SYSTEM AND METHOD FOR USER EQUIPMENT INITIATED LINK MANAGEMENT - Patent application

Abstract

Aspects of the present disclosure provide a solution for UE-initiated beam switching, beam pair switching, or link switching based on the use of association of at least two types of reference signals. The at least two types of reference signals include, but are not limited to, beam management reference signals (BM-RS), tracking reference signals (T-RS), and channel state information acquisition reference signals (CSIA-RS). The method and device may reduce latency and overhead incurred during channel tracking and channel state information (CSI) acquisition after a UE-initiated beam, beam pair, or link switching. Aspects of the present disclosure may reduce ambiguity between a base station and a UE regarding beam, beam pair, or link prediction behavior, and may improve the efficiency and reliability of UE-initiated beam switching, beam pair switching, or link switching.

Description

[Technical field]

[0001] TECHNICAL FIELD The present disclosure relates generally to wireless communications and, in particular embodiments, to a system and method for user equipment (UE) initiated link management. [Background technology]

[0002] In some wireless communication systems, a user equipment (UE) communicates wirelessly with a base station (e.g., a NodeB, an evolved NodeB, or a gNB) to transmit data to the base station and / or receive data from the base station. Wireless communication from the UE to the base station is called uplink communication. Wireless communication from the base station to the UE is called downlink communication. Wireless communication from a first UE to a second UE is called sidelink (SL) communication or device-to-device (D2D) communication.

[0003] Resources are required to perform uplink and downlink communications. For example, a base station may transmit data, such as a transport block (TB), wirelessly to a UE in a downlink transmission at a particular frequency for a particular duration. Frequency and duration are examples of resources.

[0004] Some wireless communication systems use beamforming, where communication signals are sent in a specific direction rather than being sent in all directions. High frequency communication is a potential technology to improve the performance (i.e., improve data rates) of future cellular networks due to the wide bandwidth for communication. However, the higher the frequency, the greater the propagation path loss. Therefore, more antennas may be required in multiple-input multiple-output (MIMO) systems to facilitate high frequency communication (e.g., by improving the signal-to-noise ratio (SNR) at the receiver).

[0005] Beamforming can be performed at the base station (BS), the user equipment (UE), or both. To extend the coverage of the millimeter wave (mmWave) frequency band or frequency range 2 (FR2), analog beamforming is usually employed at both the BS and the UE. FIG. 1 shows a base station 10 including a beam 15 directed to the UE 20, and the UE 20 includes a beam 25 directed to the base station 10. The combination of beams 15 and 25 may be considered a beam pair. The beam pair includes a transmit beam on one side of the communication link and a receive beam on the other side of the communication link.

[0006] When beamforming is used in the UE, the UE may have better knowledge of whether an update is required, e.g., handover to another base station, or use of a different receiving beam in the UE. Beam tracking may be a function used by the UE to make an informed decision on selecting a different beam or beam pair. To speed up the beam tracking process, the UE may initiate a beam management procedure, including beam measurement, reporting, and beam switching and / or link switching of beam pairs. After switching to a new beam, beam pair, or more generally a new link, continuous channel tracking and acquisition of up-to-date channel state information (CSI) of the new beam, beam pair, or link may cause additional latency and overhead if not properly handled. In other words, allowing the UE to initiate beam switching is not always sufficient for smooth mobility support in multi-beam systems.

[0007] Beam prediction may potentially reduce the latency of beam switching and thereby reduce the variations caused in link quality. Beam prediction may be performed in the base station or the UE, or both. However, coordination between the base station and the UE may be required. Without proper coordination, the efficiency of beam prediction can hardly be guaranteed. Summary of the Invention

[0008] Aspects of the present disclosure propose merging channel tracking and CSI acquisition with a UE-initiated beam selection process to provide less latency and more reliable link adaptation after beam switching. Some aspects of the present disclosure also propose a method to coordinate beam prediction behavior between the base station and the UE so that one device can have additional knowledge of possible operations at the other device. Some aspects of the present disclosure also provide a method for the UE to initiate beam or link switching, for example, when predictive beam or link switching may be used, with information regarding trigger conditions and timing. [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a method is provided that includes receiving, by a user equipment (UE), an indication of association between at least two of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS) and a channel state information acquisition reference signal (CSIA-RS); selecting, by the UE, a new link for link switching based on measurements of at least one of the BM-RS, the T-RS and the CSIA-RS; and transmitting, by the UE, an indication of link switching to a base station, the indication including the new link and feedback information regarding the new link, based on the measurements of at least one of the BM-RS, the T-RS and the CSIA-RS.

[0010] In some embodiments, the method further includes receiving, by the UE, a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) from the base station on the new link.

[0011] In some embodiments, the association between at least two of the BM-RS, T-RS and CSIA-RS is a one-to-one association, a one-to-many association, or a many-to-one association between any two types of reference signals.

[0012] In some embodiments, the method further includes performing, by the UE, measurements on at least two of the BM-RS, the T-RS, and the CSIA-RS based on the association indication.

[0013] In some embodiments, taking measurements of the BM-RS includes measuring the BM-RS and determining a reference signal received power (RSRP) or a signal-to-interference-and-noise ratio (SINR), taking measurements of the T-RS includes tracking the T-RS and determining large-scale parameters of a channel of the new link on which the T-RS is monitored, the large-scale parameters including one or more of an average delay, a delay spread, a Doppler shift, and a Doppler spread, and taking measurements of the CSIA-RS includes estimating channel state information (CSI) of the channel of the new link on which the CSIA-RS is received based on one or more of a rank indicator (RI), a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a layer indicator (LI).

[0014] In some embodiments, the method further includes receiving, by the UE, a confirmation from the base station of the link switching indication sent by the UE.

[0015] In some embodiments, the method further includes updating, by the UE, a PDCCH quasi-co-location (QCL) or a PDSCH QCL based on the new link.

[0016] In some embodiments, selecting a new link for link switching includes one of the following steps: selecting a link with the lowest Doppler shift or Doppler spread among candidate links with RSRP or SINR above a threshold; selecting a link with the highest predicted data rate determined from the measured CSI among candidate links with RSRP or SINR above a threshold and Doppler shift or Doppler spread below a threshold; selecting a link with the highest predicted data rate determined from the measured CSI among candidate links with RSRP or SINR above a threshold and Doppler shift or Doppler spread below a threshold; and selecting a link with the highest measured RSRP, SINR, RI or CQI.

[0017] In some embodiments, the method further includes determining, by the UE, an association between the at least two types of reference signals based on the received indication of association.

[0018] In some embodiments, the method further relates to the received indication including at least one of an indication that the T-RS is quasi-co-located (QCLed) with the BM-RS and an indication that the UE derives an association for a UE initiated link switch based on the already indicated QCL relationship.

[0019] In some embodiments, the method further includes receiving, by the UE, an indication as to whether the UE is permitted to perform link prediction when selecting a new link for link switching.

[0020] In some embodiments, the indication indicates that the UE is permitted to perform link prediction, and an indication of a maximum time offset of the predicted link relative to the most recent measurement occasion is received by the UE.

[0021] In some embodiments, the indication of a link switch to the base station includes an indication that the new link and feedback information regarding the new link are based on predicted results.

[0022] In some embodiments, the method further includes transmitting, by the UE, at least one of a timestamp indicating when the link is predicted to have a corresponding quality identified in the feedback information and a confidence level used for the link prediction.

[0023] In some embodiments, the method further includes selecting, by the UE, a new link for link switching using the beam or link prediction result.

[0024] According to an aspect of the present disclosure, a method is provided that includes: selecting, by a UE, a new link for link switching based on measurements of at least one of BM-RS, T-RS, and CSIA-RS and a prediction result of link quality for a future time; and transmitting, by the UE, an indication of link switching to a base station, including an indication of the new link and feedback information regarding the new link and the prediction result, based on the measurements of at least one of BM-RS, T-RS, and CSIA-RS, wherein the indication is transmitted in a one-off uplink transmission requested by the UE or in a periodic uplink transmission configured by the base station.

[0025] In some embodiments, the method further includes determining whether to initiate link switching based on at least one of the rate at which the link quality changes and a reporting periodicity when the periodic uplink transmissions are configured by the base station.

[0026] In some embodiments, when sending an indication to the base station to switch links, the UE sends an indication indicating that the new link and feedback information regarding the new link are based on predictions.

[0027] In some embodiments, the method further includes transmitting, by the UE, at least one of a timestamp indicating when the link is predicted to have a corresponding quality identified in the feedback information and a confidence level used for the link prediction.

[0028] In some embodiments, the method further includes selecting, by the UE, a new link for link switching using the beam or link prediction result.

[0029] According to an aspect of the present disclosure, a method is provided that includes: selecting, by a UE, a new link for link switching based on measurements of at least one of BM-RS, T-RS, and CSIA-RS and a predicted result of link quality at a future time, where the selecting of the new link for link switching includes selecting, by the UE, the new link based on the new link having a link quality that is within at least one current link quality threshold; and transmitting, by the UE, an indication of link switching including an indication of the new link and feedback information regarding the new link.

[0030] According to one aspect of the present disclosure, there is provided an apparatus including a processor and a computer readable medium having stored thereon computer executable instructions that, when executed by the processor, cause the apparatus to perform any of the methods described above.

[0031] According to one aspect of the present disclosure, a method is provided that includes: sending, by a base station, an indication of association between at least two of the BM-RS, the T-RS, and the CSIA-RS; and receiving, by the base station, from the UE, an indication of link switching including an indication of a new link and feedback information regarding the new link based on measurements made in the UE of at least one of the BM-RS, the T-RS, and the CSIA-RS.

[0032] In some embodiments, the method further includes transmitting, by the base station, the information, a PDCCH or a PDSCH, over the link to the UE.

[0033] In some embodiments, the association between at least two of the BM-RS, T-RS and CSIA-RS is a one-to-one association, a one-to-many association, or a many-to-one association between any two types of reference signals.

[0034] In some embodiments, the method further includes transmitting, by the base station, a confirmation of the link switching indication received from the UE.

[0035] In some embodiments, the method further includes an indication of an association between the at least two types of reference signals, the indication being an explicitly disclosed association between the at least two types of reference signals or an implicitly disclosed association between the at least two types of reference signals used by the UE to determine the association between the at least two types of reference signals.

[0036] In some embodiments, the implicitly disclosed association includes at least one of an indication that the T-RS is quasi-co-located (QCLed) with the BM-RS and an indication that the UE derives an association for UE-initiated link switching based on the already indicated QCL relationship.

[0037] In some embodiments, the method further includes transmitting, by the base station, an indication as to whether the UE is permitted to perform link prediction when selecting a new link for link switching.

[0038] In some embodiments, if the indication indicates that the UE is permitted to perform link prediction, the UE sends an indication of a maximum time frame value of the time offset of the predicted link relative to the latest measurement occasion.

[0039] In some embodiments, the indication of the link switch from the UE includes an indication of the new link and feedback information regarding the new link is based on predicted results.

[0040] In some embodiments, the method further includes receiving, by the base station, at least one of a timestamp indicating when the link is predicted to have a corresponding quality identified in the feedback information and a confidence level used for the link prediction.

[0041] According to one aspect of the present disclosure, a method is provided that includes receiving, by a base station, a link switching instruction from a user equipment (UE), the link switching instruction including an instruction for a new link and feedback information regarding the new link, based on measurements of at least one of a beam measurement reference signal (BM-RS) and a tracking reference signal (T-RS) performed at the UE and a predicted result of link quality for a future time, the instruction being received in a one-off uplink transmission requested by the UE or in a periodic uplink transmission configured by the base station.

[0042] In some embodiments, the method further includes indicating a link switch based on at least one of a rate at which the link quality changes and a reporting periodicity when periodic uplink transmissions are configured by the base station.

[0043] According to one aspect of the present disclosure, a method is provided that includes receiving, by a base station, from a user equipment (UE), a link switching instruction including an instruction for a new link and feedback information regarding the new link based on measurements of at least one of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS) performed at the UE and a predicted result of link quality for a future time, wherein the link switching instruction is based on the new link having a link quality within at least one current link quality threshold.

[0044] According to one aspect of the present disclosure, there is provided an apparatus including a processor and a computer readable medium having stored thereon computer executable instructions that, when executed by the processor, cause the apparatus to perform any of the methods described above.

[0045] For a more complete understanding of the present embodiments and their advantages, reference is now made to the following descriptions taken, by way of example, in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0046] [Figure 1] FIG. 2 is a schematic diagram of beamforming used by a base station and a UE. [Figure 2A] 1 is a schematic diagram of a communication system in which embodiments of the present disclosure may occur; [Figure 2B] FIG. 2 is another schematic diagram of a communication system in which embodiments of the present disclosure may occur. [Diagram 3] FIG. 1 is a block diagram illustrating units or modules within a device in which embodiments of the present disclosure may occur. [Figure 4] FIG. 1 is a block diagram illustrating units or modules within a device in which embodiments of the present disclosure may occur. [Diagram 5] FIG. 1 is a block diagram illustrating associations between beam measurement reference signals (BM-RS), tracking reference signals (T-RS), and channel state information acquisition reference signals (CSIA-RS) for multiple different beams according to one aspect of the present disclosure. [Figure 6] A block diagram showing various examples of associations between a BM-RS, a T-RS, and a CSIA-RS according to one embodiment of the present disclosure. [Figure 7] FIG. 2 is a block diagram illustrating how a set of BM-RS, T-RS, and CSIA-RS and their respective reference signals are associated with each other, according to one embodiment of the present disclosure. [Figure 8]FIG. 1 is an example of base station and UE operations, including different types of UE initiated link management, including beam selection, channel tracking, channel state information acquisition, UE reporting and base station acknowledgment, that occur over time when using reference signal association in accordance with one aspect of the present disclosure. [Figure 9] 13 is an example of an allowed time range configuration for prediction usage according to one aspect of the present disclosure. [Figure 10] A diagram showing an example of reporting timestamps for a predicted beam, beam pair or link according to one aspect of the present disclosure. [Figure 11] FIG. 1 illustrates an example of UE-initiated predictive link switching using one-off reporting, according to one aspect of the present disclosure. [Figure 12] FIG. 1 illustrates an example of UE-initiated predictive link switching using periodic reporting occasions, according to one aspect of the present disclosure. [Figure 13] FIG. 2 is a schematic diagram illustrating a UE-initiated predictive link switching based on smooth transition according to one aspect of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] By way of example only, certain exemplary embodiments will now be described in more detail below in conjunction with the drawings in which:

[0048] The embodiments set forth herein represent sufficient information to practice the claimed subject matter and show how to practice such subject matter. Upon reading the following description in light of the accompanying drawings, one of ordinary skill in the art will understand the concepts of the claimed subject matter and recognize applications of those concepts not specifically addressed herein. It should be understood, however, that these concepts and applications are within the scope of this disclosure and the appended claims.

[0049] It will also be understood that any module, component, or device disclosed herein that executes instructions may include or otherwise have access to one or more non-transitory computer / processor readable storage media for storage of information such as computer / processor readable instructions, data structures, program modules, and / or other data. A non-exhaustive list of examples of non-transitory computer / processor readable storage media includes magnetic cassettes, magnetic tapes, magnetic disk storage media, or other magnetic storage devices, optical disks such as compact disk read only memory (CD-ROM), digital video disks, or digital versatile disks (i.e., DVDs), Blu-ray disks™, or other optical storage, volatile and non-volatile removable and non-removable media implemented in any manner or technology, random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory, or other memory technology. Any such non-transitory computer / processor storage media may be part of the device or may be accessible or connectable to the device. Computer / processor readable / executable instructions for implementing the applications or modules described herein may be stored by or otherwise maintained on such non-transitory computer / processor readable storage media.

[0050] Aspects of the present disclosure provide a solution for UE-initiated beam switching, beam pair switching, or link switching based on the use of association of at least two types of reference signals. The at least two types of reference signals include, but are not limited to, beam management reference signals (BM-RS), tracking reference signals (T-RS), and channel state information acquisition reference signals (CSIA-RS). The methods and devices provided herein may reduce latency and overhead incurred during channel tracking and channel state information (CSI) acquisition after a UE-initiated beam, beam pair, or link switching. In addition, aspects of the present disclosure may reduce ambiguity between a base station and a UE regarding beam, beam pair, or link prediction behavior, and may improve the efficiency and reliability of UE-initiated beam switching, beam pair switching, or link switching. It should be understood that when referring to either beam switching, beam pair switching, or link switching, these expressions mean substantially the same thing.

[0051] 2A, 2B, and 3 below provide context for networks and devices that may be present within the networks and that may implement aspects of the disclosure.

[0052] Referring to FIG. 2A, as an illustrative and non-limiting example, a simplified schematic diagram of a communication system is shown. The communication system 100 comprises a radio access network 120. The radio access network 120 may be a next generation (e.g., sixth generation (6G) or later) radio access network or a legacy (e.g., 5G, 4G, 3G, or 2G) radio access network. One or more communicating electric devices (EDs) 110a-120j (generally referred to as 110) may be interconnected with each other or alternatively connected to one or more network nodes (170a, 170b, collectively referred to as 170) in the radio access network 120. A core network 130 may be part of the communication system and may or may not depend on the radio access technology used in the communication system 100. The communication system 100 also comprises a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.

[0053] 2B illustrates an example of a communication system 100 in which embodiments of the present disclosure can be implemented. Typically, the system 100 allows multiple wireless or wired elements to communicate data or other content. The purpose of the system 100 may be to provide content (voice, data, video, text) by broadcast, by narrowcast, from user device to user device, etc. The system 100 may operate efficiently by sharing resources such as bandwidth.

[0054] In this example, the communications system 100 includes electronic devices (EDs) 110a-110c, radio access networks (RANs) 120a-120b, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160. Although a particular number of these components or elements are illustrated in FIG. 2B, any reasonable number of these components or elements may be included in the system 100.

[0055] The EDs 110a-110c are configured to operate, communicate, or both in the system 100. For example, the EDs 110a-110c are configured to transmit, receive, or both over wireless communication channels. Each of the EDs 110a-110c represents any suitable end-user device for wireless operation and may include (or be referred to as) a user equipment / device (UE), a wireless transceiver unit (WTRU), a mobile station, a mobile subscriber unit, a cellular telephone, station (STA), a machine type communication device (MTC), a personal digital assistant (PDA), a smartphone, a laptop, a computer, a touchpad, a wireless sensor, or a consumer electronic device, or other device.

[0056] 2B illustrates an example of a communication system 100 in which embodiments of the present disclosure can be implemented. In general, the communication system 100 allows multiple wireless or wired elements to communicate data and other content. The purpose of the communication system 100 may be to provide content (voice, data, video, text) by broadcast, by multicast, by unicast, from user device to user device, etc. The communication system 100 may operate efficiently by sharing resources such as bandwidth.

[0057] In this example, communications system 100 includes electronic devices (EDs) 110a-110d, radio access networks (RANs) 120a-120c, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160. Although a particular number of these components or elements are shown in FIG. 2B, any reasonable number of these components or elements may be included in communications system 100.

[0058] The EDs 110a-110d are configured to operate, communicate, or both in the communication system 100. For example, the EDs 110a-110d are configured to transmit, receive, or both over wireless or wired communication channels. Each of the EDs 110a-110d represents any suitable end-user device for wireless operation and may include (or be referred to as) a user equipment / device (UE), a wireless transceiver unit (WTRU), a mobile station, a fixed or mobile subscriber unit, a cellular telephone, station (STA), a machine type communication (MTC) device, a personal digital assistant (PDA), a smartphone, a laptop, a computer, a touchpad, a wireless sensor, or a consumer electronic device, or other device.

[0059] In FIG. 2B, the RANs 120a-120b include base stations 170a-170b, respectively. The base stations may also be referred to as transmit reception points (TRPs), as labeled in FIG. 2B. Each base station 170a-170b is configured to wirelessly interface with one or more of the EDs 110a-110c to enable access to any other base stations 170a-170b, the core network 130, the PSTN 140, the Internet 150, and / or other networks 160. For example, the base stations 170a-170b may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node B (NodeB), an evolved Node B (eNodeB), a home eNodeB, a gNodeB, a site controller, an access point (AP), or a wireless router.

[0060] In some examples, one or more of the base stations 170a-170b may be terrestrial base stations or terrestrial TRPs (T-TRPs) that are mounted on the ground. For example, the terrestrial base stations may be mounted on buildings or towers. Alternatively, one or more of the base stations 172 may be non-terrestrial base stations or non-terrestrial TRPs (NT-TRPs) that are not mounted on the ground. An airborne base station is one example of a non-terrestrial base station. An airborne base station may be implemented using communication equipment supported or carried by an airborne device. Non-limiting examples of airborne devices include airborne platforms (e.g., blimps or airships, etc.), balloons, quadcopters, and other aircraft. In some implementations, an airborne base station may be supported or carried by an unmanned aerial vehicle (UAV), such as an unmanned aerial system (UAS) or drone. An airborne base station may be a mobile or mobile base station that can be flexibly deployed at different locations to meet network demands. A satellite base station is another example of a non-terrestrial base station. A satellite base station may be implemented using communication equipment supported or carried by a satellite. A satellite base station may also be referred to as an orbiting base station.

[0061] Any of the EDs 110a-110d may alternatively or additionally be configured to interface with, access, or communicate with any other base stations 170a-170b, 172, the Internet 150, the core network 130, the PSTN 140, other networks 160, or any combination of the above.

[0062] The EDs 110a-110d and the base stations 170a-170b, 172 are examples of communication equipment that may be configured to perform some or all of the operations and / or embodiments described herein. In the embodiment shown in FIG. 2B, the base station 170a forms part of the RAN 120a, which may include other base stations, base station controller(s) (BSC), radio network controller(s) (RNC), relay nodes, elements and / or devices. Any base station 170a, 170b may be a single element as shown, or may be multiple elements distributed in a corresponding RAN or otherwise. Also, the base station 170b forms part of the RAN 120b, which may include other base stations, elements and / or devices. Each base station 170a-170b transmits and / or receives radio signals within a particular geographic region or area, which may be referred to as a "cell" or "coverage area." The cells may be further divided into cell sectors, and the base stations 170a-170b may use multiple transceivers, for example, to serve multiple sectors. In some embodiments, picocells or femtocells may be established, and the radio access technology supports this. In some embodiments, multiple transceivers may be used per cell, for example, using multiple-input multiple-output (MIMO) technology. The number of RANs 120a-120b shown is merely exemplary. Any number of RANs may be contemplated in conceiving the communication system 100.

[0063] The base stations 170a-170b, 172 communicate with one or more of the EDs 110a-110d over one or more air interfaces 190a, 190c using wireless communication links, e.g., radio frequency (RF), microwave, infrared (IR), etc. The air interfaces 190a, 190c may utilize any suitable wireless access technology. For example, the communication system 100 may implement one or more orthogonal or non-orthogonal channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single carrier FDMA (SC-FDMA), over the air interfaces 190a, 190c.

[0064] The base stations 170a-170b, 172 may implement Universal Mobile Telecommunications System (UMTS) Terrestrial-based Radio Access (UTRA) to establish the air interface 190a, 190c using Wideband Code Division Multiple Access (WCDMA). In doing so, the base stations 170a-170b, 172 may implement protocols such as High Speed ​​Packet Access (HSPA), Evolved High Speed ​​Packet Access (HSPA+) optionally including High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSPUA), or both. Alternatively, the base stations 170a-170b, 172 may establish the air interface 190a, 190c with Evolved UMTS Terrestrial-based Radio Access (E-UTRA) using LTE, LTE-A, and / or LTE-B. It is contemplated that the communication system 100 may employ multiple channel access capabilities including those schemes described above. Other wireless technologies for implementing the air interface include IEEE 802.11, 802.15, 802.16, CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, IS-2000, IS-95, IS-856, GSM, EDGE, and GERAN. Of course, other multiple access schemes and wireless protocols may be utilized.

[0065] The RANs 120a-120b communicate with the core network 130 to provide various services, such as voice, data, and other services, to the EDs 110a-110c. The RANs 120a-120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown), which may or may not be served directly by the core network 130 and which may or may not use the same radio access technology as the RANs 120a, 120b, or both. The core network 130 may also serve as a gateway access between (i) the RANs 120a-120b and / or the EDs 110a-110c, and (ii) other networks (such as the PSTN 140, the Internet 150, and other networks 160).

[0066] The EDs 110a-110c communicate with one another over one or more sidelink (SL) air interfaces 190b, 190d using wireless communication links, such as, for example, radio frequency (RF), microwave, infrared (IR), etc. The SL air interfaces 190b, 190d may utilize any suitable radio access technology and may be substantially similar to or substantially different from the air interfaces 190a, 190c through which the EDs 110a-110c communicate with one or more of the base stations 170a-170b. For example, the communication system 100 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single carrier FDMA (SC-FDMA), in the SL air interfaces 190b, 190d. In some embodiments, the SL air interface 180 may be implemented, at least in part, over an unlicensed spectrum.

[0067] Additionally, some or all of the EDs 110a-110d may include operations for communicating with different wireless networks over different wireless links using different wireless technologies and / or protocols. Instead of (or in addition to) wireless communication, the EDs may communicate over wired communication channels to a service provider or switch (not shown) and the Internet 150. The PSTN 140 may include a circuit-switched telephone network for providing plain old telephone service (POTS). The Internet 150 may include a network of computers and / or subnets (intranets) and may incorporate protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), etc. The EDs 110a-110d may be multi-mode devices capable of operating with multiple wireless access technologies and may incorporate multiple transceivers necessary to support multiple wireless access technologies.

[0068] In some embodiments, the signal is transmitted from a terrestrial BS to the UE or directly from the UE to the terrestrial BS, in either case the signal is not reflected by a reconfigurable intelligent surface (RIS). However, the signal may be reflected by obstacles and reflectors such as buildings, walls and furniture. In some embodiments, the signal is communicated between a UE and a non-terrestrial BS such as a satellite, a drone, and a high altitude platform. In some embodiments, the signal is communicated between a relay and a UE, or between a relay and a BS, or between two relays. In some embodiments, the signal is transmitted between two UEs. In some embodiments, one or more RISs are utilized to reflect signals from a transmitter and a receiver, either of which includes a UE, a terrestrial BS or a non-terrestrial BS, and a relay.

[0069] 3 shows another example of ED 110 and network devices, including base stations (at 170) 170a, 170b and NT-TRP 172. ED 110 is used to connect people, objects, machines, etc. ED 110 may be widely used in various scenarios, such as cellular communication, device-to-device (D2D), vehicle-to-everything (V2X), peer-to-peer (P2P), machine-to-machine (M2M), machine-type communication (MTC), Internet of Things (IOT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility.

[0070] Each ED 110 represents, among various possibilities, any suitable end-user device for wireless operation, and may include (or be referred to as) a user equipment / device (UE), a wireless transceiver unit (WTRU), a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA), a machine type communication (MTC) device, a personal digital assistant (PDA), a smartphone, a laptop, a computer, a touchpad, a wireless sensor, or a consumer electronic device, a smartbook, a vehicle, an automobile, a truck, a bus, a train, or an IoT device, an industrial device, or an apparatus (e.g., a communication module, a modem, or a chip) within the above devices. Future generation EDs 110 may be referred to using other terms. Base stations 170a and 170b are T-TRPs, hereinafter referred to as T-TRP 170. As also shown in FIG. 2B, the NT-TRP is hereinafter referred to as NT-TRP 172. Depending on one or more of the availability of the connection and the need for the connection, each ED110 connected to the T-TRP170 and / or NT-TRP172 can be dynamically or semi-statically turned on (i.e., established, activated or enabled), off (i.e., released, deactivated or disabled) and / or configured.

[0071] The ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is shown. Alternatively, one, some, or all of the antennas may be panels. The transmitter 201 and the receiver 203 may be integrated as a transceiver. The transceiver is configured to modulate data or other content for transmission by at least one antenna 204 or a network interface controller (NIC). The transceiver is also configured to demodulate data or other content received by at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or wired. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals.

[0072] The ED 110 includes at least one memory 208. The memory 208 stores instructions and data used, generated or collected by the ED 110. For example, the memory 208 can store software instructions or modules executed by the processing unit 210 configured to perform some or all of the functions and / or embodiments described herein. Each memory 208 includes any suitable volatile and / or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc.

[0073] The ED 110 may further include one or more input / output devices (not shown) or interfaces (such as a wired interface to the Internet 150 of FIG. 2A or FIG. 2B). The input / output devices enable interaction with a user or other devices in a network. Each of the input / output devices includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display or touch screen, including network interface communications.

[0074] The ED 110 further includes a processor 210 for performing operations including operations related to preparing a transmission for uplink transmission to the NT-TRP 172 and / or the T-TRP 170, operations related to processing a downlink transmission received from the NT-TRP 172 and / or the T-TRP 170, and operations related to processing a sidelink transmission / reception from another ED 110. Processing operations related to preparing a transmission for uplink transmission may include operations such as encoding, modulation, transmit beamforming, and generating symbols for transmission. Processing operations related to processing a downlink transmission may include operations such as receive beamforming, demodulation and decoding of received symbols. Depending on the embodiment, the downlink transmission may be received by the receiver 203, possibly using receive beamforming, and the processor 210 may extract the signaling from the downlink transmission (e.g., by detecting and / or decoding the signaling). One example of signaling may be a reference signal transmitted by the NT-TRP 172 and / or the T-TRP 170. In some embodiments, the processor 210 performs transmit beamforming and / or receive beamforming based on beam direction instructions, e.g., beam angle information (BAI), received from the T-TRP 170. In some embodiments, the processor 210 may perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as operations related to detecting synchronization sequences, decoding and obtaining system information, etc. In some embodiments, the processor 210 may perform channel estimation, for example, using reference signals received from the NT-TRP 172 and / or the T-TRP 170.

[0075] Although not shown, the processor 210 may form part of the transmitter 201 and / or the receiver 203. Although not shown, the memory 208 may form part of the processor 210.

[0076] The processor 210 and the processing components of the transmitter 201 and receiver 203 may be implemented by the same or different processor or processors, each configured to execute instructions stored in a memory, such as the memory 208. Alternatively, some or all of the processor 210 and the processing components of the transmitter 201 and receiver 203 may be implemented using special purpose circuitry, such as a programmed field programmable gate array (FPGA), a graphics processing unit (GPU) or an application specific integrated circuit (ASIC).

[0077] In some implementations, the T-TRP 170 may be referred to by other names such as base station, base transceiver station (BTS), radio base station, network node, network device, network side device, transmitting / receiving node, Node B, evolved Node B (eNodeB or eNB), home eNodeB, next generation Node B (gNB), transmission point (TP), site controller, access point (AP), wireless router, relay station, remote radio head, terrestrial node, terrestrial network device, terrestrial base station, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, among other possibilities. The T-TRP 170 may be a macro BS, pico BS, relay node, donor node, etc., or combinations thereof. The T-TRP 170 may refer to a forging device, or an apparatus (e.g., a communication module, modem, or chip) within the aforementioned devices. Although the figures and accompanying description of the examples and embodiments of the present disclosure generally use the terms AP, BS and AP or BS, it should be understood that such devices can be of any of the types described above.

[0078] In some embodiments, parts of the T-TRP 170 may be distributed. For example, some of the modules of the T-TRP 170 may be located at a location remote from the equipment housing the antenna of the T-TRP 170 and may be coupled to the equipment housing the antenna via a communication link (not shown), sometimes known as a fronthaul, such as a Common Public Radio Interface (CPRI). Thus, in some embodiments, the term T-TRP 170 may also refer to network-side modules that perform processing operations such as determining the location of the ED 110, resource allocation (scheduling), message generation, and encoding / decoding, and that are not necessarily part of the equipment housing the antenna of the T-TRP 170. The modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP 170 may actually be multiple T-TRPs operating together to serve the ED 110, for example via coordinated multipoint transmission.

[0079] The T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is shown. Alternatively, one, some, or all of the antennas may be panels. The transmitter 252 and receiver 254 may be integrated as a transceiver. The T-TRP 170 further includes a processor 260 for performing operations including operations related to preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaul transmission to the NT-TRP 172, and processing a transmission received via the backhaul from the NT-TRP 172. The processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulation, precoding (e.g., multiple-input multiple-output (MIMO) precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over the backhaul may include operations such as receive beamforming, and demodulation and decoding of received symbols. The processor 260 may also perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as generating the content of a synchronization signal block (SSB), generating system information, etc. In some embodiments, the processor 260 also generates a beam direction indication, e.g., a BAI, which may be scheduled by the scheduler 253 for transmission. The processor 260 performs other network side processing operations described herein, such as determining the location of the ED 110, determining where to deploy the NT-TRP 172, etc. In some embodiments, the processor 260 may generate signaling, for example, to configure one or more parameters of the ED 110 and / or one or more parameters of the NT-TRP 172. Any signaling generated by the processor 260 is sent by the transmitter 252.It should be noted that "signaling" as used herein may alternatively be referred to as control signaling. Dynamic signaling may be transmitted on a control channel, e.g., the Physical Downlink Control Channel (PDCCH), and static or semi-static higher layer signaling may be included in packets transmitted on a data channel, e.g., the Physical Downlink Shared Channel (PDSCH).

[0080] The scheduler 253 may be coupled to the processor 260. The scheduler 253 may be included within the T-TRP 170 or may operate separately from the T-TRP 170 and may schedule uplink, downlink and / or backhaul transmissions, including issuing scheduling grants and / or configuring scheduling-free ("configured grant") resources. The T-TRP 170 further includes a memory 258 for storing information and data. The memory 258 stores instructions and data used, generated or collected by the T-TRP 170. For example, the memory 258 may store software instructions or modules configured to implement some or all of the functions and / or embodiments described herein and executed by the processor 260.

[0081] Although not shown, the processor 260 may form part of the transmitter 252 and / or the receiver 254. Also, although not shown, the processor 260 may implement the scheduler 253. Although not shown, the memory 258 may form part of the processor 260.

[0082] The processor 260, the scheduler 253, and the processing components of the transmitter 252 and the receiver 254 may be implemented by the same or different processor or processors, each configured to execute instructions stored in a memory, such as the memory 258. Alternatively, some or all of the processing components of the processor 260, the scheduler 253, and the transmitter 252 and the receiver 254 may be implemented using special purpose circuitry, such as an FPGA, a GPU, or an ASIC.

[0083] Although the NT-TRP 172 is shown as a drone only as an example, the NT-TRP 172 may be implemented in any suitable non-terrestrial form. Also, in some implementations, the NT-TRP 172 may be known by other names, such as a non-terrestrial node, a non-terrestrial network device, or a non-terrestrial base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is shown. Alternatively, one of the antennas may be a panel, some may be panels, or all may be panels. The transmitter 272 and the receiver 274 may be integrated as a transceiver. The NT-TRP 172 further includes a processor 276 for performing operations including operations related to preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaul transmission to the T-TRP 170, and processing a transmission received via the backhaul from the T-TRP 170. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulation, precoding (e.g., MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing a received transmission in the uplink or over the backhaul may include operations such as receive beamforming, and demodulation and decoding of received symbols. In some embodiments, the processor 276 performs transmit beamforming and / or receive beamforming based on beam direction information (e.g., BAI) received from the T-TRP 170. In some embodiments, the processor 276 may generate signaling, for example, to configure one or more parameters of the ED 110. In some embodiments, the NT-TRP 172 performs physical layer processing but does not perform higher layer functions, such as functions at the medium access control (MAC) layer or radio link control (RLC) layer. This is just one example, so more generally, the NT-TRP 172 may perform higher layer functions in addition to physical layer processing.

[0084] The NT-TRP 172 further includes a memory 278 for storing information and data. Although not shown, the processor 276 may form part of the transmitter 272 and / or the receiver 274. Although not shown, the memory 278 may form part of the processor 276.

[0085] The processor 276 and the processing components of the transmitter 272 and the receiver 274 may be implemented by one or more processors, which may be the same or different, each configured to execute instructions stored in a memory, such as the memory 278. Alternatively, some or all of the processing components of the processor 276 and the transmitter 272 and the receiver 274 may be implemented using dedicated circuitry, such as a programmed FPGA, GPU, or ASIC. In some embodiments, the NT-TRP 172 may actually be multiple NT-TRPs operating together to serve the ED 110, for example, via coordinated multipoint transmission.

[0086] T-TRP170, NT-TRP172 and / or ED110 may include other components, which have been omitted for clarity.

[0087] One or more steps of the method of the embodiments provided herein may be performed by a corresponding unit or module according to FIG. 3. FIG. 3 shows units or modules in a device such as ED110, T-TRP170 or NT-TRP172. For example, the signal may be transmitted by a transmitting unit or a transmitting module. The signal may be received by a receiving unit or a receiving module. The signal may be processed by a processing unit or a processing module. Other steps may be performed by an artificial intelligence (AI) or machine learning (ML) module. Each unit or module may be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For example, one or more of the units or modules may be an integrated circuit such as a programmed FPGA, GPU or ASIC. It will be understood that when modules are implemented using software, for example for execution by a processor, they may be acquired in single or multiple instances, individually or together, for processing by the processor, in whole or in part, as necessary, and the modules themselves may include instructions for further deployment and instantiation.

[0088] Further details regarding ED110, T-TRP170 and NT-TRP172 are known to those skilled in the art, and therefore these details are omitted herein.

[0089] One or more steps of the method of the embodiments provided herein may be performed by a corresponding unit or module according to FIG. 4. FIG. 4 shows units or modules in a device such as ED110, T-TRP170 or NT-TRP172. For example, the signal may be transmitted by a transmitting unit or a transmitting module. The signal may be received by a receiving unit or a receiving module. The signal may be processed by a processing unit or a processing module. Other steps may be performed by an artificial intelligence (AI) or machine learning (ML) module. Each unit or module may be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For example, one or more of the units or modules may be an integrated circuit such as a programmed FPGA, GPU or ASIC. It will be understood that when modules are implemented using software, for example for execution by a processor, they may be acquired in single or multiple instances, individually or together, for processing by the processor, in whole or in part, as necessary, and the modules themselves may include instructions for further deployment and instantiation.

[0090] Further details regarding ED110, T-TRP170 and NT-TRP172 are known to those skilled in the art, and therefore these details are omitted herein.

[0091] In future wireless networks, the number of new devices may increase exponentially with diverse functionalities. Also, many new applications and new use cases in future wireless networks may emerge with more diverse quality of service requirements than exist in 5G. These bring new Key Performance Indicators (KPIs) for future wireless networks (e.g., 6G networks) that may be very challenging, so sensing and AI techniques, especially ML (Deep Learning) techniques, are being introduced in telecommunications to improve system performance and efficiency.

[0092] AI / ML technology applied communication including AI / ML communication in the physical layer and AI / ML communication in the media access control (MAC) layer. For the physical layer, AI / ML communication may be useful to optimize component design and improve algorithm performance, such as AI / ML for channel coding, channel modeling, channel estimation, channel decoding, modulation, demodulation, MIMO, waveform, multiple access, optimization and update of PHY element parameters, beam forming, tracking, sensing and positioning. For the MAC layer, AI / ML communication may utilize AI / ML capabilities along with learning, prediction, and make decisions to solve complex optimization problems with better strategies and optimal solutions, such as intelligent TRP management, intelligent beam management, intelligent channel resource allocation, intelligent power control, intelligent spectrum utilization, intelligent MCS, intelligent hybrid automatic repeat request (HARQ) strategy, intelligent transmit / receive (Tx / Rx) mode adaptation, etc., to optimize the functions of MAC.

[0093] AI / ML architectures typically include multiple nodes that can be organized in two modes: centralized and distributed, both of which can be deployed in access networks, core networks or edge computing systems or third-party networks. Centralized training and computing architectures are limited by huge communication overhead and strict user data privacy. Distributed training and computing architectures include several frameworks, e.g., distributed machine learning and federated learning. AI / ML architectures comprise intelligent controllers that can be performed as single agents or multi-agents, based on joint or individual optimization. New protocols and signaling mechanisms are required so that the corresponding interface links can be personalized with customized parameters to meet specific requirements, while minimizing signaling overhead and maximizing the spectral efficiency of the entire system through personalized AI techniques.

[0094] Further terrestrial and non-terrestrial networks can enable a new range of services and applications such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility. Terrestrial and non-terrestrial network-based sensing can provide intelligent context-aware networks to enhance the UE experience. For example, terrestrial and non-terrestrial network-based sensing may include localization and sensing application opportunities based on new sets of features and service capabilities. Applications such as THz imaging and spectroscopy have the potential to provide continuous, real-time physiological information via dynamic, non-invasive, non-contact measurements for future digital health technologies. Simultaneous localization and mapping (SLAM) methods not only enable advanced cross-reality (XR) applications but also enhance the navigation of autonomous objects such as vehicles and drones. Furthermore, in terrestrial and non-terrestrial networks, measured channel data as well as sensing and positioning data can be acquired by high bandwidth, new spectrum, high density networks and more line-of-sight (LOS) links. Based on these data, a radio environment map can be derived via AI / ML methods, and the channel information is linked to its corresponding positioning or environmental information to provide an enhanced physical layer design based on this map.

[0095] Sensing coordinators are nodes in the network that can assist in sensing operations. These nodes can be standalone nodes dedicated to sensing operations only, or other nodes (e.g., TRP170, ED110 or core network nodes) that perform sensing operations in parallel with communication transmissions. To meet specific requirements while minimizing signaling overhead and maximizing the spectral efficiency of the entire system, new protocols and signaling mechanisms are needed so that the corresponding interface links can be made with customized parameters.

[0096] AI / ML and sensing methods are data intensive. To include AI / ML and sensing in wireless communication, more and more data needs to be collected, stored and exchanged. The characteristics of wireless data are multi-dimensional and very wide ranging, e.g., carrier frequencies from sub-6GHz, mmWave to terahertz, scenarios from space, outdoor to indoor, and text, audio to video. These data collection, processing and usage operations are performed in a unified framework or in different frameworks.

[0097] Some aspects of the present disclosure propose merging channel tracking and CSI acquisition with a UE-initiated beam selection process to provide less latency and more reliable link adaptation after beam switching. Some aspects of the present disclosure also propose a method to coordinate beam prediction behavior between the base station and the UE so that one device can have additional knowledge of possible operations at the other device. Some aspects of the present disclosure also provide a method for the UE to initiate beam or link switching, for example, when predictive beam or link switching may be used, with information regarding trigger conditions and timing.

[0098] One aspect of the present disclosure relates to establishing an association between parameters for beam measurement, channel tracking, and CSI acquisition. Specifically, a base station, or a network of which the base station is a part, may provide an association, e.g., a mapping relationship, between reference signals used for beam measurement, channel tracking, and CSI acquisition (CSIA). A reference signal for beam measurement may be referred to as a beam measurement reference signal (BM-RS). A reference signal for channel tracking may be referred to as a channel tracking reference signal (T-RS). A reference signal for CSIA may be referred to as a CSIA reference signal (CSIA-RS). FIG. 5 illustrates an example of a set 520 of one-to-one mappings that may be used for beams 512, 514, and 516 of a base station 510. A first one-to-one mapping 522 of the set 520 for the first beam 512 includes an association between BM-RS#1, T-RS#1, and CSIA-RS#1. The second one-to-one mapping 524 of the set 520 for the second beam 514 includes an association between BM-RS#2, T-RS#2, and CSIA-RS#2. The nth one-to-one mapping 526 of the set 520 for the nth beam 516 includes an association between BM-RS#N, T-RS#N, and CSIA-RS#N.

[0099] The UE may perform beam measurements using the BM-RS identified in the mapping, then start channel tracking using the T-RS associated in the mapping with the selected BM-RS, and then measure CSI using the CSIA-RS associated with the selected BM-RS and / or TRS in the mapping. In this way, when the UE starts beam switching to the selected new beam or beam pair, channel tracking is ongoing and CSI is ready. For this reason, beam switching may be generalized and referred to as link switching, since channel tracking and CSI acquisition of the communication link occurring on this beam or beam pair are included and taken into account in such switching procedure. In some embodiments, beam selection at the UE may be performed based on the link quality measured based on the BM-RS of the new beam, beam pair, or link. The measured link quality may be one or more parameters, such as Reference Signal Received Power (RSRP) and Signal to Interference and Noise Ratio (SINR).

[0100] In some embodiments, the UE may initiate beam switching to a new beam, beam pair, or link based on CSI obtained from the CSIA-RS associated with the selected BM-RS and / or T-RS, such as a rank indicator (RI) and / or a channel quality indicator (CQI) and / or an expected data rate, assuming that the corresponding rank and modulation coding scheme (MCS) will be used for subsequent data transmission. In some embodiments, the UE may initiate switching to a new beam, beam pair, or link by sending a CSI report to the base station, which may help to expedite link adaptation of the selected new beam, beam pair, or link.

[0101] The BM-RS is a reference signal used for beam measurements. For example, the BM-RS may be a synchronization signal block (SSB) on which beam measurements such as RSRP or SINR measurements are made. The BM-RS may be a channel state information reference signal (CSI-RS) configured for RSRP or SINR measurements. The CSI-RS may belong to a CSI-RS resource set that is configured for use based on a configuration parameter. An example of a configuration parameter is a New Radio System (NR) 5G configuration parameter known as "repetition". In 5G NR, if the "repetition" parameter is configured as "ON", the UE assumes that the base station transmits CSI-RS resources in the CSI-RS resource set with the same spatial domain transmit filter, or with the same beam, which allows the UE to perform receive beam training by receiving CSI-RS resources with different receive beams. If the parameter "repetition" is set as "OFF", the UE cannot make such an assumption. The repetition parameter may be configured as a single bit field where "1" is "ON" and "0" is "OFF", or vice versa.

[0102] The T-RS is a reference signal that may be used for downlink (DL) time and frequency tracking. For example, the T-RS may be a CSI-RS configured for tracking purposes. The T-RS may belong to a CSI-RS resource set that is configured for use based on a configuration parameter. An example of a configuration parameter is the 5G NR configuration parameter known as "trs-Info." In 5G NR, for a CSI-RS resource set configured using the parameter "trs-Info," the UE may assume that the CSI-RS resources in the CSI-RS resource set are transmitted using the same antenna port, whereby the UE performs time and frequency tracking to estimate large-scale parameters such as average delay, delay spread, Doppler shift and Doppler spread.

[0103] The CSIA-RS is a reference signal that may be used for CSI acquisition. For example, the CSIA-RS may be a CSI-RS configured to measure and report CSI. Examples of CSI include a rank indicator (RI), a channel quality indicator (CQI), a precoding matrix indicator (PMI), and / or a layer indicator (LI). For the purposes of this disclosure, beam-related measurements and reports (parameters such as RSRP and / or SINR) and CSI-related measurements and reports (parameters such as RI, CQI, PMI, and / or LI) are considered as two different categories. In some embodiments, beam-related measurements and reports may alternatively be considered and / or labeled as one type of CSI measurement, such as considering RSRP and / or SINR reports as one type of CSI report. The three types of RS referenced are named in terms of function. These RS may be different CSI-RS configured for different functions, even though they may all be considered more generally as CSI-RS.

[0104] In some embodiments, the association or mapping between the BM-RS, T-RS and CSIA-RS may be one-to-many or many-to-1. As specific examples, one BM-RS may be mapped to multiple T-RS, one T-RS may be mapped to multiple CSIA-RS, or multiple T-RS may be mapped to one CSIA-RS.

[0105] 6 shows two different examples of sets of BM-RS, T-RS and CSIA-RS associations or mappings. In the first set 610, there is a one-to-many mapping between the BM-RS BM-RS#1 615 and two T-RSs, T-RS#1 620 and T-RS#2 625. Also in the first set 610, there is a one-to-many mapping between the T-RS#2 620 and two CSIA-RSs, CSIA-RS#1 630 and CSIA-RS#2 635. In the second set 650, there is a one-to-one mapping between the first BM-RS BM-RS#2 655 and the first T-RS T-RS#3 670 and between the second BM-RS BM-RS#3 660 and the second T-RS T-RS#4 665. Also in the second set 650, there is a many-to-one mapping between T-RS#3 670 and T-RS#4 665 and a single CSIA-RS CSIA-RS#3 675.

[0106] FIG. 7 shows an example where there is a set of BM-RS 710, a set of T-RS 720 and a set of CSIA-RS 730. There is a first association between BM-RS#1 712, T-RS#2 722 and CSIA-RS#1 732, a second association between BM-RS#2 714, T-RS#2 724 and CSIA-RS#2 734 and a third association between BM-RS#N 716, T-RS#N 726 and CSIA-RS#N 736. Once the association or mapping between BM-RS, T-RS and CSIA-RS is provided to the UE, the UE may perform beam selection based on the BM-RS indicated in the mapping. The selection of a new beam, beam pair or link may be based on measurements such as RSRP or SINR. After selecting a new beam, beam pair, or link corresponding to one of the BM-RSs, the UE may start tracking large-scale parameters of a downlink (DL) channel corresponding to the selected new beam, beam pair, or link based on a T-RS associated with the selected BM-RS. The large-scale parameters may be parameters such as average delay, delay spread, Doppler shift, and Doppler spread. After obtaining one or more large-scale parameters of the DL channel, the UE may estimate a CSI of the DL channel corresponding to the selected new beam, beam pair, or link based on a CSIA-RS associated with the BM-RS and / or T-RS of the selected new beam, beam pair, or link. The CSI may include information on one or more of RI, CQI, PMI, and LI. Based on the estimated CSI, the UE may initiate a link switch of the selected new beam, beam pair, or link by sending a feedback report to the base station. The feedback report may include feedback information such as an indication of one or more of the BM-RS, T-RS and CSIA-RS of the selected new beam, beam pair or link, and corresponding values ​​of one or more of the RSRP, SINR, RI, CQI, PMI and LI.

[0107] In some embodiments, after a delay after initiating a beam or link switch or after receiving a confirmation message from the base station for the beam or link switch, the UE may perform DL reception including a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) using the selected beam or link. In some embodiments, after a delay after initiating a beam or link switch or after receiving a confirmation message from the base station for the beam or link switch, the UE may perform UL transmission including a physical uplink control channel (PUCCH) and a physical downlink shared channel (PUSCH) using the selected beam or link. The delay in initiating a beam or link switch or in receiving a confirmation message from the base station for the beam or link switch may be a predetermined or preconfigured delay.

[0108] In some embodiments, the UE may assume that the PDCCH and / or PDSCH received at the UE is quasi-co-located (QCL) with the selected T-RS and / or BM-RS and / or CSIA-RS in terms of QCL-Type D. For example, the UE may apply the receive beam used to receive the selected T-RS and / or BM-RS and / or CSIA-RS to receive the PDCCH and / or PDSCH. In some embodiments, the UE may be provided with an indication indicating the PDCCH and / or PDSCH that is quasi-co-located (QCLed) with one or more of the reference signals.

[0109] In some embodiments, the UE may transmit the PUCCH and / or PUSCH using the selected BM-RS and / or T-RS and / or CSIA-RS as a source reference signal for determining the spatial transmit filter. For example, the UE may apply the same beam (if beam correspondence is held in the UE) or the corresponding transmit beam (if beam correspondence is not held in the UE and a mapping between receive beams and transmit beams is maintained) to transmit the PUCCH and / or PUSCH. Beam correspondence refers to whether the UE beam selected for DL ​​reception can also be used for UL transmission, i.e., whether the UE can use the same beam for DL ​​reception and UL transmission.

[0110] In some embodiments, the association or mapping may be ordered such that the BM-RS maps to the CSIA-RS and the CSIA-RS maps to the T-RS. In such embodiments, the UE performs beam selection based on the BM-RS and then obtains CSI based on the CSIA-RS associated with the BM-RS. The UE then tracks large-scale parameters of the DL channel of the selected new beam, beam pair or link based on the T-RS associated with the BM-RS and / or CSIA-RS of the selected new beam, beam pair or link.

[0111] In some embodiments, the UE may track large-scale parameters of the DL channel directly from the selected BM-RS and estimate the CSI of the DL channel under the selected new beam, beam pair or link based on the CSIA-RS associated with the selected BM-RS of the selected new beam, beam pair or link, in which case the association or mapping configured for the UE is between the BM-RS and the CSIA-RS and does not include the T-RS.

[0112] In some embodiments, the UE may estimate the CSI of the DL channel of the selected new beam, beam pair, or link based directly on the BM-RS or based on the T-RS associated with the BM-RS. In such embodiments, the association or mapping configured for the UE is an association between the BM-RS and the T-RS, and the CSIA-RS is not included in the association or mapping. If the CSIA-RS is not associated with the other two RS types, the UE may directly estimate the CSI from the BM-RS of the selected new beam, beam pair, or link.

[0113] When an association between at least two of the BM-RS, T-RS, and CSIA-RS is configured for the UE, the above examples are possible implementations for the UE to measure and select a new beam, beam pair, or link associated with at least one of the BM-RS, T-RS, and / or CSIA-RS. It should be understood that these examples are not intended to limit the association of reference signals to a specific order of association of reference signal types for measurement at the UE. For example, instead of measuring the T-RS first and then the CSIA-RS, it is also possible to measure the CSIA-RS first and then the T-RS.

[0114] Figure 8 illustrates an example of communication between a base station (BS) 810 and a UE 820. In Figure 8, several functions are shown occurring from left to right. The arrangement of the functions from left to right along the horizontal axis indicates the functions occurring at different subsequent times. However, as noted above, this arrangement of the functions is merely an example arrangement and other arrangements are possible.

[0115] It should be appreciated that the UE is aware of the association or mapping between the BM-RS, T-RS and / or CSIA-RS since the association or mapping is provided to the UE as described above.

[0116] The first function is beam selection 830 of a new beam, beam pair or link. Each of the base station 810 and the UE 820 are shown utilizing three beams in a general direction. The UE 820 may perform measurements of the BM-RS and select a new beam pair 834 including a base station beam 834a and a UE beam 834b for possible eventual communication between the base station 810 and the UE 820. The beam selection function may be performed based on the base station 810 sending an indication of the BM-RS that may be measured at the UE 829 as described above. The base station 810 may also send an indication of association of the BM-RS, T-RS and / or CSIA-RS. The UE 820 may then use the selected new beam pair 834 to perform measurements of other types of reference signals in association in subsequent functions such as channel tracking 840 and CSI acquisition 850.

[0117] The second function is channel tracking 840. Based on the BM-RS to T-RS association 805, the UE 820 starts tracking large scale parameters of the DL channel corresponding to the selected new beam, beam pair or link based on the T-RS associated with the selected BM-RS on the UE beam 834b.

[0118] The third function is CSI acquisition 850. After acquiring one or more large-scale parameters of the DL channel, based on the association 805 between the T-RS and the CSIA-RS, the UE 820 measures and estimates the CSI of the DL channel on the UE beam 834b based on the BM-RS and / or the CSIA-RS associated with the T-RS.

[0119] The fourth function is CSI reporting 860. Based on the estimated CSI acquired in the CSI acquisition function 850, the UE 820 may initiate a beam switch, beam pair switch or link switch from the active beam, beam pair or link to the selected new beam, beam pair or link by sending 865 feedback information to the base station 810, where the feedback information may include an indication of one or more of the BM-RS, T-RS and CSIA-RS of the selected new beam, beam pair or link and one or more corresponding parameter values ​​of the RSRP, SINR, RI, CQI, PMI and LI.

[0120] An optional fifth function is the base station 810 performing beam switching, beam pair switching, or link switching confirmation 870. The base station 810 may send (875) a confirmation that the base station 810 received the UE feedback information 865.

[0121] The sixth function is QCL Update 880. As mentioned above, the UE 820 may assume that the PDCCH and / or PDSCH reception is quasi-co-located (QCLed) with one or more of the reported BM-RS, T-RS and CSIA-RS from a QCL-TypeD perspective. Although a single arrow 885 is shown between the channel tracking functions indicating that the PDCCH and / or PDSCH reception is quasi-co-located (QCLed) with the T-RS, it should be understood that the PDCCH and / or PDSCH reception may be quasi-co-located (QCLed) with either the BM-RS or CSIA-RS as well.

[0122] In some embodiments, the UE 820 may continuously repeat the process of measuring reference signals during various functions of beam selection 830, channel tracking 840, and CSI acquisition 850 based on association of at least two of the BM-RS, T-RS, and CSIA-RS. For example, when the UE is moving, the UE may continue to perform measurements periodically, aperiodically, or one-off in any desired manner to determine whether there is an alternative new beam, beam pair, or link that may be preferable to the current beam, beam pair, or link.

[0123] In a particular example, when one BM-RS (e.g., associated with one wide beam) is associated with multiple T-RS (e.g., associated with multiple narrow beams), if the selected BM-RS is the same (e.g., same wide beam) and a new T-RS is selected (e.g., new narrow beam), the UE may still initiate a link switch to the selected T-RS (e.g., newly selected narrow beam) by transmitting a report to the base station that may include the BM-RS, T-RS and / or CSIA-RS associated with the selected new beam, beam pair or link, and one or more indicators of the corresponding RSRP, SINR, RI, CQI, PMI and / or LI. It should be understood that while wide and narrow beams are mentioned in the above examples, this is not intended to be limiting. In general, a wide beam covers a wider angular range than a narrow beam.

[0124] In another particular example, when a T-RS (e.g., associated with a wide beam) is associated with multiple CSIA-RSs (e.g., associated with multiple narrow beams), if one of the multiple CSIA-RSs is selected (e.g., a new narrow beam), the UE may initiate a link switch to the selected CSIA-RS by sending a report to the base station, which may include the BM-RS, T-RS and / or CSIA-RS associated with the selected new beam, beam pair or link, and one or more indicators of the corresponding RSRP, SINR, RI, CQI, PMI and / or LI.

[0125] The preferred new beam, beam pair or link may be determined based on measurement results from one or more of the BM-RS, T-RS and / or CSI-RS. In the above example, the preferred new beam, beam pair or link is determined based on measurements of parameters such as RSRP or SINR or CSI of the DL channel of the selected new beam, beam pair or link. In addition to these parameters, it may also be possible to determine the preferred new beam, beam pair or link based on multiple measurement results. For example, the UE may select a new beam, beam pair or link with the lowest Doppler shift or Doppler spread among those with RSRP or SINR above a certain threshold. The UE may select a new beam, beam pair or link with the highest predicted data rate calculated from the measured CSI (including RI and CQI) among those with RSRP or SINR above a certain threshold. The UE may select a new link with the highest predicted data rate calculated from the measured CSI (including RI and CQI) among those with RSRP or SINR above a certain threshold and Doppler shift or Doppler spread below a certain threshold.

[0126] The association between two or more of the above-mentioned BM-RS, T-RS and CSIA-RS may be provided to the UE by configuration signaling. In some embodiments, the configuration signaling may be similar configuration signaling used to inform the UE of the QCL relationship between the reference signals. For example, the base station may inform the UE that the BM-RS, T-RS and CSIA-RS are one-to-one mapped or associated (as shown in FIG. 5), and the UE may derive the association based on the configured QCL relationship between these reference signals (e.g., CSIA-RS#1 is quasi-co-located (QCLed) with T-RS#1, and TRS#1 is quasi-co-located (QCLed) with BM-RS#1).

[0127] In some embodiments, the associations may be predefined or assumed by the UE without relying on explicit or implicit signaling from the base station. If the associations are provided to the UE or predefined, the UE may store a lookup table including the associations between two or more of the BM-RS, T-RS and CSIA-RS and subsequently check the stored lookup table during a beam switch, beam pair switch, or link switch process initiated by the UE. In some embodiments, the base station may send configuration signaling to update the associations stored in the UE. The updates to the associations may be updates to the entire association table or updates to a portion of the table, such as one or more entries in the table, but not all entries.

[0128] In some embodiments, the latency and overhead resulting from channel tracking and CSI acquisition may be reduced, leading to faster and smoother link adaptation in multi-beam systems including UE initiated beam management, beam pair management or link management.

[0129] In some embodiments, the base station and the UE exchange information to enable the UE and the base station to have an aligned understanding of possible beam, beam pair, link prediction behavior on each side of the link. In particular, the base station may transmit configuration information indicating whether the UE is permitted or prohibited to perform beam prediction, beam pair prediction, or link prediction, which may include reporting beams, beam pairs, or links that are predicted to have adequate link quality at a given time in the future, along with expected link qualities such as RSRP, SINR, RI, CQI, PMI, and / or LI. Such configuration information may further include an indication of an authorized time frame for the UE to predict beam quality, beam pair quality, or link quality, which indication informs the UE of a time range in which the UE is permitted to use beam prediction, beam pair prediction, or link prediction as part of link selection. The indication of the time range may be expressed in the form of a number of frames, slots, or symbols, or a step size (e.g., 1, 2, 4, or 8 slots) and a number of steps (e.g., a multiple of the step size). The base station may indicate a reference time point for the indicated time range, i.e., from which point the time range is counted. The reference time may be the latest measurement occasion or time instance for which feedback information is transmitted to the base station. In this way, the base station can be assured of possible time frames in which the selected new beam, beam pair or link will have the predicted link quality.

[0130] In some embodiments, the base station may additionally send configuration information to the UE to configure a threshold based on a particular confidence level for the UE, and the UE is expected to report a predicted beam, beam pair or link only if the UE is confident that the prediction is accurate within the configured confidence level.

[0131] The feedback information transmitted from the UE to the base station may include an indication of whether the selected new beam, beam pair or link and the corresponding link quality are based on a prediction. In some embodiments, when the UE reports a selected new beam, beam pair or link based on a predicted link quality such as RSRP, SINR, RI, CQI, PMI and / or LI, the UE may be configured to transmit feedback information identifying a time instance when the beam, beam pair or link is predicted to have the corresponding link quality. Such time instance information may be reported with reference to the latest measurement occasion of the BM-RS, T-RS and / or CSIA-RS, or a time instance or reference point at which the feedback information is transmitted by the UE may be reported by the UE. Relative to the configured or reported reference time, the time offset and corresponding quality of the predicted beam, beam pair or link may be expressed in the form of a number of frames, slots or symbols, or a step size (e.g., 1, 2, 4 or 8 slots) and a number of steps (e.g., a multiple of the step size).

[0132] In some embodiments, the feedback information from the UE to the base station may include a calculated confidence level of the predicted link quality.

[0133] FIG. 9 illustrates an example of an aspect when prediction is used as part of a beam, beam pair, or link selection process. FIG. 9 illustrates a signal being transmitted from a base station 910 to a UE 920. The signal may include an indication of a time range that may be used by the UE 920 as part of a prediction for beam selection, beam pair selection, or link selection. The horizontal axis indicates increasing time from left to right. The time range limits 960 for the prediction are illustrated in FIG. 9. The indication of the time range transmitted by the base station 910 may refer to the latest measurement occasion 940 for the BM-RS, T-RS, and / or CSIA-RS, or the time instance at which a report is transmitted by the UE to the base station (950).

[0134] Figure 10 illustrates another example of an aspect when predictions are used as part of a beam, beam pair, or link selection process. Figure 10 illustrates a signal being transmitted from a UE 1020 to a base station 1010. The horizontal axis illustrates increasing time from left to right. The signal may include feedback information 1040, such as one or more of an indication of the selected new beam, beam pair, or link 1042, a timestamp 1044 indicating a time instance 1050 of the predicted link quality, the predicted link quality 1046, and a confidence level 1048 of the prediction.

[0135] In embodiments for a multi-beam system in which the UE is permitted to perform predictions as part of beam selection, beam pair selection or link selection and to report the selected beam, beam pair or link, the base station may have improved knowledge and control of the behavior of the beam, beam pair or link predictions at the UE, resulting in improved coordination and operating efficiency.

[0136] In some embodiments, the UE initiates beam switching, beam pair switching, or link switching based on predicted beam quality, beam pair quality, or link quality. For example, if a new beam, beam pair, or link is predicted to be better than the active beam, beam pair, or link at a future time, the UE may transmit feedback information including information such as the selected new beam, beam pair, or link, predicted link quality, and / or corresponding time instance of link quality prediction to the base station to initiate link switching based on the selected new beam, beam pair, or link. The method of beam selection, channel tracking, CSI acquisition, switching process, and / or beam, beam pair, or link prediction in the UE may follow the steps described in the previous embodiments. If the new beam, beam pair, or link is better than the active beam, beam pair, or link, such comparison may be based on link quality including parameters such as RSRP, SINR, RI, CQI, etc.

[0137] In some embodiments, the feedback information may be carried on UL transmission resources requested by the UE and then scheduled by the base station. For example, the feedback information may be transmitted on a PUSCH. In some embodiments, the feedback information may be carried over periodic and semi-persistent UL transmissions configured by the base station. For example, the feedback information may be transmitted on periodic PUCCH transmissions. In some embodiments, the feedback information may be carried on a configured grant-based UL transmission.

[0138] In some embodiments, the feedback information may be carried in an uplink control information (UCI) and / or a media access control control element (MAC-CE). For example, the UE may be configured to perform periodic reporting. In some embodiments, the UE may request one or more aperiodic UL transmission opportunities separate from the periodic reporting instances to inform the base station of the selected new beam, beam pair or link, the predicted link quality, and / or the corresponding time instance of the link quality in addition to the periodic reporting. In some embodiments, the aperiodic UL transmission from the UE to the base station may request aperiodic transmission of the T-RS and / or the CSIA-RS at the time instance indicated in the request, which may help to speed up the overall link adaptation at the UE. In some embodiments, the aperiodic UL transmission from the UE to the base station may request aperiodic transmission of the T-RS and / or the CSIA-RS after a certain delay that may start from the UL transmission or the time instance indicated in the report.

[0139] FIG. 11 shows an example graphical plot of received power at a UE for two different base station beams B1 and B2 as the UE is moving. The horizontal axis of the plot is increasing time moving from left to right. The vertical axis is measured link quality such as RSRP, SINR, RI and / or CQI. The measured link quality of base station beam B1 increases and then decreases. The measured link quality of base station beam B2 increases and then decreases. Between a first instance of time T1 and a second instance of time T2, there is a period during which the link quality of base station beam B1 decreases and the link quality of base station beam B2 increases. If the UE initiates a beam, beam pair or link switch at a second instance of time T2 after observing that base station beam B2 has better link quality than beam B1, it takes additional time to complete the beam switching process after T2. In some embodiments, the UE initiates a link switch at an earlier instance of time, such as at or shortly after T1, and the measured link quality of base station beam B2 may still be worse than base station beam B1, but is predicted to be better shortly thereafter. In other words, the UE initiates the link switching process based on predicting the link quality at a future time instance. In this way, the UE and the base station may initiate the link switching process at an earlier time to reduce performance degradation during the transition region. In some embodiments, the UE may initiate the link switching when the predicted link quality of the base station beam B2 is better than the predicted link quality of the base station beam B1 by a certain margin or threshold. Such margin or threshold or margin may be predetermined or configured by the base station.

[0140] In some embodiments, the UE may decide whether to initiate a link switch based on the rate of change of the link quality. For example, when the link quality of the base station beam B1 is slowly deteriorating and / or the link quality of the base station beam B2 is slowly improving, the UE may not have a strong motivation to initiate a predictive beam switch, beam pair switch, or link switch, and the UE may choose not to initiate a link switch. However, when the link quality of the base station beam B1 is rapidly deteriorating and / or the link quality of the base station beam B2 is rapidly improving, the UE may initiate a predictive link switch for faster link adaptation and / or to avoid link outages.

[0141] Referring back to FIG. 11, the UE may start reporting feedback information and thereby initiate link switching at UL transmission opportunities. In some embodiments, the reporting opportunities are preconfigured by the base station and occur periodically. FIG. 12 shows another graph plot of an example of received power at the UE for two different base station beams B1 and B2 as the UE is moving. The horizontal and vertical axes are similar to those in FIG. 11. The base station beams B1 and B2 have similar measured link quality patterns over time as FIG. 11. The example periodic reporting of time instances preconfigured by the base station is shown as T1, T2, T3, T4 in FIG. 12. Although the measured link quality of base station beam B1 may be better than base station beam B2 at T2, the UE may provide feedback information indicating that base station beam B2 is preferred for link switching (as indicated by "B1" and "B2" with vertical arrows at T2) and the predicted link quality in the reporting instance of T2 if the link quality of base station beam B2 is expected to be better and exceed base station beam B1 after some time and / or by a certain margin. In the feedback information transmitted at T2, the UE may indicate whether the selected new beam, beam pair or link and the associated link quality are predicted or not. As a result, the UE may initiate switching to base station beam B2 at T2 instead of T3 if base station beam B2 has a better measured link quality. Initiating link switching based on the predicted link quality may help reduce performance degradation during the transition region. In some embodiments, the UE may determine whether to initiate a predictive link switch based on one or more of a predicted difference between the new beam, beam pair or link and the active beam, beam pair or link at a future time instance, a threshold for such predicted difference, a reporting periodicity, and a confidence in such prediction (e.g., whether, with 90% confidence, BS beam B2 is predicted to be 3 dB better than base station beam B1 at T3 in terms of RSRP or SINR).

[0142] Although the examples of Figures 11 and 12 are described with respect to two beams, beam pairs or links, it should be understood that the same method may occur simultaneously for more than two beams, beam pairs or links.

[0143] In some embodiments, the UE may be permitted to initiate predictive link switching in a multi-beam system, which may reduce performance degradation during the transition region and facilitate the handling of UE initiated beam switching, beam pair switching or link switching.

[0144] In some embodiments, the UE may select a new beam, beam pair, or link based on the smoothness of the transition from the active beam, beam pair, or link to the new beam, beam pair, or link. For example, the UE may select a new beam, beam pair, or link that has a link quality that is within a margin or threshold of the link quality of the active beam, beam pair, or link. In this manner, performance variations may be reduced during the transition from the active beam, beam pair, or link to the selected new beam, beam pair, or link. In some embodiments, for a UE with multiple antenna panels, considering the link quality of the multiple beams, beam pairs, or links, the UE may end up selecting different receive beams from the same antenna panel as opposed to selecting receive beams from different antenna panels since beams, beam pairs, or links on the same antenna panel have a smooth transition due to their similar configurations and / or orientations.

[0145] FIG. 13 shows an example graph plot of received power at a UE for three different BS beams B1, B2, and B3 as the UE moves. BS beams B1 and B2 are beams received at the same antenna panel 1320 of the UE 1310, and BS beam B3 is a beam received at a different antenna panel 1330 of the UE 1310. The horizontal and vertical axes are similar to those in FIG. 11. In the example of FIG. 13, as the UE moves from left to right, even though BS beam B3 has a higher link quality, the UE 1320 may select BS beam B2 instead of BS beam B3 because the measured quality of BS beam B2 is closer to that of BS beam B1, such that a smooth transition from BS beam B1 to BS beam B2 is achieved.

[0146] In some embodiments, the UE may be enabled to select a beam, beam pair, or link based on the smoothness of the transition from an active beam, beam pair, or link to a new beam, beam pair, or link, which may result in improved smoothness of beam tracking, beam pair tracking, or link tracking.

[0147] It is of course understood that one or more steps of the method of the embodiments provided herein may be performed by a corresponding unit or module. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Each unit / module may be hardware, software or a combination thereof. For example, one or more of the units / modules may be an integrated circuit such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). It will be understood that when the modules are software, they may be obtained by a processor, in whole or in part, separately or together for processing, in single or multiple instances as required, and the modules themselves may include instructions for further deployment and instantiation.

[0148] Although combinations of features are shown in the illustrated embodiments, not all of these need to be combined to realize the benefits of various embodiments of the present disclosure. In other words, a system or method designed according to an embodiment of the present disclosure does not necessarily include all of the features shown in any one of the figures or all of the parts shown diagrammatically in the figures. Furthermore, selected features of one exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0149] While the present disclosure has been described with reference to exemplary embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the exemplary embodiments, as well as other embodiments of the present disclosure, will be apparent to those skilled in the art upon reference to the description. It is therefore intended that the appended claims cover such modifications or embodiments. [Explanation of symbols]

[0150] 10, 170, 170a, 170b, 172, 510, 810, 910, 1010 base station 15, 25, 512, 514, 516 Beam 20, 820, 920, 1020, 1310UE 100 Communication Systems 110, 110a, 110b, 110c, 110d, 110e, 110f, 110g, 110h, 110i, 120j Electrical devices for communication 120, 120a, 120b, 120c Radio access network 130 Core Network 140 Public Switched Telephone Network 150 Internet 160 other networks 190a, 190b, 190c, 190d Air Interface 201, 252, 272 Transmitters 203, 254, 274 Receiver 204, 256, 280 Antenna 208, 258, 278 memory 210, 260, 276 processors 253 Scheduler 520, 610, 650, 710, 720, 730 Set 522, 524, 526 one-to-one mapping 615, 712 BM-RS#1 620, 722 T-RS#1 625, 724 T-RS#2 630, 732 CSIA-RS#1 635, 734 CSIA-RS#2 655, 714 BM-RS#2 660 BM-RS#3 670 T-RS#3 665 T-RS#4 675 CSIA-RS#3 716 BM-RS#N 726 T-RS#N 736 CSIA-RS#N 805 Association 830 Beam Selection 834 Beam Pair 834a Base Station Beam 834b UE Beam 840 Channel Tracking 850 CSI acquisition 860 CSI Report 865, 1040 Feedback Information 870, 875 confirmed 880 QCL update 885 Arrow 940 Measurement Opportunities 950 Send 960 limit 1042 New beam, beam pair or link 1044 Timestamp 1046 Predicted Link Quality 1048 Prediction Confidence 1050 hour instances 1320, 1330 Antenna Panel

Claims

1. receiving, by a user equipment (UE), an indication of association between at least two of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS); selecting, by the UE, a new link for link switching based on measurements of at least one of the BM-RS, the T-RS, and the CSIA-RS; sending, by the UE, a link switching indication to a base station based on the measurement value of the at least one of the BM-RS, the T-RS, and the CSIA-RS, the link switching indication including the new link indication and feedback information regarding the new link; A method comprising:

2. 2. The method of claim 1, further comprising receiving, by the UE, a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) from the base station on the new link.

3. 3. The method of claim 1 or 2, wherein the association between the at least two of the BM-RS, the T-RS and the CSIA-RS is a one-to-one association, a one-to-many association, or a many-to-one association between any two types of reference signals.

4. The method of any one of claims 1 to 3, further comprising: performing, by the UE, measurements on at least two of the BM-RS, the T-RS and the CSIA-RS based on the indication of association.

5. the step of measuring the BM-RS includes measuring the BM-RS and determining a Reference Signal Received Power (RSRP) or a Signal to Interference and Noise Ratio (SINR); the step of taking measurements of the T-RS includes tracking the T-RS and determining large-scale parameters of a channel of a new link in which the T-RS is monitored, the large-scale parameters including one or more of a mean delay, a delay spread, a Doppler shift, and a Doppler spread; the step of measuring the CSIA-RS includes estimating channel state information (CSI) of the channel of the new link through which the CSIA-RS is received based on one or more of a rank indicator (RI), a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a layer indicator (LI). The method of claim 4.

6. The method according to any one of claims 1 to 5, further comprising the step of receiving, by the UE, from the base station a confirmation of the indication of link switching sent by the UE.

7. The method according to any one of claims 1 to 6, further comprising updating, by the UE, a PDCCH Quasi-Collocation (QCL) or a PDSCH QCL based on the new link.

8. The step of selecting the new link for link switching comprises: selecting a link with the lowest Doppler shift or Doppler spread among the candidate links whose RSRP or SINR are above a threshold; selecting, from among the candidate links whose RSRP or SINR is above a threshold, the link with the highest predicted data rate as determined from the measured CSI; selecting, from among the candidate links having an RSRP or SINR above a threshold and a Doppler shift or Doppler spread below a threshold, a link having the highest predicted data rate as determined from the measured CSI; Selecting the link with the highest measured RSRP, SINR, RI or CQI. The method according to any one of claims 1 to 7, comprising one of the following:

9. The method of any one of claims 1 to 8, further comprising determining, by the UE, the association between at least two types of the reference signals based on the received indication of association.

10. The received instruction: an indication that the T-RS is quasi-colocated (QCLed) with the BM-RS; and An indication that the UE derives an association for a link switch initiated by the UE based on the previously indicated QCL relationship. The method of claim 9, comprising at least one of:

11. The method of any one of claims 1 to 10, further comprising the step of receiving, by the UE, an indication as to whether the UE is permitted to perform link prediction when selecting the new link for link switching.

12. 12. The method of claim 11, wherein if the indication indicates that the UE is authorized to perform link prediction, an indication of a maximum time offset of a predicted link relative to a latest measurement occasion is received by the UE.

13. 13. The method of claim 12, wherein the indication of a link switch to the base station includes an indication that the new link and the feedback information regarding the new link are based on predicted results.

14. By the UE, a timestamp indicating when the link was predicted to have the corresponding quality identified in the feedback information; and Confidence used in link prediction The method of claim 13 , further comprising the step of transmitting at least one of:

15. The method according to any one of claims 11 to 14, further comprising the step of selecting, by the UE, the new link for link switching using a beam or link prediction result.

16. selecting, by a user equipment (UE), a new link for link switching based on measurements of at least one of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS) and a prediction result of link quality for a future time; sending, by the UE, a link switching instruction to a base station, the link switching instruction including a new link instruction and feedback information regarding the new link and the prediction result based on a measurement of at least one of the BM-RS, the T-RS, and the CSIA-RS, the instruction being sent in a one-off uplink transmission requested by the UE or a periodic uplink transmission configured by the base station; A method comprising:

17. the rate at which the link quality changes; and Reporting periodicity when periodic uplink transmissions are configured by the base station 20. The method of claim 16, further comprising: determining whether to initiate link switching based on at least one of:

18. 18. The method of claim 16 or 17, further comprising sending, by the UE, an indication that the new link and the feedback information regarding the new link are based on a prediction when sending the indication of link switching to the base station.

19. By the UE, a timestamp indicating when the link was predicted to have the corresponding quality identified in the feedback information; and Confidence used in link prediction The method according to any one of claims 16 to 18, further comprising the step of transmitting at least one of:

20. The method according to any one of claims 16 to 19, further comprising the step of selecting, by the UE, the new link for link switching using a beam or link prediction result.

21. selecting, by a user equipment (UE), a new link for link switching based on measurements of at least one of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS) and a predicted result of link quality at a future time, wherein the selecting of the new link for link switching includes selecting, by the UE, the new link based on a new link having a link quality that is within at least one current link quality threshold; sending, by the UE, a link switching indication, the link switching indication including an indication of the new link and feedback information regarding the new link; A method comprising:

22. An apparatus comprising: A processor; a computer-readable medium having stored thereon computer-executable instructions which, when executed by said processor, cause said apparatus to perform the method of any one of claims 1 to 21; 13. An apparatus comprising:

23. transmitting, by the base station, an indication of association between at least two of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS); receiving, by the base station, from a user equipment (UE) a link switching indication, the link switching indication including a new link indication and feedback information regarding the new link, based on measurements made in the UE of at least one of the BM-RS, the T-RS, and the CSIA-RS; A method comprising:

24. 24. The method of claim 23, further comprising transmitting, by the base station, information, a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH), to the UE on the link.

25. 25. The method of claim 23 or 24, wherein the association between the at least two of the BM-RS, the T-RS and the CSIA-RS is a one-to-one association, a one-to-many association or a many-to-one association between any two types of reference signals.

26. The method according to any one of claims 23 to 25, further comprising the step of transmitting, by the base station, a confirmation of the indication of link switching received from the UE.

27. The indication of the association between at least two types of reference signals includes: an explicitly disclosed association between said at least two types of reference signals; or an implicitly disclosed association between the at least two types of reference signals used by the UE to determine the association between the at least two types of reference signals; The method according to any one of claims 23 to 26, wherein

28. The implicitly disclosed association is an indication that the T-RS is quasi-colocated (QCLed) with the BM-RS; and An indication that the UE derives an association for a link switch initiated by the UE based on the previously indicated QCL relationship.

28. The method of claim 27, comprising at least one of:

29. The method according to any one of claims 23 to 28, further comprising the step of transmitting, by the base station, an indication as to whether the UE is allowed to perform link prediction when selecting the new link for link switching.

30. 30. The method of claim 29, further comprising: if the indication indicates that the UE is permitted to perform link prediction, sending by the UE an indication of a maximum time frame value of a time offset of a predicted link relative to a latest measurement occasion.

31. 31. The method of claim 30, wherein the indication of a link switch from the UE includes an indication that the new link and the feedback information about the new link are based on predicted results.

32. By the base station, a timestamp indicating when the link was predicted to have the corresponding quality identified in the feedback information; and Confidence used in link prediction 32. The method of claim 31, further comprising receiving at least one of:

33. receiving, by a base station, from a user equipment (UE), a link switching indication including a new link indication and feedback information regarding the new link based on at least one of a beam measurement reference signal (BM-RS) and a tracking reference signal (T-RS) measurement performed at the UE and a link quality prediction result for a future time, the indication being received in a one-off uplink transmission requested by the UE or a periodic uplink transmission configured by the base station; A method comprising:

34. The instruction to switch links is the rate at which the link quality changes; and Reporting periodicity when periodic uplink transmissions are configured by the base station The method of claim 33, based on at least one of:

35. receiving, by the base station, from a user equipment (UE) a link switching indication including a new link indication and feedback information regarding the new link based on at least one measurement of a beam measurement reference signal (BM-RS), a tracking reference signal (T-RS), and a channel state information acquisition reference signal (CSIA-RS) performed at the UE and a link quality prediction result for a future time, the link switching indication being based on the new link having a link quality within at least one current link quality threshold; A method comprising:

36. An apparatus comprising: A processor; a computer-readable medium having stored thereon computer-executable instructions which, when executed by said processor, cause said apparatus to perform the method of any one of claims 23 to 35; 13. An apparatus comprising:

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