The process of associating a sounding reference signal (SRS) resource with a random access channel (RACH)

Abstract

Techniques for wireless communications are disclosed. In one aspect, a user equipment (UE) participating in a positioning session with a transmit-receive point (TRP) receives a configuration of one or more sounding reference signal (SRS) resources during a first state, receives a first association between at least one of the one or more SRS resources and at least one of the one or more random access channel (RACH) resources, switches out of the first state during the ongoing positioning session, and while outside of the first state, uses a transmission characteristic based on the first association between at least one SRS resource and at least one RACH resource to send at least a first signal of a RACH process to the TRP.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority under 35 U.S.C. §119 to Greek Patent Application No. 20190100545, filed on December 5, 2019, entitled “PROCEDURESFOR ASSOCIATING A SOUNDING REFERENCE SIGNAL (SRS) RESOURCE TO RANDOM ACCESS CHANNEL (RACH)” and U.S. Non-Provisional Patent Application No. 16 / 942,115, filed on July 29, 2020, entitled “PROCEDURES FOR ASSOCIATING A SOUNDING REFERENCE SIGNAL (SRS) RESOURCE TO RANDOM ACCESS CHANNEL (RACH)”, both of which have been assigned to the assignee of this application and are expressly incorporated herein by reference in their entirety. Technical Field

[0003] Aspects of the present disclosure generally relate to wireless communications. Background Art

[0004] Wireless communication systems have evolved over several generations, including first generation analog wireless telephone service (1G), second generation (2G) digital wireless telephone service (including temporary 2.5G networks), third generation (3G) high speed data, Internet-enabled wireless services, and fourth generation (4G) services (e.g., LTE or WiMax). There are many different types of wireless communication systems in use today, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the 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 Communications (GSM), and the like.

[0005] The fifth generation (5G) wireless standard, known as New Radio (NR), enables higher data transfer speeds, more connections, and better coverage, among other improvements. According to the Next Generation Mobile Network Alliance, the 5G standard aims to provide data rates of tens of megabits per second for each of tens of thousands of users, and 1 gigabit per second for dozens of workers on an office floor. In order to support large wireless sensor deployments, hundreds of thousands of simultaneous connections should be supported. Therefore, the spectral efficiency of 5G mobile communications should be significantly improved compared to the current 4G standard. In addition, signaling efficiency should be improved and latency should be significantly reduced compared to the current standard. Summary of the invention

[0006] A simplified summary of one or more aspects disclosed herein is presented below. Therefore, the following summary should not be considered as a broad overview related to all expected aspects, nor should it be considered as identifying key or important elements related to all expected aspects or as describing the scope associated with any particular aspect. Thus, the sole purpose of the following summary is to present certain concepts related to one or more aspects involving the mechanisms disclosed herein in a simplified form before the detailed description presented below.

[0007] On the one hand, a method for wireless communication performed by a user equipment (UE) includes: during a first state, receiving a configuration of one or more sounding reference signal (SRS) resources; obtaining a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more random access channel (RACH) resources; and when outside the first state, using a transmission characteristic based on the first association between at least one SRS resource or resource set and at least one RACH resource to send at least a first signal of a RACH process to a transmit-receive point (TRP).

[0008] On the one hand, a method of wireless communication performed by a TRP includes: receiving one or more SRS on one or more SRS resources from a UE; receiving at least a first signal of a RACH process having a transmission characteristic based on a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more RACH resources from the UE during a positioning session with the UE; and performing positioning measurements of the first signal of the RACH process.

[0009] In one aspect, the 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 is configured to: during a first state, receive a configuration of one or more SRS resources; obtain a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more RACH resources; and when outside the first state, use a transmission characteristic based on the first association between the at least one SRS resource or resource set and the at least one RACH resource to send at least a first signal of a RACH process to the TRP.

[0010] In one aspect, the TRP 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 is configured to: receive one or more SRSs on one or more SRS resources from a UE; receive at least a first signal of a RACH process having a transmission characteristic based on a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more RACH resources from the UE during a positioning session with the UE; and perform positioning measurements of the first signal of the RACH process.

[0011] On the one hand, the UE includes a component for receiving a configuration of one or more SRS resources during a first state; a component for obtaining a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more RACH resources; and a component for using a transmission characteristic based on the first association between at least one SRS resource or resource set and at least one RACH resource when being outside the first state to send at least a first signal of a RACH process to a TRP.

[0012] In one aspect, the TRP includes components for receiving one or more SRSs on one or more SRS resources from a UE; components for receiving at least a first signal of a RACH process having a transmission characteristic based on a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more RACH resources from the UE during a positioning session with the UE; and components for performing positioning measurements of the first signal of the RACH process.

[0013] On the one hand, 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 configuration of one or more SRS resources during a first state; at least one instruction instructing the UE to obtain a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more RACH resources; and at least one instruction instructing the UE to use a transmission characteristic based on the first association between at least one SRS resource or resource set and at least one RACH resource to send at least a first signal of a RACH process to a TRP when the UE is outside the first state.

[0014] On the one hand, a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions, which include: at least one instruction instructing a TRP to receive one or more SRSs on one or more SRS resources from a UE; at least one instruction instructing the TRP to receive at least a first signal of a RACH process having a transmission characteristic based on a first association between at least one SRS resource or resource set among the one or more SRS resources and at least one RACH resource among one or more RACH resources from the UE during a positioning session with the UE; and at least one instruction instructing the TRP to perform positioning measurements of the first signal of the RACH process.

[0015] Other objects and advantages associated with the 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

[0016] The accompanying drawings are presented to aid in describing aspects of the disclosure and are provided solely for illustration of these aspects and not limitation thereof.

[0017] Figure 1

[0013] An exemplary wireless communication system in accordance with various aspects is illustrated.

[0018] Figure 2A and Figure 2B Example wireless network structures in accordance with various aspects are illustrated.

[0019] FIG. 3A to FIG. 3C is a simplified block diagram of several sample aspects of components that may be employed in a wireless communication node and configured to support communications as taught herein.

[0020] Figure 4A and Figure 4B is a schematic diagram illustrating an example of a frame structure and channels within the frame structure according to aspects of the present disclosure.

[0021] Figure 5 and Figure 6 An exemplary random access procedure according to aspects of the present disclosure is illustrated.

[0022] Figure 7 Different radio resource control (RRC) states in NR according to aspects of the present disclosure are illustrated.

[0023] Figure 8 is a schematic diagram of an exemplary positioning process between a UE and two TRPs according to aspects of the present disclosure.

[0024] Fig. 9 and Fig.10 A method of wireless communication according to aspects of the present disclosure is illustrated. DETAILED DESCRIPTION

[0025] Aspects of the present disclosure are provided in the following description and in the related drawings for various examples provided for illustrative purposes. Alternative aspects may be designed without departing from the scope of the present disclosure. In addition, well-known elements of the present disclosure will not be described in detail or omitted to avoid confusing the relevant details of the present disclosure.

[0026] The words "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.

[0027] Those skilled in the art will recognize that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, code elements, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc.

[0028] In addition, many aspects are described in terms of a sequence of actions to be performed by, for example, an element of a computing device. It will be appreciated that the various actions described herein may be performed by a specific 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 considered to be fully implemented in any form of non-transitory computer-readable storage medium in which a corresponding computer instruction set is stored, which, after executing these instructions, will cause or instruct the associated processor of the device to perform the functionality described herein. Therefore, various aspects of the present disclosure may be implemented in a variety of different forms, all of which are considered to be within the scope of the claimed subject matter. In addition, for each aspect described herein, the corresponding form of any such aspect may be described herein as, for example, "logic, configured to" perform the described actions.

[0029] As used herein, unless otherwise specified, the terms "user equipment" (UE) and "base station" are not intended to be specific to or otherwise limited to any particular 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.) that is used by a user to communicate over a wireless communication network. A UE may be mobile or may be stationary (e.g., at certain times) 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 device", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile device", "mobile terminal", "mobile station" or variants 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) and to other UEs. Of course, the UE may also use other mechanisms to connect to the core network and / or the Internet, such as through a wired access network, a wireless local area network (WLAN) network (for example, based on IEEE 802.11, etc.), etc.

[0030] A base station may operate according to one of several RATs for communicating with a UE, depending on the network in which it is deployed, and may alternatively be referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation NodeB (ng-eNB), a new radio (NR) NodeB (also referred to as a gNB or gNodeB), etc. A base station may be primarily used to support wireless access for a UE, including supporting data, voice, and / or signaling connections for supported UEs. In some systems, a base station may provide a pure edge node signaling function, while in other systems, it may provide additional control and / or network management functions. The communication link through which a UE may send a signal to a 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 a base station may send a signal to a 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 either an uplink / reverse channel or a downlink / forward traffic channel.

[0031] 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 a cell (or several cell sectors) of the base station. Where the term "base station" refers to multiple co-located physical TRPs, the physical TRP may be an array of antennas 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 source 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 TRPs may be a serving base station that receives measurement reports from the UE and a neighboring base station whose reference RF signal (or simply "reference signal") the UE is measuring. Because as used herein, a TRP is the point at which a base station transmits and receives wireless signals, references to transmissions from or receptions at a base station will be understood to refer to the specific TRP of that base station.

[0032] In some embodiments of supporting positioning of a UE, a base station may not support wireless access by the UE (e.g., may not support data, voice, and / or signaling connections for the UE), but may instead send a reference signal to be measured by the UE to the UE, and / or may receive and measure a signal sent by the UE. Such a base station may be referred to as a positioning beacon (e.g., when sending a signal to the UE) and / or as a position measurement unit (e.g., when receiving and measuring a signal from the UE).

[0033] "RF signals" include electromagnetic waves of a given frequency that transport information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit 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 transmitted RF signal on different paths between a transmitter and a receiver may be referred to as a "multipath" RF signal. As used herein, RF signals may also be referred to as "wireless signals" or simply "signals," where it is clear from the context whether the term "signal" refers to a wireless signal or to an RF signal.

[0034] According to various aspects, Figure 1An exemplary wireless communication system 100 is illustrated. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 and various UEs 104. The base stations 102 may include macro cell base stations (high power cellular base stations) and / or small cell base stations (low power cellular base stations). In one aspect, the macro cell base stations may include eNBs and / or ng-eNBs (in the case where the wireless communication system 100 corresponds to an LTE network), or gNBs (in the case where the wireless communication system 100 corresponds to an NR network), or a combination of the two, and the small cell base stations may include femto cells, pico cells, micro cells, etc.

[0035] 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 5G core (5GC)) through a backhaul link 122, and interface with one or more location servers 172 (which may be part of the core network 170 or may be external to the core network 170) through 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 setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment 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., through the EPC / 5GC) through a backhaul link 134, which may be wired or wireless.

[0036] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a respective geographic coverage area 110. In one aspect, one or more cells can be supported by base station 102 in each geographic 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), a cell global identifier (CGI)) 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), etc.), which can provide access for different types of UEs. Because a cell is supported by a specific base station, the term "cell" can refer to one or both of the logical communication entity and the base station supporting it, depending on the context. In addition, because a TRP is typically a physical transmission point of a cell, the terms "cell" and "TRP" can be used interchangeably. In some cases, the term “cell” may also refer to a geographic coverage area (eg, a sector) of a base station, as long as a carrier frequency can be detected and used for communications within some portion of the geographic coverage area 110 .

[0037] Although the geographic coverage areas 110 of neighboring macrocell base stations 102 may partially overlap (e.g., in a handover area), some of the geographic coverage areas 110 may substantially overlap with a larger geographic coverage area 110. For example, a small cell base station 102' may have a 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 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).

[0038] 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 (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna techniques, including 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 compared to the uplink).

[0039] 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 in an unlicensed spectrum (e.g., 5 GHz) via a communication link 154. 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) process to determine whether the channel is available before communicating.

[0040] The small cell base station 102' can operate in licensed and / or unlicensed spectrum. When operating in the 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 AP150. The small cell base station 102' adopting LTE / 5G in the unlicensed spectrum can improve the coverage of the access network and / or increase its capacity. 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.

[0041] The wireless communication system 100 may also include a millimeter wave (mmW) base station 180, which can operate at mmW frequencies and / or near mmW frequencies to communicate with UE 182. Extremely high frequency (EHF) is a part of RF in the electromagnetic spectrum. The range of EHF is 30GHz to 300GHz, and the wavelength is between 1 mm and 10 mm. The radio waves in this band can be called millimeter waves. Near mmW can extend down to 3GHz frequencies with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3GHz and 30GHz, also known as centimeter waves. Communications using mmW / near mmW radio frequency bands have high path loss and relatively short range. The mmW base station 180 and UE 182 can utilize beamforming (sending and / or receiving) through the mmW communication link 184 to compensate for extremely high path loss and short range. In addition, it will be appreciated that in alternative configurations, one or more base stations 102 can also use mmW or near mmW and beamforming to send. Thus, it will be appreciated that the foregoing description is merely exemplary, and should not be construed as limiting the various aspects disclosed herein.

[0042] Transmit beamforming is a technique for focusing an RF signal 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., a 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 the receiving device. In order to change the directionality 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 (called a "phased array" or "antenna array") that creates a beam of RF waves that can be "steered" to point in different directions without actually moving the antennas. Specifically, the RF current from the transmitter is fed to each antenna in the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in the desired direction while canceling to suppress the radiation in the undesired direction.

[0043] The transmit beams can be quasi-collocated, 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 collocated. In NR, there are four types of quasi-collocated (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about the second reference RF signal on the second beam can be derived from information about the source reference RF signal on the source beam. Therefore, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the second reference RF signal sent on the same channel.

[0044] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, a receiver may increase a gain setting and / or adjust a phase setting of an antenna array in a particular direction to amplify RF signals received from that direction (e.g., increase its gain level). Thus, when a receiver is said to beamform in a certain direction, this means that the beam gain in that direction is higher relative to beam gains along other directions, or that the beam gain in that direction is highest compared to the beam gains in that direction for all other receive beams available to the receiver. 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.) for the RF signal received from that direction.

[0045] The receive beams may be spatially correlated. The spatial relationship means that the parameters of the transmit beam for the second reference signal may be derived from information about the receive beam for the first reference signal. For example, the UE may receive one or more reference downlink reference signals (e.g., positioning reference signal (PRS), navigation reference signal (NRS), tracking reference signal (TRS), phase tracking reference signal (PTRS), cell-specific reference signal (CRS), channel state information reference signal (CSI-RS), primary synchronization signal (PSS), secondary synchronization signal (SSS), synchronization signal block (SSB), etc.) from a base station using a specific receive beam. The UE may then form a transmit beam based on the parameters of the receive beam for sending one or more uplink reference signals (e.g., uplink positioning reference signal (UL-PRS), sounding reference signal (SRS), demodulation reference signal (DMRS), PTRS, etc.) to the base station.

[0046] Note that a "downlink" beam can be either 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 to send a reference signal to the UE, then the downlink beam is a transmit beam. However, if the UE is forming a downlink beam, then it is a receive beam that receives the downlink reference signal. Similarly, an "uplink" beam can be either 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, then it is an uplink receive beam, and if the UE is forming an uplink beam, then it is an uplink transmit beam.

[0047] 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) used 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 reestablishment 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), which can be configured and used to provide additional radio resources once an RRC connection is established between the UE 104 and the anchor carrier. 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, those specific to the UE may not be present in the secondary carrier, because both the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carrier. The network is able to change the primary carrier of any UE 104 / 182 at any time. For example, this is done to balance the load on different carriers. Because a "serving cell" (whether PCell or SCell) corresponds to a carrier frequency / component carrier through which a certain base station is communicating, the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. can be used interchangeably.

[0048] For example, still refer to Figure 1 , one of the frequencies used by macrocell base station 102 may be an anchor carrier (or "PCell"), and the other frequencies used by macrocell base station 102 and / or mmW base station 180 may be secondary carriers ("SCells"). Simultaneous transmission and / or reception of multiple carriers enables 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 would theoretically result in a two-fold increase in data rate (i.e., 40 MHz) compared to that obtained by a single 20 MHz carrier.

[0049] The wireless communication system 100 may also include one or more UEs (such as UE 190) that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) or peer-to-peer (P2P) links. Figure 1 In the example of FIG. 1 , UE 190 has a D2D P2P link 192 with one of UEs 104 connected to one of base stations 102 (e.g., through which UE 190 can indirectly obtain cellular connectivity) and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (through which UE 190 can indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 can be supported by any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), wait.

[0050] The wireless communication system 100 may also include a UE 164, which may communicate with the macrocell base station 102 via a communication link 120 and / or communicate with the mmW base station 180 via a 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.

[0051] According to various aspects, Figure 2A An example wireless network structure 200 is illustrated. For example, 5GC 210 (also referred to as Next Generation Core (NGC)) can be functionally viewed as control plane functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane functions 212 (e.g., UE gateway functions, access data network, IP routing, etc.), which operate in conjunction to form a core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect gNB 222 to 5GC 210, and in particular to control plane functions 214 and user plane functions 212. In additional configurations, ng-eNB 224 can also be connected to 5GC 210 via NG-C 215 to control plane functions 214 and NG-U 213 to user plane functions 212. In addition, ng-eNB 224 can communicate directly with gNB 222 via 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 both ng-eNBs 224 and gNBs 222. The gNB 222 or the ng-eNB 224 may communicate with the UE 204 (e.g., Figure 1204). Another optional aspect may include a location server 230 that can communicate with the 5GC 210 to provide location assistance for 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 spread across multiple physical servers, etc.), or alternatively, each can correspond to a single server. The location server 230 can be configured to support one or more location services for the UE 204, and the UE 204 can be connected to the location server 230 via the core network, the 5GC 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.

[0052] According to various aspects, Figure 2B Another example wireless network structure 250 is illustrated. For example, the 5GC 260 can be functionally viewed as a control plane function provided by an access and mobility management function (AMF) 264 and a user plane function provided by a user plane function (UPF) 262, which operate in conjunction to form a core network (i.e., the 5GC 260). The user plane interface 263 and the control plane interface 265 connect the ng-eNB 224 to the 5GC 260, and in particular to the UPF 262 and the AMF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the 5GC 260 via a control plane interface 265 to the AMF 264 and a user plane interface 263 to the UPF 262. In addition, with or without gNB direct connectivity to the 5GC 260, the ng-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 both ng-eNBs 224 and gNBs 222. The gNB 222 or the ng-eNB 224 may communicate with the UE 204 (e.g., Figure 1 The base stations of the new RAN 220 communicate with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface.

[0053] The functions of AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transport of session management (SM) messages between UE 204 and session management function (SMF) 266, transparent proxy service for routing SM messages, access authentication and access authorization, transport of short message service (SMS) messages between UE 204 and short message service function (SMSF) (not shown), and security anchor functionality (SEAF). AMF 264 also interacts with authentication server function (AUSF) (not shown) and UE 204, and receives intermediate keys established as a result of the UE 204 authentication process. In the case of authentication based on UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), AMF 264 retrieves security materials from AUSF. The functions of AMF 264 also include security context management (SCM). SCM receives keys from SEAF for deriving keys specific to access networks. The functionality of AMF 264 also includes location service management for regulatory services, transportation of location service messages between UE 204 and location management function (LMF) 270 (which acts as location server 230), transportation of location service messages between new RAN 220 and LMF 270, allocation of evolved packet system (EPS) bearer identifiers for interworking with EPS, and notification of mobility events for UE 204. In addition, AMF 264 also supports functionality for non-3GPP access networks.

[0054] The functions of the UPF 262 include acting as an anchor point for intra-RAT / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point for interconnection with 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 usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node. The UPF 262 can also support the transmission of location service messages over the user plane between the UE 204 and a location server (such as a secure user plane location (SUPL) location platform (SLP) 272).

[0055] The functions of SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at UPF 262 for routing traffic to the correct destination, control of a portion of QoS and policy enforcement, and downlink data notification. The interface through which SMF 266 communicates with AMF 264 is called the N11 interface.

[0056] Another optional aspect may include an LMF 270 that can communicate with the 5GC 260 to provide location assistance for the UE 204. The LMF 270 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternatively, each can correspond to a single server. The LMF 270 can be configured to support one or more location services for the UE 204, and the UE 204 can be connected to the LMF 270 via the core network, the 5GC 260, and / or via the Internet (not shown). The SLP 272 can support similar functions to the LMF 270, but the LMF 270 can communicate with the AMF 264, the new RAN 220, and the UE 204 through the control plane (e.g., using interfaces and protocols intended to convey signaling messages but not voice or data), and the SLP 272 can communicate with the UE 204 and external clients (e.g., using protocols intended to carry voice and / or data, such as the Transmission Control Protocol (TCP) and / or IP) through the user plane. Figure 2B (not shown) communications.

[0057] Figure 3A , Figure 3B and Figure 3C Several exemplary components (represented by corresponding blocks) that may be incorporated into a UE 302 (which may correspond to any UE described herein), a base station 304 (which may correspond to any base station described herein), and a network entity 306 (which may correspond to or implement any network function described herein, including a location server 230, an LMF 270, and an SLP 272) to support file transfer operations as taught herein are illustrated. It will be appreciated that these components may be implemented in different types of devices (e.g., in an ASIC, in a system on a chip (SoC), etc.) in different implementations. The illustrated components may also be incorporated into other devices in a communication system. For example, other devices in the system may include components similar to those described to provide similar functionality. Moreover, a given device may include one or more of these 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.

[0058] 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) (such as 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 (such as other UEs, access points, base stations (e.g., ng-eNBs, gNBs), etc.) via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communication medium of interest (e.g., a certain set of time / frequency resources in a specific spectrum). Depending on the designated RAT, WWAN transceivers 310 and 350 can be configured differently to send and encode signals 318 and 358 (e.g., messages, indications, information, etc.), respectively, and conversely, to receive and decode signals 318 and 358 (e.g., messages, indications, information, pilots, etc.), respectively. 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.

[0059] 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 via at least one designated RAT (e.g., WiFi, LTE-D, The WLAN transceivers 320 and 360 communicate with other network nodes (such as other UEs, access points, base stations, etc.) over a wireless communication medium of interest. Depending on the specified RAT, the WLAN transceivers 320 and 360 can be configured differently to send 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. Specifically, the WLAN transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, for sending and encoding signals 328 and 368, respectively, and one or more receivers 322 and 362, respectively, for receiving and decoding signals 328 and 368, respectively.

[0060] The transceiver circuitry including at least one transmitter and at least one receiver may comprise an integrated device (e.g., a transmitter circuit and a receiver circuit implemented as a single communication device) in some embodiments, may comprise a separate transmitter device and a separate receiver device in some embodiments, or may be implemented in other ways in other embodiments. 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 array of antennas, 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), such that the corresponding device can only receive or transmit at a given time, but not both at the same time. The wireless communication devices of the UE 302 and / or the base station 304 (eg, one or both of the transceivers 310 and 320 and / or 350 and 360) may also include a network listening module (NLM) or the like for performing various measurements.

[0061] At least in some cases, UE 302 and base station 304 also include satellite positioning system (SPS) receivers 330 and 370. SPS receivers 330 and 370 can be connected to one or more antennas 336 and 376, respectively, for receiving SPS signals 338 and 378, 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. SPS receivers 330 and 370 can include any suitable hardware and / or software for receiving and processing SPS signals 338 and 378, respectively. SPS receivers 330 and 370 appropriately request information and operations from other systems, and use measurements obtained by any suitable SPS algorithm to perform calculations necessary to determine the location of UE 302 and base station 304.

[0062] In one aspect, the WWAN transceiver 310, the WLAN transceiver and / or the SPS receiver 330 may share the same receiver and / or transmitter. That is, the receiver 312, the receiver 322 and / or the SPS receiver 330 may be the same receiver, and / or the transmitter 314 and the transmitter 324 may be the same transmitter. This may be the case where the WWAN transceiver 310, the WLAN transceiver and / or the SPS receiver 330 are integrated into a single communication device. Alternatively, the WWAN transceiver 310, the WLAN transceiver and / or the SPS receiver 330 may be separate (discrete) communication devices.

[0063] 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 or wireless backhaul connection. In some aspects, the network interfaces 380 and 390 can be implemented as transceivers configured to support wired or wireless signal communication. Such communication can involve, for example, sending and receiving messages, parameters and / or other types of information.

[0064] 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 functionality related to, for example, positioning operations and for providing other processing functionality. Base station 304 includes processing system 384 for providing functionality related to, for example, positioning operations disclosed herein and for providing other processing functionality. Network entity 306 includes processing system 394 for providing functionality related to, for example, positioning operations disclosed herein and for providing other processing functionality. 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.

[0065] UE 302, base station 304, and network entity 306 include memory circuitry 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 circuitry that is part of or coupled to processing systems 332, 384, and 394, respectively, which, when executed, causes UE 302, base station 304, and network entity 306 to perform the functionality described herein. In other aspects, positioning components 342, 388, and 398 may be external to processing systems 332, 384, and 394 (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. Figure 3A-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 functionality described herein.

[0066] 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. For example, sensor 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. Moreover, sensor 344 may include multiple different types of devices and combine their outputs to provide motion information. For example, sensor 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.

[0067] 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., after 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.

[0068] 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 functionality 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 functionality associated with broadcasting of 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 functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with transmission of upper layer packet data units (PDUs), 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 functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0069] Transmitter 354 and receiver 352 can implement layer 1 functionality associated with various signal processing functions. Layer 1 including the physical (PHY) layer can include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. 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 can then be split into parallel streams. Each stream can 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 using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to produce 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 from reference signals 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.

[0070] At UE 302, receiver 312 receives the signal through its corresponding antenna 316. Receiver 312 recovers the information modulated onto the RF carrier and provides the information to processing system 332. Transmitter 314 and receiver 312 implement layer 1 functionality associated with various signal processing functions. Receiver 312 can perform spatial processing on the information to recover any spatial stream destined for UE 302. If multiple spatial streams are destined for UE 302, they can be combined into a single OFDM symbol stream by receiver 312. 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 symbol on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by 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 base station 304. The data and control signals are then provided to processing system 332, which implements layer 3 and layer 2 functionality.

[0071] In the uplink, 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.

[0072] Similar to the functionality described in conjunction with downlink transmission of base station 304, processing system 332 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel priority.

[0073] The transmitter 314 may select an appropriate coding and modulation scheme 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.

[0074] 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 respective antenna 356. The receiver 352 recovers the information modulated onto the RF carrier and provides the information to the processing system 384.

[0075] In the uplink, 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.

[0076] For convenience, UE 302, base station 304 and / or network entity 306 may Figure 3A-3C 1 and 2. The schematic diagram of the embodiment of the present invention is shown as including various components that can be configured according to various examples described herein. However, it should be appreciated that the blocks shown may have different functionality in different designs.

[0077] The various components of the UE 302, base station 304, and network entity 306 may communicate with each other via data buses 334, 382, ​​and 392, respectively. Figure 3A-3C The components of can be implemented in various ways. In some embodiments, Figure 3A-3C The components may be implemented in one or more circuits, such as, 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 combine at least one memory component for storing information or executable code used by the circuit to provide such functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by the processor and memory components of UE 302 (e.g., by the execution of appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by the processor and memory components of base station 304 (e.g., by the execution of appropriate code and / or by appropriate configuration of the processor components). Moreover, some or all of the functionality represented by blocks 390 to 398 may be implemented by the processor and memory components of network entity 306 (e.g., by the execution of appropriate code and / or by appropriate configuration of the processor components). 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 specific components or combinations of components of the UE, base station, positioning entity, etc., such as processing systems 332, 384, 394, transceivers 310, 320, 350 and 360, memory components 340, 386 and 396, positioning components 342, 388 and 398, etc.

[0078] 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 450 illustrating an example of a UL frame structure according to aspects of the present disclosure. Figure 4B is a diagram 480 illustrating an example of channels within a UL frame structure according to aspects of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0079] exist Figure 4A and Figure 4B In the example of , 15kHz numerology is used. Therefore, in the time domain, a frame (e.g., 10 milliseconds (ms)) is divided into 10 equally sized subframes, each subframe is 1 ms, and each subframe includes one time slot. Figure 4A and Figure 4B, time is represented horizontally (eg, on the X-axis), with time increasing from left to right, and frequency is represented vertically (eg, on the Y-axis), with frequency increasing (or decreasing) from bottom to top.

[0080] 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. The resource grid is further divided into a plurality of resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. Figure 4A and Figure 4B In numerology, for a normal cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and seven consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and 6 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.

[0081] LTE, and in some cases NR, uses OFDM on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. However, unlike LTE, NR can also choose to use 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, intervals, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM, while modulation symbols are sent in the time domain with 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 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 can also be divided 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 a system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0082] LTE supports a single numerology (subcarrier spacing, symbol length, etc.). In contrast, NR can support multiple numerologies (μ), for example, 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz or larger subcarrier spacing may be available. Table 1 provided below lists some different parameters for different NR numerologies.

[0083]

[0084]

[0085] Table 1

[0086] like Figure 4A As shown in , some of the REs carry a demodulation reference signal (DMRS) for channel estimation at the base station. The UE may additionally send a sounding reference signal (SRS), for example, in the last symbol of a 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 the "comb size") indicates the number of subcarriers that carry a reference signal (here, SRS) in each symbol period. For example, a comb size of comb-4 means that every four subcarriers of a given symbol carry a reference signal, while a comb size of comb-2 means that every two subcarriers of a given symbol carry a reference signal. In Figure 4A In the example shown, the SRS shown are all comb-2. SRS can be used by the base station 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 effect of scattering, fading, and power attenuation with distance. The system uses SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0087] Figure 4B Examples of various channels within an uplink subframe of a frame according to aspects of the present disclosure are illustrated. A random access channel (RACH), also known as a physical random access channel (PRACH), may be within one or more subframes within a frame configured based on the PRACH. 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.

[0088] The set of resource elements used for SRS transmission 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, the SRS resource occupies consecutive PRBs. An "SRS resource set" is a set of SRS resources used for transmission of an SRS signal and is identified by an SRS resource set ID (SRS-ResourceSetId).

[0089] Generally speaking, 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), multi-round trip time (multi-RTT), angle of arrival (AOA), etc.

[0090] Several enhancements to the previous definition of SRS have been proposed for SRS for positioning (also known as "UL-PRS"), such as new interleaving patterns within SRS resources (in addition to single codeword / comb-2), new comb types for SRS, new sequences for SRS, a larger number of SRS resource sets per component carrier, and a larger number of SRS resources per component carrier. In addition, the parameters SpatialRelationInfo and PathLossReference will be configured based on the downlink reference signal or SSB from the adjacent TRP. Also, one SRS resource can be sent outside the active BWP, and one SRS resource can span multiple component carriers. Moreover, SRS can be configured in the RRC connected state and sent only within the active BWP. In addition, there can be no frequency hopping, no repetition factor, a single antenna port, and new lengths for SRS (e.g., 8 and 12 codewords). There can also be open-loop power control and non-closed-loop power control, and comb-8 can be used (i.e., SRS is sent every eight subcarriers in the same codeword). Finally, the UE may transmit from multiple SRS resources for UL-AoA through the same transmit beam. All of these are additional features to the current SRS framework, which is configured through RRC high-layer signaling (and potentially triggered or activated through MAC Control Element (CE) or DCI).

[0091] Figure 5 An exemplary four-step random access procedure 500 according to aspects of the present disclosure is illustrated. The four-step random access procedure 500 is performed between a UE 504 and a base station 502 (which may correspond to any of the UEs and base stations described herein, respectively).

[0092] There are various situations in which the UE may perform the four-step random access procedure 500 (also referred to as a "RACH procedure", "PRACH procedure", etc.). For example, the UE may perform the four-step random access procedure 500 when acquiring initial network access after leaving the RRC idle state, when performing an RRC connection reestablishment procedure, during handover, when downlink or uplink data arrives and the UE is in the RRC connected state but its uplink synchronization state is "unsynchronized", when transitioning from the RRC deactivated state, when establishing time alignment for the addition of an SCell, when requesting other synchronization information, or when performing beam failure recovery.

[0093] Before performing the four-step random access procedure 500, 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 500. 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 to use for communicating 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.

[0094] When the UE sends the first message of the four-step random access procedure 500 to the base station 502, it sends a specific pattern called a preamble (also called a RACH preamble, a PRACH preamble, or a 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 will 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.

[0095] At 510, the UE 504 selects one of the 64 RACH preambles to send as a RACH request to the base station 502. This message is referred to as "Message 1" or "Msg1" in the four-step RACH process. Based on the synchronization information (i.e., SIB1) from the base station 502, the 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 the base station 502 to determine which beam the UE 504 has selected, a specific mapping is defined between the SSB and the RO (occurring every 10, 20, 40, 80, or 160 ms). By detecting at which RO the UE 504 sent the preamble, the base station 502 can determine which SSB / beam the UE 504 has selected.

[0096] Note that a RO is a time-frequency transmission opportunity for sending a RACH preamble, and a 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 may be configured by the base station 502 to the UE 504 in the SIB. A RACH resource is an RO in which one RACH preamble index is sent. Therefore, the terms "RO" (or "RACH opportunity") and "RACH resource" may be used interchangeably depending on the context.

[0097] Due to reciprocity, 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 base station 502). That is, UE 504 determines the parameters of the uplink transmission beam using the parameters of the downlink reception beam used to receive the beam from base station 502. If reciprocity is available at base station 502, UE 504 can transmit the preamble on one beam. Otherwise, UE 504 repeats the transmission of the same preamble on all its uplink transmission beams.

[0098] 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 from 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 transmission power by a fixed step size and sends the RACH preamble / Msg1 again.

[0099] At 520, the base station 502 sends a random access response (RAR) to the UE 504 on the selected beam, which is 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 based on the time slot (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 grant 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 grant 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 a coarse beam alignment that can be used in subsequent steps.

[0100] 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 on resources scheduled by base station 502, base station 502 therefore knows where to detect Msg3 and which uplink receive beam should be used. Note that Msg3 PUSCH can be sent on the same or different uplink transmit beam as Msg1.

[0101] UE 504 identifies itself in Msg3 by the C-RNTI assigned in the previous step. This message contains the identity of UE 504 and the connection establishment cause. The identity of UE 504 is a temporary mobile subscriber identity (TMSI) or a random value. If UE 504 has been connected to the same network before, the TMSI is used. UE 504 is identified by the TMSI in the core network. If UE 504 is connected to the network for the first time, a random value is used. The reason for using a random value or TMSI is that due to multiple requests arriving at the same time, the C-RNTI may have been assigned to more than one UE in the previous step. The connection establishment cause indicates the reason why UE 504 needs to connect to the network, and will be further described below.

[0102] At 540, if Msg3 is successfully received, the 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, the base station 502 sends Msg4 in the PDSCH using the downlink transmit beam determined in the previous step.

[0103] The above four-step random access procedure 500 is a contention-based random access procedure. 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 identity to prevent its request from conflicting with requests from other UEs. When the UE 504 is in RRC connected mode before the random access procedure, such as in the case of handover, the contention-free random access procedure can be performed.

[0104] Figure 6 An exemplary two-step random access procedure 600 according to aspects of the present disclosure is illustrated. The two-step random access procedure 600 may be performed between a UE 604 (eg, any UE described herein) and a base station 602 (eg, any base station described herein).

[0105] At 610, UE 604 sends a RACH message A ("MsgA") to base station 602. In the two-step random access procedure 600, the above reference Figure 5 The described Msg1 and Msg3 are folded (e.g., combined) into MsgA and sent to the base station 602. Thus, MsgA includes a RACH preamble and a PUSCH, similar to Msg3 PUSCH of the four-step RACH process. The RACH preamble may have been selected from 64 possible preambles, as described above with reference to Figure 5 , and can be used as a reference signal for demodulating the data sent in MsgA. At 620, UE 604 receives RACH message B ("MsgB") from base station 602. MsgB can be the reference signal of the above reference. Figure 5 Described combination of Msg2 and Msg4.

[0106] The combination of Msg1 and Msg3 into one MsgA and the combination of Msg2 and Msg4 into one MsgB allows the UE 604 to reduce the RACH procedure setup time to support the low latency requirements of 5G NR. Although the UE 604 can be configured to support the two-step random access procedure 600, if the UE 604 cannot use the two-step random access procedure 600 due to some limitations (e.g., high transmit power requirements, etc.), the UE 604 can still support the four-step random access procedure 500 as an alternative. Therefore, the UE in 5G / NR can be configured to support both the two-step random access procedure and the four-step random access procedure, and can determine which random access procedure to configure based on the RACH configuration information received from the base station.

[0107] After the random access procedure 500 / 600, the UE 504 / 604 is in an RRC connected state. The RRC protocol is used for the air interface between the UE and the base station. The main functions of the RRC protocol include connection establishment and release functions, broadcasting of system information, radio bearer establishment, reconfiguration and release, RRC connection mobility procedures, paging notification and release, and outer loop power control. In LTE, the UE can be in one of two RRC states (connected or idle), while in NR, the UE can be in one of three RRC states (connected, idle or deactivated). Different RRC states have different radio resources associated with them, which the UE can use when it is in a given state.

[0108] Figure 7Different RRC states in NR according to aspects of the present disclosure are illustrated. When the UE is powered on, it is initially in the RRC disconnected / idle state 710. After the random access procedure 500 or 600, it moves to the RRC connected state 720. If there is no activity from the UE for a short period of time, it can suspend its session by moving to the RRC deactivated state 730. The UE can resume its session by performing the random access procedure 500 or 600 to transition back to the RRC connected state 720. Therefore, whether the UE is in the RRC idle state 710 or the RRC deactivated state 730, the UE needs to perform the random access procedure 500 or 600 to transition to the RRC connected state 720.

[0109] Operations performed in the RRC idle state 710 include public land mobile network (PLMN) selection, broadcast of system information, cell reselection mobility, paging for mobile terminal data (initiated and managed by 5GC), discontinuous reception (DRX) for core network paging (configured by NAS). Operations performed in the RRC connected state 720 include 5GC (e.g., 5GC260) and new RAN (e.g., new RAN 220) connection establishment (both control plane and user plane), UE context storage at the new RAN and UE, new RAN knowledge of the cell to which the UE belongs, transmission of unicast data to / from the UE, and network controlled mobility. Operations performed in the RRC deactivated state 730 include broadcast of system information, cell reselection for mobility, paging (initiated by the new RAN), RAN-based Notification Area (RNA) management (by the new RAN), DRX for RAN paging (configured by the new RAN), 5GC and new RAN connection establishment for the UE (both control plane and user plane), storage of UE context in the new RAN and UE, and new RNA knowledge of the RAN to which the UE belongs.

[0110] In some cases, the UE may transition from the RRC connected state 720 to the RRC idle state 710 or the RRC deactivated state 730 during an ongoing positioning session, such as a multiple round trip time (multi-RTT) session (which may be uplink only or downlink and uplink), an uplink time difference of arrival (UL-TDOA) session (uplink only), an uplink angle of arrival (UL-AoA) session (uplink only), etc.

[0111] In the RTT process, the initiator (base station or UE) sends an RTT measurement signal (e.g., PRS or SRS) to the responder (UE or base station), and the responder RTT response signal (e.g., SRS or PRS) is sent back to the initiator. The RTT response signal includes the difference between the ToA of the RTT measurement signal and the transmission time of the RTT response signal, which is called the received-to-sent (Rx-Tx) measurement. The initiator calculates the difference between the transmission time of the RTT measurement signal and the ToA of the RTT response signal, which is called the "Tx-Rx" measurement. The propagation time (also called "flight time") between the initiator and the responder can be calculated from the Tx-Rx and Rx-Tx measurements. Based on the propagation time and the known speed of light, the distance between the initiator and the responder can be determined. For multi-RTT (also called "multi-cell RTT") positioning, the UE performs an RTT process with multiple base stations to enable its position to be triangulated based on the known positions of the base stations. RTT and multi-RTT methods can be combined with other positioning technologies (such as UL-AoA and DL-AoD) to improve positioning accuracy.

[0112] In a UL-TDOA session, the UE sends an uplink reference signal (e.g., SRS) received by a reference base station and one or more non-reference base stations. The base station reports the time of arrival (ToA) of the uplink reference signal to the positioning entity (e.g., UE, serving base station, location server 230, LMF 270, SLP272), and the positioning entity calculates the reference signal time difference (RSTD) of the uplink reference signal between the reference base station and each non-reference base station. Based on the known positions of the base stations involved and the RSTD measurements, the positioning entity can estimate the position of the UE.

[0113] Unlike multi-RTT and UL-TDOA positioning methods that require three or more base stations to measure signals from the UE, a UL-AoA session can be performed between the UE and a single base station. In the UL-AoA process, for UL-AoA positioning, the base station measures the angle and other channel characteristics (e.g., gain level) of the uplink receive beam used to communicate with the UE to estimate the position of the UE. The UE and the base station can also perform an RTT process to further refine the position estimate.

[0114] During an ongoing positioning session, there are a variety of reasons why the UE may transition from the RRC connected state 720 to the RRC idle state 710 or the RRC deactivated state 730. For example, the DRX cycle that the UE has configured may require the UE to transition to the RRC deactivated state 730, or the UE's serving base station may instruct the UE to transition to the RRC deactivated state 730, or the UE may be disconnected from the network for some reason and transition to the RRC idle state 710. Regardless of the reason, it would be beneficial for the UE to be able to take advantage of the subsequent random access procedure 500 or 600 to continue the ongoing positioning session before the UE transitions back to the RRC connected state 720.

[0115] Thus, the present disclosure provides techniques for associating SRS resources with RACH resources for a UE in an RRC idle state 710 or an RRC deactivated state 730 during an uplink-only (e.g., AoA, UL-TDOA) or uplink-downlink (e.g., RTT) positioning session. Figure 8 800 is a diagram of an exemplary positioning process between a UE 804 and two TRPs 802-1 and 802-2 (collectively referred to as TRPs 802) according to aspects of the present disclosure. UE 804 can correspond to any UE described herein, and TRP 802 can correspond to any base station described herein (or be a TRP of any base station). The positioning session can be a multi-RTT session, a UL-TDOA session, a UL-AoA session, etc.

[0116] During a first RRC connection state 810 (which may correspond to RRC connection state 720), UE 804 is configured with a first set of one or more SRS resources on which one or more SRS 812 are sent to TRP 802 for a positioning session. Specifically, UE 804 is configured with one or more SRS resources (labeled "SRS1") on which one or more SRS 812-1 are sent to TRP 802-1, and one or more SRS resources (labeled "SRS2") on which one or more SRS 812-2 are sent to TRP 802-2. In one aspect, the one or more SRS resources may be a set of SRS resources.

[0117] In the first RRC connection state 810, the UE 804 obtains a first association of at least one SRS resource (or at least one SRS resource set) among the one or more SRS resources with at least one RACH resource among the one or more RACH resources for each TRP 802. More specifically, the UE 804 obtains an association of at least one SRS resource (or at least one SRS resource set) among the one or more SRS resources on which the one or more SRS 812-1 are sent with at least one RACH resource among the one or more RACH resources allocated for transmitting a RACH message (e.g., Msg1, Msg3, MsgA) to the TRP 802-1. Similarly, the UE 804 obtains an association of at least one SRS resource (or at least one SRS resource set) among the one or more SRS resources on which the one or more SRS 812-2 are sent with at least one RACH resource among the one or more RACH resources allocated for transmitting a RACH message (e.g., Msg1, Msg3, MsgA) to the TRP 802-2. UE 804 may receive (be configured with) an association from a serving TRP (e.g., one of TRPs 802-1 and 802-2) or corresponding TRPs 802-1 and 802-2. In one aspect, the association may be received together with the SRS resource configuration or in a separate transmission. The at least one SRS resource may be, for example, one or more SRS resources, a set of SRS resources, etc.

[0118] Subsequently, UE 804 transitions to an RRC idle state or an RRC deactivated state 820. For example, this may be due to a command from a serving TRP (e.g., one of TRPs 802-1 and 802-2), expiration of a DRX timer, etc. When UE 804 determines to switch from the RRC idle / deactivated state 820 to the second RRC connected state 830, it sends a RACH message 822 (e.g., Msg1 and Msg3, or MsgA) of an associated random access procedure (e.g., random access procedure 500 / 600) using the configured association between the RACH resources and the SRS resources (or SRS resource sets) received during the RRC connected state 810. More specifically, UE 804 sends a RACH message 822-1 (e.g., Msg1 and Msg3, or MsgA) to TRP 802-1 using transmission characteristics inherited from at least one associated SRS resource (or SRS resource set) on which SRS 812-1 is sent. Similarly, UE 804 sends a RACH message 822-2 (e.g., Msg1 and Msg3 or MsgA) to TRP 802-2 using transmission characteristics inherited from at least one associated SRS resource (or SRS resource set) on which SRS 812-2 is sent. TRP 802 measures RACH messages on associated RACH resources just as they measure SRS resources for positioning (e.g., ToA, AoA, etc.). The transmission characteristics inherited from at least one associated SRS resource may include an uplink spatial transmit filter for at least one SRS resource, a path loss reference resource, a path loss estimate and / or a transmit power estimate for at least one SRS resource, a transmission timing for at least one SRS resource, a subcarrier spacing (SCS), a duration, and / or a transmission bandwidth for at least one SRS resource. Note that MsgA contains a RACH preamble and a PUSCH, and the PUSCH carries a DMRS. Therefore, if the RACH message 822 is MsgA, then the preamble or the DMRS or both can be used for positioning.

[0119] More specifically, in one aspect, the configured association may associate an uplink spatial transmit filter (also referred to as an uplink transmit beam) of at least one SRS resource (or SRS resource set) with at least one RACH resource. In that case, UE 804 may send a PRACH preamble (e.g., a PRACH preamble for Msg1 or MsgA) on at least one RACH resource of the uplink spatial transmit filter using at least one SRS resource. Additionally or alternatively, the configured association may associate a path loss reference resource, a path loss estimate, and / or a transmission power estimate of at least one SRS resource (or SRS resource set) with at least one RACH resource. In that case, UE804 may send a PRACH preamble on at least one RACH resource using a transmission power estimate, a path loss estimate, and / or a path loss reference resource of at least one SRS resource. Additionally or alternatively, the configured association may associate the transmission timing of at least one SRS resource (or SRS resource set) with at least one RACH resource. In that case, the UE 804 may send a PRACH preamble on at least one RACH resource using the transmission timing of the at least one SRS resource. Additionally or alternatively, the configured association may associate a first SCS, a first duration, and / or a first transmission bandwidth of at least one SRS resource (or a set of SRS resources) with the at least one RACH resource. In that case, the UE 804 may send a PRACH preamble on at least one RACH resource using a second SCS, a second duration, and / or a second transmission bandwidth based on the first SCS, the first duration, and / or the first transmission bandwidth of the at least one SRS resource.

[0120] With reference in more detail to the SCS, duration, and / or transmission bandwidth of at least one SRS resource (or set of SRS resources), the at least one SRS resource may have a different SCS, duration, and / or transmission bandwidth than that allowed by the RACH resource. Therefore, it may be necessary to have a mapping between the SCS of at least one SRS resource and the SCS of at least one RACH resource, between the duration of at least one SRS resource and the duration of at least one RACH resource, and / or between the transmission bandwidth of at least one SRS resource and the transmission bandwidth of at least one RACH resource. Such mappings may be defined by relevant standards. These mappings may take the form of one or more rules. For example, a rule may provide that if the duration of at least one SRS resource is greater than "X", then "Y" is selected as the duration of at least one RACH resource.

[0121] When UE 804 sends a RACH message 822, it needs to identify itself to the receiving TRP 802 in each RACH resource. To this end, as a first option, a one-to-one mapping of RACH opportunities to UEs can be provided to each TRP 802. That is, each UE (e.g., UE 804) will be associated with its own RACH opportunity. This mapping can be provided by a location server (e.g., location server 230, LMF 270, SLP 272) or a TRP (e.g., a serving TRP). As a second option, the identifier of UE 804 can be communicated to the network in the Msg3 or MsgA payload. As a third option, there can be some association between UE 804 and the corresponding RACH resource. For example, a RACH preamble index can be mapped to a specific UE. This information can be provided by a location server or a TRP (e.g., a serving TRP). As a fourth option, a group of UEs may be associated with a set of one or more RACH resources, one or more RACH opportunities, one or more RACH preamble indices, or any combination thereof, and the UE 804 may provide a shorter identifier in the RACH message payload that uniquely identifies the UE 804 within that group. Again, this mapping may be provided by a location server or a TRP (e.g., a serving TRP).

[0122] It may also be necessary to have a trigger mechanism to notify the involved TRPs (here, TRPS 802-1 and 802-2) to monitor the associated RACH resources instead of the SRS resources for positioning. As a first option, the serving TRP (e.g., one of TRPs 802-1 and 802-2) can notify the location server (e.g., location server 230, LMF 270, SLP 272), which can notify the neighboring TRP (e.g., the other of TRPs 802-1 and 802-2). As a second option, the serving TRP can notify the neighboring TRP directly over the backhaul link.

[0123] After the random access procedure (e.g., random access procedure 500 / 600) with TRP 802, UE 804 is in a second RRC connection state 830 (e.g., RRC connection state 720). At this time, UE 804 is configured (e.g., by positioning server 230, LMF 270, SLP 272) with a new set of one or more SRS resources (or SRS resource sets) for positioning purposes for each TRP 802. UE 804 continues the positioning session by sending one or more SRS 832-1 to TRP 802-1 on the newly configured SRS resources for TRP 802-1 and sending one or more SRS 832-2 to TRP 802-2 on the newly configured SRS resources for TRP 802-2. At some time after entering the second RRC connected state 830, the UE 804 may receive a second association of at least one SRS resource (or set of SRS resources) in the set of one or more SRS resources allocated for each TRP 802 with at least one RACH resource in the one or more RACH resources allocated for each TRP 802. Again, the UE 804 may receive the association from the serving TRP (e.g., one of TRPs 802-1 and 802-2) or from the corresponding TRP 802. The UE 804 may store this association until the next time it transitions to the RRC idle or disconnected state during the same positioning session. Thus, as will be appreciated, the UE 804 may repeat the above operations until the positioning session is completed.

[0124] Because the RACH message 822 is sent as part of an ongoing positioning session, the TRP 802 performs positioning measurements (e.g., ToA, AoA) of the SRS 812, RACH message 822, and SRS 832. The TRP 802 may then report these measurements to a positioning entity, such as a location server (e.g., location server 230, LMF 270, SLP 272), UE 804 (for UE-based positioning), or a serving TRP (e.g., one of TRPs 802-1 and 802-2). If the positioning session is a multi-RTT session, the TRP 802 may send a downlink reference signal in response to the received SRS 812, RACH message 822, and SRS 832. As is known in the art, the payload of these response signals may include the amount of time between the reception of the SRS 812, RACH message 822, and SRS 832 and the transmission of the response signals (i.e., the TRP's 802 Rx-Tx measurements). Alternatively, the TRP 802 may send this information to a positioning entity. The location of the UE 804 may then be estimated using known techniques.

[0125] As will be appreciated, the various network nodes described above may communicate over different interfaces and using different protocols. For example, UE 804 may communicate with a location server using LTE Positioning Protocol (LPP) signaling, and vice versa. TRP 802 may communicate with a location server using LTE Positioning Protocol Type A (LPPa) or NR Positioning Protocol Type A (NRPPa) signaling. TRPs 802 may communicate with each other over a backhaul connection (e.g., backhaul connection 223). UE 804 may communicate with TRP 802 using a wireless cellular protocol such as an LTE or NR protocol.

[0126] Fig. 9 An exemplary wireless communication method 900 according to aspects of the present disclosure is illustrated. The method 900 may be performed by a UE (eg, any UE described herein, such as UE 804).

[0127] At 910, the UE receives a configuration of one or more SRS resources (e.g., one or more SRS resources or one or more SRS resource sets) during a first state (e.g., RRC connected state 720). One or more SRS resources may be configured specifically for positioning. In one aspect, operation 910 may be performed by WWAN transceiver 310, processing system 332, memory component 340, and / or positioning component 342, any or all of which may be considered as means for performing the operation.

[0128] At 920, the UE obtains a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more RACH resources. The one or more RACH resources may be allocated to the UE to send a RACH message to a specific TRP. The UE may obtain the first association during the first state or during a previous RRC connected state 720. In an aspect, operation 920 may be performed by the WWAN transceiver 310, the processing system 332, the memory component 340, and / or the positioning component 342, any or all of which may be considered as means for performing the operation.

[0129] At 930, the UE uses a transmission characteristic based on a first association between at least one SRS resource or resource set and at least one RACH resource to send at least a first signal (e.g., Msg1, Msg3, MsgA) of a RACH procedure to the TRP when the UE is outside the first state (e.g., in the RRC disconnected / idle state 710 or the RRC deactivated state 730). In an aspect, operation 930 may be performed by the WWAN transceiver 310, the processing system 332, the memory component 340, and / or the positioning component 342, any or all of which may be considered as means for performing the operation.

[0130] Fig.10 An example method 1000 of wireless communication according to aspects of the present disclosure is illustrated. The method 1000 may be performed by a TRP (eg, any base station, or a TRP of any base station, as described herein, such as one of TRPs 802).

[0131] At 1010, the TRP receives one or more SRS on one or more SRS resources from a UE (e.g., any UE described herein, such as UE 804). The one or more SRS resources may be specifically configured for positioning. In one aspect, operation 1010 may be performed by WWAN transceiver 350, processing system 384, memory component 386, and / or positioning component 388, any or all of which may be considered as means for performing the operation.

[0132] At 1020, the TRP receives from the UE at least a first signal (e.g., Msg1, Msg3, MsgA) of a RACH process having a transmission characteristic based on a first association between at least one SRS resource or resource set of one or more SRS resources and at least one RACH resource of one or more RACH resources during a positioning session (e.g., a multi-RTT session, a UL-TDOA session, or an AoA session) with the UE. In an aspect, operation 1020 may be performed by the WWAN transceiver 350, the processing system 384, the memory component 386, and / or the positioning component 388, any or all of which may be considered as means for performing the operation.

[0133] At 1030, the TRP performs positioning measurements (e.g., ToA, AoA) of the first signal of the RACH process. In an aspect, operation 1030 may be performed by WWAN transceiver 350, processing system 384, memory component 386, and / or positioning component 388, any or all of which may be considered means for performing the operation.

[0134] Those skilled in the art will recognize that any of a variety of different technologies and techniques may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0135] In addition, it will be appreciated by those skilled in the art that the various illustrative logical blocks, modules, circuits and algorithmic steps described in conjunction with the aspects disclosed herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been generally described above in terms of their functionality. Whether this functionality is implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. The technician can implement the described functionality in various ways for each specific application, but this implementation decision should not be interpreted as causing a departure from the scope of the present disclosure.

[0136] The various illustrative logical blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed 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 an 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, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or other such configurations.

[0137] The methods, sequences and / or algorithms described in conjunction with the 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 the storage medium and 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., UE). In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0138] 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 or sent as one or more instructions or codes on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium that promotes the transmission of a computer program from one place to another. Storage media can be any available medium that can be accessed by a computer. As an example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or may be used to carry or store any other medium of a desired program code in the form of an instruction or data structure and that can be accessed by a computer. Moreover, any connection is appropriately referred to as a computer-readable medium. For example, if software is sent from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are all included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0139] Although the foregoing disclosure shows the 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 aspects of the present disclosure described herein do not need to be performed in any particular order. In addition, although the elements of the present disclosure may be described or claimed in singular form, it may also be considered in plural form unless it is explicitly stated to be limited to the singular form.

Claims

1. 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: During a first state, receiving a configuration of one or more sounding reference signal (SRS) resources; obtaining a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more random access channel (RACH) resources allocated for a subsequent RACH procedure; as well as When outside of the first state, the at least one transceiver is caused to use a transmission characteristic based on the first association between the at least one SRS resource or resource set and the at least one RACH resource to send at least a first signal of the RACH process to a transmit-receive point (TRP).

2. The UE according to claim 1, wherein: The at least one processor being configured to obtain the first association includes the at least one processor being configured to: receiving said first association from a serving TRP during a first state; or The first association is determined.

3. The UE according to claim 1, wherein: The at least one processor is further configured to: receiving a configuration of one or more second SRS resources during the second state; and receiving a second association between at least one SRS resource of the one or more second SRS resources and at least one RACH resource of the one or more second RACH resources, The second state includes a radio resource control (RRC) connection state.

4. The UE according to claim 1, wherein: The transmission characteristics include an uplink spatial transmit filter for the at least one SRS resource or resource set, and The at least one processor is further configured to cause the at least one transceiver to transmit a physical random access channel (PRACH) preamble on the at least one RACH resource of the uplink spatial transmit filter using the at least one SRS resource or resource set.

5. The UE of claim 1, wherein: The transmission characteristics include a path loss reference resource, a path loss estimate and / or a transmission power estimate of the at least one SRS resource or resource set, and The at least one processor is further configured to cause the at least one transceiver to send a PRACH preamble on the at least one RACH resource using the transmit power estimate, the path loss estimate, and / or the path loss reference resource of the at least one SRS resource or resource set.

6. The UE according to claim 1, wherein: The transmission characteristics include transmission timing of the at least one SRS resource or resource set, and The at least one processor is further configured to cause the at least one transceiver to transmit a PRACH preamble on the at least one RACH resource using the transmission timing of the at least one SRS resource or resource set.

7. The UE of claim 1, wherein: The transmission characteristics include a first subcarrier spacing (SCS), a first duration, a first transmission bandwidth, or any combination thereof, of the at least one SRS resource or resource set, and The at least one processor is also configured to cause the at least one transceiver to send a PRACH preamble code on the at least one RACH resource using a second SCS, a second duration, a second transmission bandwidth, or any combination thereof based on the first SCS, the first duration, the first transmission bandwidth, or any combination thereof of the at least one SRS resource or resource set.

8. The UE according to claim 1, wherein: The first signal of the RACH process includes RACH message A, RACH message 1, RACH message 3, a demodulation reference signal (DMRS) of RACH message A, or a DMRS of RACH message 3.

9. The UE according to claim 1, wherein: The at least one processor is further configured to: During transmission of the first signal of the RACH process, an identifier of the UE is indicated to the TRP.

10. The UE according to claim 9, wherein: The identifier of the UE is included in a payload of a RACH message A when the RACH procedure is a two-step RACH procedure, or the identifier of the UE is included in a payload of a RACH message 3 when the RACH procedure is a four-step RACH procedure.

11. The UE of claim 9, wherein: indicating an identifier of the UE to the TRP based on an association between the UE and one or more RACH preamble indices, indicating an identifier of the UE to the TRP based on a one-to-one mapping between the UE and at least one RACH opportunity, or An identifier of the UE is indicated to the TRP based on the UE being a member of a group of UEs associated with the at least one RACH resource, RACH opportunity, RACH preamble index, or any combination thereof.

12. The UE according to claim 11, wherein: The identifier of the UE is unique within the group of UEs and is included in the first signal of the RACH procedure.

13. The UE according to claim 1, wherein: The one or more RACH resources include a set of time, frequency and / or sequence resources allocated for transmitting at least the first signal of the RACH procedure.

14. The UE according to claim 1, wherein: The one or more SRS resources are configured at least for a positioning session for the UE.

15. The UE according to claim 14, wherein: The positioning session includes an uplink time difference of arrival (UL-TDOA) session, a multiple round trip time (multi-RTT) session, an AoA session, or any combination thereof.

16. The UE of claim 14, wherein: The positioning session includes a multi-RTT session, and The at least one processor is further configured to: reporting one or more receive-transmit (Rx-Tx) measurements; and Report the SRS resource or resource set identifier, RACH opportunity, RACH preamble index, or RACH slot associated with one or more reported Rx-Tx measurements.

17. The UE according to claim 1, wherein: The first state comprises a radio resource control (RRC) connected state.

18. The UE according to claim 1, wherein: The first association is received during the first state.

19. A transmit-receive point (TRP), 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 one or more sounding reference signal (SRS) on one or more SRS resources from a user equipment (UE); receiving, after receiving the one or more SRSs on the one or more SRS resources, receiving, from the UE during a positioning session with the UE, at least a first signal of a random access channel (RACH) procedure having a transmission characteristic based on a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of one or more RACH resources allocated for the RACH procedure; as well as Perform positioning measurement of the first signal of the RACH process.

20. The TRP of claim 19, wherein: The at least one processor is further configured to: The at least one transceiver is caused to send the first association to the UE.

21. The TRP of claim 19, wherein: The transmission characteristics include an uplink spatial transmit filter for the at least one SRS resource or resource set, and The at least one processor is further configured to receive a physical random access channel (PRACH) preamble on the at least one RACH resource of the uplink spatial transmit filter using the at least one SRS resource or resource set.

22. The TRP of claim 19, wherein: The transmission characteristics include a path loss reference resource, a path loss estimate and / or a transmission power estimate of the at least one SRS resource or resource set, and The at least one processor is further configured to receive a PRACH preamble on the at least one RACH resource using the transmit power estimate, the path loss estimate, and / or the path loss reference resource of the at least one SRS resource or resource set.

23. The TRP of claim 19, wherein: The transmission characteristics include transmission timing of the at least one SRS resource or resource set, and The at least one processor is further configured to receive a PRACH preamble on the at least one RACH resource at the transmission timing using the at least one SRS resource or resource set.

24. The TRP of claim 19, wherein: The transmission characteristics include a first subcarrier spacing (SCS), a first duration, a first transmission bandwidth, or any combination thereof, of the at least one SRS resource or resource set, and The at least one processor is also configured to receive a PRACH preamble code on the at least one RACH resource using a second SCS, a second duration, a second transmission bandwidth, or any combination thereof based on the at least one SRS resource or resource set.

25. The TRP of claim 19, wherein: The at least one processor is further configured to: An indication of an identifier of the UE is received upon receiving the first signal of the RACH procedure, wherein the identifier of the UE is included in a payload of a RACH message A when the RACH procedure is a two-step RACH procedure, or the identifier of the UE is included in a payload of a RACH message 3 when the RACH procedure is a four-step RACH procedure.

26. The TRP of claim 25, wherein: indicating an identifier of the UE based on an association between the UE and a specified RACH preamble index, indicating an identifier of the UE based on a one-to-one mapping between the UE and the at least one RACH opportunity, or An identifier of the UE is indicated based on the UE being a member of a group of UEs associated with the at least one RACH resource, RACH opportunity, RACH preamble index, or any combination thereof.

27. The TRP of claim 19, wherein The at least one processor is further configured to: A trigger for performing the positioning measurement of the first signal of the RACH procedure is received from a location server or another TRP.

28. The TRP of claim 19, wherein The at least one processor is further configured to: causing the at least one transceiver to send a trigger for the positioning measurement of the first signal for performing the RACH process to another TRP.

29. A wireless communication method performed by a user equipment (UE), comprising: During a first state, receiving a configuration of one or more sounding reference signal (SRS) resources; obtaining a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more random access channel (RACH) resources allocated for a subsequent RACH procedure; as well as While outside of the first state, a transmission characteristic is used based on the first association between the at least one SRS resource or resource set and the at least one RACH resource to send at least a first signal of the RACH process to a transmit-receive point (TRP).

30. A wireless communication method performed by a transmit-receive point (TRP), comprising: receiving one or more sounding reference signal (SRS) on one or more SRS resources from a user equipment (UE); receiving, after receiving the one or more SRSs on the one or more SRS resources, receiving, from the UE during a positioning session with the UE, at least a first signal of a random access channel (RACH) procedure having a transmission characteristic based on a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of one or more RACH resources allocated for the RACH procedure; as well as Perform positioning measurement of the first signal of the RACH process.

31. A user equipment (UE), comprising: During a first state, means for receiving a configuration of one or more sounding reference signal (SRS) resources; means for acquiring a first association between at least one SRS resource or resource set of one or more SRS resources and at least one RACH resource of one or more random access channel (RACH) resources allocated for a subsequent RACH procedure; as well as When outside of the first state, means for transmitting at least a first signal of the RACH process to a transmit-receive point (TRP) using a transmission characteristic based on the first association between the at least one SRS resource or resource set and the at least one RACH resource.

32. A transmit-receive point (TRP), comprising: means for receiving one or more sounding reference signal (SRS) on one or more SRS resources from a user equipment (UE); means for receiving, after receiving the one or more SRS on the one or more SRS resources, at least a first signal of a random access channel (RACH) procedure from the UE during a positioning session with the UE having a transmission characteristic based on a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one of one or more RACH resources allocated for the RACH procedure; as well as Means for performing positioning measurements of the first signal of the RACH procedure.

33. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions comprising at least one instruction instructing a user equipment (UE) to: During a first state, receiving a configuration of one or more sounding reference signal (SRS) resources; obtaining a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of the one or more RACH resources allocated for a subsequent random access channel (RACH) procedure; and While outside of the first state, a transmission characteristic is used based on the first association between the at least one SRS resource or resource set and the at least one RACH resource to send at least a first signal of the RACH process to a transmit-receive point (TRP).

34. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions comprising at least one instruction indicating a transmit-receive point (TRP): receiving one or more sounding reference signal (SRS) on one or more SRS resources from a user equipment (UE); receiving, after receiving the one or more SRSs on the one or more SRS resources, receiving, from the UE during a positioning session with the UE, at least a first signal of a random access channel (RACH) procedure having a transmission characteristic based on a first association between at least one SRS resource or resource set of the one or more SRS resources and at least one RACH resource of one or more RACH resources allocated for the RACH procedure; as well as Perform positioning measurement of the first signal of the RACH process.

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