To illustrate, aeronautical frameworks reference the axes as vertical (yaw), lateral (pitch), and longitudinal (roll) axes, while other movement frameworks reference the axes as vertical, sagittal, and frontal axes. As one example, position 336 generally points to a center position of the APD 180 that corresponds to a baseline position (e.g., position (0,0,0) using XYZ coordinates).

[0038] In aspects, the APD manager 320 communicates a rotational adjustment (e.g., rotational adjustments 338) around the X-axis 330 to the motor controller 326, where the rotational adjustment includes a rotational direction (e.g., clockwise or counterclockwise), an amount of rotation (e.g. , degrees), and/or a rotation velocity. Alternatively or additionally, the APD manager 320 communicates a linear adjustment 340 along the X-axis, where the linear adjustment includes any combination of a direction, a velocity, and/or a distance of the adjustment. At times, the APD manager 320 communicates adjustments around the other axes as well, such as any combination of rotational adjustments 342 around the Y-axis 332, linear adjustments 344 along the Y-axis 332, rotational adjustments 346 around the Z-axis 334, and/or linear adjustments 348 along the Z-axis 334. Thus, the position configuration can include combinations of rotational and/or linear adjustments in all three degrees of spatial freedom, in addition to movement supported by a frame or platform (e.g., avionics drone or vehicle) to which an APD is mounted. This allows the APD manager 320 to communicate physical adjustments to the APD 180. Alternatively or additionally, the APD manager communicates RIS surface configurations as further described.

[0039] FIG. 4 illustrates at 400 an example of a base station configuring an adaptive phase changing device in accordance with various aspects. The example 400 includes instances of a base station 120 and an APD 180, which may be implemented similarly as described with reference to FIGs. 1-3. The RIS implemented by the APD 180 includes an array of “N” independently selectable and configurable surface elements, such as configurable surface element 402, configurable surface element 404, configurable surface element 406, and so forth, where “N” represents the number of configurable surface elements of the RIS.

[0040] In implementations, the base station 120 manages a configuration of the RIS of the APD 180 through use of a surface-configuration codebook 408, which can be preconfigured and/or known by both the base station 120 and the APD 180. Alternatively or additionally, the base station 120 may also manage a time-varying configuration of the RIS of the APD 180 through use of a beam sweeping codebook, such as described with reference to FIGs. 6A-18. In some cases, the base station 120 transmits a surface-configuration codebook 408 and/or a beam sweeping codebook using the wireless link 133, such as over an APD-slow-control channel using one or more messages. In aspects, the base station 120 uses the APD-slow-control channel to communicate large quantities of data, to communicate data without low-latency requirements, and/or to communicate data without timing requirements. At times, the base station 120 transmits multiple surface-configuration codebooks to the APD 180, such as a first surface-configuration codebook for downlink communications, a second surface-configuration codebook for uplink communications, a phase vector codebook, a beam sweeping codebook, or the like. In response, the APD 180 stores the surface-configuration codebook(s) 408 and/or other codebooks in CRM, which is representative of codebook(s) 316 in CRM 312 as described with reference to FIG. 3. Alternatively or additionally, the APD 180 obtains the surface-configuration and other codebooks through manufacturing (e.g., programming), calibration, or installation processes that store the surface-configuration codebook(s) 408 and other codebooks in the CRM 312 of the APD 180 during assembly, installation, calibration, verification, network association, or through an operator manually adding or updating the codebook(s).

[0041] The surface-configuration codebook 408 includes configuration information that specifies a surface configuration for some or all of the configurable surface elements (e.g., elements 324) forming the RIS of the APD 180. As one example, each index of the code book corresponds to a phase vector with configuration information for each configurable surface element of the APD 180. Index 0, for instance, maps phase configuration 0 to configurable surface element 402, phase configuration 1 to configurable surface element 404, phase configuration 2 to configurable surface element 406, and so forth. Similarly, index 1 maps phase configuration 3 to configurable surface element 402, phase configuration 4 to configurable surface element 404, phase configuration 5 to configurable surface element 406, and so forth. The surface- configuration codebook 408 can include any number of phase vectors that specify configurations for any number of configurable surface elements such that a first phase vector corresponds to a first surface configuration for the APD 180 (by way of configurations for each configurable surface element in the RIS), a second phase vector corresponds to a second surface configuration for the APD 180, and so on. Alternatively or additionally, the codebook 508 specifies phase vectors that configure a subset of configurable surface elements. In aspects, one or more surface configurations or phase vectors may be mapped or calibrated to specific angle information of incident and/or reflective wireless signals (e.g., reference signals), signal rays, beamformed transmissions of the base station 120, beamformed transmissions of the UE 110, or the like. In various implementations, the base station 120 may use this angle information corresponding to the surface configuration or phase vector to compute the angular information used for determining a phase vector for the APD 180, a phase steering vector for the base station 120, a receive beam configuration for the base station 120, or a phase steering vector for the UE 110. In aspects, a phase vector may indicate, include, and/or be associated with angular information of incident and/or reflected signal rays or beams that encounter the RIS of the APD 180. For example, a phase vector may include or indicate an angle of reflection of the wireless signal from the APD 180 and/or an angle of incidence at which the wave form of the wireless signal reaches the UE 110. Thus, the base station 120 may select a specific phase vector (e.g., APD RIS/surface configuration) to enable directionally controlled reflections of uplink and/or downlink communications in accordance with one or more aspects. In some cases, the various configurations of the surface of the APD 181 (e.g., RIS 410) may be calibrated such that specific or reference angular information is associated with a surface configuration (e.g. , a respective phase vector), which enables the base station 120 to determine angular information relating to signals transmitted to/at the APD 180, signals reflected by the APD 180, and/or signals reaching/received by the UE 110 or the base station 120.

[0042] While the surface-configuration codebook 408 of FIG. 4 includes phase vector information, alternative or additional codebooks store beam configuration information, such as a first surface configuration that specifies a first beam with a first (propagation) direction, a second surface configuration that specifies a second beam with a second direction, and so on. Thus, in various implementations, the surface-configuration codebook 408 corresponds to a beam- codebook, which the APD 180 may use to implement beamforming of incident wireless signals. Similarly, to configure the surface of the APD 180, the base station 120 determines the desired beam configuration for the transformed signal and identifies an entry in the beam-codebook corresponding to the desired beam configuration. In some aspects, a beam-sweeping codebook indicates a pattern of surface configurations and/or beam configurations, such as surface configurations and/or beam configurations as indicated by the surface-configuration codebook 408 and beam configurations specified by the beam-codebook. To illustrate, the beam-sweeping codebook indicates an order or sequence of surface configurations, timing or periodicity information, and/or APD reflection identifiers to cycle through in order to beam sweep reflections of downlink or uplink signals in a horizontal direction or vertical direction. Alternatively or additionally, the beam-sweeping codebook indicates a time duration or synchronization information (e.g., for an incident wireless signal) for applying each surface configuration effective to provide reflected beams in a specific direction at a specified time (e.g., in synchronization with a downlink reference signal or uplink sounding signal) and/or for the duration of time.

[0043] The surface-configuration information stored in a codebook can correspond to a full configuration that specifies an exact configuration (e.g., configure with this value or phase vector), or a delta configuration that specifies a relative configuration (e.g., modify a current state by this value). In one or more implementations, the phase configuration information specifies a directional increment and/or angular adjustment between an incident signal and a transformed signal. For instance, the phase configuration 0 can specify an angular adjustment configuration for element 402 such that the configurable surface element 402 reflects the incident waveform with a “phase configuration 0” relative angular or directional shift. As shown in FIG. 4, the base station 120 (or a UE 110) communicates an indication to the APD 180 that specifies a surface configuration. In the present example, the indication specifies a surface configuration index 410 (SC index 410) that maps to a corresponding surface configuration of the APD 180. In response to receiving the indication, the APD manager 320 retrieves the surface configuration from the surface-configuration codebook 408 using the index and applies the surface configuration to the RIS. For example, the APD manager 320 configures each configurable surface element 402, 404, and 406 as specified by a respective entry in the surface-configuration codebook 408 or a phase sweeping codebook. Alternatively or additionally, a codebook entry or phase vector may include a data structure (a vector) that contains or indicates a phase shift applied (e.g., an RIS configuration), to an incident signal, by one or more surface elements of the RIS.

[0044] In various implementations, the base station 120 communicates timing information (not shown) to the APD 180, which may be included with a surface configuration or beam sweeping index. For instance, the base station 120 sometimes indicates, to the APD 180 and using the wireless link 133, a start time for the application of an indicated surface configuration or beam sweeping pattern. In aspects, the base station 120 communicates a stop time that indicates when to remove and/or change the surface configuration or beam sweeping pattern. In some cases, timing information for a surface configuration or beam sweeping pattern includes a periodicity at which one or more different surface configurations are applied to one of the configurable surface elements of the APD 180. In changing the surface configuration, the APD 180, by way of the APD manager 320, can apply a default surface configuration, return to a previous surface configuration (e.g., a surface configuration used prior to the indicated surface configuration), and/or apply a new surface configuration to control a direction in which the APD 180 reflects wireless signals. To maintain synchronized timing with the base station 120 or the UE 110 (e.g., for incident wireless signals), the APD 180 can receive and/or process a base station or network- based synchronizing signal (e.g., primary synchronization signal (PSS) or secondary synchronization signal (SSS) of an SSB).

[0045] By specifying the timing information, the base station 120 can synchronize and/or configure the APD 180 for use in a channel sounding process or channel state information (CSI) process with a particular UE (e.g., UE 110) in accordance with various aspects of phase vector training for APD-enabled communication. In some implementations, the base station 120 configures the APD 180 with a beam sweeping pattern and timing information (e.g. , start and stop times for a time slot assigned to the particular UE) that corresponds to a transmission of uplink sounding signals by the particular UE. In aspects, the base station 120 transmits surface- configuration indications and/or timing information using an APD-fast-control channel, which allows the base station 120 to dynamically configure the APD 180 on a slot-by-slot basis. For example, the base station 120 transmits a surface-configuration schedule to the APD that indicates when to apply different surface configurations to the RIS/configurable surface elements. Alternatively or additionally, the base station 120 communicates surface configuration changes on a slot-by-slot basis using signaling on the APD fast-control channel. These allow the base station to configure the APD for multiple UEs, such as in scenarios where different UEs are assigned different time slots or different numerologies, and enable concurrent determination of APD phase vectors or phase steering vectors for multiple UEs, improve data rates, spectral efficiency, data throughput, and reliability for the multiple UEs and the corresponding wireless network.

Phase Vector Training for APD-Enabled Communication

[0046] To facilitate communications at higher frequencies (e.g., at or above-6 GHz), a base station 120 may use an APD 180 to mitigate LoS conditions or LoS obstructions that impair direct communications between the base station 120 and a UE 110. Before communicating through an APD-enabled communication path, the base station 120 may characterize the communication path and train a phase adjustment of the APD 180. To do so, the base station 120 may implement a downlink channel state information (CSI) process or direct the UE 110 to implement an uplink sounding process through a channel or communication path that includes the APD 180. Generally, the base station 120 may associate (e.g., synchronize) respective resources of the uplink sounding process or the downlink CSI process with the implementation of phase vectors by the APD to direct reflections of uplink sounding signals or downlink CSI signals to a receiving entity. By so doing, the base station 120 can select, based on identifiers and/or signal quality parameters of reflections received by the base station or the UE, phase vectors for the APD 180 to use when reflecting subsequent communications between the base station and the UE. Alternatively or additionally, the base station 120 may use information of the channel characterization processes to select a phase steering vector for the base station 120, select a phase steering vector for the UE 110, or select receive beam configurations for antennas of the base station.

[0047] FIGs. 5-12 illustrate various examples of a base station communicating with a UE through the use of an APD in accordance with one or more aspects of phase vector training for APD-enabled communication. The described examples include using an APD to reflect downlink wireless signal rays to a UE or reflect uplink wireless signal rays to a base station (e.g., FIG. 5), using an APD to sweep reflections of uplink sounding signals for reception by a base station (e.g. , FIGs. 6A and 6B), modulating beam identifiers onto uplink sounding signals and reflections of uplink sounding signals to provide reflection identifiers (e.g., FIGs. 7A and 7B), and beam sweeping reflections of uplink sounding signals with an APD (e.g., FIG. 8). Based on received reflections of the uplink sounding signals, the examples also include configuring beams of a base station to receive direct and/or APD-reflected uplink communications (e.g., FIG. 9). With reference to downlink communications, the examples also include using an APD to sweep reflections of downlink reference signals for reception by a UE (e.g., FIG. 10), modulating beam identifiers onto downlink reference signals and reflections of downlink sounding signals to provide reflection identifiers (e.g., FIGs. 11A and 11B), and beam sweeping reflections of downlink reference signals with an APD (e.g., FIG. 12). Aspects described with reference to one example may be combined with other examples, transactions of FIGs. 13-15, or methods of FIGs. 16-18 to implement operations for phase vector training for APD-enabled communication in various ways or scenarios. For example, a base station may configure the APD and UE to implement beam sweeping of respective beam patterns for broad (or wide) beams of uplink signals to select a combination of the wide UE and APD beams to use for uplink communication. The base station may then implement an uplink sounding process to select, from within the respective wide beams, a phase vector for the APD or a phase steering vector for the UE to provide a narrower beam to further improve the APD-enabled communication channel between the base station and the UE.

[0048] FIG. 5 illustrates at 500 an example of a base station using an adaptive phase changing device to communicate with a user equipment in accordance with one or more aspects. Generally, the example 500 shows a base station 120 using an APD 180 to direct or steer a reflection of a wireless signal communicated between the base station 120 and a user equipment 110. The APD 180 may be selected from a set of multiple APDs 180 deployed within communication range of the base station 120. Thus, the base station 120 may select or configure any of the APDs 180 within range for use in communicating with the UE 110 or other UEs (not shown). Alternatively or additionally, the operations described with reference to FIG. 5 may be used to implement various aspects of phase vector training for APD-enabled communication, such as those described with reference to FIGs. 6A-12, transactions of FIGs. 13-15, or methods of FIGs. 16-18.

[0049] In aspects, the base station 120 communicates with the UE 110 over the wireless link 131 (see FIG. 1) by transmitting downlink communications or receiving uplink communications through one or more wireless communication paths between the base station 120 and the UE 110. As described herein, a communication path may include a direct communication path between the base station 120 and the UE 110 or an indirect communication path that includes an APD 180. With reference to downlink communications, the base station 120 transmits a downlink wireless signal 502 that covers a spatial region determined by a transmitting antenna radiation pattern of the base station. For example, the base station 120 can transmit a reference signal (e.g., independent of an active wireless link) using a beam pattern (e.g, one broad or multiple narrow beams) that reaches the APD 180 and/or the UE 110 to implement aspects of phase vector training for APD-enabled communication.

[0050] To illustrate, the wireless signal 502 transmitted by the base station 120 includes the signal ray 190 that propagates toward the UE 110 in a LoS manner, the signal ray 191 that propagates toward the APD 180, and the signal ray 193 that propagates toward obstructions 504 (illustrated as structures and foliage) that block or otherwise degrade the signal ray 193 to keep it from reaching the UE 110. To implement various aspects of phase vector training for APD- enabled communication, the base station 120 generally transmits a wireless signal 502 with a direct signal ray (e.g., signal ray 191) propagating toward the APD 180 and optionally with direct signal rays (e.g., signal rays 190 and/or 193) propagating toward the UE 110. In aspects, the base station 120 transmits wireless signals to the APD 180 in a high-frequency band at or above-6 GHz, such that obstructions (e.g., temporary LoS obstructions of signal ray 190, not shown) may block signal rays 190 and/or 193. The base station may transmit individual signal rays 190, 191, 193 of the wireless signal 502 simultaneously or at different times using antenna beam management techniques such as beamwidth control, beam sweeping, and beam steering.

[0051] With reference to uplink communications, the UE 110 may transmit an uplink wireless signal that covers a spatial region determined by a transmitting antenna radiation pattern of the UE 110. In various implementations, the UE 110 transmits the uplink wireless signals over the wireless link 131, independent of the wireless link 131, or over another wireless connection with the base station 120 (e.g., a sub-6 GHz low-band connection). For example, the UE 110 can transmit a sounding signal (e.g. , independent of an active wireless link) using a beam pattern (e.g. , an omnidirectional pattern or multiple beams) that reaches the APD 180 and/or the base station 120 to implement aspects of phase vector training for APD-enabled communication. To illustrate, an uplink wireless signal transmitted by the UE 110 may include a signal ray that propagates toward the base station 120 in a LoS manner (e.g., opposite of signal ray 190), a signal ray that propagates toward the APD 180 (e.g., opposite of signal ray 192), and a signal ray 194 that propagates toward obstructions 504 that block or otherwise degrade the signal ray 194 to keep it from reaching the base station 120.

[0052] To implement various aspects of phase vector training for APD-enabled communication, the base station 120 may direct the UE 110 to transmit a wireless signal with a direct signal ray propagating toward the APD 180 and optionally with direct signal rays propagating toward the base station 120. In aspects, the UE 110 transmits wireless signals to the base station 120 in a high-frequency band at or above-6 GHz, such that obstructions (e.g., temporary LoS obstructions of signal ray 190, not shown) may block some direct UE-to-BS signal rays. The UE 110 may transmit individual signal rays of an uplink wireless signal simultaneously or at different times using antenna beam management techniques such as beamwidth control, beam sweeping, and beam steering. In the context of FIG. 5, various implementations of wireless communication between the base station 120 and the UE 110 are described with reference to the APD 180 and may be implemented similarly or differently with any other APD 180 within communication range of the base station 120 and the UE 110.

[0053] In various implementations, the APD 180 participates in the uplink, downlink, and/or phase vector training communications (e.g. , uplink sounding signals or downlink reference signals) between the base station 120 and the UE 110 by transforming (e.g. , reflecting) waveforms using an RIS of the APD 180 with a surface configuration determined by the base station 120. To illustrate, the signal ray 191 strikes the surface of the APD 180, shown as a configurable surface element 402 (e.g., a RIS 402), and transforms into the signal ray 192, which is directed toward the UE 110. As part of receiving the wireless signal 502, the UE 110 may receive the signal ray 190 and the reflected signal ray 192 (but not the signal ray 193). In implementations, the base station 120 configures the configurable surface element 402 (or RIS) to direct how the signal ray 191 transforms into the signal ray 192 and reflects from the APD 180 for downlink, reference signal (e.g., CSI reference signal or CSI-RS), and/or synchronization signals (e.g., SSB) communications. Alternatively or additionally, the base station 120 configures the configurable surface element 402 (or RIS) to direct how uplink signal rays (e.g., a signal ray opposite to DL signal ray 192) transforms into the reflected signal rays (e.g., a signal ray opposite DL signal ray 191) and reflect from the APD 180 for uplink and/or sounding signal (e.g., SRS signal) communications. [0054] The base station 120 or a PVF 268 associated with a base station 120 may selectively determine to use and configure an APD 180 to communicate uplink signals or downlink signals between the base station 120 and the UE 110. Generally, various aspects of uplink and downlink phase vector training are described as balanced processes, which may apply when the base station 120, UE 110, and/or APD 180 are non-stationary or moving (e.g., a non terrestrial base station or drone-based APD). In most cases, however, a base station 120 and APD 180 are likely stationary while the UE 110 is more likely moving (e.g., dynamic position or orientation). Thus, in most implementations, the most-frequent phase vector training processes include a downlink channel estimation (e.g., CSI process) or synchronization feedback process (e.g., SSB) in which reflections of downlink signals (e.g., signal ray 192) are swept by the APD 180 for reception by the UE 110. As such, the more frequent downlink channel estimates or beam selections for a non-stationary UE 110 may affect phase vector training or beam sweep operation timings of the entities (e.g., the base station may sweep signal ray 192 to the UE more frequently than using the UE to sweep signal ray 191 to the base station).

[0055] In aspects of phase vector training for APD-enabled communication, the base station 120 may bind or associate phase sweeping of the APD 180 with an uplink sounding process or a downlink channel state information (CSI) process to coordinate the phase vectors of the APD with transmission of uplink sounding signals by the UE 110 or transmission of downlink reference signals by the base station 120. By so doing, the base station 120 can use the APD 180 to direct reflections of the uplink sounding signals that reach the base station 120 or direct reflections of the downlink reference signals that reach the UE 110. Based on respective identifiers and/or signal quality parameters of the reflections that reach the UE 110 or the base station 120, the base station 120 can select a phase vector for the APD to reflect subsequent communications between the base station and the UE. Alternatively or additionally, the base station 120 may select a phase steering vector for the base station to use for downlink communications, a phase steering vector for the UE to use for uplink communications, or receive a beam configuration for the base station to use for receiving reflected or direct uplink communications.

[0056] FIGs. 6A and 6B illustrate examples of using an APD to reflect uplink signals for phase vector training in accordance with one or more aspects. The examples illustrated include an example 600 of an APD reflecting an omnidirectional uplink transmission, an example 601 of the APD reflecting a broad beam uplink transmission, and an example 602 of the APD reflecting a narrow beam transmission. In various aspects, a base station 120 may implement one or more iterations of beam sweeping to select a phase vector for the APD 180 and/or a phase steering vector for the UE 110. Thus, the base station 120 may start with an omnidirectional UL transmission and broad APD-reflection beams due to an unknown position and/or orientation of the UE 110. From an initial or previous uplink beam sweeping, the base station 120 may implement additional iterations of phase vector training of narrowing spatial sweeps (e.g., from broad to narrow transmit and/or reflection beams) until a signal quality parameter of a reflection received at the base station 120 exceeds a threshold, at which point the base station 120 may determine to cease uplink phase vector training. The aspects described with reference to the examples 601, 602, and 603 may be implemented by or with any suitable entities, including those described with reference to FIGs. 1-5 or FIGs. 7A-18. Prior to implementing or while using the APD 180 to beam sweep reflections of uplink beams, the base station may select, configure, manage, or use the APD 180 or the UE 110 as described with reference to FIGs. 1-5, FIGs. 7A- 12, the transactions of FIGs. 13-15, or the methods of FIGs. 16-18.

[0057] In aspects, the base station 120 implements beam sweeping and/or reflection sweeping of uplink sounding signals through various communication paths. As described herein, a base station 120 and a UE 110 may communicate through one or more communication paths of an environment in which the base station 120 and UE 110 operate. With respect to uplink channel sounding, the base station 120 can direct the UE 110 to implement an uplink channel sounding process in which the UE 110 transmits uplink sounding signals through one or more communication paths to the base station 120. Based on signal quality parameters or other metrics of the uplink sounding signals received by the base station 120, the base station 120 estimates characteristics of the communication path, which may include measurements indicative of combinations of UE transmit configurations (e.g., phase steering vectors) and APD reflective configurations (e.g., phase vectors) that result in reflections of uplink signals reaching the base station. Using the respective characteristics of the communication path, the base station 120 then selects phase vector configurations for the UE 110, the base station 120, and/or the APD 180 for communication paths that include the APD. In aspects, the base station 120 or the PVF 268 of the base station binds or associates phase vectors of the APD 180 with sounding signal resources of the uplink sounding signals, which may align phase vectors implemented with the APD to the uplink sounding signals sent by the UE 110. By so doing, the base station 120 may use respective identifiers and signal quality parameters of received reflections of the uplink sounding signals along with APD phase vector information to determine which combination of sounding signals (e.g., uplink beam) and APD phase vector enable or improve communication between the base station and the UE through the communication path that includes the APD.

[0058] In aspects, the base station 120 (or PVF 268) manages or interacts with an APD 180 of a wireless network to implement phase vector training for APD-enabled communication. Generally, the base station 120 (e.g., a terrestrial or non-terrestrial base station) has a known position from which the base station 120 manages or coordinates respective phase vector training operations of various entities. Oftentimes the APD 180 also has a known position, which may include a location of the APD 180 (e.g., relative to the base station 120) and an orientation of a surface of the APD 180. For example, the APD 180 may have a fixed location that is set at a time of installation or determined by a position sensor 308 (GNSS receiver) of the APD 180. In aspects, the base station 120 or PVF 268 obtains position and/or orientation information from the APD 180 via an APD control channel, which may include the APD-slow-control channel or APD-fast- control channel implemented via the wireless link 133. In this example, an APD control channel is implemented as a separate APD control channel 610 between the base station 120 and the APD 180. Alternatively or additionally, the base station 120 can query a server for position information and/or capabilities of APDs 180 proximate the UE 110, such as by contacting a server included in the core network 150 of FIG. 1.

[0059] Based on the position information of one or more APDs 180, the base station 120 can select an APD 180 to use for an uplink sounding process with the UE 110. For example, the base station 120 may select an APD 180 that is near the UE 110 (e.g., UE’s estimated position), an APD 180 located near a LoS communication path between the base station and the UE, or an APD 180 that is likely to provide an APD-enabled communication path between the base station and the UE (e.g. , based on historical records or recent APD activity). Alternatively or additionally, the base station 120 may estimate a position of the UE 110, such as through a low-band connection 615 (e.g., GNSS-based UE-position or base station-UE low-band signaling). In aspects, the base station 120 may select and/or configure an APD 180 to participate in an uplink sounding process based on the position of the APD 180 (e.g. , location and orientation) and/or the estimated position of the UE. To implement an uplink sounding process in accordance with one or more aspects, the base station 120 coordinates (e.g., synchronizes) transmission of uplink sounding signals by aUE 110 with one or more phase sweeping vectors implemented by an APD 180. To do so, the base station may associate or bind uplink sounding signal resources of an air interface that extends between the base station and the UE with the APD phase sweeping vectors. In some cases, the base station schedules UE uplink sounding signal resources for both a direct communication path (non-APD-enabled communication) to the base station and for a communication path that includes reflection by the APD (APD-enabled communication).

[0060] With reference to uplink beam sweeping, the base station 120 schedules a beam sweeping pattern (UE beam sweeping pattern) of uplink sounding signals by the UE 110 for a same time that the base station schedules a beam sweeping pattern (APD beam sweeping pattern) of the APD 180 to provide reflections of the uplink beams for reception by the base station. For example, the base station 120 can configure and schedule the uplink sounding process of the UE 110 through downlink communications on layer 2 (L2) or layer 3 (L3) of the low-band connection 615. Alternatively or additionally, the base station 120 configures and schedules the APD phase sweeping pattern of the APD 180 through the APD control channel 610. In doing so, the base station may synchronize the uplink beams with respective phase vector information and/or identifiers to enable analysis of beam reflections or direct beams that reach the base station 120. When the UE 110 is capable of transmitting multiple beams, the base station 120 can pair or bind beams of uplink signals with respective phase vectors to provide a UE-to-APD beam binding, an APD-to-BS reflected beam binding, and/or a UE-to-BS beam binding (e.g., for direct beams, not shown).

[0061] Returning to FIG. 6A, the base station 120 may implement multiple iterations or stages of beam sweeping and/or reflection sweeping (e.g., dual-sweep operations) in accordance with one or more aspects. For example, the base station 120 can start a beam sweeping process with omnidirectional or broad beam uplink transmissions when a position or orientation of a UE 110 is unknown. From the omnidirectional or broad beam uplink sweeps, the base station 120 may perform subsequent uplink beam sweeps with narrower beams (e.g., more-precise narrow beams) based on the success of previous uplink beam or reflection sweeps. In the context of the example 600, the base station 120 sends a beam sweeping index 620 (BS index 620 “21”) to the APD 180 over the APD control channel 610 and sends an uplink beam sweeping index 625 (UL BS index 625 “0”) to the UE 110 over the low-band connection 615, though the base station may use any suitable communication link to convey the respective pattern or timing information.

[0062] As shown at 600, the UL BS index 625 “0” directs the UE to implement an omnidirectional transmission 631 of uplink sounding signals, which may include signal rays (individual rays not shown) that reach the APD 180 and/or the base station 120. Based on the BS index 620 “21”, APD 180 implements an associated beam sweeping pattern 622 (BS pattern 622 “21”) of broad (or wide) reflection beams 661, 662, and 663. In the example 600, the broad reflection beams 661, 662, and 663 may each cover approximately 60 degrees, resulting in a broad sweep of the reflection of incident uplink signals that covers approximately 180 degrees. In addition to the respective beam sweeping patterns, the base station 120 also sends timing information (e.g. , time slots or periodicity information) to the APD 180 and the UE 110 that directs the entities to perform the reflection beam sweeping and the uplink transmission concurrently or during a same duration of time. In some cases, the timing information includes a predefined time to initiate the respective beam sweeping operations, assigned time slots, or respective periodicity information for the reflection beam sweeping and the uplink beam sweeping. By specifying the uplink sounding resource periodicity for the UE 110 and the reflection beam sweeping periodicity for the APD 180, the base station 120 can determine which pairings of APD reflection angles and UE uplink beams result in reflections that reach the base station. The base station 120 may also configure repetition or periodicity of the respective beam sweeping patterns to implement the iterative reflection sweeps or beam sweeps of the uplink sounding signals.

[0063] Based on various combinations of the beams of uplink sounding signals and APD phase vectors of the uplink sounding process, one or more reflections of the uplink sounding signals may reach the base station 120 as BS-received signals. Additionally, the base station may receive uplink sounding signals that reach the base station directly from the UE 110 without reflection by the APD 180. In the context of examples 600, 601, and 602, assume the obstructions (e.g., foliage and water vapor) between the UE 110 and base station 120 prevent the base station 120 from receiving the uplink sounding signals directly from the UE 110. With respect to the reflected uplink sounding signals, the base station 120 receives the broad reflection beam 662 of the uplink sounding signals from the APD 180. Based on the reception of the broad reflection beam 662, the base station 120 determines that the APD-enabled communication path provided by the APD 180 is viable (e.g., successful reception and decoding of reflected signals in beam 662) and proceeds with another iteration of beam sweeping. In aspects, the base station 120 may select beam sweeping patterns of less angular sweep for the UE 110 and/ or APD 180 based on the success of a previous iteration.

[0064] To illustrate, the base station 120 selects respective beam sweeping patterns for the UE 110 and the APD 180 based on the success of the broad reflection beam 662 of the omnidirectional uplink transmission 631. Thus, in example 601, the base station 120 selects an uplink beam sweeping pattern for the UE 110 of broad beams (e.g., approximately 90 degrees) to cover different quadrants of spatial area previously covered by the omnidirectional transmission 631. The base station 120 also selects a beam sweeping pattern of narrower beams for the APD 180 to cover a sweep area limited to approximately the angular sweep of the successful broad reflection beam 662. To implement this iteration of beam sweeping, the base station 120 sends another BS index 620 “41” to the APD 180 over the APD control channel 610 and sends another UL BS index 625 “11”) to the UE 110 over the low-band connection 615. The base station 120 may also send timing information to the UE 110 and APD 180 to synchronize the next iteration of uplink beam sweeping by the UE and the reflective beam sweeping by the APD. Alternatively, the UE 110 or APD 180 may use periodicity information previously provided by the base station 120 to schedule a respective beam sweep during the next iteration of uplink channel sounding.

[0065] As shown at 601, the UL BS index 625 “11” directs the UE 110 to transmit broad beams 641, 642, 643, and 644 in a clockwise fashion while the APD 180 implements the phase vectors for narrower reflection beams 671, 672, and 673. Based on the broad beam 642 of uplink sounding signal reaching the APD 180, the narrow reflection beam 672 of the uplink sounding signals reaches the base station from the APD 180. The base station 120 then decodes signals from the narrow reflection beam 672 to determine an identifier for the BS-received signals. As described herein (e.g., FIGs. 7A-8), the base station 120 can use the identifier of a reflection beam to determine which combination of uplink beam and APD phase vector resulted in the reflection that reached the base station 120. In aspects, the base station 120 provides feedback to the UE 110 indicative of which uplink beam is successfully received, although the UE 110 may not be aware of the presence of the APD 180 in the communication path to the base station. Thus, based on the feedback on broad beam 642, the UE 110 can estimate a general direction (e.g., within the approximate 90 degrees of beam 642) or position of the base station 120 or APD 180 for subsequent beam sweeping operations or uplink communications.

[0066] In aspects, the base station 120 also measures signal quality parameters (e.g., an RSRP) of the received reflection, which the base station may use to evaluate the received reflection relative to other received reflections, to determine to implement another iteration of beam sweeping with the UE 110 and/or APD 180, cease beam sweeping operations (e.g., select phase vectors for APD-enabled communication), and so forth. For example, the base station 120 may cease the beam sweeping operations during any particular iteration when the base station- received (BS-received) signal strength meets a threshold (e.g., a minimum RSRP threshold), which should speed up the dual-sweep process by the UE 110 and APD 180, especially when beam-narrowed iterations are involved. In the context of example 601, assume that the RSRP of the BS-received signal rays of beam 672 does not exceed an RSRP threshold for high-band (e.g., above-6 GHz) communication and in response the base station 120 determines to implement another iteration of beam sweeping to identify a combination of respective phase vectors for the UE 110 and APD 180 that provide BS-received signals with a higher RSRP.

[0067] As described herein, the base station 120 can use the results (e.g., successfully received beams) of previous beam sweeping iterations to refine or limit angular coverage of subsequent beam sweeps by the UE 110 and/or APD 180. In the context of example 602, the base station 120 selects an uplink beam sweeping pattern for the UE 110 of narrower beams (e.g., approximately 20 degrees) to sweep through the angular coverage of the broader beam 642. The base station also selects a beam sweeping pattern of narrower beams (e.g., 15 degrees) for the APD 180 to sweep through an area limited to approximately the angular sweep of the successful narrow reflection beam 672 of the previous iteration. To implement the third iteration of the dual sweep process, the base station 120 sends another BS index 620 “61” to the APD 180 over the APD control channel 610 and sends another UL BS index 625 “27” to the UE 110 over the low- band connection 615. As shown at 602, the UL BS index 625 “61” directs the UE 110 to transmit narrow beams 651, 652, and 653 while the APD 180 implements the phase vectors for narrow reflection beams 681, 682, and 683. Based on the narrow beam 652 of uplink sounding signal reaching the APD 180, the base station 120 receives reflected signal rays that correspond to narrow reflection beam 682.

[0068] The base station 120 then compares the RSRP value of the received reflection beam

682 to the RSRP threshold of the beam sweeping process. Here, assume that the RSRP value of the reflected beam 682 exceeds the threshold and, in response to RSRP value exceeding the threshold, the base station 120 ends the beam sweeping process. Concluding the present example, the base station 120 uses the identifier of the reflected beam 682 (e.g., as described with reference to FIGs. 7A-8) to select respective phase vectors for the UE HO andthe APD 180 that correspond to the uplink narrow beam 652 and the narrow reflection beam 682 in accordance with aspects of phase vector training for APD-enabled communication. Having discussed various aspects of the dual-sweep process for uplink channel sounding, next consider ways in which the base station 120 can use the UE 110 and/or APD 180 to modulate uplink signals with various identifiers to enable aspects of phase vector training for APD-enabled communication.

[0069] FIGs. 7 A and 7B illustrate examples of modulating uplink sounding signals with beam identifiers in accordance with one or more aspects. Generally, a base station 120 can define or map an uplink sounding process to one or more APD phase sweeping vectors such that reflections of the uplink UE beams of the sounding process correspond to respective APD phase vectors. To enable identification and use of reflected signal rays (reflections) and/or LoS signal rays (e.g., direct signal rays) that reach the base station 120 (e.g., during a dual-sweep process), a UE 110 or APD 180 may modulate or encode at least a portion of a signal ray or reflection of a signal ray with an identifier. In aspects, the base station 120 may associate or bind resources of the uplink sounding process (e.g., specific beam) with one or more corresponding APD vectors and uplink sounding signal identifiers (e.g., signal or reflection identifiers). By so doing, the base station 120 can identify and measure signal quality parameters for reflections or LoS uplink sounding signals that reach the base station, which in turn enables the base station to determine which combination of UE beam(s) and APD vector enable or improve communication between the base station and UE.

[0070] By way of example, FIG. 7 A illustrates the UE 110 transmitting a broad beam 632 (e.g., omnidirectional signal) of signal rays that propagate toward the base station 120 and/or the APD 180 (shown in more detail than the other rays 756, 757). In this case, the broad beam 632 includes a signal ray 751 that is reflected by the APD 180 as a reflection 752 that reaches the base station 120. The broad beam 632 also includes signal rays 753, 754, and 755, of which, signal ray 755 is a LoS or direct signal ray that reaches the base station while rays 753, 754, 756, and 757 (as well as the other rays 750) are not received by the base station either directly, indirectly via APD reflections, or indirectly via non-APD reflections. With reference to a table at 701 of modulated uplink identifiers for incident sounding signals and reflections of the sounding signals, a sounding signal and a reflection of the sounding signal may be modulated or encoded to carry same or different identification information. In this example, a UE 110 can modulate a beam or signal ray with a beam identifier modulation 706 (UE-beam ID modulation), and the APD can modulate a reflection of a sounding signal or signal ray with a reflected beam ID modulation 708 (APD-reflected beam ID modulation). In various implementations, an identifier of a reflection, or reflection ID 710, may carry information from one or both identification modulations by the UE 110 and/or the APD 180. For example, the reflection ID 710 for a reflection of a wireless signal or signal ray may include the APD-ID modulation, the UE-ID modulation, or both APD-ID and UE-ID modulations. Because the APD 180 does not modulate a direct or LoS signal ray ( e.g . signal ray 755), the signal ray ID 712 may include only the UE-ID information or null information (e.g., when the UE 110 does not module an identifier on the uplink signal). Thus, the base station 120 may decode received signals to obtain a reflection ID 710 for reflections that reach the base station or a signal ray ID 712 for signal rays that reach the base station without reflection by the APD.

[0071] With reference to the rows of table 701, the base station 120 may use the identifiers 710 or 712, which may be referred to received ray IDs, to determine that a reflection of a BS- received signal occurred. For example, when the UE 110 does not modulate a UE-ID on transmitted uplink signals and the APD 180 modulates reflections with an APD-ID as shown in row 1 of table 701, the base station 120 can use the APD-ID on BS-received signals to distinguish the reflections with the APD-IDs from non-reflected signal rays. In the case when both the direct signal ray and the reflected ray include only the UE-ID modulation (e.g., row 2 of table 701), the base station 120 may use a difference in observed time-of-arrival or angle-of-arrival to determine which BS-received signal ray is reflected by an APD 180. With reference to row 3 of table 701, which corresponds to using both the UE-IDs 706 and an APD-ID 708 as shown at 700, the direct signal ray 755 and the reflection 752 that reach the base station carry different respective identifiers 710 and 712 when the APD 180 modulates the APD-ID on reflection and the UE 110 modulates the UE-ID on the uplink transmissions. Here, note that all signal rays 750 of the omnidirectional transmission 632 carry a same UE-ID because the signal rays 750 were sent using a single omnidirectional beam from the UE 110.

[0072] Expanding on the example of row 3 of table 701, consider a table at 702 of example reflection and signal ray identifiers that the UE 110 and APD 180 can modulate on the signal rays 750. Generally, the reflection information modulated onto a signal ray or reflection may include any suitable information useful to distinguish which UE beam and APD phase vector combination results in a received direct or reflected signal ray. In this example, the UE 110 modulates all signal rays 750 (signal ray column 714) of the omnidirectional transmission 632 with a beam ID 706 prefix and the APD 180 modulates the reflection 752 (reflection column 716) of the incident signal ray 751 with a reflected beam ID 708 suffix. The direct and reflected signal rays received by the base station 120, which decodes a received ray ID 718 to obtain the modulated IDs of the direct and reflected signal rays. In other words, the base station 120 decodes the received ray ID 718 and uses the modulated identifiers to determine whether the signal rays are received directly from the UE 110 or reflected by the APD 180. In this example, the base station 120 decodes a received ray ID 718 of the reflection 752 as a combined UE-beamID and APD-ID (e.g., “1.3”) and decodes the received ray ID of the directly received signal ray 755 as the UE-beam ID (e.g., “1.0”). Thus, based on the decoded received ray IDs 718, the base station 120 can classify the received signal rays as direct or reflected signal rays. Here, note that the base station 120 does not receive the signal rays 753, 754, 756, 757, or other signal rays 750 of the omnidirectional transmission 632 that the UE modulates with the UE-beam ID 706. After decoding the respective identifiers of the direct and/or reflected signal rays, the base station 120 can determine (e.g., via a lookup table) a corresponding APD phase vector and UE beams to evaluate results of the uplink sounding process to select respective phase vectors for the APD 180 or UE 110.

[0073] In aspects, the UE 110 may be capable of transmitting separate beams of uplink sounding signals that may reach the APD 180 and the base station 120. For example, the UE 110 may include two mmWave modules for transmitting two beams of high-band uplink sounding signals or two omnidirectional antennas for transmitting a beam of high-band uplink sounding signals and a beam low-band uplink sounding signals. In the context of separate beam transmission, FIG. 7B illustrates at 703 the UE 110 transmitting a narrow beam 654 that includes signal ray 771 that reaches an RIS of the APD 180, which is reflected as reflection 772 (e.g., reflected signal ray) toward the base station 120. Here, assume that the base station 120 has already implemented a broad beam dual-sweep process to provide the UE 110 with feedback information that enables the UE 110 to implement directional uplink transmissions to the APD 180 and/or the base station 120. The UE 110 may also concurrently, or at a different time, transmit a narrow beam 655 that includes signal rays 781 and 782 toward the base station (e.g., row 3 of table 701). As shown in FIG. 7B, the signal ray 781 propagates to the base station without reflecting off the APD 180 and an obstruction (e.g., water vapor) blocks the propagation of signal ray 782.

[0074] In the example 703, the direct signal ray 781 and the reflection 772 that reach the base station carry different identification information when the APD 180 modulates or adds APD- specific information to the reflected signal ray. Alternatively or additionally, as shown in a table at 704, the UE 110 may modulate the signal rays of beams 654 and 655 with different information, enabling the base station 120 to distinguish the signals rays from one another without timing information. In this example, the base station 120 decodes a received ray ID 718 of the reflection 772 as a combined UE-beam ID and APD-ID (e.g., “11.9”) and decodes the received ray ID 718 of the directly received signal ray 781 as the UE-beam ID (e.g., “15.0”) without timing information. The base station 120 can then use the decoded APD-ID and UE-ID to look up the corresponding APD phase vector and UE beams to evaluate results of the uplink sounding process.

[0075] In aspects, the base station 120 configures the APD 180 with surface configurations or beam sweeping patterns to direct or steer reflections of uplink sounding signals to the base station 120, such as described with reference to FIGs. 7A and 7B. For example, the base station 120 may configure the APD 180 to implement a phase sweeping pattern while the UE 110 transmits uplink sounding signals as part of an uplink sounding process for phase vector training. With respect to surface configurations of an APD 180, one or more phase vectors applied by the surface of the APD to an incident waveform may be calibrated such that the base station 120 can select, using phase vector knowledge, a direction of a wave front of the wireless signal or reflection that reaches the base station. In some implementations, the base station 120 evaluates the APD phase vector (e.g., angular information) and signal quality parameters of a reflection to select a phase vector for the APD and/or a phase steering vector for the UE to enable or improve communication between the base station and the UE.

[0076] FIG. 8 illustrates example 800 of a base station using an APD to beam sweep reflections of uplink signals in accordance with various aspects of phase vector training. The example 800 includes a base station 120 managing the APD 180 and the UE 110 to beam sweep sounding signal reflections toward the base station 120. Aspects described with reference to the example 800 may be implemented by or with any suitable entities, including those shown in FIGs. 7A and 7B (e.g., for beam identifiers), or other entities described with reference to FIGs. 1-7B. Prior to implementing or while using the APD 180 to beam sweep reflections of uplink sounding signals, the base station may select, configure, manage, or use the APD 180 or the UE 110 as described with reference to FIGs. 1-7B, FIGs. 9-12, the transactions of FIGs. 13-15, or the methods of FIGs. 16-18.

[0077] In aspects, the base station 120 may use the APD 180 to implement beam sweeping to steer or direct (e.g., by beamforming) reflections of uplink sounding signals that may reach the base station 120. In some implementations, the UE 110 may also beam sweep broad or narrow beams of uplink sounding signals that reach the APD 180, such as to determine an initial uplink beam that provides reflections capable of reaching the base station. Based on reflection identifiers and/or signal quality parameters of the reflections, the base station 120 can evaluate combinations of APD phase vectors and UE beams to select or determine a phase vector for the APD 180 or a phase steering vector for the UE 110 to enable or improve communications through a communication path that includes the APD. Alternatively or additionally, the base station 120 may also evaluate the reflection identifiers and/or signal quality parameters of the reflections to select or configure receive beams of antenna panels of the base station.

[0078] Generally, a beam sweeping pattern of the APD 180 may include a sequence of surface configurations, phase vectors, calibrated angle information, timing information (e.g., slot timing), reflection identifiers (APD-beam ID), or the like. Thus, a beam sweeping pattern implemented by an APD 180 may include a sequence of surface configuration indexes, APD beam IDs (reflected beam IDs 708), and timing information by which an APD manager 320 configures a RIS of the APD 180 prior to or during beam sweeping operations. Alternatively or additionally, the base station 120 may select and coordinate encoding or modulation of a UE-beam ID (beam ID modulations 706) on a transmitted sounding signal(s) (e.g., uplink sounding beam 632), which may correspond to a UE uplink beam and/or the sequence of surface configurations of a beam sweeping pattern. As such, the base station 120 may use an APD 180 to beamform, via a selected phase vector, an uplink sounding signal having a reflection identifier (e.g., UE-beam ID and/or APD beam ID) toward the base station. In other cases, the base station may use the APD 180 to beamform, via a sequence phase vectors, portions of a sounding signal each encoded with a unique reflection identifier (e.g., UE-beam ID and/or APD beam ID) toward the base station at different respective directions or angles.

[0079] To enable identification of phase vectors associated with received reflections of the sounding signals, the base station 120 may temporally align encoding of the UE-beam IDs on the transmitted signal with the sequence of phase vectors implemented at the APD. In other words, the APD 180 may sweep (e.g., advance) through a sequence of APD surface configurations while reflecting the incident signal transmitted by the UE 110 with multiple UE-beam IDs to beam sweep a sequence of uniquely identifiable signal rays toward the base station 120. Alternatively or additionally, the APD 180 can also sweep through a sequence of APD beam IDs to modulate the sequence of signal rays with reflection identifiers. Thus, as described with reference to FIGs. 7A and 7B, a received ray ID 718 of a reflected signal ray or sounding signal that reaches the base station 120 may include information of a UE-beam ID, information of an APD beam ID, and/or information of both the UE-beam ID and the APD beam ID.

[0080] By way of example, consider the example 800 in which the base station 120 implements beam sweeping with an APD 180 of reflections of an uplink sounding signal transmitted by a UE 110. The base station 120 or PVF 268 may select a broad beam sweeping pattern, such as a pattern that spans or sweeps a spatial region of approximately 70 degrees to 90 degrees. In the present example, the base station 120 sends a beam sweeping pattern index 620 (BS index 620, e.g., BS Index 63) to the APD 180 via the APD control channel 610. The beam sweeping index 620 indicates or conveys to the APD 180 which beam sweeping codebook, beam sweeping pattern, APD beam IDs, or phase vector sequence to use when implementing beamforming of incident wireless signals (e.g., UE-originated uplink sounding signals). Based on the beam sweeping index 620, the APD manager 320 accesses a beam sweeping codebook (not shown) of the APD 180 and selects a corresponding beam sweeping pattern 622 (e.g, beam sweeping pattern 63). As shown at 801 in a table of beam sweeping information for APD 180, the example beam sweeping pattern 63 includes entries for a set of phase vectors 802 and corresponding reflection angles 804, which may be calibrated or verified for one or more of the phase vectors 802.

[0081] In this example, assume the UE 110 modulates UE-beam IDs onto signal rays that correspond to reflection identifiers and the APD 180 does not modulate APD beam ID information on reflections of the signal rays. Thus, the sounding signal 871 may represent a transmission of a sounding signal modulated with a sequence UE-beam IDs 706 (and/or APD beam IDs, not shown) or a series of individually transmitted reference signals each modulated with a different UE-beam ID 706 (and/or APD beam ID, not shown). By coordinating or synchronizing respective timing of a transmission of sounding signals (e.g, sounding signal 871) and RIS reconfigurations at the APD 180 that implements beam sweeping, each reflection 716 may have and/or correspond with a received ray ID 718, which the base station 120 uses to identify a phase vector 802 and/or UE beam associated with the reflection.

[0082] In aspects, the base station 120 coordinates the UE’s transmission of the sounding signal 871 and implementation of the beam sweeping pattern 622 by the APD 180 to beam sweep a set of reflected sounding signals, or reflections 872-876 that include UE-beam ID 706 for reception by the base station. Generally, the base station 120 or PVF 268 may select a beam sweeping pattern 622 to cover a relatively broad area for a first or preliminary beam sweeping operation to determine a combination of broad UE beams and broad APD beams that result in a reflection reaching the base station. In aspects, the base station 120 can refine or narrow respective beam sweeping patterns of the UE and APD based on results of preceding dual-sweep operations for subsequent beam sweeping of more-narrow beams (e.g, progressively limited angular ranges) for phase vector training.

[0083] Returning to example 800, the base station receives one or more of the reflections of the sounding signal 871 from which the base station decodes received ray IDs 718. In aspects, the base station 120 may decode or demodulate a received ray ID 718 and/or obtain one or more signal quality parameters (e.g. , RSRP) for the uplink signal reflections received at the base station. In the present example, the base station receives and is able to decode received ray IDs 718 for five of the reflections, which include the reflection 874 of the sounding signal 871. The base station 120 also determines or obtains RSRP values 806 for some of the received reflections. As shown in the table at 801, others of the reflections may not reach the base station or reach the base station with insufficient signal strength (e.g., less than -140 dBm) or signal quality to permit decoding of a received ray ID 718. In aspects, the base station 120 can use the received ray IDs 718 and RSRP values 806 to determine a combination of a UE phase steering vector and an APD phase vector that enables or improves uplink communication via the APD 180. Concluding the present example, the base station 120 selects phase vector 91 (-105 dBm) and the UE phase steering vector associated with uplink sounding signal 871 (or UE uplink beam) for use in subsequent uplink communication or sounding (e.g., with narrower beams) operations.

[0084] FIG. 9 illustrates an example 900 of a base station configuring multiple antenna panels to receive a reflection of an uplink sounding signal and a direct sounding signal in accordance with one or more aspects. In this example, a receiver sub-system of a base station 120 of FIG. 2 is shown in greater detail and includes an RF front end 254 that is coupled to first and second antennas panels 252-1 and 252-2 of the base station 120. Although not shown, the base station 120 may include any suitable number of antenna panels coupled to the RF front end 254 to enable transmit and receive operations of the base station. The wireless transceivers 256 of the base station 120 are also illustrated with various receive chain components that include a digital signal processing (DSP) block 922, a cyclic prefix (CP) removal block 924, and a Fast Fourier transform (FFT) block 926. In aspects, the receiver subsystem of the base station 120 may process multiple uplink sounding signals received from the same UE through different respective communication paths.

[0085] In the context of the signals of FIG. 7B, the base station 120 can use a first antenna panel 252-1 to receive the reflection 772 of the uplink sounding signal and a second antenna panel 252-2 to receive the direct uplink sounding signal 781 from the UE 110. The base station 120 can condition, process, and analyze the received uplink signals to determine separate respective identifiers or signal quality parameters for the reflection 772 and direct uplink sounding signal 781. For example, when received within a same cyclic prefix, the base station 120 can use the DSP block 922, CP removal block 924, and FFT block 926 to implement processing (e.g., OFDM processing) to separate and analyze the multiple reflections and uplink sounding signals. In aspects, the base station 120 may also use the identifiers and/or signal quality parameters of the received reflections or uplink sounding signals to determine configurations for receive beams 931 and 932 for the antennas (e.g. , antenna panels 252-1 and 252-2) to receive uplink sounding signals.

[0086] FIG. 10 illustrate examples of using an APD to reflect downlink signals for phase vector training in accordance with one or more aspects. The examples illustrated include an example 1000 of an APD reflecting a broad beam downlink transmission and an example 1001 of the APD reflecting a narrow beam downlink transmission. In various aspects, a base station 120 may implement one or more iterations of beam sweeping to select a phase vector for the APD 180 and/or a phase steering vector for the base station 120. Because respective locations of the base station 120 and the APD 180 are generally known, the base station 120 may start with a broad beam DL transmission that includes signal rays that reach the UE 110 directly and via reflection by the APD. Based on the success of the broad downlink and/or reflection beams, the base station 120 can implement additional iterations of phase vector training of narrowing spatial sweeps until a signal quality parameter of a reflection received at the UE 110 exceeds a threshold, at which point the base station 120 may determine to cease the dual-sweep operations. The aspects described with reference to the examples 1001 and 1002 may be implemented by or with any suitable entities, including those described with reference to FIGs. 1-9 or FIGs. 11A-18. Prior to implementing or while using the APD 180 to beam sweep reflections of downlink beams, the base station may select, configure, manage, or use the APD 180 or the UE 110 as described with reference to FIGs. 1-5, FIGs. 11A-12, the transactions of FIGs. 13-15, or the methods of FIGs. 16-18.

[0087] In aspects of phase vector training, the principle of reciprocity generally applies between the described uplink operations (e.g., FIGs. 6A-8) and the downlink operations (e.g., FIGs. 10-12). Thus, the base station 120 can analyze a phase vector configuration of the APD used to provide reflections of uplink sounding signals that reach the base station 120 (e.g., a narrow beam or narrow beam sweep pattern that results in a peak (received) signal strength or quality) and then uses a reciprocity theorem to configure antennas of the base station (e.g., phase steering vectors) and the APD phase vector for reflecting downlink reference signals to the UE 110. In other words, the base station can use a “best” RSRP value of the reflected uplink ray 752 to determine downlink communications settings that result in a “best” RSRP of a downlink reflectionll52 (or vice versa). As another example, the base station can start a phase vector training process with downlink CSI-RSs or SSBs that match closely to SRSs of uplink ray 752 in direction and the base station can start the APD beam sweep with angles around the angle of 751. Alternatively, when the base station conducts a downlink dual-sweep to find reflection 1152, the base station can more-quickly find reflection 752 for the uplink signaling. To aid in referencing between the described uplink aspects of FIGs. 6A-8 and the described downlink aspects of FIGs. 10-12, the reference numbers (e.g., tens and ones positions) of the downlink figures correspond to the reference numbers of the uplink drawing but with reciprocity and will not be repeated for the sake of brevity. [0088] As shown in FIG. 10, the base station 120 can implement multiple iterations or stages of beam sweeping and/or reflection sweeping in accordance with one or more aspects. For example, the base station 120 can start a beam sweeping process with a broad beam downlink beam based on an estimated position of the UE 110. From the broad beam downlink and/or reflection sweeps, the base station 120 may perform subsequent downlink reflection beam sweeps with narrower beams based on the success of previous downlink beam or reflection sweeps. In the context of the example 1000, the base station 120 sends a beam sweeping index 620 (BS index 620 “42”) to the APD 180 over the APD control channel 610 and synchronizes the downlink transmission of broad beam 1042 (e.g., CSI-RSs) with timing information of the APD beam sweep. Although not shown in detail, signal rays of the broad beam 1042 may reach both the APD 180 and the UE 110 directly.

[0089] Based on various combinations of the downlink beam 1042 and APD phase vectors of the CSI sounding process, the UE 110 may receive one or more reflections of the downlink reference or synchronization signals. With respect to the reflected downlink reference signals, the base station 120 receives a narrow reflection beam 1072 of the downlink reference signals from the APD 180. Here, note that the APD reflections may start with narrow beams based on an estimated position of the UE, thereby saving time by avoiding the use of broad reflection beams during an initial CSI process. Based on a downlink signal report 1010 (DL signal report 1010) provided by the UE 110, the base station 120 determines that the APD-enabled communication path provided by the APD 180 is viable (e.g., successful reception and decoding of beam 1072) and proceeds with another iteration of downlink beam sweeping. In aspects, the base station 120 may select beam sweeping patterns of less angular sweep for the UE 110 and/or APD 180 based on the success of a previous iteration.

[0090] To illustrate, the base station 120 selects a beam sweeping pattern or more-narrow beams for the APD 180 based on the success of narrow reflection beam 1072 and sends another BS index 620 to configure the APD for a subsequent round of beam sweeping. The base station 120 also updates its antenna panel configuration to implement a narrow beam 1052 of downlink signal based on the success of the previous broad beam 1042. Thus, in example 1001, the base station 120 transmits narrow beam 1052 of downlink reference signals while the APD 180 implements the phase vectors for narrow reflection beams 1081, 1082, and 1083. Based on the narrow beam 1052 of downlink reference signals, the narrow reflection beam 1082 reaches the UE 110, which decodes an identifier of the reflection for use by the base station 120. As described herein (e.g., FIGs. 11A-12), the base station 120 can use the identifier of a reflection beam to determine which combination of downlink beam and APD phase vector resulted in the reflection that reached the UE 110. In aspects, the UE 110 provides feedback to the base station 120 via the DL signal report 1010 to enable base station analysis of the received reflection and signal information (e.g., signal quality parameters). Based on the information relating to the reflections and/or direct signals that reach the UE 110, the base station may determine to implement another iteration of downlink beam sweeping with the APD 180, cease beam sweeping operations (e.g., select phase vectors for APD-enable communication), or so forth. For example, the base station 120 may cease the beam sweeping operations during any particular iteration when the UE-received signal strength meets a threshold (e.g., a minimum RSRP threshold), which should speed up the dual-sweep process by the base station 120 and APD 180, especially when beam-narrowed iterations are involved. In the context of example 1001, assume that the RSRP of the UE-received signal rays of reflection beam 1082 exceeds an RSRP threshold for high-band (e.g., above-6 GHz) communication (ending the dual-sweep process) and in response the base station 120 determines to use the corresponding phase steering vector of the base station (e.g., for beam 1052) and phase vector of the APD (e.g., reflection beam 1082) for APD-enabled communication with the UE 110.

[0091] FIGs. 11A and 11B illustrate examples of modulating downlink reference signals with beam identifiers in accordance with one or more aspects. Generally, a base station 120 can define or map a downlink CSI or synchronization process to one or more APD phase sweeping vectors such that the downlink CSI process has an associated downlink base station beam and associated APD phase vector. Alternatively or additionally, the base station 120 associates SSB indexes (e.g., SSB indexes correspond to DL beams) to one or more phase sweeping vectors to enable signal or beam identification by SSB index. When implementing a downlink CSI process or synchronization process (e.g., SSBs) with a UE 110, the base station 120 may configure the APD 180 and/or DL beam IDs based on aspects of the described uplink processes using the theorem of reciprocity (e.g., binding CSI-RSs and APD phase vectors).

[0092] In aspects, the base station 120 may associate or bind resources of the downlink CSI or synchronization process (e.g. , specific beam) with one or more corresponding APD vectors and downlink reference signal identifiers (e.g., signal or reflection identifiers). This enables the UE 110 can identify and measure signal quality parameters for reflections or LoS downlink reference signals that reach the UE, which in turn provides information (e.g., CSI) to the base station via the DL signal report for analysis of the downlink beams and APD vectors. Based on the analysis, the base station can determine which combination of downlink beam(s) and APD vector enable or improve communication between the base station and UE.

[0093] As shown in FIG. 11 A, the base station 120 transmits a broad beam 1156 toward the UE 110 and/or the APD 180, which includes a signal ray 1151 that is reflected by the APD 180 as a reflection 1152 toward the UE 110. The broad beam 1156 also includes signal ray 1153, 1154, 1155, and 1156 of which, signal ray 1155 is a LoS or direct signal ray that reaches the UE 110. With reference to a table at 1101 of modulated downlink identifiers for incident reference signals and reflections of the reference signals, a reference signal and a reflection of the reference signal may be modulated or encoded (e.g., similar to the uplink signals) to carry same or different identification information. As such, the table 1101 illustrates various combinations of APD-ID modulation, BS-ID modulation, or both APD-ID and BS-ID modulations that a signal ray or reflection may carry. Because the APD 180 does not modulate a direct or LoS signal ray (e.g. signal ray 1155), a signal ray ID 1155 may include null information or only the BS-ID information.

[0094] In the case when both the direct signal ray and the reflected ray including only the BS-ID modulation, the UE 110 may use a difference in observed time-of-arrival or angle-of-arrival to determine which received signal ray is reflected by an APD 180. As shown in a table at 1102 of example reflection and signal ray identifiers, the reflection information modulated onto a signal ray or reflection may include any suitable information useful to distinguish which base station beam and APD phase vector combination results in the received signal ray or reflection of the signal ray. In this example, the base station 120 modulates the signal rays of beam 1156 with a beam ID 1106 prefix and the APD 180 modulates the reflection 1152 of the signal ray with a reflected beam ID 708 suffix. As received by the UE 110, the UE decodes the received ray ID 1118 (e.g., “5.7”) of the reflection 1152 and the received ray ID 1118 (e.g., “5.0”) of the signal ray 1155. The UE 110 then sends the received ray IDs 1118 to the base station 120 via the DL signal report, along with other CSI or information relating to received signals or reflections. The base station may then use the reported signal information to lookup a corresponding APD phase vector and base station beams to evaluate results of the downlink CSI process and/or select respective phase vectors for the APD 180 or base station 120.

[0095] As shown in FIG. 1 IB, the base station 120 may transmit separate downlink beams toward the APD 180 and the UE 110. In the context of separate beam transmission, the base station 120 transmits a narrow beam 1054 that includes signal ray 1171 toward an RIS of the APD 180, which is reflected as reflection 1172 (e.g., reflected signal ray) toward the UE 110. The base station 120 may also concurrently, or at a different time, transmit a beam 1055 that includes signal rays 1181 and 1182 directly toward the UE and without reflecting off the APD 180. In this example, the direct signal ray 1181 and the reflection 1172 that reach the UE 110 may carry different identification information when the APD 180 modulates or adds APD-specific information to the reflected signal ray. Because these beam transmissions do not reach both the APD 180 and the UE, the base station 120 may modulate the signal rays 1171 and 1181 with different information, enabling the UE 110 to distinguish the signals rays from one another without timing information. As received by the UE 110, the UE can decode the received ray ID 1118 (e.g. , “7.9”) for the reflection 1172 and the received ray ID 1118 (e.g., “12.0”) of the signal ray 1181 without timing information. The UE then provides the received ray IDs to the base station as part of the DL signal report 1010, which may also include other CSI or information relating to received signals or reflections. The base station may then use the reported information to lookup a corresponding APD phase vector and base station beams to evaluate results of the downlink CSI process and select respective phase vectors for the APD 180 or base station 120.

[0096] FIG. 12 illustrates an example of a base station using an APD to beam sweep reflections of downlink signals in accordance with various aspects. Aspects described with reference to the example 1200 may be implemented by or with any suitable entities, including those shown in FIGs. 11A and 11B (e.g., for beam identifiers), or other entities described with reference to FIGs. 1-10. Prior to implementing or while using the APD 180 to beam sweep reflections of downlink reference signals toward the UE 110, the base station may select, configure, manage, or use the APD 180 or the UE 110 as described with reference to FIGs. 1-1 IB, the transactions of FIGs. 13-15, or the methods of FIGs. 16-18.

[0097] In aspects, the base station 120 may use the APD 180 to implement beam sweeping to steer or direct (e.g., by beamforming) reflections of downlink reference signals or synchronization signals toward the UE 110. Based on UE feedback (e.g., DL signal report 1010) indicative of reflection identifiers and/or signal quality parameters of the reflections, the base station 120 can evaluate combinations of APD phase vectors and base station beams to select or determine a phase vector for the APD 180 or a phase steering vector for the base station 120 to enable or improve communications through a communication path that includes the APD. When implementing a downlink CSI process or synchronization process (e.g., SSBs) with aUE 110, the base station 120 may configure the APD 180 and / or DL beam IDs using the theorem of reciprocity and based on aspects of the uplink processes (e.g., binding CSI-RSs and APD phase vectors) described herein. In the example illustrated at 1200, the base station 120 implements beam sweeping with an APD 180 of reflections of a downlink reference signal 1271 transmitted (e.g., narrow beam 1056) by the base station based on an APD beam sweeping pattern index 620 (BS index 620, e.g., BS Index 19) to sweep reflections 1276-1272, some of which reach the UE 110 for analysis and decoding.

[0098] As shown in a table at 1201, the UE 110 receives one or more of the reflections of the reference signal 1271 that the APD 180 beam sweeps toward the UE. In aspects, the UE 110 decodes or demodulate a received ray ID 1118 and/or obtain one or more signal quality parameters (e.g., RSRP) for the downlink signal reflections received at the UE. In the present example, the UE 110 receives and is able to decode received ray IDs 1118 for five of the reflections, which include the reflection 1274 of the reference signal 1271. The UE 110 also determines or obtains RSRP values 1206 for some of the received reflections of the downlink reference signals. As shown in the table at 1201, others of the reflections may not reach the UE or reach the UE with insufficient signal strength (e.g., less than -140 dBm) or signal quality to permit decoding of a received ray ID 1118. The UE then sends the respective identifiers, signal quality parameters, CSI, or SSB index information of the received reflections (or direct signals) to the base station 120 via a DL signal report 1010 for analysis in accordance with aspects of phase vector training.

[0099] Using the information provided by the UE 110 (e.g. , via low-band connection 615), the base station 120 can use the received ray IDs 1118 and RSRP values 1206 to determine a combination of a base station phase steering vector and an APD phase vector that enables or improves downlink communication via the APD 180. Concluding the present example, the base station 120 selects phase vector 91 (-97 dBm) and the base station phase steering vector associated with downlink reference signal 1271 (or base station downlink beam) for use in subsequent downlink communication or downlink CSI (e.g., with narrower beams) operations. As described herein, the base station 120 may leverage reciprocity in uplink and downlink directions (e.g., for time division duplex (TDD) systems) to select a same APD phase vector for reflecting both uplink and downlink communications. In other aspects, the base station 120 may select separate phase vectors for the APD to reflect uplink and downlink communications at different respective frequencies (e.g., frequency division duplex (FDD) systems).

Transactions of Phase Vector Training for APD-enabled Communication

[0100] Various aspects of phase vector training for APD-enabled communication phase vector training for APD-enabled communication enable a base station to determine channel information for a communication path (or channel) that includes an APD. Based on the channel information, the base station can select a phase vector for the APD, a phase steering vector for the UE, or a phase steering vector for the base station for subsequent communications through the wireless channel. By so doing, the base station may select one or more of the phase vectors to provide respective transmit or reflection beams that can improve link quality or throughput between the base station and the UE, such as for communications above-6 GHz.

[0101] FIGs. 13-15 provide some examples of signaling and control transactions performed between entities, such as a base station (e.g., base station 120), an APD (e.g., APD 180), and UE (e.g., UE 110), to implement various aspects of phase vector training for APD- enabled communication. The described examples include using an APD for phase vector training with uplink signals (e.g., FIG. 13), using an APD to beam sweep reflected uplink beams (e.g., FIG. 14), and using an APD for phase vector training with downlink signals (e.g., FIG. 15). Various operations described with reference to FIGs. 13-15 can be performed by any entity described with reference to FIGs. 1-12, combined with operations of other examples of FIGs. IS IS, or combined with operations of the methods illustrated in FIGs. 16-18.

[0102] For example, a base station 120 may estimate an approximate location (e.g., a position within a few meters) of a UE 110 though a low-band connection based on radio resource management (RRM) measurements, reported GNSS-based UE-position, or observed time difference of arrival (OTDOA). Based on the approximate location of the UE 110, the base station 120 selects an APD near the approximate location of the UE or an APD having possible LoS paths with both the base station and UE. Generally, positions of the base station 120 and APD 180 are known or fixed, while a position or orientation of the UE 110 may be dynamic or unknown. The base station then configures a beam sweeping pattern of the APD to reflect uplink sounding signals transmitted by the UE. The base station directs the APD to implement the beam sweeping pattern of multiple phase vectors and directs the UE to transmit the uplink sounding signals for reflection by the APD. In aspects, the beam sweeping pattern of the APD is associated or bound with time and frequency resources and/or identifiers of the uplink sounding signals to enable the base station to determine which APD phase vectors are associated with the reflections that reach the base station. Based on identifiers and signal quality metrics (e.g., RSRP) of respective reflections of at least one of the uplink signals received by the base station, the base station can select a phase vector for the APD or a phase steering vector for the UE to use for subsequent communication.

[0103] FIG. 13 illustrates at 1300 example details of signaling and control transactions for configuring and using an adaptive phase-changing device for phase vector training with uplink signals. The described transactions may enable a base station 120 or APD-enabled phase vector function 268 to configure and use an APD 180 to provide reflections of uplink sounding for reception by the base station. The base station 120, the APD 180, and/or the UE 110 may be implemented similar to the entities described with reference to FIGs. 1-12. The example is presented in the context of phase vector training through an uplink channel sounding process, though operations described with reference to FIG. 14 may be initiated or performed by the entities independent of the uplink channel sounding process, such as described with reference to FIG. 14, FIG. 15, or methods of FIGs. 16-18. For example, the base station 120 may select and/or configure an APD 180 as described with reference to FIGs. 14-18 before or while implementing phase vector training for an APD, a base station, and/or user equipment to enable communication through a wireless communication path that includes the APD.

[0104] In an example, a base station 120 determines at 1305 to communicate with a UE 110 using an APD 180. For example, the base station may detect a decrease in signal quality, a decrease in throughput, or loss of a wireless link with the UE through a direct (e.g. LoS path) communication path or a communication path through a different APD. In some cases, the base station selects an APD to use for communication with the UE based on a proximity of the APD to a position of the UE or historical records of using the APD to communicate with UEs proximate the position of the UE. Alternatively or additionally, the base station selects a beam sweeping pattern the APD based on the position of the UE.

[0105] At 1310, the base station 120 associates a UE channel sounding process with an APD phase sweeping pattern. The base station may associate or synchronize resources (e.g., air interface resources) of the channel sounding process with respective phase vectors of the APD phase sweeping pattern and/or identifiers of uplink sounding signals or reflections of the uplink sounding signals. Alternatively or additionally, the base station may associate or bind the phase sweeping pattern of the APD with signal resources (e.g., SRSs or SRS symbols) or antenna ports of the uplink sounding process of the UE.

[0106] At 1315, the base station 120 configures the APD 180 with the phase sweeping pattern. The base station 120 may send an index of the phase sweeping pattern to the APD to direct the APD to access and load the phase sweeping pattern from a local memory of the APD. In some cases, the base station schedules the APD to implement the phase sweeping pattern at a point in time to align (or synchronize) the transmission of the uplink sounding signals by the UE with respective phase vectors of the phase sweeping pattern implemented by the APD.

[0107] At 1320, the base station 120 configures the UE 110 for the channel sounding process. The base station may send parameters of the channel sounding process (e.g., an SRS procedure) to the UE to configure the UE to implement the channel sounding process associated with the phase sweeping pattern of the APD. For example, the base station can schedule the UE to implement the uplink sounding process using selected time and frequency resources of an air interface that extends between the UE and the base station. The selected time resources may align with the point in time at which the APD initiates the phase sweeping pattern of phase vectors for one or more RIS of the APD. Optionally, the parameters of the channel sounding process may include resources for beams of uplink sounding signals directed to the base station without reflection by the APD (e.g., a separate UE-to-BS beam).

[0108] At 1325, the base station 120 initiates the channel sounding process of the UE 110 and the phase sweeping pattern of the APD 180. As described herein, the base station may schedule the channel sounding process of the UE to coincide with the phase sweeping pattern implemented by the APD. The channel sounding process may include resources for an uplink sounding signal that reaches the APD and another uplink sounding signal that reaches the base station directly. In some cases, the base station directs the UE to transmit the separate uplink sounding signals within a same cyclic prefix. Alternatively, the base station 120 may direct the UE 110 to implement an omnidirectional or broad beam transmission of uplink sounding signals that includes signal rays that reach the base station and the APD.

[0109] At 1330, the UE 110 transmits uplink sounding signals that may reach the APD 180 and optionally, at 1335, the UE 110 transmits uplink sounding signals that may reach base station 120. As described with reference to FIGs. 7A, 7B, and 8, the uplink sounding signals may be modulated or encoded with beam identifiers to enable the base station 120 to identify respective reflections or uplink sounding signals that reach the base station.

[0110] At 1340, the APD 180 transforms the uplink sounding signals to direct reflections of the uplink sounding signals for reception by the base station 120. Generally, the base station 120 may use the APD 180 to steer, via a phase vector of the beam sweeping pattern, one or more reflections of the uplink sounding signals that may reach the base station. Alternatively or additionally, the APD 180 may modulate an APD-beam ID onto a respective reflection, such that an identifier of the reflection includes information provided by the UE-beam ID of the UE 110 and/or the APD-beam ID.

[Olll] At 1345, the base station 120 receives respective reflections of at least one of the uplink sounding signals from the APD 180. As described herein (e.g., FIGs. 7A, 7B, and 8), the base station 120 may also decode or demodulate a reflection identifier and/or obtain at least one signal quality parameter for a reflection of the uplink sounding signals that reaches the base station. The signal quality parameter of a reflection may include one or more of an RSSI, an SINR, or an RSRP of the respective reflection of the at least one uplink sounding signal.

[0112] Optionally at 1350, the base station 120 receives the other uplink sounding signals from the UE 110. The base station 120 may also decode or demodulate an identifier and/or obtain at least one signal quality parameter for the uplink sounding signal received directly from the UE. The signal quality parameter of the uplink sounding signal may include one or more of an RSSI, an SINR, or an RSRP of the uplink sounding signal. In aspects in which the UE is capable of transmitting multiple beams, the base station may receive, via the APD, the respective reflection of the uplink sounding signal from a first antenna of the UE and receive the uplink sounding signal directly from a second antenna of the UE. Alternatively or additionally, the base station may receive a reflection of an uplink sounding signal from the APD and an uplink sounding signal from the UE within a same cyclic prefix.

[0113] At 1355, the base station 120 selects a phase vector based on respective identifiers of at least one of the reflections of the uplink sounding signal that reaches the base station. The base station 120 may select a phase vector for the APD or a phase steering vector for the UE based on an analysis of identifiers, sounding resources (SRS resources), and/or signal quality parameters of the reflections that reach the base station. For example, the base station may analyze the respective identifiers and signal quality parameters of the reflections that reach the base station to determine which combination of APD phase vector and UE UL beam provide a reflective signal with a highest RSRP at the base station. Alternatively or additionally, the base station can select another phase steering vector for the UE (e.g., for direct UE-to-BS communications) based on identifiers and signal quality parameters of uplink sounding signals received directly from the UE. In some aspects, the base station may also determine receive beam configurations for antennas of the base station (e.g., as described with reference to FIG. 9) based on the reflections and uplink sounding signals that reach the base station.

[0114] At 1360, the base station 120 configures a respective phase vector of the APD 180 or the UE 110 for communication through the communication path that includes the APD. For example, the base station may configure the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE through the communication path that includes the APD. Alternatively or additionally, the base station configures the UE to use the selected phase steering vector for subsequent uplink communications to the base station through the communication path that includes the APD. In some cases, the base station may also configure the UE with another phase steering vector for uplink communications to the base station through the wireless path that does not include the APD (e.g., direct path).

[0115] FIG. 14 illustrates at 1400 example details of signaling and control transactions for configuring and using an APD to beam sweep reflected uplink beams in accordance with one or more aspects. The described transactions may enable a base station 120 or APD-enabled phase vector function 268 to use an APD to beam sweep reflected uplink beams through a communication path that includes the APD. The base station 120, the APD 180, and/or the UE 110 may be implemented similar to the entities described with reference to FIGs. 1-12. The example is presented in the context of sweeping reflected uplink beams or sweeping direct uplink beams, though operations described with reference to FIG. 14 may be initiated or performed by the entities independent of the uplink beam sweeping process, such as for various downlink operations described with reference to FIG. 15 or methods of FIGs. 16-18. For example, the base station 120 may select, configure, and/or control an APD 180 as described with reference to FIG. 13 or FIGs. 15-18 to implement various aspects of beam sweeping UE-originated uplink signals or beam sweeping base station-originated downlink beams.

[0116] In an example, a base station 120 determines at 1405 to communicate with a UE 110 using an APD 180. The base station 120 may determine to use the APD 180 to communicate with the UE in response to detecting a channel impairment of a direct wireless link between the base station and the UE or a wireless link that uses a different APD. For example, the base station may detect reduced signal quality, reduced throughput, or a loss of a LoS communication link between the base station and the UE.

[0117] At 1410, the base station 120 schedules a UL beam sweeping pattern for uplink beams with the UE 110. Alternatively, the base station 120 may schedule an omnidirectional uplink transmission of uplink sounding signals by the UE 110. In some cases, the base station 120 selects a UL beam sweeping pattern based on an estimated location of the UE 110 relative to the APD 180. The base station may communicate the UL beam sweeping pattern or timing information for uplink channel sounding to the UE 110 via layer 2 (L2) or layer 3 (L3) signaling. At 1415, the base station 120 schedules the APD 180 with a beam sweeping pattern for reflecting uplink beams that reach the APD. The base station can configure the APD for sweeping beam reflections via an APD control channel as described herein. Generally, the base station schedules the UL beam sweeping pattern of the UE and the beam sweeping patten of the APD such that respective phase vectors (e.g., UE phase steering vectors and APD reflective phase vectors) are aligned in time at the APD and at UE side. In other words, the base station schedules the UL beam sweeping pattern of uplink sounding signals by UE for a same time as the beam sweeping pattern of multiple phase vectors by the APD. By so doing the base station can use the APD to beam sweep reflections of UE-originated uplink beams through the communication path that includes the APD.

[0118] At 1420, the UE 110 transmits uplink beams based on the UL beam sweeping pattern. The UE may transmit beams of uplink sounding signals that includes SRS symbols of an uplink sounding process. Alternatively, the UE 110 may transmit the uplink sounding signals via an omnidirectional antenna pattern. In some cases, the UE 110 transmits multiple uplink beams based on the UL beam sweeping pattern, which may include UL beams that reach the APD 180 and other beams that reach the base station 120 without reflection by the APD 180. For example, a UE 110 implemented with multiple transmit-capable radio modules (e.g., multiple mmWave modules) can associate or pair resources of the uplink sounding process with multiple UL beams to provide identifiable pairings or bindings for UE-to-APD beams, APD-to-BS reflected beams, and UE-to-BS direct link beams.

[0119] At 1425, the APD 180 reflects the uplink beams based on the APD beam sweeping pattern. As described herein, the base station 120 may schedule or initiate the beam sweeping pattern of the APD 180 at the same time the UE 110 implements transmissions in accordance with the UL beam sweeping pattern. In some cases, the base station 120 also specifies a UL sounding resource periodicity of the UE 110 to align with the phase sweeping periodicity of the APD 180 to enable the base station to identify or determine which combination of UE UL beam and APD reflection beam results in a beam reflection that reaches the base station. [0120] At 1430, the base station 120 receives at least one of the reflected uplink beams. Generally, the base station 120 can decode or demodulate a reflection identifier and/or obtain at least one signal quality parameter for a reflection of the uplink beam that reaches the base station. The signal quality parameter of a reflected beam may include one or more of an RSSI, an SINR, or an RSRP of the respective reflection of the at least one uplink sounding signal. Optionally at 1435, the base station 120 receives at least one of the other uplink beams from the UE 110. As described herein (e.g., FIGs. 6A-8), the base station 120 may also decode or demodulate an identifier and/or obtain at least one signal quality parameter for the uplink beam that reaches the base station directly. The signal quality parameter of the uplink beam may include one or more of an RSSI, an SINR, or an RSRP of the uplink beam received from the UE.

[0121] At 1440, the base station 120 selects respective beams from the UE beam sweeping pattern or the APD beam sweeping pattern. Alternatively, the base station 120 may select a respective beam for the UE or the APD from another sweeping pattern or select a different sweeping pattern for the UE and/or APD. The base station may select the respective beams or corresponding phase vectors for the APD and/or UE based on an analysis of identifiers, sounding resources (SRS resources), and/or signal quality parameters of the beam reflections that reach the base station. For example, the base station may analyze the respective identifiers and signal quality parameters of the beam reflections to determine which combination of APD phase vector and UE UL beam provide a reflection beam with a highest RSRP at the base station. The base station may use the selected beams of the UE and the APD to enable or improve communication between the base station and the UE, or to implement subsequent rounds of beams sweeping operations to select different or more-narrow beams.

[0122] Optionally, from 1440, the base station 120 may return to 1410 to schedule another iteration of beam sweeping with the APD 180 and/or the UE 110. For example, with multiple iterations of beam sweeping, the base station can direct the APD and UE to implement an initial iteration of beam sweeping a few broad (or wide) beams (e.g., 45 to 60 degrees of spatial coverage), and when the broad beams are selected for the UE and APD, the base station can implement another iteration of the transactions of 1400 to select narrow beams (e.g., 15 to 35 degrees of spatial coverage) from within the broad beams.

[0123] At 1445, the base station 120 configures the APD 180 or the UE 110 for communication through the wireless communication channel that includes the APD. For example, in response to an RSRP of a received reflection exceeding a threshold, the base station determines to cease beam sweeping operations and configures the APD with a phase vector and configures the UE 110 with a phase steering vector for subsequent communication through the wireless channel. In some cases, the base station configures the APD and UE for communication after one iteration of beam sweeping (e.g., for static or slow moving UEs). Alternatively, the base station may configure the APD and UE for communication after multiple iterations of beam sweeping (e.g., moving UEs or changing channel conditions).

[0124] FIG. 15 illustrates at 1500 example details of signaling and control transactions for configuring and using an adaptive phase-changing device for phase vector training with downlink signals in accordance with one or more aspects. The described transactions may enable a base station 120 or APD-enabled phase vector function 268 to beam sweep reflected downlink beams from an APD 180 through a communication path that includes the APD. The base station 120, the APD 180, and/or the UE 110 may be implemented similar to the entities described with reference to FIGs. 1-12. The example is presented in the context of phase vector training through a downlink CSI process, though operations described with reference to FIG. 15 may be initiated or performed by the entities independent of the downlink CSI process, such as described with reference to FIG. 13, FIG. 14, or methods of FIGs. 17-19. For example, the base station 120 may select, configure, and/or control an APD 180 as described with reference to FIG. 13, FIG. 14, or FIGs. 16-19 to implement various aspects of beam sweeping base station-originated downlink beams through a communication path that includes the APD.

[0125] In an example, the base station 120 determines at 1505 to communicate with a UE 110 using an APD 180. As described herein, base station 120 may determine to use the APD 180 to communicate with the UE in response to detecting a channel impairment of a direct wireless link between the base station and the UE or a wireless link that uses a different APD. At 1510, the base station 120 associates a CSI process with an APD phase sweeping pattern. The base station may associate resources (e.g., air interface resources) of the CSI process with respective phase vectors of the APD phase sweeping pattern and/or identifiers of downlink reference signals or reflections of the downlink reference signals. Alternatively or additionally, the base station may associate or bind the phase sweeping pattern of the APD with signal resources (e.g., CSI signals, SSB indexes, or antenna ports) of the downlink CSI process of the base station. In other implementations, the base station may associate or bind SSB indexes (that are mapped to BS- beams) with respective phase vectors of the APD phase sweeping pattern.

[0126] At 1515, the base station 120 configures the APD with the phase sweeping pattern. The base station 120 may send an index of the phase sweeping pattern to the APD to direct the APD to access and load the phase sweeping pattern from a local memory of the APD. In some cases, the base station schedules the APD to implement the phase sweeping pattern at a point in time to align the transmission of the downlink reference signals by the base station with respective phase vectors of the phase sweeping pattern implemented by the APD. [0127] At 1520, the base station 120 initiates the CSI process and the phase sweeping pattern of the APD. Generally, the base station schedules the CSI process of downlink signal transmission to coincide with the phase sweeping pattern implemented by the APD. In some cases, the base station uses the APD control channel to initiate or coordinate the phase sweeping pattern of the APD to ensure that APD phase sweeping vectors align with transmission of the downlink reference signals toward the APD, as well as the direct BS-to-UE downlink reference signals. As such, the CSI process may include resources for a downlink reference directed toward the APD and another downlink reference signal directed toward the UE.

[0128] At 1525, the base station 120 transmits downlink reference signals toward the RIS of the APD and optionally at 1530, the base station 120 transmits downlink reference signals toward the UE 110. As described with reference to FIGs. 11 A- 12, the downlink reference signals may be modulated or encoded with beam identifiers to enable the UE to identify respective reflections or downlink reference signals that reach the UE. The base station may transmit the downlink reference signal toward the APD and the downlink reference signal toward the APD within a same cyclic prefix to facilitate processing and decoding of received downlink signals.

[0129] At 1535, the APD 180 transforms the downlink reference signals to direct reflections of the downlink reference signals for reception by the UE 110. Generally, the base station 120 may use the APD 180 to steer, via a phase vector of the beam sweeping pattern, one or more reflections of the downlink reference signals toward the UE. Alternatively or additionally, the APD 180 modulates an APD-beam ID onto a respective reflection, such that an identifier of the reflection includes information provided by the BS-beam ID of the base station 120 and/or the APD-beam ID.

[0130] At 1540, the UE 110 receives reflections of the downlink reference signals from the APD 180. As described herein (e.g., FIGs. 11A-12), the UE 110 may also decode or demodulate a reflection identifier and/or obtain at least one signal quality parameter for a reflection of the downlink reference signals that reach the UE 110. The signal quality parameter of a reflection may include one or more of an RSSI, an SINR, or an RSRP of the respective reflection of the at least one downlink reference signal.

[0131] Optionally at 1545, the UE 110 receives downlink reference signals directly from the base station 120 without reflecting off the APD 180. The UE 110 may also decode or demodulate an identifier and/or obtain at least one signal quality parameter for the downlink reference signal received directly from the base station. For example, UE 110 may receive and process a composite CSI reference signal from the base station via APD and from the base station directly, which the UE can use to provide CSI feedback (e.g., RSRP, RSRQ, SINR, or the like). [0132] At 1550, the UE 110 transmits information associated with the reflections of the downlink reference signals received by the UE 110. As described herein, the UE 110 can decode or demodulate a reflection identifier and/or obtain one or more signal quality parameters (e.g., RSRP) for reflections or direct downlink reference signals received at the UE 110. The UE 110 then sends an indication or report of the reflection identifier and/or one or more signal quality parameters back to the base station 120.

[0133] At 1555, the base station 120 selects a phase vector for the APD 180 or the base station 120 based on the reflection information. The base station 120 may select a phase vector for the APD or a phase steering vector for the base station based on an analysis of identifiers, CSI information, SSB index, and/or other signal quality parameters of the reflections provided by the UE as feedback for the reflections/signals that reach the UE. For example, the base station may analyze the respective identifiers and signal quality parameters of the reflections to determine which combination of APD phase vector and base station downlink beam provide a reflective signal with a highest RSRP at the UE. Alternatively or additionally, the base station can select another phase steering vector for the base station based on identifiers and signal quality parameters of downlink reference signals that reach the UE directly from the base station.

[0134] At 1560, the base station 120 configures a respective phase vector of the APD 180 or the base station 120. For example, the base station configures the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE through the communication path that includes the APD. Alternatively or additionally, the base station configures an antenna panels of the base station with the selected phase steering vector for subsequent downlink communications to the UE through the communication path that includes the APD. In some cases, the base station also configures the antenna panels of the base station with another phase steering vector for downlink communications to the UE through the wireless path that does not include the APD (e.g., direct path).

Example Methods for Phase Vector Training for APD-enabled Communication

[0135] Example methods 1600- 1800 are described with reference to FIG. 16 through FIG. 18 in accordance with one or more aspects of phase vector training for APD-enabled communication. The order in which the method blocks are described are not intended to be construed as a limitation, and any number of the described method blocks can be skipped or combined in any order to implement a method or an alternative method. Generally, any of the components, modules, methods, and operations described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example methods may be described in the general context of executable instructions stored on computer-readable storage memory that is local and/or remote to a computer processing system, and implementations can include software applications, programs, functions, and the like. Alternatively or additionally, any of the functionality described herein can be performed, at least in part, by one or more hardware logic components, such as, and without limitation, Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SoCs), Complex Programmable Logic Devices (CPLDs), and the like.

[0136] FIG. 16 illustrates an example method 1600 for phase vector training based on uplink signals reflected by an APD in accordance with one or more aspects. In various implementations, operations of the method 1600 are performed by or with a base station, APD, or phase vector function, such as the base station 120, APD 180, and/or APD-enabled phase vector function 268 as described with reference to any of FIGs. 1-15. At times, aspects of the method 1600 operate in conjunction with transactions of FIGs. 13-15, the method 1700, and/or the method 1800.

[0137] At block 1605, a base station determines to communicate with a UE using an APD. For example, the base station may detect a decrease in signal quality, a decrease in throughput, or loss of a wireless link with the UE through a direct ( e.g . LoS) communication path or a communication path through a different APD. The base station may also select the APD and/or a phase sweeping pattern for the APD as described herein (e.g., as described with reference FIGs. 13-15).

[0138] At block 1610, the base station configures the APD with a phase sweeping pattern. The base station 120 may send an index of the phase sweeping pattern to the APD to direct the APD to access and load the phase sweeping pattern from a local memory of the APD. Alternatively or additionally, the base station may send timing information as described herein, which may include a point in time to initiate the beam sweeping pattern or one or more time slots during which to implement respective phase vectors of the phase sweeping pattern.

[0139] At block 1615, the base station configures the UE to implement an uplink channel sounding process. In aspects, the base station sends parameters of the channel sounding process to the UE to configure the UE to implement the channel sounding process at a predefined time and with uplink sounding resources (e.g., SRS resources) associated with the phase sweeping pattern of the APD. Optionally, the parameters of the channel sounding process may include resources (e.g., SRS symbols or antenna ports) for beams of uplink sounding signals that may reach the base station without reflection off the APD.

[0140] At block 1620, the base station directs the APD to implement the phase sweeping pattern while the UE transmits uplink sounding signals that correspond to the uplink sounding process. As described herein, the base station may schedule the channel sounding process of the UE to coincide with the phase sweeping pattern implemented by the APD. Thus, the base station may direct the UE to transmit beams of uplink sounding signals while the APD implements phase vectors of the phase sweeping pattern to sweep reflections of the uplink sounding signals that reach the APD. The base station may also direct the UE to transmit an omnidirectional, broad beam, or separate beams of uplink signals that reach the APD and/or the base station directly. These uplink signals may be transmitted or adjusted (e.g., via timing advance) such that direct signals and reflections of the signals reach the base station within a same cyclic prefix.

[0141] At block 1625, the base station receives, from the APD, respective reflections of at least one of the uplink sounding signals transmitted by the UE. Generally, the base station can decode or demodulate reflection identifier and/or obtain at least one signal quality parameter for a reflection of the uplink sounding signals that reaches the base station. Optionally at block 1630, the base station receives another of the uplink sounding signals from the UE. The base station may also decode or demodulate an identifier and/or obtain at least one signal quality parameter for an uplink sounding signal received directly from the UE.

[0142] At block 1635, the base station selects a phase vector based on respective identifiers and/or signal quality parameters of reflections received by the base station. The base station 120 may select a phase vector for the APD or a phase steering vector for the UE based on an analysis of identifiers, sounding resources (SRS resources), and/or signal quality parameters of the reflections that reach the base station. For example, the base station may analyze the respective identifiers and signal quality parameters of the reflections to determine which combination of APD phase vector and UE UL beam provided the reflective signal received at the base station with a highest RSRP.

[0143] At block 1640, the base station configures the APD with the selected phase vector. Based on a selected phase vector for the APD, the base station can configure the APD to use the selected phase vector to establish or improve APD-enabled communications between the base station and the UE. Optionally, from block 1640, the method 1600 may return to block 1610 or 1615 to implement another iteration of the method 1600 to select a different phase vector (e.g., in response to UE movement) or select another APD phase vector that is associated with a narrower beam (e.g., for further phase vector training or beam refinement).

[0144] At block 1645, the base station configures the UE with the selected phase steering vector. Based on a selected phase steering vector for the UE, the base station can configure the UE to use the selected phase steering vector to enable or improve APD-enabled communications between the base station and the UE. Alternatively or additionally, the base station can configure the UE with another phase steering vector for direct uplink communications that do not reflect off the APD. Optionally, from block 1645, the method 1600 may return to block 1610 or 1615 to implement another iteration of the method to select a different phase vector (e.g., in response to UE movement) or select another UE phase steering vector that is associated with a narrower beam (e.g., for further phase vector training or beam refinement).

[0145] FIG. 17 illustrates an example method 1700 for directing an APD to beam sweep reflections of uplink signals in accordance with one or more aspects. In various implementations, operations of the method 1700 are performed by or with a base station, APD, or phase vector function, such as the base station 120, APD 180, and/or APD-enabled phase vector function 268 as described with reference to any of FIGs. 1-15. At times, aspects of the method 1700 operate in conjunction with transactions of FIGs. 13-15, the method 1600, and/or the method 1800.

[0146] At block 1705, a base station determines to communicate with a UE using an APD. The base station 120 may determine to use the APD 180 to communicate with the UE in response to detecting a channel impairment of a direct wireless link between the base station and the UE or a wireless link that uses a different APD. For example, the base station may detect reduced signal quality, reduced throughput, or a loss of a LoS communication link between the base station and the UE.

[0147] At block 1710, configures the UE to transmit beams of uplink sounding signals in accordance with an uplink beam sweeping pattern. In some cases, the base station 120 selects a UL beam sweeping pattern based on an estimated position or orientation of the UE 110 relative to the APD 180 (e.g., from low-band communications). The base station may communicate the UL beam sweeping pattern or timing information for uplink channel sounding to the UE 110 via L2 or L3 signaling. Alternatively or additionally, the base station schedules the UE to initiate the transmission of the beams of the uplink sounding signals of the UE beam sweeping pattern at a point in time or time slot to align transmission of the uplink beams with a phase sweeping by the APD.

[0148] At block 1715, the base station configures the APD with a beam sweeping pattern of multiple phase vectors. In some cases, the base station selects the beam sweeping pattern based on the estimated position or orientation of the UE or historical records of APD use for UEs proximate the location of the UE. As described herein, the base station can schedule the UL beam sweeping pattern of the UE and the beam sweeping patten of the APD based on the same point in time or time slot such that respective phase vectors (e.g., UE phase steering vectors and APD reflective phase vectors) are aligned in time at the APD and at UE side.

[0149] At block 1720, the base station directs the APD to perform the beam sweeping pattern while the UE transmits the beams of the uplink sounding signals. Accordingly, the APD implements a sequence phase vectors of the beam sweeping pattern while the UE 110 transmits multiple uplink beams based on the UL beam sweeping pattern. The multiple uplink beams transmitted by the UE may include UL beams that reach the APD 180 and other beams that reach the base station 120 without reflection off the APD 180.

[0150] At block 1725, the base station receives, from the APD, respective reflections of at least one beam of the uplink sounding signals transmitted by the UE. The base station 120 can decode or demodulate a reflection identifier and/or obtain at least one signal quality parameter for a reflection of the uplink beam that reaches the base station. Optionally at block 1730, the base station receives another beam of the uplink sounding signals from the UE that do not reflect off the APD. As described herein (e.g., FIGs. 7A-8), the base station 120 may also decode or demodulate an identifier and/or obtain at least one signal quality parameter for the direct uplink beam that reaches the base station. The signal quality parameter of the uplink beam may include one or more of an RSSI, an SINR, or an RSRP of the uplink beam received from the UE.

[0151] At block 1735, the base station selects a beam for the APD or a beam for the UE based on the received reflections of the at least one beam of the uplink sounding signals. The base station may select the respective beams or corresponding phase vectors for the APD and/or UE based on an analysis of identifiers, sounding resources (SRS resources), and/or signal quality parameters of the beam reflections that reach the base station. For example, the base station may analyze the respective identifiers and signal quality parameters of the beam reflections to determine which combination of APD phase vector and UE UL beam provided the reflection beam received by the base station with a highest RSRP. Alternatively or additionally, the base station may select a beam for the UE to use for direct UE-to-BS communications based on analysis of uplink beams received directly from the UE.

[0152] Optionally at block 1740, the base station configures the APD with the selected APD beam. For example, the base station configures the APD with a phase vector associated with the reflected beam that reaches the base station with the highest RSRP value. In some cases, the base station configures the APD for communication after an iteration of beam sweeping when a reflection is received at the base station with an RSRP that exceeds a threshold for beam sweeping operations. Alternatively, the base station may configure the APD for communication after multiple iterations of beam sweeping in which different or more-narrow beams are selected after at least one iteration.

[0153] Optionally at block 1745, the base station configures the UE with the selected UE beam. For example, the base station configures the UE with a phase steering vector associated with the reflected beam that reaches the base station with the highest RSRP value. The base station may configure the UE for communication after an iteration of beam sweeping as described herein or use the selected phase steering vector for a subsequent beam sweeping process to select a narrower phase steering vector for the UE.

[0154] FIG. 18 illustrates an example method 1800 for phase vector training based on downlink signals reflected by an APD in accordance with one or more aspects. In various implementations, operations of the method 1800 are performed by or with a base station, APD, or phase vector function, such as the base station 120, APD 180, and/or APD-enabled phase vector function 268 as described with reference to any of FIGs. 1-15. At times, aspects of the method 1800 operate in conjunction with transactions of FIGs. 13-15, the method 1600, and/or the method 1700.

[0155] At block 1805, a base station determines to communicate with a UE using an APD. The base station 120 may determine to use the APD 180 to communicate with the UE in response to detecting a channel impairment of a direct wireless link between the base station and the UE or a wireless link that uses a different APD. The base station may also select the APD and/or a phase sweeping pattern for the APD as described herein (e.g., as described with reference FIGs. 13-15).

[0156] At block 1810, the base station configures the APD to implement a phase sweeping pattern. The base station 120 may send an index of the phase sweeping pattern to the APD to direct the APD to access and load the phase sweeping pattern from a local memory of the APD. Alternatively or additionally, the base station may send timing information as described herein, which may include a point in time to initiate the beam sweeping pattern or one or more time slots during which to implement respective phase vectors of the phase sweeping pattern.

[0157] At block 1815, the base station directs the APD to implement the phase sweeping pattern. The APD may implement a sequence of phase vectors of the phase sweeping pattern at the predetermined point in time or during the time slots as specified by the base station. At block 1820, the base station transmits downlink reference signals toward an RIS of the APD while the APD implements the phase sweeping pattern and optionally, at block 1825, the base station transmits other downlink reference signals toward the UE. As described with reference to FIGs. 11A-12, the downlink reference signals may be modulated or encoded with beam identifiers to enable the UE to identify respective reflections or downlink signals that reach the UE. The base station may transmit the downlink reference signal toward the APD and the downlink reference signal toward the APD within a same cyclic prefix to facilitate processing and decoding of received down link signals.

[0158] At block 1830, the base station receives, from the UE, a report of received reflections of the downlink reference signals. Optionally, the report may include information relating to the other downlink CSI signals or SSBs received from the base station. For example, the UE 110 can decode or demodulate a reflection identifier and/or obtain one or more signal quality parameters (e.g., RSRP) for reflections or direct downlink reference signals received at the UE 110. The UE 110 then sends the report indicative of the reflection identifier and/or one or more signal quality parameters back to the base station 120.

[0159] At block 1835, the base station selects a phase vector for the APD or a phase steering vector for the base station based on the report of the received reflections of the downlink reference signals. The base station 120 may select a phase vector for the APD or a phase steering vector for the base station based on an analysis of identifiers, CSI information, SSB indexes, and/or other signal quality parameters of the reflections that the UE provides as feedback for the reflections that reach the UE. Alternatively or additionally, the base station can select another phase steering vector for the base station based on identifiers and signal quality parameters of downlink reference signals that reach the UE directly from the base station.

[0160] At block 1840, the base station configures the APD with the selected phase vector. The base station may configure the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE through the communication path that includes the APD. At block 1845, the base station configures the base station with the selected phase steering vector. In some cases, the base station configures an antenna array of the base station with the selected phase steering vector for subsequent downlink communications to the UE through the communication path that includes the APD. Alternatively or additionally, the base station configures the antenna array of the base station with another phase steering vector for downlink communications to the UE through the wireless path that does not include the APD (e.g. , direct path). By so doing the base station may establish or improve communication between the base station and UE through the communication path that includes the APD.

[0161] Although aspects of phase vector training for APD-enabled communication have been described in language specific to features and/or methods, the subject of the appended claims is not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as example implementations of phase vector training for APD- enabled communication and other equivalent features and methods are intended to be within the scope of the appended claims. Thus, the appended claims include a list of features that can be selected in “any combination thereof,” which includes combining any number and any combination of the listed features. Further, various different aspects are described, and it is to be appreciated that each described aspect can be implemented independently or in connection with one or more other described aspects.

[0162] Various example of phase vector training for APD-enabled communication are described below: Example 1: A method performed by a base station to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring an adaptive phase-changing device, APD, with a phase sweeping pattern of multiple phase vectors; configuring a user equipment, UE, to implement an uplink sounding process through a wireless channel; directing the APD to implement the phase sweeping pattern while the UE transmits at least one uplink sounding signal that corresponds to the uplink sounding process; receiving, from the APD and based on the phase sweeping pattern, at least one reflection of the at least one uplink sounding signal transmitted by the UE, each of the reflections having a respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern; selecting a phase vector for the APD based on the respective identifier of the at least one reflection; and configuring the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE.

Example 2: The method as recited in example 1, further comprising: demodulating, by the base station, the at least one reflection of the at least one uplink sounding signal to obtain the respective identifiers that correspond to at least one of the multiple phase vectors of the phase sweeping pattern.

Example 3: The method as recited in example 1 or example 2, further comprising: selecting the phase vector for the APD based on: the respective identifiers of the at least one reflection of the at least one uplink sounding signal; and respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal.

Example 4a: The method as recited in any preceding example, further comprising: selecting a phase steering vector for the UE based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal; and configuring the UE to use the selected phase steering vector for a subsequent uplink communication to the base station.

Example 5a: The method as recited in any preceding example, further comprising: selecting a beam configuration for the base station to receive subsequent uplink communications based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal; and configuring an antenna of the base station with the beam configuration to receive the subsequent uplink communication from the UE.

Example 5b: The method as recited in any preceding example, further comprising: selecting a beam configuration for the base station to transmit subsequent downlink communications based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal (e.g., employing reciprocity); and configuring an antenna of the base station with the beam configuration to transmit a subsequent downlink communication to the UE.

Example 6: The method as recited in any preceding example, wherein: the at least one uplink sounding signal is a first uplink sounding signal, the wireless channel that includes the APD is a first wireless communication channel, and the method further comprises: receiving, from the UE, a second of the uplink sounding signals through a second wireless communication channel between the base station and UE that does not include reflection off the APD; selecting a phase steering vector for the UE based on an identifier of the second uplink sounding signal; and configuring the UE to use the selected phase steering vector for subsequent uplink communications to the base station through the second wireless communication channel.

Example 7: The method as recited in any preceding example, further comprising: directing the UE to transmit the first uplink sounding signal and the second uplink sounding signal within a same cyclic prefix; or receiving the reflection of the first uplink sounding signal from the APD and receiving the second uplink sounding signal from the UE within a same cyclic prefix.

Example 8: The method as recited in any preceding example, further comprising: receiving, via the APD, the respective reflection of the first uplink sounding signal from a first antenna of the UE; and receiving the second uplink sounding signal from a second antenna of the UE.

Example 9: The method as recited in any preceding example, further comprising: receiving, from the APD, the respective reflection of the first uplink sounding signal at a frequency that is above six gigahertz, GHz; or receiving the second uplink sounding signal from the UE at a frequency that is above six GHz.

Example 10: The method as recited in any preceding example, wherein the respective signal quality parameters of the at least one reflection includes an indication of one of: a received signal strength indicator, RSSI, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal; a signal-to-interference-plus-noise ratio, SINR, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal; or a reference signal received power, RSRP, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal.

Example 11: The method as recited in any preceding example, further comprising: configuring the UE to transmit the at least one uplink sounding signal as one or more uplink sounding reference signals, SRSs, or SRS symbols.

Example 12: The method as recited in any preceding example, further comprising: associating the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE; synchronizing the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE; or binding (e.g., associating or mapping) the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE.

Example 13: The method as recited in any preceding example: associating beam identifiers of the at least one uplink sounding signal or the reflection identifiers of the APD with corresponding ones of the multiple phase vectors of the phase sweeping pattern to provide the respective identifiers of the reflections that correspond to the multiple phase vectors of the phase sweeping pattern; or binding (e.g., associating or mapping) beam identifiers of the at least one uplink sounding signal or reflection identifiers of the APD with corresponding ones of the multiple phase vectors of the phase sweeping pattern to provide the respective identifiers of the reflections that correspond to the multiple phase vectors of the phase sweeping pattern.

Example 14: The method as recited in any preceding example, wherein directing the APD to implement the phase sweeping pattern while the UE transmits the at least one uplink sounding signal comprises: scheduling the UE to implement the uplink sounding process using one or more time resources of an air interface that extends between the UE and the base station; and scheduling the APD to implement the phase sweeping pattern at a point in time to align the transmission of the at least one uplink sounding signal with respective phase vectors of the phase sweeping pattern.

Example 15: The method as recited in any preceding example, further comprising: configuring the UE to transmit, as part of the uplink sounding process, the at least one uplink sounding signal as beams of the at least one uplink sounding signal in accordance with an uplink beam sweeping pattern; directing the APD to implement the multiple phase vectors of the beam sweeping pattern while the UE transmits the beams of the at least one uplink sounding signal in accordance with the uplink beam sweeping pattern; receiving, from the APD, at least one reflection of at least one beam of the uplink sounding signals transmitted by the UE, each of the reflections of the beams having the respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern; and selecting the phase vector for the APD based on the respective identifier of the at least one reflection of the at least one beam of uplink sounding signals.

Example 16: The method as recited in any preceding example, further comprising: selecting the phase steering vector for the UE based on the respective identifiers of the at least one reflection of the at least one beam of uplink sounding signals.

Example 17: The method as recited in any preceding example, further comprising: selecting the phase steering vector for the UE to use for the subsequent uplink communication based on: the respective identifiers of the at least one reflection of the at least one beam of uplink sounding signals; and respective signal quality parameters of the at least one reflection of the at least one beam of uplink sounding signals; or selecting the phase vector for the APD to use for the reflecting of the subsequent incident signal based on: the respective identifiers of the at least one reflection of the at least one beam of uplink sounding signals; and respective signal quality parameters of the at least one reflection of the at least one beam of uplink sounding signals.

Example 18: The method as recited in any preceding example, further comprising: receiving, from the UE, at least one other beam of the uplink sounding signals that is not reflected by the APD; and selecting another phase steering vector for the UE to use for the subsequent uplink communication based on: a respective identifier of the at least one other beam of uplink sounding signals that is not reflected by the APD; and a respective signal quality parameter of the at least one other beam of uplink sounding signals that is not reflected by the APD.

Example 19: The method as recited in any preceding example, wherein: the uplink beam sweeping pattern of the UE specifies a first set of beams associated with a first set of uplink sounding resources and a second set of beams associated with a second set of uplink sounding resources, and the method further comprises: receiving, from the APD, a first beam of the first set of beams as the at least one beam of uplink sounding signals reflected by the APD; and receiving, from the UE, a second beam of the second set of beams as the at least one other beam of uplink sounding signals that is not reflected by the APD.

Example 20: The method as recited in any preceding example, further comprising: selecting the phase steering vector for the UE to use from a set of phase steering vectors that correspond to the uplink beam sweeping pattern of the UE; or selecting the phase vector for the APD to use from the multiple phase vectors of the beam sweeping pattern of the APD.

Example 21: The method as recited in any preceding example, wherein: the phase steering vector selected for the UE corresponds to a beam that is narrower than one or more of the beams of uplink sounding signals of the uplink beam sweeping pattern of the UE; or the phase vector selected for the APD corresponds to a reflection beam that is narrower than one or more respective reflection beams provided by the multiple phase vectors of beam sweeping pattern of the APD.

Example 22: The method as recited in any preceding example, wherein directing the APD to implement the multiple phase vectors of the beam sweeping pattern while the UE transmits the beams of the at least one uplink sounding signal comprises: scheduling the APD to implement the multiple phase vectors of the beam sweeping pattern at a point in time; and scheduling the UE to initiate the transmission of the beams of the at least one uplink sounding signal of the uplink beam sweeping pattern at the point in time to concurrently implement respective ones of the multiple phase vectors with corresponding beams of the at least one uplink sounding signal.

Example 23: The method as recited in any preceding example, wherein: configuring the UE to transmit the beams of the at least one uplink sounding signal further comprises specifying a periodicity of uplink sounding resources by which the UE is to transmit the beams of the at least one uplink sounding signal; and configuring the APD to implement the multiple phase vectors further comprises specifying a periodicity for implementing the multiple phase vectors of the APD beam sweeping pattern to align transmission of the beams of the at least one uplink sounding signal with the implementing of respective ones of the multiple phase vectors to provide the at least one reflection of the at least one beam of uplink sounding signals.

Example 24: A method performed by a base station to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring an adaptive phase-changing device, APD, with a phase sweeping pattern of multiple phase vectors; directing the APD to implement the phase sweeping pattern of the multiple phase vectors; transmitting at least one downlink reference signal while the APD implements the phase sweeping pattern of the multiple phase vectors to reflect the at least one downlink reference signal through a wireless channel that includes the APD; receiving, from a user equipment, UE, an indication of respective identifiers of at least one reflection of at least one of the downlink reference signal that is received by the UE; selecting a phase vector for the APD based on the respective identifiers of the at least one reflection; and configuring the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE.

Example 25: The method as recited in example 24, further comprising: receiving, from the UE, an indication of respective signal quality parameters for the at least one reflection of the at least one downlink reference signal that is received by the UE; and selecting the phase vector for the APD based on: the respective identifiers of the at least one reflection of the at least one downlink reference signal; and the respective signal quality parameters of the at least one reflection of the at least one downlink reference signal.

Example 26: The method as recited in example 25, further comprising: selecting a phase steering vector for the base station based on: the respective identifiers of the at least one reflection of the at least one downlink reference signal; or the respective signal quality parameters of the at least one reflection of the at least one downlink reference signal; and configuring the base station to use the selected phase steering vector for a subsequent downlink communication to the UE.

Example 27: The method as recited in any preceding example, wherein the at least one downlink reference signal is a first downlink reference signal, the wireless channel is a first wireless communication channel, and the method further comprises: transmitting a second downlink reference signal through a second wireless communication channel that does not include the APD; receiving, from the UE, an indication of an identifier or a signal quality parameter of the second downlink reference signal that is received by the UE; selecting a phase steering vector for the base station for the second wireless communication channel based on the identifier or the signal quality parameter of the second downlink reference signal received by the UE; and configuring the base station to use the selected phase vector for a subsequent downlink communication to the UE through the second wireless communication channel.

Example 28: The method as recited in any preceding example, further comprising: transmitting the first downlink reference signal through the first wireless communication channel and transmitting the second downlink reference signal through the second wireless communication channel within a same cyclic prefix.

Example 29: The method as recited in any preceding example, further comprising: transmitting the first downlink reference signal at a frequency that is above six gigahertz; or transmitting the second downlink reference signal at a frequency that is above six gigahertz.

Example 30: The method as recited in any preceding example, further comprising: transmitting the at least one downlink reference signal as one of: channel state information reference signals, CSI-RS; or synchronization signal block, SSB, synchronization signals.

Example 31 : The method as recited in any of examples 24 to 30, further comprising: receiving the indication of the respective identifiers of the at least one reflection as one of: an indication of a CSI-RS resource for the reflection; or an indication of an SSB index for the reflection.

Example 32: The method as recited in any preceding example, wherein the signal quality parameter includes an indication of one of: a received signal strength indicator, RSSI, of the respective reflection of the at least one downlink reference signal or the second downlink reference signal; a signal-to-interference-plus-noise ratio, SINR, of the respective reflection of the at least one downlink reference signal or the second downlink reference signal; or a reference signal received power, RSRP, of the respective reflection of the at least one downlink reference signal or the second downlink reference signal.

Example 33: The method as recited in any preceding example, further comprising: associating the phase sweeping pattern of the APD with signal air interface resources of the at least one downlink reference signal transmitted by the base station; or binding the phase sweeping pattern of the APD with signal air interface resources of the at least one downlink reference signal transmitted by the base station.

Example 34: The method as recited in any preceding example, further comprising: associating beam identifiers of the at least one downlink reference signal or reflection identifiers of the APD with corresponding ones of the multiple phase vectors of the phase sweeping pattern to provide the respective identifiers of the at least one reflection that corresponds to the multiple phase vectors of the phase sweeping pattern; or binding beam identifiers of the at least one downlink reference signal or reflection identifiers of the APD with corresponding ones of the multiple phase vectors of the phase sweeping pattern to provide the respective identifiers of the at least one reflection that corresponds to the multiple phase vectors of the phase sweeping pattern. Example 35: The method as recited in any preceding example, wherein directing the APD to implement the phase sweeping pattern while transmitting the at least one downlink reference signal comprises: scheduling transmission of the at least one downlink reference signal for time resources of an air interface that extends between the UE and base station; and scheduling the APD to implement the phase sweeping pattern at a point in time to align implementation of phase vectors of the phase sweeping pattern with transmission of respective ones of the time resources by which the at least one downlink reference signal is transmitted.

Example 36: A method performed by a base station to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring an adaptive phase-changing device, APD, with a phase sweeping pattern of multiple phase vectors; configuring a user equipment, UE, to implement an uplink sounding process through a wireless channel; directing the APD to implement the phase sweeping pattern while the UE transmits at least one uplink sounding signal that corresponds to the uplink sounding process; receiving, from the APD and based on the phase sweeping pattern, at least one reflection of at least one of the uplink sounding signal transmitted by the UE, each of the reflections having a respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern; selecting a phase steering vector for the UE based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal; and configuring the UE to use the selected phase steering vector for a subsequent uplink communication to the base station.

Example 37: The method as recited in example 36, further comprising the features recited by any of examples 2, 3 and/or 5b to 23.

Example 38. A method performed by a base station to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring an adaptive phase-changing device, APD, with a phase sweeping pattern of multiple phase vectors; directing the APD to implement the phase sweeping pattern of the multiple phase vectors; transmitting at least one downlink reference signal while the APD implements the phase sweeping pattern of the multiple phase vectors to reflect the at least one downlink reference signal through a wireless channel that includes the APD; receiving, from a user equipment, UE, an indication of respective identifiers of at least one reflection of the at least one of the downlink reference signal that is received by the UE; selecting a phase steering vector for the base station based on (i) the respective identifiers of the at least one reflection of the at least one downlink reference signal, and/or (ii) the respective signal quality parameters of the at least one reflection of the at least one downlink reference signal; and configuring the base station to use the selected phase steering vector for a subsequent downlink communication to the UE. Example 39: The method as recited in example 36, further comprising the features recited by any of examples 27 to 35.

Example 40: A base station apparatus comprising: at least one wireless transceiver; a processor; and computer-readable storage media comprising instructions, responsive to execution by the processor, for directing the base station apparatus to perform any one of the methods recited in examples 1 to 39 using the at least one wireless transceiver.

Example 41: A computer-readable storage media comprising instructions that, responsive to execution by a processor, cause a method as recited in any one of examples 1 to 39 to be performed.

Claims

CLAIMS What is claimed is:

1. A method performed by a base station (120) to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring (1315) an adaptive phase-changing device, APD (180), with a phase sweeping pattern of multiple phase vectors; configuring (1320) a user equipment, UE (110), to implement an uplink sounding process through a wireless channel; directing (1325) the APD to implement the phase sweeping pattern while the UE transmits at least one uplink sounding signal that corresponds to the uplink sounding process; receiving (1345), from the APD and based on the phase sweeping pattern, at least one reflection of the at least one uplink sounding signal, each of the reflections having a respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern; selecting (1355) a phase vector for the APD based on at least one of the respective identifiers of the at least one reflection; and configuring (1360) the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE.

2. The method as recited in claim 1, further comprising: demodulating, by the base station, the at least one reflection of the at least one of uplink sounding signal to obtain the at least one respective identifier that corresponds to one of the multiple phase vectors of the phase sweeping pattern.

3. The method as recited in claim 1, further comprising: selecting the phase vector for the APD based on the respective identifiers of the at least one reflection of the at least one uplink sounding signal and respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal; or selecting a phase steering vector for the UE based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal and configuring the UE to use the selected phase steering vector for subsequent uplink communications to the base station.

4. The method as recited in any one of claims 1 to 3, further comprising: selecting a beam configuration for the base station to receive subsequent uplink communications based on the respective identifiers or respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal; and configuring an antenna of the base station with the beam configuration to receive the subsequent uplink communications from the UE.

5. The method as recited in any one of claims 1 to 4, wherein: the at least one uplink sounding signal is a first uplink sounding signal, the wireless channel that includes the APD is a first wireless communication channel, and the method further comprises: receiving, from the UE, a second of the uplink sounding signals through a second wireless communication channel between the base station and UE that does not include reflection off the APD; selecting a phase steering vector for the UE based on an identifier of the second uplink sounding signal; and configuring the UE to use the selected phase steering vector for subsequent uplink communications to the base station through the second wireless communication channel.

6. The method as recited in any one of claims 3 to 5, wherein the respective signal quality parameters of the at least one reflection of the at least one uplink sounding signal include an indication of one of: a received signal strength indicator, RSSI, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal; a signal-to-interference-plus-noise ratio, SINR, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal; or a reference signal received power, RSRP, of the respective reflection of the at least one uplink sounding signal or the second uplink sounding signal.

7. The method as recited in any one of claims 1 to 6, further comprising: configuring the UE to transmit the at least one uplink sounding signal as one or more uplink sounding reference signals, SRSs, or SRS symbols; associating the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE; synchronizing the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE; and/or binding the phase sweeping pattern of the APD with signal resources of the uplink sounding process of the UE.

8. A method performed by a base station (120) to implement phase vector training for adaptive phase-changing device-enabled communication, the method comprising: configuring (1515) an adaptive phase-changing device, APD (180), with aphase sweeping pattern of multiple phase vectors; directing (1520) the APD to implement the phase sweeping pattern of the multiple phase vectors; transmitting (1525) at least one downlink reference signal while the APD implements the phase sweeping pattern of the multiple phase vectors to reflect the at least one downlink reference signal through a wireless channel that includes the APD; receiving (1550), from a user equipment, UE (110), an indication of at least one respective identifier of at least one reflection of at least one downlink reference signal that is received by the UE; selecting (1555) a phase vector for the APD based on the at least one respective identifier; and configuring (1560) the APD to use the selected phase vector to reflect subsequent communications between the base station and the UE.

9. The method as recited in claim 8, further comprising: receiving, from the UE, an indication of at least one respective signal quality parameter for the at least one reflection of the at least one downlink reference signal that is received by the UE; and selecting the phase vector for the APD based on: the at least one respective identifier; and the at least one respective signal quality parameter.

10. The method as recited in claim 9, further comprising: selecting a phase steering vector for the base station based on: the respective identifier of the at least one reflection of the at least one downlink reference signal; or the respective signal quality parameters of the at least one reflection of the at least one downlink reference signal; and configuring the base station to use the selected phase steering vector for subsequent downlink communications to the UE.

11. The method as recited in any of claims 8 to 10, wherein the at least one downlink reference signal is a first downlink reference signal, the wireless channel is a first wireless communication channel, and the method further comprises: transmitting a second downlink reference signal through a second wireless communication channel that does not include the APD; receiving, from the UE, an indication of an identifier or a signal quality parameter of the second downlink reference signal that is received by the UE; selecting a phase steering vector for the base station for the second wireless communication channel based on the identifier or the signal quality parameter of the second downlink reference signal received by the UE; and configuring the base station to use the selected phase vector for subsequent downlink communications to the UE through the second wireless communication channel.

12. The method as recited in any one of claims 8 to 11, further comprising: transmitting the at least one downlink reference signal as one or more of a channel state information reference signal, CSI-RS; or a synchronization signal block, SSB, synchronization signal; or receiving the indication of the respective identifiers of the at least one reflection as one of an indication of a CSI-RS resource for the reflection or an indication of an SSB index for the reflection.

13. The method as recited in any one of claims 8 to 12, further comprising: associating the phase sweeping pattern of the APD with signal air interface resources of the at least one downlink reference signal transmitted by the base station; or binding the phase sweeping pattern of the APD with signal air interface resources of the at least one downlink reference signal transmitted by the base station.

14. The method as recited in any one of claims 8 to 13, wherein directing the APD to implement the phase sweeping pattern while transmitting the at least one downlink reference signal comprises: scheduling transmission of the at least one downlink reference signal for time resources of an air interface that extends between the UE and base station; and scheduling the APD to implement the phase sweeping pattern at a point in time to align implementation of phase vectors of the phase sweeping pattern with transmission of respective ones of the time resources by which the at least one downlink reference signal is transmitted.

15. A base station apparatus (120) comprising: at least one wireless transceiver (256); a processor (258); and computer-readable storage media (260) comprising instructions, responsive to execution by the processor, for directing the base station apparatus (120) to perform any one of the methods recited in claims 1 to 14 using the at least one wireless transceiver (256).