Wireless communication method performed by UE, UE, and non-transitory computer readable medium

Abstract

Disclosed are techniques for wireless communication. In an aspect, a user equipment (UE) receives a positioning configuration comprising at least an identifier of a first downlink reference signal from a neighbor cell to be used to estimate downlink path loss; determining that the first downlink reference signal received from the neighbor cell cannot be used to estimate the downlink path loss; in response to the determination, estimating the downlink path loss based on a second downlink reference signal received from the neighbor cell or the serving cell; and transmitting an uplink reference signal for positioning having a set of transmit power based on the estimated downlink path loss.

Description

[0001] This application is a divisional application of the invention patent application with application number 202080035983.6 filed on May 19, 2020 and invention name “UE and wireless communication method performed by UE and location server”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims the benefit of U.S. Provisional Application No. 62 / 850,503, filed on May 20, 2019, entitled “REPORTING OF INFORMATION RELATED TO SOUNDING REFERENCE SIGNALS (SRS) TIMING ADJUSTMENTS,” and U.S. Non-Provisional Application No. 16 / 876,851, filed on May 18, 2020, entitled “FALLBACK PROCEDURES WHEN THE PATHLOSS OR SPATIAL TRANSMIT QUASI-COLLOCATION (QCL) REFERENCE FROM NEIGHBORING CELLS IS FAILING FOR SOUNDING REFERENCE SIGNALS (SRS) FOR POSITIONING,” both of which are assigned to the assignee herein and are expressly incorporated herein by reference in their entireties. Technical Field

[0004] Aspects of the present disclosure relate generally to telecommunications, and more particularly to reporting of information related to uplink reference signal timing adjustments for enhanced uplink reference signal processing. Background Art

[0005] Wireless communication systems have evolved over several generations, including first generation analog wireless telephone service (1G), second generation (2G) digital wireless telephone service (including transitional 2.5G and 2.75G networks), third generation (3G) high speed data, wireless services with Internet capabilities, and fourth generation (4G) services (e.g., Long Term Evolution (LTE) or WiMax). There are currently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include cellular analog Advanced Mobile Phone System (AMPS) and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), global system for mobile access (GSM) variants of TDMA, and the like.

[0006] The fifth generation (5G) wireless standard, known as New Radio (NR), calls for higher data transfer speeds, a greater number of connections, and better coverage, among other improvements. According to the Next Generation Mobile Network Alliance, the 5G standard is designed to provide data rates of tens of megabits per second to each of tens of thousands of users and 1 gigabit per second to dozens of workers in an office building. In order to support large-scale sensor deployments, hundreds of thousands of simultaneous connections should be supported. Therefore, the spectrum efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard. In addition, signaling efficiency should be enhanced, and latency should be significantly reduced compared to the current standard.

[0007] To support position estimation in terrestrial wireless networks, mobile devices can be configured to measure and report the observed time difference of arrival (OTDOA) or reference signal timing difference (RSTD) between reference signals received from two or more network nodes (e.g., different base stations or different transmission points (e.g., antennas) belonging to the same base station). Summary of the invention

[0008] A brief summary of one or more aspects disclosed herein is provided below. Therefore, the following summary should not be considered a broad overview related to all expected aspects, nor should the following summary be considered to identify key or important elements related to all expected aspects or to delineate the scope associated with any particular aspect. Therefore, the sole purpose of the following summary is to provide certain concepts about one or more aspects related to the mechanisms disclosed herein in a simplified form before the detailed description given below.

[0009] In one aspect, a wireless communication method performed by a user equipment (UE) includes: receiving a positioning configuration, the positioning configuration including at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss or determining an uplink spatial transmit beam; determining that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss or determine the uplink spatial transmit beam; in response to the determination, estimating the downlink path loss or determining the uplink spatial transmit beam based on a second downlink reference signal received from a neighboring cell or a serving cell; and transmitting an uplink reference signal for positioning based on the estimated downlink path loss, the determined uplink spatial transmit beam, or a combination thereof.

[0010] In one aspect, a wireless communication method performed by a location server includes: configuring a UE to receive at least a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss or determining an uplink spatial transmit beam; receiving a report indicating a signal quality of the first downlink reference signal from the UE; and based on the signal quality of the first downlink reference signal being lower than a threshold, configuring the UE to receive at least a second downlink reference signal from a neighboring cell or a serving cell for estimating downlink path loss or determining an uplink spatial transmit beam.

[0011] In one aspect, a wireless communication method performed by a UE includes: receiving a configuration from a network node to use at least a first downlink reference signal from a neighboring cell to estimate a downlink path loss or determine an uplink spatial transmit beam; sending a report indicating a signal quality of the first downlink reference signal to the network node; and based on the signal quality of the first downlink reference signal being lower than a threshold, receiving a configuration from the network node to use at least a second downlink reference signal from a neighboring cell or a serving cell to estimate the downlink path loss or determine the uplink spatial transmit beam.

[0012] In one aspect, a UE includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive a positioning configuration via the at least one transceiver, the positioning configuration including at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating a downlink path loss or determining an uplink spatial transmit beam; determine that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss or determine the uplink spatial transmit beam; in response to the determination, estimate the downlink path loss or determine the uplink spatial transmit beam based on a second downlink reference signal received from a neighboring cell or a serving cell; and cause the at least one transceiver to send an uplink reference signal for positioning based on the estimated downlink path loss, the determined uplink spatial transmit beam, or a combination thereof.

[0013] In one aspect, a location server includes a memory, at least one network interface, and at least one processor communicatively coupled to the memory and the at least one network interface, the at least one processor being configured to: configure a UE to receive at least a first downlink reference signal from a neighboring cell to be used for estimating a downlink path loss or determining an uplink spatial transmit beam; receive a report indicating a signal quality of the first downlink reference signal from the UE; and based on the signal quality of the first downlink reference signal being lower than a threshold, configure the UE to receive at least a second downlink reference signal from a neighboring cell or a serving cell for estimating a downlink path loss or determining an uplink spatial transmit beam.

[0014] In one aspect, a UE comprises a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive a configuration from a network node to estimate downlink path loss or determine an uplink spatial transmit beam using at least a first downlink reference signal from a neighboring cell; send a report indicating a signal quality of the first downlink reference signal to the network node; and receive a configuration from the network node to estimate downlink path loss or determine an uplink spatial transmit beam using at least a second downlink reference signal from a neighboring cell or a serving cell based on the signal quality of the first downlink reference signal being lower than a threshold.

[0015] In one aspect, a UE comprises: a component for receiving a positioning configuration, the positioning configuration comprising at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss or determining an uplink spatial transmit beam; a component for determining that a first downlink reference signal received from a neighboring cell cannot be used to estimate the downlink path loss or determine the uplink spatial transmit beam; in response to the determination, a component for estimating the downlink path loss or determining the uplink spatial transmit beam based on a second downlink reference signal received from a neighboring cell or a serving cell; and a component for sending an uplink reference signal for positioning based on the estimated downlink path loss, the determined uplink spatial transmit beam, or a combination thereof.

[0016] In one aspect, a location server comprises: a component for configuring a UE to receive at least a first downlink reference signal from a neighboring cell to be used for estimating a downlink path loss or determining an uplink spatial transmit beam; a component for receiving a report indicating a signal quality of the first downlink reference signal from the UE; and a component for configuring the UE to receive at least a second downlink reference signal from a neighboring cell or a serving cell to estimate a downlink path loss or determine an uplink spatial transmit beam based on the signal quality of the first downlink reference signal being lower than a threshold.

[0017] In one aspect, a UE comprises: a component for receiving a configuration from a network node to use at least a first downlink reference signal from a neighboring cell to estimate a downlink path loss or determine an uplink spatial transmit beam; a component for sending a report indicating a signal quality of the first downlink reference signal to the network node; and a component for receiving a configuration from the network node to use at least a second downlink reference signal from a neighboring cell or a serving cell to estimate the downlink path loss or determine the uplink spatial transmit beam based on the signal quality of the first downlink reference signal being lower than a threshold.

[0018] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions, which include: at least one instruction instructing a UE to receive a positioning configuration, the positioning configuration including at least an identifier of a first downlink reference signal from a neighboring cell to be used to estimate downlink path loss or determine an uplink spatial transmit beam; at least one instruction instructing the UE to determine that a first downlink reference signal received from a neighboring cell cannot be used to estimate downlink path loss or determine an uplink spatial transmit beam; at least one instruction instructing the UE to estimate downlink path loss or determine an uplink spatial transmit beam based on a second downlink reference signal received from a neighboring cell or a serving cell in response to the determination; and at least one instruction instructing the UE to send an uplink reference signal for positioning based on the estimated downlink path loss, the determined uplink spatial transmit beam, or a combination thereof.

[0019] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions, which include: at least one instruction to instruct a location server to configure a UE to receive at least a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss or determining an uplink spatial transmit beam; at least one instruction to instruct the location server to receive a report indicating the signal quality of the first downlink reference signal from the UE; and at least one instruction to instruct the location server to configure the UE to receive at least a second downlink reference signal from a neighboring cell or a serving cell for estimating downlink path loss or determining an uplink spatial transmit beam based on the signal quality of the first downlink reference signal being lower than a threshold.

[0020] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions, which include: instructing a UE to receive a configuration from a network node to use at least a first downlink reference signal from a neighboring cell to estimate a downlink path loss or determine an uplink spatial transmit beam; instructing the UE to send a report indicating the signal quality of the first downlink reference signal to the network node; and instructing the UE to receive a configuration from the network node to use at least a second downlink reference signal from a neighboring cell or a serving cell to estimate a downlink path loss or determine an uplink spatial transmit beam based on the signal quality of the first downlink reference signal being lower than a threshold. At least one instruction.

[0021] Other objects and advantages associated with the various aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are provided to aid in describing the various aspects of the disclosure and are provided solely for illustration of these aspects and not limitation thereof.

[0023] Figure 1 An exemplary wireless communication system in accordance with various aspects of the present disclosure is shown.

[0024] Figure 2A and Figure 2B Exemplary wireless network structures according to various aspects of the present disclosure are shown.

[0025] FIG. 3A to FIG. 3C is a simplified block diagram of several exemplary aspects of components that may be employed in a wireless communication node and configured to support communications in accordance with various aspects of the present disclosure.

[0026] 4A to 4D Exemplary frame structures and channels within the frame structures according to aspects of the present disclosure are shown.

[0027] Figure 5A and Figure 5B An exemplary random access procedure according to aspects of the present disclosure is shown.

[0028] Figure 6 is a diagram of an exemplary random access-based SpCell beam failure recovery process according to various aspects of the present disclosure.

[0029] Figure 7 is a diagram illustrating an exemplary technique for determining the location of a mobile device using information obtained from multiple base stations.

[0030] Figures 8 to 10

[0013] An exemplary method of wireless communication according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0031] Various aspects of the present disclosure are provided in the following description and related drawings relating to various examples provided for the purpose of specification. Alternative aspects can be thought of without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted to avoid obscuring the relevant details of the present disclosure.

[0032] The terms "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects of the disclosure" does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation.

[0033] Those skilled in the art will recognize that the information and signals described below may be represented using any of a variety of different techniques and technologies. For example, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc., data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0034] In addition, many aspects are described in terms of a sequence of actions to be performed by, for example, elements of a computing device. It should be appreciated that the various actions described herein may be performed by a dedicated circuit (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of the two. In addition, the sequence of actions described herein may be viewed as fully embodied in any form of a non-transitory computer-readable storage medium having a set of corresponding computer instructions stored therein, which, when executed, will cause or instruct the processor of the associated device to perform the functions described herein. Therefore, various aspects of the present disclosure may be embodied in many different forms, all of which are contemplated to fall within the scope of the subject matter claimed. In addition, for each of the various aspects described herein, the corresponding form of any of these aspects may be described herein as, for example, a "logic unit" that is "configured to" perform the described actions.

[0035] As used herein, unless otherwise indicated, the terms "user equipment" (UE) and "base station" are not intended to be dedicated to or limited to any specific radio access technology (RAT). In general, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, a wearable device (e.g., a smart watch, glasses, augmented reality (AR) / virtual reality (VR) headsets, etc.), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE may be mobile or may be fixed (e.g., at a particular time) and may communicate with a radio access network (RAN). As used herein, the term "UE" may be interchangeably referred to as an "access terminal" or "AT", "client device", "wireless device", "subscriber equipment", "subscriber terminal", "subscriber station", "user terminal" or UT, "mobile terminal", "mobile station" or variations thereof. In general, a UE may communicate with a core network via a RAN, and through the core network, the UE may be connected to an external network such as the Internet or to other UEs. Of course, other mechanisms for the UE to connect to the core network and / or the Internet are also possible, such as through a wired access network, a wireless local area network (WLAN) network (eg, based on IEEE802.11, etc.), etc.

[0036] Depending on the network in which it is deployed, the base station may operate according to one of several RATs when communicating with the UE, and may be alternatively referred to as an access point (AP), a network node, a node B, an evolved node B (eNB), a new wireless (NR) node B (also referred to as a gNB or g node B), etc. In addition, in some systems, the base station may simply provide edge node signaling functions, while in other systems, it may provide additional control and / or network management functions. The communication link through which the UE can send a signal to the base station is referred to as an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link through which the base station can send a signal to the UE is referred to as a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to an uplink / reverse or downlink / forward traffic channel.

[0037] The term "base station" may refer to a single physical transmit-receive point (TRP), or to multiple physical TRPs that may or may not be co-located. For example, where the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to the cell of the base station. Where the term "base station" refers to multiple co-located physical TRPs, the physical TRP may be an antenna array of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming). Where the term "base station" refers to multiple non-co-located physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common resource via a transmission medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRP may be a serving base station that receives measurement reports from a UE and a neighbor base station whose reference signal the UE is measuring. Because, as used herein, a TRP is a point from which a base station transmits and receives wireless signals, references to transmissions from a base station or receptions at a base station should be understood to refer to a specific TRP of a base station.

[0038] Radio frequency (RF) signals include electromagnetic waves with a given frequency that transmit information through the space between a transmitter and a receiver. As used herein, a transmitter may send a single RF signal or multiple RF signals to a receiver. However, due to the propagation characteristics of RF signals through multipath channels, a receiver may receive multiple RF signals corresponding to each transmitted RF signal. The same RF signal transmitted on different paths between a transmitter and a receiver may be referred to as a "multipath" RF signal.

[0039] According to various aspects, Figure 1 An exemplary wireless communication system 100 is shown. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled as "BS") and various UEs 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macrocell base station 102 may include an eNB (where the wireless communication system 100 corresponds to an LTE network) or a gNB (where the wireless communication system 100 corresponds to an NR network) or a combination of both, and the small cell base station 102' may include a femtocell, a picocell, a microcell, etc.

[0040] The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a next generation core (NGC)) via a backhaul link 122, and interface with one or more location servers 172 via the core network 170. The base stations 102 may perform, among other functions, functions related to one or more of: transmitting user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., via EPC / NGC) via a backhaul link 134 (which may be wired or wireless).

[0041] The base station 102 can communicate with the UE 104 wirelessly. Each of the base stations 102 can provide communication coverage for a respective geographic coverage area 110. In one aspect, the base station 102 can support one or more cells in each coverage area 110. A "cell" is a logical communication entity used to communicate with a base station (e.g., on a certain frequency resource (referred to as a carrier frequency, component carrier, carrier, frequency band, etc.)), and can be associated with an identifier (e.g., a physical cell identifier (PCI), a virtual cell identifier (VCI)) for distinguishing cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB) or other protocol types) that can provide access to different types of UEs. Because a cell is supported by a specific base station, the term "cell" can refer to either or both of a logical communication entity and a base station supporting the logical communication entity, depending on the context. In some cases, the term “cell” may also refer to a geographic coverage area (eg, a sector) of a base station within which a carrier frequency may be detected and used for communications within some portion of the geographic coverage area 110 .

[0042] Although the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in a handover region), some of the geographic coverage areas 110 may substantially overlap with the larger geographic coverage areas 110. For example, a small cell base station 102' (labeled "SC" for "small cell") may have a geographic coverage area 110' that substantially overlaps with the geographic coverage areas 110 of one or more macrocell base stations 102. A network that includes both small cell base stations and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include a home eNB (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG).

[0043] The communication link 120 between the base station 102 and the UE 104 may include uplink (also referred to as reverse link) transmissions from the UE 104 to the base station 102 and / or downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna technology, which may include spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be over one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers may be allocated for the downlink than for the UL).

[0044] The wireless communication system 100 may also include a wireless local area network (WLAN) access point (AP) 150 that communicates with a WLAN station (STA) 152 via a communication link 154 in an unlicensed spectrum (e.g., 5 GHz). When communicating in the unlicensed spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or a listen before talk (LBT) procedure before communicating to determine whether a channel is available.

[0045] The small cell base station 102' can operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell base station 102' can adopt LTE or NR technology and use the same 5GHz unlicensed spectrum used by the WLAN AP 150. The small cell base station 102' adopting LTE / 5G in the unlicensed spectrum can improve the coverage of the access network and / or increase the capacity of the access network. NR in the unlicensed spectrum can be referred to as NR-U. LTE in the unlicensed spectrum can be referred to as LTE-U, License Assisted Access (LAA) or MulteFire.

[0046] The wireless communication system 100 may also include a millimeter wave (mmW) base station 180 that communicates with the UE 182, which may operate in mmW frequencies and / or near mmW frequencies. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and has a wavelength between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near mmW can be extended down to a frequency of 3 GHz with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using mmW / near mmW radio frequency bands have high path loss and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (sending and / or receiving) on ​​the mmW communication link 184 to compensate for extremely high path loss and short distances. In addition, it will be appreciated that in alternative configurations, one or more base stations 102 may also use mmW or near mmW and beamforming for transmission. Accordingly, it will be appreciated that the foregoing description is merely exemplary and should not be construed as limiting the various aspects disclosed herein.

[0047] Transmit beamforming is a technique for focusing RF signals in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). With transmit beamforming, the network node determines where a given target device (e.g., UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal to (one or more) receiving devices. In order to change the direction of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that broadcast the RF signal. For example, the network node can use an array of antennas (referred to as a "phased array" or "antenna array") that creates a beam of RF waves that can be "guided" to points in different directions without actually moving the antenna. Specifically, the RF current from the transmitter is fed to a single antenna with the correct phase relationship so that the radio waves from the separate antennas are added together to increase radiation in the desired direction and destructively in the undesired direction to suppress radiation.

[0048] Transmit beams can be quasi-co-located, which means that they appear to the receiver (e.g., UE) to have the same parameters, regardless of whether the transmit antennas of the network nodes themselves are physically co-located. In NR, there are four types of quasi-co-located (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about the second reference signal on the second beam can be derived from information about the source reference signal on the source beam. Therefore, if the source reference signal is QCL type A, the receiver can use the source reference signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference signal sent on the same channel. If the source reference signal is QCL type B, the receiver can use the source reference signal to estimate the Doppler shift and Doppler spread of the second reference signal sent on the same channel. If the source reference signal is QCL type C, the receiver can use the source reference signal to estimate the Doppler shift and average delay of the second reference signal sent on the same channel. If the source reference signal is QCL type D, the receiver can use the source reference signal to estimate the spatial reception parameters of the second reference signal sent on the same channel.

[0049] In receive beamforming, the receiver uses a receive beam to amplify the RF signal detected on a given channel. For example, the receiver may increase the gain setting and / or adjust the phase setting of the antenna array in a particular direction to amplify the RF signal received from that direction (e.g., to increase the gain level of the RF signal). Therefore, when a receiver is said to be beamforming in a certain direction, it means that the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain of all other receive beams available to the receiver in its direction. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal to interference plus noise ratio (SINR), etc.) of the RF signal received from that direction.

[0050] The transmit and receive beams may be spatially correlated. Spatial correlation means that parameters of a second beam (e.g., a transmit beam or a receive beam) for a second reference signal may be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may use a specific receive beam to receive a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station. The UE may then form a transmit beam for sending an uplink reference signal (e.g., a sounding reference signal (SRS)) to the base station based on the parameters of the receive beam.

[0051] Note that a "downlink" beam can be a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station is forming a downlink beam for sending a reference signal to the UE, the downlink beam is a transmit beam. However, if the UE is forming a downlink beam, it is a receive beam for receiving a downlink reference signal. Similarly, an "uplink" beam can be a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station is forming an uplink beam, it is an uplink receive beam, and if the UE is forming an uplink beam, it is an uplink transmit beam.

[0052] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system (such as 5G), one of the carrier frequencies is called the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell", and the remaining carrier frequencies are called "secondary carriers" or "secondary serving cells" or "SCells". In carrier aggregation, the anchor carrier is a carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and the cell in which the UE 104 / 182 performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels and can be a carrier in a licensed frequency (however, this is not always the case). A secondary carrier is a carrier operating on a second frequency (e.g., FR2), wherein the second frequency may be configured once an RRC connection is established between the UE 104 and the anchor carrier, and may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, there may be no UE-specific signaling information and signals in the secondary carrier, because both the primary uplink carrier and the primary downlink carrier are usually UE-specific. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. This is also true for the uplink primary carrier. The network is able to change the primary carrier of any UE 104 / 182 at any time. This is done to, for example, balance the load on different carriers. Because a "serving cell" (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier on which a base station is communicating, the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. may be used interchangeably.

[0053] For example, still referring to Figure 1 , one of the frequencies utilized by the macrocell base station 102 may be an anchor carrier (or "PCell"), and the other frequencies utilized by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers ("SCells"). Simultaneous transmission and / or reception of multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rate. For example, two 20 MHz aggregated carriers in a multi-carrier system (compared to the data rate achieved by a single 20 MHz carrier) would theoretically result in a two-fold increase in data rate (i.e., 40 MHz).

[0054] The wireless communication system 100 may also include one or more UEs (such as UE 190) indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. Figure 1 In the example of FIG. 1 , UE 190 has a D2D P2P link 192 connected to one of UEs 104 connected to one of base stations 102 (e.g., through D2D P2P link 192, UE 190 can indirectly obtain cellular connectivity) and a D2D P2P link 194 connected to WLAN STA 152 connected to WLAN AP 150 (through D2D P2P link 194, UE 190 can indirectly obtain WLAN-based Internet connectivity). In the example, any well-known D2D RAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), etc.) to support D2D P2P links 192 and 194.

[0055] The wireless communication system 100 may also include a UE 164 that may communicate with the macrocell base station 102 over the communication link 120 and / or communicate with the mmW base station 180 over the mmW communication link 184. For example, the macrocell base station 102 may support a PCell and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0056] According to various aspects, Figure 2AAn example wireless network architecture 200 is shown. For example, the NGC 210 (also referred to as "5GC") can be functionally viewed as a control plane functional unit (C-plane) 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane functional unit (U-plane) 212 (e.g., UE gateway functions, access to data networks, IP routing, etc.), which operate cooperatively to form a core network. The user plane interface (NG-U) 213 and the control plane interface (NG-C) 215 connect the gNB 222 to the NGC 210, and specifically, to the user plane functional unit 212 and the control plane functional unit 214. In additional configurations, the eNB 224 can also be connected to the NGC 210 via the NG-C 215 to the control plane functional unit 214 and the NG-U 213 to the user plane functional unit 212. In addition, the eNB 224 can communicate directly with the gNB 222 via the backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of the eNB 224 and the gNB 222. The gNB 222 or the eNB 224 can communicate with the UE 204 (e.g., Figure 1 204). Another optional aspect may include a location server 230 that can communicate with the NGC 210 to provide location assistance to the UE 204. The location server 230 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively, can each correspond to a single server. The location server 230 can be configured to support one or more location services for a UE 204 that can be connected to the location server 230 via the core network, the NGC 210, and / or via the Internet (not shown). In addition, the location server 230 can be integrated into a component of the core network, or alternatively, can be external to the core network.

[0057] According to various aspects, Figure 2BAnother exemplary wireless network structure 250 is shown. For example, the NGC 260 (also referred to as "5GC") can be functionally viewed as a control plane functional unit provided by an access and mobility management function unit (AMF) / user plane functional unit (UPF) 264, and a user plane functional unit provided by a session management function unit (SMF) 262, which operate in conjunction to form a core network (i.e., NGC 260). The user plane interface 263 and the control plane interface 265 connect the eNB 224 to the NGC 260, and specifically to the SMF 262 and the AMF / UPF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the NGC 260 via a control plane interface 265 to the AMF / UPF 264 and a user plane interface 263 to the SMF 262. In addition, with or without a gNB direct connection to the NGC 260, the eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of the eNBs 224 and the gNBs 222. The gNBs 222 or the eNBs 224 may communicate with the UE 204 (e.g., Figure 1 The base station of the new RAN 220 communicates with the AMF side of the AMF / UPF 264 over the N2 interface and communicates with the UPF side of the AMF / UPF 264 over the N3 interface.

[0058] The functions of AMF include registration management, connection management, reachability management, mobility management, lawful interception, transmission of session management (SM) messages between UE204 and SMF 262, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of short message service (SMS) messages between UE 204 and short message service function unit (SMSF) (not shown), and security anchor function (SEAF). AMF also interacts with authentication server function unit (AUSF) (not shown) and UE 204, and receives intermediate keys established as a result of UE 204 authentication process. In the case of authentication based on UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), AMF obtains security materials from AUSF. The functions of AMF also include security context management (SCM). SCM receives keys from SEAF, where SCM uses the keys to derive access network specific keys. The functions of AMF also include location service management for management services, transmission of location service messages between UE 204 and location management function unit (LMF) 270 and between new RAN 220 and LMF 270, allocation of EPS bearer identifiers for interworking with Evolved Packet System (EPS), and notification of mobility events of UE 204. In addition, AMF also supports functions for non-3GPP access networks.

[0059] The functions of the UPF include: acting as an anchor point for intra-RAT / inter-RAT mobility (where applicable), acting as an external protocol data unit (PDU) session point for interconnection to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic utilization reporting, Quality of Service (QoS) processing for the user plane (e.g., UL / DL rate enforcement, reflective QoS marking in DL), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in uplink and DL, downlink packet buffering and downlink data notification triggering, and sending and forwarding one or more "end flags" to the source RAN node.

[0060] The functions of SMF 262 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, traffic steering configuration to route traffic to the correct destination at UPF, control of parts of QoS and policy implementation, and downlink data notification. The interface on which SMF 262 communicates with the AMF side of AMF / UPF 264 is called the N11 interface.

[0061] Another optional aspect may include LMF 270, which may communicate with NGC 260 to provide location assistance to UE 204. LMF 270 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed among multiple physical servers, etc.), or alternatively, each may correspond to a single server. LMF 270 can be configured to support one or more location services for UE 204, which may connect to LMF 270 via a core network, NGC 260, and / or via the Internet (not shown).

[0062] Figure 3A , 3B 3C show several exemplary components (represented by corresponding boxes) that may be incorporated into UE 302 (which may correspond to any UE described herein), base station 304 (which may correspond to any base station described herein), and network entity 306 (which may correspond to or embody any network function described herein, including location server 230 and LMF 270) to support file transfer operations as taught herein. It will be appreciated that these components may be implemented in different types of devices in different implementations (e.g., in an ASIC, in a system on a chip (SoC), etc.). The components shown may also be incorporated into other devices in the communication system. For example, other devices in the system may include components similar to the components described to provide similar functionality. In addition, a given device may include one or more of the components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0063] UE 302 and base station 304 each include a wireless wide area network (WWAN) transceiver 310 and 350, respectively, which is configured to communicate via one or more wireless communication networks (not shown) (e.g., NR network, LTE network, GSM network, etc.). WWAN transceivers 310 and 350 can be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes (e.g., other UEs, access points, base stations (e.g., eNBs, gNBs), etc.) via at least one designated RAT (e.g., NR, LTE, GSM, etc.) on a wireless communication medium of interest (e.g., certain time / frequency resource sets in a specific spectrum). WWAN transceivers 310 and 350 can be configured differently for sending and encoding signals 318 and 358 (e.g., messages, indications, information, etc.), respectively, and conversely, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, etc.), respectively, according to the designated RAT. Specifically, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, respectively, and one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358, respectively.

[0064] At least in some cases, UE 302 and base station 304 also include wireless local area network (WLAN) transceivers 320 and 360, respectively. WLAN transceivers 320 and 360 can be connected to one or more antennas 326 and 366, respectively, for communicating over the wireless communication medium of interest via at least one designated RAT (e.g., WiFi, LTE-D, The WLAN transceivers 320 and 360 may be configured differently to transmit and encode signals 328 and 368 (e.g., messages, indications, information, etc.), respectively, and conversely, to receive and decode signals 328 and 368 (e.g., messages, indications, information, pilots, etc.), respectively, according to a specified RAT. Specifically, the WLAN transceivers 320 and 360 include one or more transmitters 324 and 364 for transmitting and encoding signals 328 and 368, respectively, and one or more receivers 322 and 362 for receiving and decoding signals 328 and 368, respectively.

[0065] The transceiver circuitry including at least one transmitter and at least one receiver may include an integrated device (e.g., a transmitter circuit and a receiver circuit embodied as a single communication device) in some implementations, may include a separate transmitter device and a separate receiver device in some implementations, or may be embodied in other ways in other implementations. In one aspect, the transmitter may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the corresponding device to perform transmit "beamforming" as described herein. Similarly, the receiver may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the corresponding device to perform receive beamforming as described herein. In one aspect, the transmitter and receiver may share the same multiple antennas (e.g., antennas 316, 326, 356, 366) so that the corresponding device can only receive or transmit at a given time, rather than receiving and transmitting at the same time. The wireless communication devices of UE 302 and / or base station 304 (eg, one or both of transceivers 310 and 320 and / or transceivers 350 and 360 ) may also include a network listening module (NLM) or the like for performing various measurements.

[0066] At least in some cases, the UE 302 and the base station 304 also include satellite positioning system (SPS) receivers 330 and 370, respectively. The SPS receivers 330 and 370 can be connected to one or more antennas 336 and 376, respectively, for receiving SPS signals 338 and 378, respectively, such as global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian regional navigation satellite system (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. The SPS receivers 330 and 370 can include any suitable hardware and / or software for receiving and processing the SPS signals 338 and 378, respectively. The SPS receivers 330 and 370 request appropriate information and operations from other systems and use measurements obtained by any suitable SPS algorithm to perform calculations required to determine the location of the UE 302 and the base station 304.

[0067] The base station 304 and the network entity 306 each include at least one network interface 380 and 390 for communicating with other network entities. For example, the network interfaces 380 and 390 (e.g., one or more network access ports) can be configured to communicate with one or more network entities via a wired backhaul connection or a wireless backhaul connection. In some aspects, the network interfaces 380 and 390 can be implemented as transceivers that are configured to support wired or wireless signal communications. The communication can involve, for example, sending and receiving messages, parameters, and / or other types of information.

[0068] UE 302, base station 304, and network entity 306 also include other components that can be used in conjunction with the operations disclosed herein. UE 302 includes processor circuitry that implements processing system 332 for providing functions related to, for example, positioning operations, and for providing other processing functions. Base station 304 includes processing system 384 for providing functions related to, for example, positioning operations, and for providing other processing functions. Network entity 306 includes processing system 394 for providing functions related to, for example, positioning operations, and for providing other processing functions. In one aspect, processing systems 332, 384, and 394 may include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), or other programmable logic devices or processing circuits.

[0069] UE 302, base station 304, and network entity 306 include memory circuits implementing memory components 340, 386, and 396, respectively (e.g., each including a memory device), for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). In some cases, UE 302, base station 304, and network entity 306 may include positioning components 342, 388, and 398, respectively. Positioning components 342, 388, and 398 may be hardware circuits that are part of or coupled to processing systems 332, 384, and 394, respectively, which when executed cause UE 302, base station 304, and network entity 306 to perform the functions described herein. In other aspects, positioning components 342, 388, and 398 may be external to processing systems 332, 384, and 394, respectively (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the positioning components 342, 388 and 398 may be memory modules (such as memory modules) stored in the memory components 340, 386 and 396, respectively. FIG. 3A to FIG. 3C ), which, when executed by the processing systems 332, 384, and 394 (or a modem processing system, another processing system, etc.), causes the UE 302, the base station 304, and the network entity 306 to perform the functions described herein.

[0070] UE 302 may include one or more sensors 344 coupled to processing system 332 to provide movement and / or orientation information independent of motion data derived from signals received by WWAN transceiver 310, WLAN transceiver 320, and / or SPS receiver 330. As an example, sensor(s) 344 may include an accelerometer (e.g., a microelectromechanical system (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of motion detection sensor. In addition, sensor(s) 344 may include multiple different types of devices and combine their outputs to provide motion information. For example, sensor(s) 344 may use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate a position in a 2D and / or 3D coordinate system.

[0071] In addition, the UE 302 includes a user interface 346 for providing indications to the user (e.g., auditory and / or visual indications) and / or for receiving user input (e.g., when the user actuates a sensing device such as a keyboard, touch screen, microphone, etc.). Although not shown, the base station 304 and the network entity 306 may also include a user interface.

[0072] Referring to the processing system 384 in more detail, in the downlink, IP packets from the network entity 306 may be provided to the processing system 384. The processing system 384 may implement functions for the RRC layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Medium Access Control (MAC) layer. The processing system 384 may provide RRC layer functions associated with broadcasting system information (e.g., master information block (MIB), system information block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with upper layer packet data unit (PDU) transmission, error correction through automatic repeat request (ARQ), concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0073] The transmitter 354 and the receiver 352 may implement layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The transmitter 354 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator may be used to determine coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived based on a reference signal and / or channel condition feedback sent by the UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with a corresponding spatial stream for transmission.

[0074] At the UE 302, the receiver 312 receives the signal through its corresponding (one or more) antennas 316. The receiver 312 recovers the information modulated onto the RF carrier and provides the information to the processing system 332. The transmitter 314 and the receiver 312 implement layer 1 functions associated with various signal processing functions. The receiver 312 can perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, the receiver 312 can combine them into a single OFDM symbol stream. The receiver 312 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the most likely signal constellation point sent by the base station 304. These soft decisions can be based on channel estimates calculated by a channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 304. The data and control signals are then provided to the processing system 332, which implements layer 3 and layer 2 functions.

[0075] In the UL, the processing system 332 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the core network. The processing system 332 is also responsible for error detection.

[0076] Similar to the functions described in conjunction with downlink transmissions performed by the base station 304, the processing system 332 provides: RRC layer functions associated with system information (e.g., MIB, SIB) capture, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with upper layer PDU transmission, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0077] The transmitter 314 may select appropriate coding and modulation schemes, and facilitate spatial processing, using channel estimates derived by a channel estimator from a reference signal or feedback sent by the base station 304. The spatial streams generated by the transmitter 314 may be provided to different antennas 316. The transmitter 314 may modulate an RF carrier with a corresponding spatial stream for transmission.

[0078] The uplink transmission is processed at the base station 304 in a manner similar to that described in conjunction with the receiver functionality at the UE 302. The receiver 352 receives the signal through its corresponding antenna(s) 356. The receiver 352 recovers the information modulated onto the RF carrier and provides the information to the processing system 384.

[0079] In the UL, the processing system 384 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 302. The IP packets from the processing system 384 may be provided to the core network. The processing system 384 is also responsible for error detection.

[0080] For convenience, UE 302, base station 304 and / or network entity 306 may be configured to: FIG. 3A to FIG. 3C 1 and 2. The schematic diagram of the embodiment of the present invention is shown to include various components that can be configured according to various examples described herein. However, it should be appreciated that the blocks shown may have different functions in different designs.

[0081] The various components of UE 302, base station 304, and network entity 306 may communicate with each other via data buses 334, 382, ​​and 392, respectively. FIG. 3A to FIG. 3C The components of can be implemented in various ways. In some implementations, FIG. 3A to FIG. 3C The components may be implemented in one or more circuits, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide the function. For example, some or all of the functions represented by blocks 310 to 346 may be implemented by the processor and (one or more) memory components of UE 302 (e.g., by running appropriate code and / or by appropriately configuring the processor component). Similarly, some or all of the functions represented by blocks 350 to 388 may be implemented by the processor and (one or more) memory components of base station 304 (e.g., by running appropriate code and / or by appropriately configuring the processor component). In addition, some or all of the functions represented by blocks 390 to 398 may be implemented by the processor and (one or more) memory components of network entity 306 (e.g., by running appropriate code and / or by appropriately configuring the processor component). For simplicity, various operations, actions and / or functions are described herein as being performed by "UE", "by base station", "by positioning entity", etc. However, as will be appreciated, such operations, actions and / or functions may actually be performed by a specific component or combination of components of the UE, base station, positioning entity, etc. (e.g., processing systems 332, 384, 394, transceivers 310, 320, 350 and 360, memory components 340, 386 and 396, positioning components 342, 388 and 398, etc.).

[0082] Various frame structures may be used to support downlink and uplink transmissions between network nodes (eg, base stations and UEs). Figure 4A is a diagram 400 illustrating an example of a downlink frame structure in accordance with aspects of the present disclosure. Figure 4B is a diagram 430 illustrating an example of channels within a downlink frame structure in accordance with aspects of the present disclosure. Figure 4C is a diagram 450 illustrating an example of an uplink frame structure in accordance with aspects of the present disclosure. Figure 4D is a diagram 480 illustrating an example of channels within an uplink frame structure in accordance with aspects of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0083] LTE (and in some cases, NR) utilizes OFDM on the downlink and single carrier frequency multiplexing (SC-FDM) on the uplink. However, unlike LTE, NR also has the option of using OFDM on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. Typically, modulation symbols are sent in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the spacing of the subcarriers can be 15kHz, and the minimum resource allocation (resource block) can be 12 subcarriers (or 180kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal FFT size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0084] LTE supports a single parameter set (subcarrier spacing, symbol length, etc.). In contrast, NR may support multiple parameter sets (μ), for example, 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz or larger subcarrier spacing may be available. Table 1 provided below lists some of the various parameters used for different NR parameter sets.

[0085]

[0086]

[0087] Table 1

[0088] exist Figure 4A-4D In the example of , a parameter set of 15 kHz is used. Therefore, in the time domain, a frame (e.g., 10 ms) is divided into 10 equally sized subframes, each subframe is 1 ms, and each subframe includes one time slot. 4A to 4D , time is represented horizontally (eg, on the X-axis), where time increases from left to right, and frequency is represented vertically (eg, on the Y-axis), where frequency increases (or decreases) from bottom to top.

[0089] A resource grid may be used to represent a time slot, each of which includes one or more time concurrent resource blocks (RBs) (also called physical RBs (PRBs)) in the frequency domain. A resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. Figures 4A-4D In the parameter set of , for a normal cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and six consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0090] like Figure 4A As shown in , some of the REs carry downlink reference (pilot) signals (DL-RS) for channel estimation at the UE. DL-RS may include a demodulation reference signal (DMRS), a channel state information reference signal (CSI-RS), a cell-specific reference signal (CRS), a positioning reference signal (PRS), a navigation reference signal (NRS), a tracking reference signal (TRS), etc. Figure 4A Exemplary positions in are marked as "R".

[0091] A set of resource elements (REs) used to send PRS is called a "PRS resource" and can be identified by the parameter DL-PRS-ResourceId. A set of resource elements (REs) can span multiple PRBs in the frequency domain and N (e.g., 1 or more) consecutive symbols within a slot in the time domain. In a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

[0092] A "PRS resource set" is a collection of PRS resources used to transmit a PRS signal, where each PRS resource has a PRS resource ID (DL-PRS-ResourceId). In addition, the PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID (DL-PRS-ResourceSetId) and is associated with a specific TRP (identified by a cell ID). In addition, the PRS resources in a PRS resource set have the same periodicity, a common muting pattern configuration, and the same repetition factor across time slots. The periodicity can have 2 μ· A length of t time slots, where t is selected from the set {4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} and μ = 0, 1, 2, 3 (an identifier of the parameter set). The repetition factor may have a length of n time slots, where n is selected from the set {1, 2, 4, 6, 8, 16, 32}.

[0093] The PRS resource ID in a PRS resource set is associated with a single beam (and / or beam ID) transmitted from a single TRP (where the TRP can transmit one or more beams). That is, each PRS resource in a PRS resource set can be transmitted on a different beam, and therefore, a "PRS resource" or simply "resource" may also be referred to as a "beam". Note that this has no effect on whether the UE knows the TRP and beam on which the PRS is transmitted.

[0094] A "PRS instance" or "PRS opportunity" is an instance of a periodically repeating time window (e.g., a set of one or more consecutive time slots) where a PRS is expected to be sent. A PRS opportunity may also be referred to as a "PRS positioning opportunity," "PRS positioning instance," "positioning opportunity," "positioning instance," or simply "opportunity" or "instance."

[0095] A "positioned frequency layer" is a collection of one or more PRS resource sets across one or more TRPs that have the same subcarrier spacing (SCS) and cyclic prefix (CP) type (meaning that all parameter sets supported for the shared physical downlink channel (PDSCH) are also supported for PRS), the same A point, the same downlink PRS bandwidth value, the same starting PRB (and center frequency), and the same comb size value. The A point parameter takes the value of the parameter ARFCN-ValueNR, where "ARFCN" stands for "Absolute Radio Frequency Channel Number" and is an identifier / code that specifies a pair of physical radio channels for transmission and reception. The downlink PRS bandwidth can have a granularity of 4 PRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. The comb size indicates the number of subcarriers in each symbol that carries PRS. For example, a comb size of comb-4 means that every fourth subcarrier of a given symbol carries PRS. Currently, up to four frequency layers have been defined, and up to two PRS resource sets can be configured per frequency layer per TRP.

[0096] The downlink PRS resource ID is defined locally in the downlink PRS resource set, and the downlink PRS resource set ID is defined locally in the TRP. In order to uniquely identify the DL-PRS resources across TRPs, an ID that can be associated with multiple downlink PRS resource sets associated with a single TRP has been defined. This ID can be used together with the downlink PRS resource set ID and the downlink PRS resource ID to uniquely identify a single downlink PRS resource. This ID is referred to as DL-PRS-TRP-ResourceSetId in this article. Each TRP should be associated with only one DL-PRS-TRP-ResourceSetld. For example, DL-PRS-TRP-ResourceSetId can be a cell ID (e.g., PCI, VCI) or a TRP ID, or other identifiers that are different from the cell ID or TRP ID for positioning purposes to participate in the unique identification of PRS resources.

[0097] It should be noted that the terms "positioning reference signal" and "PRS" may sometimes refer to a specific reference signal used for positioning in an LTE system. However, as used herein, unless otherwise specified, the terms "positioning reference signal" and "PRS" refer to any type of reference signal that can be used for positioning, such as but not limited to PRS signals in LTE, NRS, TRS, CRS, CSI-RS, DMRS, primary synchronization signal (PSS), secondary synchronization signal (SSS), etc.

[0098] Figure 4B An example of various channels within a downlink timeslot of a radio frame is shown. In NR, the channel bandwidth or system bandwidth is divided into multiple bandwidth parts (BWPs). A BWP is a set of contiguous PRBs selected from a subset of contiguous common RBs for a given parameter set on a given carrier. Typically, up to four BWPs can be specified in the downlink and uplink. That is, a UE can be configured with up to four BWPs on the downlink and up to four BWPs on the uplink. Only one BWP (uplink or downlink) can be active at a given time, which means that the UE can only receive or transmit on one BWP at a time. On the downlink, the bandwidth of each BWP should be equal to or greater than the bandwidth of the SSB, but it may or may not contain the SSB.

[0099] refer to Figure 4B, the UE uses the PSS to determine the subframe / symbol timing and the physical layer identifier. The UE uses the SSS to determine the physical layer cell identifier group number and the radio frame timing. Based on the physical layer identifier and the physical layer cell identifier group number, the UE can determine the PCI. Based on the PCI, the UE can determine the location of the above-mentioned DL-RS. The physical broadcast channel (PBCH) carrying the MIB can be logically grouped with the PSS and SSS to form an SSB (also called SS / PBCH). The MIB provides the number of RBs and the system frame number (SFN) in the downlink system bandwidth. The PDSCH carries user data, broadcast system information that is not sent through the PBCH (e.g., system information block (SIB)), and paging messages.

[0100] The physical downlink control channel (PDCCH) carries downlink control information (DCI) in one or more control channel elements (CCEs), each CCE includes one or more RE group (REG) bundles (which can span multiple symbols in the time domain), each REG bundle includes one or more REGs, each REG corresponds to 12 resource elements (one resource block) in the frequency domain and one OFDM symbol in the time domain. The set of physical resources used to carry PDCCH / DCI is called a control resource set (CORESET) in NR. In NR, PDCCH is restricted to a single CORESET and is transmitted with its own DMRS. This enables UE-specific beamforming for PDCCH.

[0101] exist Figure 4B In the example of , there is one CORESET per BWP, and the CORESET spans three symbols in the time domain. Unlike the LTE control channel that occupies the entire system bandwidth, in NR, the PDCCH channel is located in a specific area (i.e., CORESET) in the frequency domain. Therefore, Figure 4B The frequency components of the PDCCH shown in are shown to be smaller than a single BWP in the frequency domain. It should be noted that although the CORESETs shown are continuous in the frequency domain, this is not required. In addition, the CORESETs may span less than three symbols in the time domain.

[0102] The DCI within the PDCCH carries information about uplink resource allocations (persistent and non-persistent) and a description of the downlink data sent to the UE. Multiple (e.g., up to eight) DCIs can be configured in the PDCCH, and these DCIs can have one of a variety of formats. For example, there are different DCI formats for uplink scheduling, for non-MIMO downlink scheduling, for MIMO downlink scheduling, and for uplink power control. The PDCCH can be transmitted by 1, 2, 4, 8, or 16 CCEs to accommodate different DCI payload sizes or code rates.

[0103] like Figure 4C As shown in , some of the REs carry DMRS for channel estimation at the base station. The UE may additionally send a sounding reference signal (SRS) in, for example, the last symbol of the subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The comb structure (also called "comb size") indicates the number of subcarriers in each symbol period that carry a reference signal (here, SRS). For example, a comb size of comb-4 means that every fourth subcarrier of a given symbol carries a reference signal, while a comb size of comb-2 means that every second subcarrier of a given symbol carries a reference signal. In Figure 4C In the example shown, the SRSs (e.g., SRS#0 and SRS#1) are both comb-2. The base station can use SRS to obtain channel state information (CSI) for each UE. CSI describes how the RF signal propagates from the UE to the base station and represents the combined effects of scattering, fading, and power attenuation with distance. The system uses SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0104] Figure 4D Examples of various channels within an uplink subframe of a frame according to various aspects of the present disclosure are shown. A random access channel (RACH), also known as a physical random access channel (PRACH), may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows a UE to perform initial system access and achieve uplink synchronization. The physical uplink control channel (PUCCH) may be located at the edge of the uplink system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, CSI reports, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The physical uplink shared channel (PUSCH) carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0105] The set of resource elements used to send SRS is called "SRS resource" and can be identified by the parameter SRS-ResourceId. The set of resource elements can span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols within a time slot in the time domain. In a given OFDM symbol, SRS resources occupy consecutive PRBs. An "SRS resource set" is a set of SRS resources used to send SRS signals and is identified by an SRS resource set ID (SRS-ResourceSetId).

[0106] Typically, the UE sends SRS to enable the receiving base station (serving base station or neighboring base station) to measure the channel quality between the UE and the base station. However, SRS can also be used as an uplink positioning reference signal for uplink positioning procedures such as uplink time difference of arrival (UL-TDOA), multiple round trip time (multi-RTT), uplink angle of arrival (UL-AoA), etc.

[0107] Figure 5A An exemplary four-step random access procedure 500A according to aspects of the present disclosure is shown. The four-step random access procedure 500A is performed between a UE 504 and a base station 502, which may correspond to any UE and base station described herein, respectively.

[0108] There are various situations in which the UE may perform the four-step random access procedure 500A (also referred to as a "RACH procedure", "PRACH procedure", etc.). For example, the UE may perform the four-step random access procedure 500A when acquiring initial network access after leaving the RRC idle state, when performing an RRC connection reestablishment procedure during a handover, when downlink data or uplink data arrives and the UE is in the RRC connected state but its uplink synchronization state is "unsynchronized", when transitioning out of the RRC INACTIVE state, when establishing time alignment for adding an SCell, when requesting other synchronization information, or when performing beam failure recovery.

[0109] Before performing the four-step random access procedure 500A, the UE 504 first reads one or more SSBs broadcast by the base station 502 with which the UE 504 is performing the four-step random access procedure 500A. In NR, each beam transmitted by a base station (e.g., base station 502) is associated with a different SSB, and the UE (e.g., UE 504) selects a certain beam for communication with the base station 502. Based on the SSB of the selected beam, the UE 504 can then read SIB type 1 (SIB1), which carries cell access related information and provides the UE 504 with the schedule of other system information blocks transmitted on the selected beam.

[0110] When the UE sends the first message of the four-step random access procedure 500A to the base station 502, it sends a specific pattern called a preamble (also called a RACH preamble, PRACH preamble, preamble sequence, or sequence). The RACH preamble distinguishes requests from different UEs 504. However, if two UEs 504 use the same RACH preamble at the same time, there may be a conflict. There are a total of 64 such patterns available to the UE 504, and for contention-based random access, the UE 504 randomly selects one of them. However, for contention-free random access, the network instructs the UE 504 which one to use.

[0111] At 510, UE 504 selects one of the 64 RACH preambles to send as a RACH request to base station 502. This message is referred to as "Message 1" or "Msgl" in the four-step RACH process. Based on the synchronization information from base station 502 (i.e., SIB1), UE 504 selects a RACH preamble and sends it at the RACH opportunity (RO) corresponding to the selected SSB / beam. More specifically, in order for base station 502 to determine which beam UE 504 has selected, specific mappings are defined between SSB and RO (they occur every 10, 20, 40, 80 or 160ms). By detecting at which RO UE 504 sends the preamble, base station 502 can determine which SSB / beam UE 504 has selected.

[0112] Note that the RO is a time-frequency transmission opportunity for sending a RACH preamble, and the RACH preamble index (i.e., a value from 0 to 63 for 64 possible preambles) enables the UE 504 to generate the type of RACH preamble expected at the base station 502. The RO and RACH preamble index can be configured by the base station 502 to the UE 504 in the SIB. The RACH resource is the RO in which the RACH preamble index is sent. Therefore, depending on the context, the terms "RO" (or "RACH opportunity") and "RACH resource" can be used interchangeably.

[0113] Due to reciprocity, the UE 504 can use the uplink transmission beam corresponding to the best downlink reception beam determined during synchronization (i.e., the best reception beam that receives the selected downlink beam from the base station 502). That is, the UE 504 determines the parameters of the uplink transmission beam using the parameters of the downlink reception beam used to receive the beam from the base station 502. If reciprocity is available at the base station 502, the UE 504 can transmit the preamble through one beam. Otherwise, the UE 504 repeats the transmission of the same preamble on all its uplink transmission beams.

[0114] The UE 504 also needs to provide its identity to the network (via the base station 502) so that the network can address it in the next step. This identity is called the Random Access Radio Network Temporary Identity (RA-RNTI) and is determined by the time slot in which the RACH preamble is sent. If the UE 504 does not receive any response from the base station 502 within a certain period of time, it increases its transmit power by a fixed step size and sends the RACH preamble / Msg1 again.

[0115] At 520, the base station 502 sends a random access response (RAR) to the UE 504 on the selected beam, referred to as "Message 2" or "Msg2" in the four-step RACH process. The RAR is sent on the PDSCH and is addressed to the RA-RNTI calculated from the timeslot (i.e., RO) in which the preamble is sent. The RAR carries the following information: cell radio network temporary identifier (C-RNTI), timing advance (TA) value, and uplink granted resources. The base station 502 assigns the C-RNTI to the UE 504 to enable further communication with the UE 504. The TA value specifies how much the UE 504 should change its timing to compensate for the round-trip delay between the UE 504 and the base station 502. The uplink granted resources indicate the initial resources that the UE 504 can use on the PUSCH. After this step, the UE 504 and the base station 502 establish coarse beam alignment, which can be utilized in subsequent steps.

[0116] At 530, using the allocated PUSCH, UE 504 sends an RRC connection request message, referred to as "Message 3" or "Msg3", to base station 502. Because UE 504 sends Msg3 over resources scheduled by base station 502, base station 502 knows where to detect Msg3 and which uplink receive beam should be used. It should be noted that Msg3 PUSCH can be sent on the same or different uplink transmit beam as Msg1.

[0117] UE 504 identifies itself in Msg3 by the C-RNTI allocated in the previous step. This message contains the UE's 504 identity and the connection establishment cause. The UE's 504 identity is a temporary mobile subscriber identity (TMSI) or a random value. If the UE 504 has been previously connected to the same network, the TMSI is used. The UE 504 is identified by the TMSI in the core network. If the UE 504 is connecting to the network for the first time, a random value is used. The reason for the random value or TMSI is because the C-RNTI may have been allocated to more than one UE in the previous step due to multiple requests arriving at the same time. The connection establishment cause indicates the reason why the UE 504 needs to connect to the network, and will be further described below.

[0118] At 540, if Msg3 is successfully received, base station 502 responds with a contention resolution message, referred to as "Message 4" or "Msg4". This message is addressed to the TMSI or random value (from Msg3), but contains a new C-RNTI to be used for further communications. Specifically, base station 502 sends Msg4 in the PDSCH using the downlink transmit beam determined in the previous step.

[0119] The above four-step random access process 500A is a contention-based random access process. In contention-based random access, any UE 504 connected to the same cell or TRP sends the same request, in which case there is a possibility of conflict between the requests from various UEs 504. In contention-free random access, the network can instruct the UE 504 to use a unique identifier to prevent its request from colliding with requests from other UEs. When the UE 504 is in RRC connected mode before the random access process (for example, in the case of handover), the contention-free random access process can be performed.

[0120] Figure 5B An exemplary two-step random access procedure 500B is shown in accordance with aspects of the present disclosure. The two-step random access procedure 500B is performed between a UE 504 and a base station 502.

[0121] At 550, UE 504 sends a RACH message A ("MsgA") to base station 502. In the two-step random access procedure 500B, as described above with reference to Figure 5A The Msg1 and Msg3 are compressed (eg, combined) into MsgA and sent to the base station 502. Thus, MsgA includes the RACH preamble and the PUSCH, similar to Msg3 PUSCH of the four-step RACH process. Figure 5A As described above, the RACH preamble may have been selected from 64 possible preambles and may be used as a reference signal for demodulating the data sent in MsgA. At 560, UE 504 receives RACH message B ("MsgB") from base station 502. MsgB may be the reference signal of the above referenced Figure 5A Described combination of Msg2 and Msg4.

[0122] Combining Msg1 and Msg3 into one MsgA and combining Msg2 and Msg4 into one MsgB allows UE 504 to reduce the RACH procedure setup time to support the low latency requirements of 5G NR. Although UE 504 can be configured to support the two-step random access procedure 500B, if UE 504 cannot use the two-step random access procedure 500B due to some limitations (e.g., high transmit power requirements, etc.), UE 504 can still support the four-step random access procedure 500A as a fallback. Therefore, the UE in 5G NR can be configured to support both the two-step and four-step random access procedures, and can determine which random access procedure to configure based on the RACH configuration information received from the base station.

[0123] After the random access procedure 500A or 500B, the UE 504 is in the RRC connected state. The RRC protocol is used on the air interface between the UE 504 and the base station 502.

[0124] Due to UE mobility / mobility, beam reconfiguration at the base station and / or other factors, a downlink beam (e.g., including a downlink control link) that may have been a preferred active beam may not be detected at the UE, or the signal quality (e.g., RSRP, RSRQ, SINR, etc.) may be below a threshold, causing the UE to consider it as a beam / link failure. A beam recovery process may be employed to recover from such a beam failure. Beam failure may refer to, for example, a failure to detect a strong (e.g., having a signal power greater than a threshold) active beam, which in some aspects may correspond to a control channel communicating control information from the network. In certain aspects, to facilitate beam failure detection, the UE may pre-configure a beam identifier (ID) of a first set of beams to be monitored (referred to as "set_qO"), a monitoring period, a signal strength threshold, etc. This recovery may be triggered when the signal strength (e.g., RSRP, RSRQ, SINR, etc.) associated with one or more monitored beams (as detected by the UE) drops below a threshold. The recovery process may include the UE identifying a new beam, for example, from a second set of possible beams (corresponding to a beam ID that may be included in a second set referred to as “set_q1”), and performing (e.g., as described in the example above) a new preferred beam using preconfigured time and frequency resources corresponding to the new preferred beam. Figure 5A and Figure 5B The UE may perform a random access procedure (shown in FIG. 1 ) for a beam failure recovery purpose. Beam IDs corresponding to beams in a second beam set (set_q1) may be preconfigured at the UE for beam failure recovery purposes. For example, the UE may monitor the downlink beams (based on the beam IDs and resources identified in the second set), perform measurements, and determine (e.g., based on the measurements) which of all received and measured beams may be optimal for reception at the UE from the perspective of the UE.

[0125] If beam correspondence is assumed (i.e., the direction of the best receive beam used by the UE is also considered the best direction of the transmit beam used by the UE), the UE can assume the same beam configuration for both reception and transmission. That is, based on monitoring the downlink reference signal from the base station, the UE can determine its preferred uplink transmit beam weight, which will be the same as the downlink receive beam used to receive the downlink reference signal.

[0126] The UE may not derive the uplink transmit beam from the downlink receive beam without assuming beam correspondence (e.g., if it is deemed unsuitable in a given situation or for other reasons). Instead, separate signaling is required to select uplink transmit beam weights and downlink receive beam weights and for UL to DL beam pairing. The UE may perform a RACH procedure (e.g., using preconfigured time and frequency resources indicated in the second beam set set_q1) to identify the uplink transmit beam. Performing the RACH procedure using the preconfigured time and frequency resources may include, for example, sending a RACH preamble on one or more uplink transmit beams (corresponding to the beam IDs in the second beam set set_q1) on allocated RACH resources corresponding to one or more beams. Based on the RACH procedure, the UE may be able to determine and confirm with the base station which uplink direction may be the best beam direction for an uplink channel (e.g., PUCCH). In this way, uplink transmit and downlink receive beams may be reestablished and beam recovery may be completed.

[0127] Figure 6 is a diagram 600 of an exemplary RACH-based SpCell beam failure recovery process in accordance with aspects of the present disclosure. Figure 6 In the example of , for simplicity, the PCell and SCell are shown as being associated with a single base station (e.g., the hardware / circuitry for implementing the PCell and SCell may be collocated in the same base station). However, in some other configurations, the PCell and SCell may be associated with different base stations that may be synchronized.

[0128] exist Figure 6 In the example, a PCell or a primary (i.e., in active use) SCell (collectively, "SpCell") is supported by a base station 602 (illustrated as a "gNB" and may correspond to any base station described herein). A UE 604 (which may correspond to any UE described herein) monitors the received signal strength (e.g., RSRP, RSRQ, SINR, etc.) of a periodic reference signal (e.g., PRS) sent by the base station 602 on a first downlink transmit beam set 606 ("set_q0") of the SpCell. The first downlink transmit beam set 606 is referred to as a "failure detection resource set" because the base station 602 sends the beam IDs in the first downlink transmit beam set 606 to the UE 604 so that the UE 604 can monitor these beams to determine whether the downlink control link (i.e., the control channel for communicating control information from the network) between the base station 602 and the UE 604 is active. In the example, a PCell or a primary (i.e., in active use) SCell (collectively, "SpCell") is supported by a base station 602 (illustrated as a "gNB" and may correspond to any base station described herein). A UE 604 (which may correspond to any UE described herein) monitors the received signal strength (e.g., RSRP, RSRQ, SINR, etc.) of a periodic reference signal (e.g., PRS) sent by the base station 602 on a first downlink transmit beam set 606 ("set_q0") of the SpCell. The first downlink transmit beam set 606 is referred to as a "failure detection resource set" because the base station 602 sends the beam IDs in the first downlink transmit beam set 606 to the UE 604 so that the UE 604 can monitor these beams to determine whether the downlink control link (i.e., the control channel Figure 6 In the example of FIG. 6 , the first downlink transmission beam set 606 includes two beams. However, there may be only one beam or more than two beams in the first downlink transmission beam set 606.

[0129] At 610, the UE 604 fails to detect a periodic reference signal transmitted on at least one beam in the first downlink transmit beam set 606 and / or detects that a quality metric associated with the reference signal (e.g., RSRP, RSRQ, SINR, etc.) has dropped below a signal quality threshold (at Figure 6 The Qout threshold may be configured by the base station 602. More specifically, the layer 1 ( Figure 6 The “LI” in the UE 604 (e.g., implemented in the WWAN transceiver 310) detects that the measured quality metric of the periodic reference signal is below the Qout threshold and sends an out-of-sync (OOS) indication to the processing system 332 (which implements the layer 2 and layer 3 functions of the UE 604). In response to receiving the OOS indication, the processing system 332 of the UE 604 starts a beam failure detection (BFD) timer and initializes a beam failure indicator (BFI) counter to “1”.

[0130] At 615, UE 604 again fails to detect the periodic reference signal transmitted on at least one beam in the first downlink transmit beam set 606 and / or again detects that the quality metric associated with the reference signal has fallen below the Qout threshold. Again, more specifically, the layer 1 function of UE 604 detects that the measured quality metric of the periodic reference signal is below the Qout threshold and sends another OOS indication to processing system 332. Processing system 332 increases the BFI count to "2." Because the BFI count has reached the maximum count ("MaxCnt") threshold (at Figure 6 , but it may be another value), UE 604 determines that there has been a beam failure of at least one beam (e.g., a downlink control beam) in the first downlink transmission beam set 606. Because there is a failure in the downlink control beam (corresponding to a downlink control channel for communicating control information from the network), UE 604 assumes that there is also a failure in the corresponding uplink control beam (corresponding to an uplink control channel for communicating control information to the network). Therefore, UE 604 needs to identify a new downlink control beam and re-establish the uplink control beam. UE 604 also resets the BFD timer.

[0131] Therefore, at 620, in response to the beam failure detection at 615, the UE 604 initiates a beam failure recovery procedure. More specifically, the processing system 332 of the UE 604 requests the layer 1 function of the UE 604 to identify at least one beam in the second downlink transmit beam set 608 ("set_q1") that carries a periodic reference signal having a received signal strength greater than a signal quality threshold (denoted as "Qin"). The second downlink transmit beam set 608 is referred to as a "candidate beam reference signal list." The UE 604 may receive the beam ID and Qin threshold of the beam in the second downlink transmit beam set 608 from the base station 602. Figure 6 In the example of , the second downlink transmit beam set 608 includes four beams, one of which (the shaded portion) carries a periodic reference signal having a received signal strength greater than the Qin threshold. However, it will be appreciated that there may be more or less than four beams in the second downlink transmit beam set 608, and there may be more than one beam that satisfies the Qin threshold. The WWAN transceiver 310 (implementing layer 1 functionality) reports the identified candidate beams to the processing system 332. The identified candidate beams may then be used as new downlink control beams, although not necessarily immediately.

[0132] At 625, to reestablish the uplink control beam, UE 604 transmits one or more candidate downlink beams identified at 620 (in Figure 6 In the example of one) execution (for example, as Figure 5A and Figure 5B ) RACH process shown. More specifically, the processing system 332 instructs the WWAN transceiver 310 to send a RACH preamble to the base station 602 (which may be pre-stored by the base station 602 or provided to the UE 604). The WWAN transceiver 310 sends a RACH preamble (also referred to as message 1 ("Msgl")) on one or more candidate uplink transmit beams corresponding to the one or more candidate downlink transmit beams identified at 620 and on pre-configured RACH resources for the one or more candidate uplink transmit beams. The pre-configured RACH resources may correspond to a SpCell (e.g., in the mmW frequency band). Although not in Figure 6 As shown in FIG. 6 , however, at 625 UE 604 also starts a beam failure recovery (BFR) timer that defines a contention free random access (CFRA) response window.

[0133] The one or more candidate downlink transmit beams identified at 620 may include a beam that is different from a downlink transmit beam associated with a beam failure. As used herein, a "beam" is defined by beam weights associated with an antenna array of UE 604. Thus, in some aspects, the weights applied to each antenna in the array to construct a transmit beam or receive beam, whether for uplink transmission by UE 604 or for downlink reception by UE 604, define the beam. Thus, one or more candidate uplink transmit beams on which to transmit a RACH preamble may have weights that are different from the weights of a downlink transmit beam associated with a beam failure, even if the candidate uplink transmit beam is substantially similar in direction to a downlink transmit beam indicated as having failed.

[0134] At 630, the base station 602 sends a RACH response (referred to as a "Msgl response") to the UE 604 via a PDCCH associated with the SpCell using the C-RNTI. For example, the response may include cyclic redundancy check (CRC) bits scrambled by the C-RNTT. After the WWAN transceiver 310 of the UE 604 processes the response received from the base station 602 via the SpCell PDCCH using the C-RNTI and determines that the received PDCCH is addressed to the C-RNTI, the processing system 332 determines that the beam failure recovery process has been completed and stops the BFR timer started at 625. In one aspect, the C-RNTI may be mapped to a beam direction of an optimal direction of an uplink channel (e.g., PUCCH) determined by the base station 602 for the UE 604. Therefore, after receiving the response from the base station 602 using the C-RNTI, the UE 604 may be able to determine the optimal uplink transmit beam that is best suited for the uplink channel.

[0135] The operations at 630 are part of a first scenario in which the UE 604 successfully recovers from the beam failure detected at 615. However, such recovery may not always occur, or at least not before the expiration of the BFR timer started at 625. If the BFR timer expires before the beam failure recovery procedure is successfully completed, then at 635, the UE 604 determines that a radio link failure (RLF) has occurred.

[0136] Figure 7 An exemplary wireless communication system 700 is shown in accordance with aspects of the present disclosure. Figure 7In the example of , a UE 704, which may correspond to any UE described herein, is attempting to calculate an estimate of its location, or assist another entity (e.g., a base station or core network component, another UE, a location server, a third-party application, etc.) in calculating an estimate of its location. The UE 704 may wirelessly communicate with a plurality of base stations 702-1, 702-2, and 702-3 (collectively referred to as base stations 702) using standardized protocols and RF signals for modulating RF signals and exchanging information packets, and the plurality of base stations 702-1, 702-2, and 702-3 may correspond to any combination of base stations described herein. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communication system 700 (e.g., base station locations, geometry, etc.), the UE 704 may determine its location in a predefined reference coordinate system, or assist in determining its location in a predefined reference coordinate system. In one aspect, the UE 704 may specify its location using a two-dimensional (2D) coordinate system, however, the aspects disclosed herein are not limited thereto, and may also be applicable to determining a location using a three-dimensional (3D) coordinate system if additional dimensions are required. Additionally, although Figure 7 One UE 704 and three base stations 702 are illustrated, but it should be understood that there may be more UEs 704 and more or fewer base stations 702 .

[0137] To support position estimation, the base station 702 may be configured to broadcast positioning reference signals (e.g., PRS, NRS, TRS, CRS, etc.) to the UEs 704 in its coverage area to enable the UEs 704 to measure the characteristics of these reference signals. For example, the OTDOA positioning method, also known as the time difference of arrival (TDOA) positioning method, is a multi-point measurement method in which the UE 704 measures the time difference between specific reference signals (e.g., PRS, NRS, TRS, CRS, etc.) sent by different pairs of network nodes (e.g., the base station 702, the antenna of the base station 702, etc.), called RSTD, and reports these time differences to a location server such as the location server 230 or the LMF 270, or calculates the position estimate itself from these time differences.

[0138] Typically, at a reference network node (e.g. Figure 7 ) and one or more neighboring network nodes (e.g., Figure 7RSTD is measured between base stations 702-2 and 702-3 in the example of UE 701). The reference network node remains the same for all RSTDs measured by UE 704 for any single positioning use of OTDOA, and typically corresponds to a serving cell for UE 704 or another nearby cell with good signal strength at UE 704. In one aspect, when the measured network node is a cell supported by a base station, the neighboring network node is typically a cell supported by a base station different from the reference cell and may have good or poor signal strength at UE 701. The position calculation can be based on the measured time difference (e.g., RSTD) and knowledge about the location and relative transmission timing of the network nodes (e.g., whether the network nodes are precisely synchronized or whether each network node transmits at some known time difference relative to the other network nodes).

[0139] To assist in positioning operations, a location server (e.g., location server 230, LMF 270) may provide OTDOA assistance data to UE 704 for use in referencing network nodes (e.g., Figure 7 ) and the neighboring network nodes relative to the reference network node (e.g., Figure 7 For example, the assistance data may provide a center channel frequency of each network node, various reference signal configuration parameters (e.g., the number of consecutive positioning subframes, the period of the positioning subframe, the silent sequence, the frequency hopping sequence, the reference signal identifier (ID), the reference signal bandwidth), a network node global ID, and / or other cell-related parameters applicable to OTDOA. The OTDOA assistance data may indicate a serving cell for UE 704 as a reference network node.

[0140] In some cases, the OTDOA assistance data may also include an "expected RSTD" parameter that provides the UE 704 with information about the RSTD value that the UE 704 expects to measure at its current location between its reference network node and each neighboring network node, as well as the uncertainty of the expected RSTD parameter. The expected RSTD, along with the associated uncertainty, may define a search window for the UE 704 within which the UE 704 is expected to measure RSTD values. The OTDOA assistance information may also include a reference signal configuration information parameter that allows the UE 704 to determine reference signal positioning opportunities relative to the reference network node, when reference signal positioning opportunities occur on signals received from various neighboring network nodes, and to determine reference signal sequences sent from various network nodes in order to measure signal arrival time (ToA) or RSTD.

[0141] In one aspect, while a location server (e.g., location server 230, LMF 270) can send assistance data to UE 704, alternatively, the assistance data can originate directly from the network node (e.g., base station 702) itself (e.g., in a periodically broadcast overhead message, etc.). Alternatively, UE 704 can detect neighboring network nodes itself without using assistance data.

[0142] UE 704 (e.g., based in part on assistance data, if provided) may measure and (optionally) report RSTD between reference signals received from a pair of network nodes. Using RSTD measurements, known absolute or relative transmission timing of each network node, and known position(s) of transmit antennas for the reference network node and neighboring network nodes, a network (e.g., location server 230 / LMF 270, base station 702) or UE 704 may estimate the location of UE 704. More specifically, the RSTD of neighboring network node “k” relative to reference network node “Ref” may be given as (ToA k –ToA Ref ), where the ToA value can be measured modulo a subframe duration (1ms) to eliminate the effect of measuring different subframes at different times. Figure 7 In the example of FIG. 7 , the measured time differences between the reference cell of base station 702-1 and the cells of neighboring base stations 702-2 and 702-3 are represented as t2–t1 and t3–t1, where t1, t2, and t3 represent the ToA of the reference signals from the transmit antenna(s) of base stations 702-1, 702-2, and 702-3, respectively. UE 704 can then convert the ToA measurements for different network nodes into RSTD measurements and (optionally) send them to location server 230 / LMF 270. Using (i) RSTD measurements, (ii) known absolute or relative transmission timing of each network node, (iii) known position(s) of the physical transmit antenna(s) of the reference network node and neighboring network nodes, and / or (iv) directional reference signal characteristics, such as transmission direction, the location of UE 704 can be determined (by UE 704 or location server 230 / LMF 270).

[0143] Still reference Figure 7, when UE 704 obtains a position estimate using the time difference measured by OTDOA, the location server (e.g., location server 230, LMF 270) can provide the necessary additional data (e.g., the location and relative transmission timing of network nodes) to UE 704. In some implementations, the position estimate of UE 704 can be obtained (e.g., by UE 704 itself or by location server 230 / LMF 270) from the time difference measured by OTDOA and other measurements made by UE 704 (e.g., signal timing measurements from GPS or other global navigation satellite system (GNSS) satellites). In these implementations, which are referred to as hybrid positioning, OTDOA measurements may help obtain a position estimate for UE 704, but may not completely determine the position estimate.

[0144] UTDOA is a positioning method similar to OTDOA, but is based on uplink reference signals (e.g., SRS, uplink PRS) transmitted by a UE (e.g., UE 704). In addition, transmit and / or receive beamforming at the base station 702 and / or UE 704 can achieve wideband bandwidth at the cell edge to improve accuracy. Beam refinement can also take advantage of the channel reciprocity process in 5GNR.

[0145] Another uplink positioning procedure is UL-AOA. In UL-AoA positioning, the base station estimates the position of the UE using the angle and other characteristics (e.g., signal strength) of the uplink receive beam on which it receives a reference signal (e.g., SRS). The base station or other positioning entity may also use the signal propagation time between the base station and the UE to determine the distance between the base station and the UE to further refine the position estimate of the UE. The signal propagation time or flight time may be determined using multiple RTTs.

[0146] The term "position estimate" is used herein to refer to a position estimate for a UE, which may be geographic (e.g., may include latitude, longitude, and possibly altitude) or urban (e.g., may include a street address, a building name, or a precise point or area within or near a building or street address, such as a specific entrance to a building, a specific room or suite in a building, or a landmark such as a town square). The position estimate may also be referred to as a "location," "position," "position fix," "location fix," "location estimate," "position estimate," or some other term. The means of obtaining a location estimate may be collectively referred to as "positioning," "fixing," or "location fix." A specific solution for obtaining a location estimate may be referred to as a "location solution." As part of a location solution, a specific method for obtaining a location estimate may be referred to as a "location method" or "positioning method."

[0147] As mentioned above, an "RF signal" includes electromagnetic waves that transmit information through space between a transmitter and a receiver. RF signals typically suffer a certain amount of path loss or path attenuation, which is the reduction in power density (attenuation) of an electromagnetic wave (RF signal) as it propagates through space. Path loss can be caused by many effects, such as free space loss, refraction, diffraction, reflection, aperture medium coupling loss, and absorption. Path loss is also affected by terrain contours, environment (e.g., urban or rural, vegetation and foliage, etc.), propagation medium (e.g., dry or humid air), distance between transmitter and receiver, and height and position of the transmitting antenna.

[0148] A transmitter (e.g., a base station or UE) may transmit a single RF signal or multiple RF signals to a receiver (e.g., a UE or base station). However, due to the propagation characteristics of RF signals through multipath channels, the receiver may receive multiple RF signals corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the transmitter and the receiver may be referred to as a "multipath" RF signal. The multipath RF signals combine at the receiver to produce a received signal that may vary greatly, depending on the distribution of the intensity and relative propagation times of the waves and the bandwidth of the transmitted signal.

[0149] As described above, during the UTDOA positioning procedure (and other uplink or uplink plus downlink positioning procedures, such as multi-RTT and UL-AoA), the UE transmits uplink reference signals, such as SRS and uplink PRS, which need to be transmitted at a sufficiently high transmit power so that neighboring cells can measure them. Because the neighboring cells may be farther away from the UE than the serving cell, the path loss between the UE and the neighboring cells may be more than the path loss between the UE and the serving cell. Therefore, these uplink reference signals may need to be transmitted at a higher transmit power than the uplink signals sent to the serving cell.

[0150] Multiple options for the transmit power of uplink reference signals that are set to be sent for positioning purposes (e.g., UTDOA) have been identified. As a first option, the transmit power of these uplink reference signals can be constant (i.e., power control is not supported). As a second option, the transmit power of the uplink reference signal can be based on an existing power control process. As a third option, the transmit power can be determined by modifying the existing power control process. For example, the downlink reference signal of an adjacent cell can be configured for path loss estimation of the uplink reference signal. More specifically, the UE can estimate the path loss of the downlink reference signal and determine the appropriate transmit power of the uplink reference signal based on the determined path loss. In one aspect, the downlink reference signal can be a CSI-RS, SSB, downlink PRS, etc.

[0151] Referring to the third option, using the downlink reference signal from the neighboring cell to estimate the path loss of the uplink reference signal, in addition to the existing legacy behavior, various other features need to be supported in 5G NR. For example, for the purpose of uplink reference signal power control, support is needed to configure the downlink reference signal of the neighboring cell as a downlink path loss reference. However, if the UE cannot obtain the path loss reference, there is currently no specified fallback procedure. Therefore, the present disclosure describes various fallback procedures when the UE cannot obtain the path loss reference.

[0152] In addition to using downlink reference signals to determine the transmit power of uplink reference signals, the UE may also use downlink reference signals from neighboring cells (also in the case of positioning procedures) to determine the spatial direction of an uplink transmit beam (also referred to as spatial transmit QCL, spatial QCL, spatial transmit beam, etc.) carrying an uplink reference signal. The downlink reference signal used to determine the transmit power of the uplink reference signal and the downlink reference signal used to determine the spatial direction of the uplink transmit beam may be, but need not be, the same downlink reference signal. Various features are currently supported for uplink beam management / alignment for serving cells and neighboring cells (in addition to UE transmit beam scanning). First, configuration of the spatial relationship between a downlink reference signal from a serving cell or (one or more) neighboring cells and a target uplink reference signal is supported. The downlink reference signals that may be used include at least SSBs, and may include CSI-RS and PRS. Secondly, for both FR1 and FR2, fixed transmit beams for uplink reference signal transmission across multiple uplink reference signal resources are supported. It should be noted that it is currently undesirable for a UE to send multiple uplink reference signal resources with different spatial relationships in the same OFDM symbol.

[0153] As described above, the UE may calculate the transmit power of the uplink reference signal based on the path loss of the downlink reference signal. The UE may proceed as follows. If the UE transmits an uplink reference signal (e.g., SRS) on the uplink BWP b of the carrier f of the serving cell c using the SRS power control adjustment state with index l, the UE determines the SRS transmit power P in the SRS transmit opportunity i. SRS,b,f,c (i,q s ,l) is as follows (in dBm):

[0154]

[0155] in:

[0156] -P CMAX.C(i) is the UE transmit power configured for carrier f of serving cell c at SRS transmission opportunity i.

[0157] -P O_SRS,b,f,c (q s ) is provided by the higher-level parameter p0 of the uplink BWP b of carrier f of serving cell c and the SRS resource set qs provided by the higher-level parameters SRS-ResourceSet and SRS-ResourceSetId. If p0 is not provided, P O_SRS,b,f,c (q s )=P O_NOMINALPUSCH,f,c (0);

[0158] -M SRS,b,f,c (i) is the SRS bandwidth in number of resource blocks for SRS transmission opportunity i on active uplink BWP b of carrier f for serving cell c, and μ is the SCS configuration;

[0159] -α SRS,b,f,c (q s ) is composed of the higher layer parameters alpha and SRS resource set q of the uplink BWP b of carrier f serving cell c s supply;

[0160] -PL b,f,c (q d ) is used by the UE to index the reference signal q d The downlink path loss estimate in dB calculated for the downlink BWP linked to the uplink BWP b and SRS resource set qs of carrier f serving cell c. Reference signal index q d By SRS resource set s The associated higher-layer parameter pathlossReferenceRS is provided and is either the higher-layer parameter ssb-index providing the SS / PBCH block index or the higher-layer parameter csi-RS-Index providing the CSI-RS resource index. If the higher-layer parameter pathlossReferenceRS is not provided to the UE or before the dedicated higher-layer parameters are provided to the UE, the UE calculates the PL using the reference signal resources obtained from the SS / PBCH block index that the UE uses to obtain the MIB b,f,c (q d ). If pathlossReferenceLinking is provided to the UE, the reference signal resources are located on the serving cell indicated by the value of pathlossReferenceLinking;

[0161] -h b,f,c (i,l)=f b,f,c(i, l), where if the higher layer parameter srs-PowerControlAdjustmentStates indicates the same power control adjustment state for SRS transmission and PUSCH transmission, then f b,f,c (i, l) is the current PUSCH power control adjustment state.

[0162] As described above, up to four BWPs may be specified in the downlink and uplink. Currently, there may be up to four path loss estimates per serving cell, one for each BWP. Specifically, the UE does not wish to maintain more than four path loss estimates per serving cell simultaneously for all PUSCH / PUCCH / SRS transmissions. The pathlossReferenceLinking parameter indicates whether the UE should use the downlink of the PCell or SCell corresponding to this uplink as a path loss reference.

[0163] As described above, some wireless communication networks, such as 5G NR, may employ mmW or near-mmW frequencies to increase network capacity. The use of mmW frequencies may be complementary to microwave frequencies (e.g., in sub-6 GHz bands), which may also support use in communications, such as when carrier aggregation is used. Because communications at high mmW frequencies utilize directionality (e.g., communicating via directional beams) to compensate for higher propagation losses, base stations and UEs may need to communicate with each other during initial network access (e.g., as Figure 5A and Figure 5B The base station and the UE may determine the best beam for communicating with each other, and subsequent communications between the base station and the UE may be conducted via the selected beam. However, due to UE mobility / movement, beam reconfiguration at the base station, and / or other factors, a downlink beam (e.g., including a downlink control link) that may have been a preferred active beam may not be detected at the UE, or the signal quality may drop below a threshold, causing the UE to view it as a beam / link failure.

[0164] It can be used (for example, Figure 6 1. The UE may perform a beam recovery procedure (as shown in FIG. 1 ) to recover from a beam failure. A beam failure may refer to, for example, a failure to detect a strong (e.g., where the signal power is greater than a threshold) downlink transmit beam, a failure to accurately measure the path loss of a reference signal (e.g., based on a signal strength threshold), etc. The recovery procedure may include the UE performing (e.g., as shown in FIG. 1 ). Figure 5A and 5BThe UE may perform a random access procedure (as shown) to request a new beam allocation. Specifically, the UE may indicate a new SSB or CSI-RS for a new transmit beam during the random access procedure. The base station allocates a new beam by sending a downlink allocation or uplink grant on the PDCCH based on a beam failure recovery request from the UE. Subsequently, a new beam pair (i.e., a transmit / receive beam pair) may be established.

[0165] Performing path loss estimation or spatial transmit beam determination (also known as spatial transmit QCL determination) on downlink reference signals from neighboring (non-serving) cells can be a difficult task because the neighboring cells can be far away. Path loss estimation is prone to errors, and therefore, the transmit power or spatial transmit determination made by the UE can be prone to errors. Therefore, there are various issues that need to be addressed, such as how the UE should notify a location server (e.g., location server 230, LMF 270) of a path loss reference signal or spatial transmit beam reference signal failure, how the UE should send uplink reference signal resources when a downlink reference signal fails, and a process to avoid path loss or spatial transmit estimation failures for neighboring cells.

[0166] When the UE is configured to use a downlink reference signal from a neighboring cell to perform path loss estimation or spatial transmission QCL determination, and the UE identifies that the reference signal cannot be used for this purpose, there are several options for how the UE can notify the location server of the reference signal failure. As a first option, the UE can notify the serving base station (which then notifies the location server) through, for example, RRC signaling, or the UE can directly notify the location server through higher layer signaling (such as the LTE Positioning Protocol (LPP)), that the path loss downlink reference signal or spatial transmission QCL downlink reference signal for a specific uplink reference signal resource has failed. As a second option, the UE can request to be configured with an alternative and / or auxiliary downlink reference signal from the serving cell to replace the affected (one or more) uplink reference signal resources. As a third option, the UE can request to be configured with an alternative and / or auxiliary downlink reference signal from (one or more) neighboring cells to replace the affected (one or more) uplink reference signal resources.

[0167] Being configured with an alternative downlink reference signal means that the UE may have been configured with multiple downlink reference signals and can select one of them. Being configured with a secondary downlink reference signal means that the UE is configured with a primary downlink reference signal, but if the primary downlink reference signal fails, the secondary downlink reference signal can be used. The first three options are complementary, as long as the UE can report that the downlink reference signal has failed (the first option) and request a replacement (the second and third options).

[0168] As a fourth option, the UE may start a random access procedure with the serving cell, as in the case of the beam failure recovery procedure, but with a preamble sequence number indicating that the downlink transmit beam of the neighboring cell has failed, instead of the downlink transmit beam from the serving cell. Based on the sequence number, the serving cell may then notify the location server or (one or more) neighboring cells of the beam failure via a higher layer protocol (e.g., the Xn interface). As a fifth option, the UE may start a partial beam failure recovery procedure, which means that the UE may report that (more than one) subset of neighboring downlink reference signals have failed. This report may be over a regular PUCCH / PUSCH channel, instead of PRACH, as in the fourth option. The serving cell may then notify the location server or (one or more) neighboring cells of the failure via a higher layer protocol (e.g., the Xn interface).

[0169] Another question is how the UE should send uplink reference signal resources when the downlink reference signal fails. When the UE is configured to use the downlink reference signal from the neighboring cell for path loss estimation, and the UE identification reference signal cannot be used for this purpose, there are multiple options that the UE can follow. If the downlink reference signal is used for path loss reference, as a first option, the UE can send the uplink reference signal at its maximum transmit power until a new downlink reference signal is configured for path loss estimation. Under the assumption that if the UE can no longer detect the downlink reference signal from the neighboring cell (this is because the neighboring cell is far away), the UE can send at its maximum transmit power. As a second option, the UE can use the configured auxiliary downlink reference signal from the serving cell or the neighboring cell (as requested above) to assist in path loss estimation. As a third option, the UE can use the path loss downlink reference signal configured for the uplink reference signal of the serving cell (or PUSCH / PUCCH). As a fourth option, for both the path loss reference signal and the spatial QCL reference signal, the UE can use the default downlink transmit beam (i.e., the same downlink transmit beam). For example, the UE may use the transmit beam with the lowest uplink reference signal resource ID.

[0170] If the downlink reference signal is used for spatial QCL reference, as a first option, the UE may use the configured auxiliary downlink reference signal from the serving cell to assist in deriving the uplink transmit beam (spatial QCL). As a second option, if the UE has been configured with multiple downlink reference signals from a specific neighboring cell, the UE may transmit the affected resources using one of the uplink transmit beams derived from other downlink reference signals of the same neighboring cell. As a third option, if the UE is only configured with one downlink reference signal from a neighboring cell, the UE may use the uplink transmit beam derived from the downlink reference signal of the serving cell to transmit the affected resources. As a fourth option, the UE may use the default downlink transmit beam (i.e., the same downlink transmit beam) for both the path loss downlink reference signal and the spatial QCL downlink reference signal. For example, the UE may use the transmit beam with the lowest uplink reference signal resource ID.

[0171] It will be appreciated that the options for both path loss and spatial QCL uplink reference signals are similar, except that the maximum transmit power is used in the case where a failed downlink reference signal is used for path loss reference.

[0172] Now referring to the process of avoiding the failure of downlink reference signals from neighboring cells to estimate path loss / spatial transmit QCL, there are several steps that can be taken. First, the location server can configure the UE with downlink reference signals from neighboring cells to perform path loss or spatial transmit beam determination. Second, the UE can periodically report the RSRP, RSRQ and / or SINR of any downlink reference signals from neighboring cells that are being used for path loss or spatial transmit QCL estimation for uplink reference signal transmission. Alternatively, the location server can configure such reports that will be helpful for those downlink reference signals. This can be done by reporting directly to the location server, or reporting to the base station, which then relays the report (e.g., via the Xn interface) to the neighboring base station or location server (e.g., location server 230, LMF270). Third, when RSRP / RSRQ / SINR is low, the positioning server can actively reconfigure the downlink reference signal.

[0173] The RSRP / RSRQ / SINR thresholds may be used to decide whether the current downlink reference signal can be used for path loss reference estimation or spatial QCL determination.

[0174] Figure 8 An exemplary method 800 of wireless communication in accordance with aspects of the present disclosure is shown. In one aspect, the method 800 may be performed by a UE (eg, any UE described herein).

[0175] At 810, the UE receives a positioning configuration (e.g., from a location server, a serving cell, or other such entity via RRC, LPP, and / or other signaling) that includes at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss or determining an uplink spatial transmit beam. In one aspect, operation 810 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of which may be considered as means for performing the operation.

[0176] At 820, the UE determines whether the first downlink reference signal received from the neighboring cell has failed. In one aspect, operation 820 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of these may be considered as means for performing the operation.

[0177] At 830, in response to determining that the first downlink reference signal has failed, the UE estimates the downlink path loss or determines the uplink spatial transmit beam based on a second downlink reference signal for the UE received from a neighboring cell or a serving cell. In one aspect, operation 830 may be performed by the WWAN transceiver 310, the processing system 332, the memory component 340, and / or the positioning component 342, and / or all of these may be considered as means for performing the operation.

[0178] At 840, the UE transmits an uplink reference signal for positioning based on the estimated downlink path loss, the determined uplink spatial transmit beam, or a combination thereof. In one aspect, operation 840 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of these may be considered as means for performing the operation.

[0179] Fig. 9 An exemplary method 900 of wireless communication in accordance with aspects of the present disclosure is shown. In one aspect, the method 900 may be performed by a location server (eg, location server 230, LMF 270).

[0180] At 910, the location server configures (e.g., via LPP) a UE (e.g., any UE described herein) to receive at least a first downlink reference signal from a neighboring cell to be used for estimating a downlink path loss or determining an uplink spatial transmit beam. In one aspect, operation 910 may be performed by (one or more) network interface 390, processing system 394, memory component 396, and / or positioning component 398, and / or all of which may be considered as means for performing the operation.

[0181] At 920, the location server receives a report from the UE indicating a signal quality of the first downlink reference signal. In one aspect, operation 920 may be performed by (one or more) network interface 390, processing system 394, memory component 396, and / or positioning component 398, and / or all of which may be considered as means for performing the operation.

[0182] At 930, based on the signal quality of the first downlink reference signal being below a threshold, the location server configures the UE to receive at least a second downlink reference signal from a neighboring cell or a serving cell for estimating a downlink path loss or determining an uplink spatial transmit beam. In one aspect, operation 930 may be performed by (one or more) network interface 390, processing system 394, memory component 396, and / or positioning component 398, and / or all of these may be considered as means for performing the operation.

[0183] Fig.10 An exemplary method 1000 of wireless communication in accordance with aspects of the present disclosure is shown. In one aspect, the method 1000 may be performed by a UE (eg, any UE described herein).

[0184] At 1010, the UE receives a configuration from a network node (e.g., a serving base station or a location server) (e.g., via RRC, LPP, and / or other signaling from a location server, a serving cell, or other such entity) to use at least a first downlink reference signal from a neighboring cell to estimate a downlink path loss or determine an uplink spatial transmit beam. In one aspect, operation 1010 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of these may be considered as means for performing the operation.

[0185] At 1020, the UE sends a report indicating the signal quality of the first downlink reference signal to the network node. In one aspect, operation 1020 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of which may be considered as means for performing the operation.

[0186] At 1030, based on the signal quality of the first downlink reference signal being below a threshold, the UE receives a configuration from a network node (e.g., from a location server, a serving cell, or other such entity via RRC, LPP, and / or other signaling) to use at least a second downlink reference signal from a neighboring cell or a serving cell to estimate a downlink path loss or determine an uplink spatial transmit beam. In an aspect, operation 1030 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, and / or all of these may be considered as means for performing the operation.

[0187] Those skilled in the art will recognize that information and signals may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0188] Those skilled in the art will recognize that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with various aspects of the present disclosure can be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above with respect to their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. The technician can implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing departure from the scope of the present invention.

[0189] The various illustrative logical blocks, modules, and circuits described in conjunction with the various aspects disclosed herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0190] The methods, sequences and / or algorithms described in conjunction with the various aspects disclosed herein may be implemented directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a random access memory (RAM), a flash memory, a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from / write information to the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., a UE). In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0191] In one or more exemplary aspects, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, these functions can be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, which include any media that facilitates the transfer of computer programs from one place to another. Storage media can be any available media that a computer can access. As an example, and not a limitation, the computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code means in the form of instructions or data structures and can be accessed by a computer. And, any connection is also properly referred to as a computer-readable medium. For example, if the software is sent from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc. Disks, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer readable media.

[0192] Although the foregoing disclosure shows illustrative aspects of the present disclosure, it should be noted that various changes and modifications may be made herein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps, and / or actions of the method claims according to the various aspects of the disclosure described herein do not need to be performed in any particular order. In addition, although elements of the present disclosure may be described or claimed in singular form, plural forms are contemplated unless limitation to the singular is explicitly stated.

Claims

1. A wireless communication method performed by a user equipment UE, comprising: receiving a positioning configuration, the positioning configuration comprising at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss; determining that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss; In response to the determining, estimating the downlink path loss based on a second downlink reference signal received from the neighboring cell or the serving cell; as well as An uplink reference signal for positioning is transmitted with a transmit power set based on the estimated downlink path loss.

2. The method of claim 1, wherein: The second downlink reference signal is a synchronization signal SS / physical broadcast channel PBCH block from the serving cell and used by the UE to obtain a master information block MIB for the serving cell.

3. The method of claim 1, further comprising: A spatial beam direction is set for a transmit beam directed toward the neighboring cell, the transmit beam carrying the uplink reference signal.

4. The method of claim 1, further comprising: Based on determining that the first downlink reference signal cannot be used to estimate the downlink path loss, reporting to the serving cell or a location server that the first downlink reference signal has failed.

5. The method of claim 1, wherein: The UE determines that the first downlink reference signal cannot be used to estimate the downlink path loss based on a signal quality of the first downlink reference signal being lower than a threshold.

6. The method of claim 5, wherein: The threshold includes a reference signal received power RSRP threshold configured for the UE.

7. The method of claim 1, further comprising: Based on determining that the first downlink reference signal cannot be used to estimate the downlink path loss, a sequence number indicating that the first downlink reference signal has failed is sent to the serving cell via a physical random access channel PRACH process.

8. The method of claim 1, further comprising: The serving cell is requested to transmit an alternative and / or auxiliary downlink reference signal configured to enable the UE to estimate the downlink path loss.

9. The method of claim 1, further comprising: The neighboring cell is requested to transmit an alternative and / or auxiliary downlink reference signal configured to enable the UE to estimate the downlink path loss.

10. The method of claim 9, wherein: The request is sent to the serving cell.

11. The method of claim 1 , further comprising: A partial beam failure recovery procedure is initialized to report that a subset of downlink reference signals from the neighboring cell has failed.

12. The method of claim 11, wherein: The subset of downlink reference signals includes more than one downlink reference signal from the neighboring cell.

13. The method of claim 1, wherein: A plurality of downlink reference signals are received from the neighboring cell, and wherein the first downlink reference signal and the second downlink reference signal are two of the plurality of downlink reference signals.

14. The method of claim 13, wherein: The first downlink reference signal is configured to be used for downlink path loss estimation of a first carrier bandwidth portion used for communication with the neighboring cell, and The second downlink reference signal is configured for downlink path loss estimation of a second carrier bandwidth portion used for communication with the neighboring cell.

15. The method of claim 1, wherein: The first downlink reference signal is the only downlink reference signal received by the UE from the neighboring cell, and The second downlink reference signal is a downlink reference signal received from the serving cell.

16. The method of claim 1, wherein: The second downlink reference signal is a default downlink reference signal for the estimated downlink path loss.

17. The method of claim 16, wherein: The second downlink reference signal is received on a transmit beam from the serving cell.

18. The method of claim 1, further comprising: After determining that the first downlink reference signal cannot be used to estimate the downlink path loss and before estimating the downlink path loss based on the second downlink reference signal, an uplink reference signal is transmitted at a maximum transmission power.

19. The method of claim 1, wherein: The second downlink reference signal is a secondary downlink reference signal from the serving cell.

20. The method of claim 1, wherein: The second downlink reference signal is a synchronization signal SS / physical broadcast channel PBCH block from the serving cell and used by the UE to obtain a master information block MIB for the serving cell.

21. A user equipment UE, comprising: Memory; at least one transceiver; as well as at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: receiving, via the at least one transceiver, a positioning configuration, the positioning configuration comprising at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss; determining that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss; In response to the determining, estimating the downlink path loss based on a second downlink reference signal received from the neighboring cell or the serving cell; as well as An uplink reference signal for positioning having a transmit power set is transmitted via the at least one transceiver based on the estimated downlink path loss.

22. The UE according to claim 21, wherein: The second downlink reference signal is a synchronization signal SS / physical broadcast channel PBCH block from the serving cell and used by the UE to obtain a master information block MIB for the serving cell.

23. The UE according to claim 21, wherein: The at least one processor is further configured to: A spatial beam direction is set for a transmit beam directed toward the neighboring cell, the transmit beam carrying the uplink reference signal.

24. The UE according to claim 21, wherein: The at least one processor is further configured to: Based on determining that the first downlink reference signal cannot be used to estimate the downlink path loss, reporting to the serving cell or a location server via the at least one transceiver that the first downlink reference signal has failed.

25. The UE according to claim 21, wherein: The UE determines, based on a signal quality of the first downlink reference signal being lower than a threshold, that the first downlink reference signal cannot be used to estimate the downlink path loss.

26. The UE according to claim 25, wherein: The threshold includes a reference signal received power RSRP threshold configured for the UE.

27. The UE according to claim 21, wherein: The at least one processor is further configured to: Based on determining that the first downlink reference signal cannot be used to estimate the downlink path loss, a sequence number indicating that the first downlink reference signal has failed is sent to the serving cell via the at least one transceiver via a physical random access channel (PRACH) procedure.

28. The UE according to claim 21, wherein: The at least one processor is further configured to: The serving cell is requested to transmit an alternative and / or auxiliary downlink reference signal configured to enable the UE to estimate the downlink path loss.

29. The UE according to claim 21, wherein: The at least one processor is further configured to: The neighboring cell is requested to transmit an alternative and / or auxiliary downlink reference signal configured to enable the UE to estimate the downlink path loss.

30. The UE according to claim 29, wherein: The request is sent to the serving cell.

31. The UE according to claim 21, wherein: The at least one processor is further configured to: A partial beam failure recovery procedure is initialized to report that a subset of downlink reference signals from the neighboring cell has failed.

32. The UE according to claim 21, wherein: The subset of downlink reference signals includes more than one downlink reference signal from the neighboring cell.

33. The UE according to claim 21, wherein: A plurality of downlink reference signals are received from the neighboring cell, and wherein the first downlink reference signal and the second downlink reference signal are two of the plurality of downlink reference signals.

34. The UE of claim 33, wherein: The first downlink reference signal is configured to be used for downlink path loss estimation of a first carrier bandwidth portion used for communication with the neighboring cell, and The second downlink reference signal is configured for downlink path loss estimation of a second carrier bandwidth portion used for communication with the neighboring cell.

35. The UE of claim 21, wherein: The first downlink reference signal is the only downlink reference signal received by the UE from the neighboring cell, and The second downlink reference signal is a downlink reference signal received from the serving cell.

36. The UE according to claim 21, wherein: The second downlink reference signal is a default downlink reference signal for the estimated downlink path loss.

37. The UE according to claim 36, wherein: The second downlink reference signal is received on a transmit beam from the serving cell.

38. The UE according to claim 1, wherein: The at least one processor is further configured to: After determining that the first downlink reference signal cannot be used to estimate the downlink path loss and before estimating the downlink path loss based on the second downlink reference signal, an uplink reference signal is transmitted at a maximum transmission power via the at least one transceiver.

39. The UE according to claim 21, wherein: The second downlink reference signal is a secondary downlink reference signal from the serving cell.

40. The UE according to claim 1, wherein: The second downlink reference signal is a synchronization signal SS / physical broadcast channel PBCH block from the serving cell and used by the UE to obtain a master information block MIB for the serving cell.

41. A user equipment UE, comprising: means for receiving a positioning configuration comprising at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss; means for determining that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss; means for estimating the downlink path loss based on a second downlink reference signal received from the neighboring cell or the serving cell; as well as Means for transmitting an uplink reference signal for positioning having a transmit power set based on the estimated downlink path loss.

42. A non-transitory computer readable medium storing computer executable instructions which, when executed by a user equipment (UE), cause the UE to: receiving a positioning configuration, the positioning configuration comprising at least an identifier of a first downlink reference signal from a neighboring cell to be used for estimating downlink path loss; determining that the first downlink reference signal received from the neighboring cell cannot be used to estimate the downlink path loss; estimating the downlink path loss based on a second downlink reference signal received from the neighboring cell or the serving cell; as well as An uplink reference signal for positioning is transmitted with a transmit power set based on the estimated downlink path loss.

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