Differential round trip time-based localization

Abstract

Methods performed by a base station, a user equipment and a network entity, and a base station, a user equipment and a network are disclosed. A method performed by a base station includes transmitting a first round trip time (RTT) measurement (RTTM) signal having a first transmit group delay; transmitting a second RTTM signal having a second transmit group delay; and transmitting information indicating the first transmit group delay and the second transmit group delay to a receiving entity.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of December 18, 2019, application number 201980082303.3 (international application number PCT / US2019 / 067192), and invention name “Positioning based on differential round-trip time”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. §119 to Greek Patent Application No. 20180100562, filed on December 19, 2018, entitled “DIFFERENTIAL ROUND TRIP TIME BASED POSITIONING,” and U.S. Non-Provisional Patent Application No. 16 / 717,794, filed on December 17, 2019, entitled “DIFFERENTIAL ROUND TRIP TIME BASED POSITIONING,” both of which are assigned to the present assignee and are expressly incorporated herein by reference in their entirety. Technical Field

[0004] Various aspects described herein relate generally to wireless communication systems and, more particularly, to differential round trip time (RTT) based positioning. Background Art

[0005] Wireless communication systems have evolved through various generations, including first generation analog wireless telephone service (1G), second generation (2G) digital wireless telephone service (including transitional 2.5G and 2.75G networks), third generation (3G) high speed data, Internet-enabled wireless services, and fourth generation (4G) services (e.g., Long Term Evolution (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), TDMA variants of the Global System for Mobile Access (GSM), and the like.

[0006] The fifth generation (5G) mobile standard, known as "New Radio" (NR), calls for higher data transmission speeds, a greater number of connections, and better coverage, among other improvements. According to the Next Generation Mobile Networks Alliance, the 5G standard aims to provide data rates of tens of megabits per second to each of tens of thousands of users, and 1 gigabit per second to dozens of employees on an office floor. Hundreds of thousands of simultaneous connections should be supported to support large sensor deployments. As a result, the spectrum 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.

[0007] Some wireless communication networks (e.g., 5G) support operation at very high and even extremely high frequency (EHF) bands (e.g., millimeter wave (mmW) bands, typically with wavelengths of 1 mm to 10 mm, or 30 to 300 GHz). These very high frequencies can support very high throughputs, e.g., up to six gigabits per second (Gbps).

[0008] To support position estimation in terrestrial wireless networks, a mobile device may be configured to measure and report an observed time difference of arrival (OTDOA) or reference signal timing difference (RSTD) between reference RF signals received from two or more network nodes (e.g., different base stations or different transmission points (e.g., antennas) belonging to the same base station). The mobile device may also be configured to report the time of arrival (ToA) of the RF signal.

[0009] With OTDOA, when a mobile device reports the time difference of arrival (TDOA) between RF signals from two network nodes, it is known that the location of the mobile device is located on a hyperbola with the locations of the two network nodes as foci. By measuring TDOA between multiple pairs of network nodes, the location of the mobile device can be solved as the intersection of the hyperbolas.

[0010] Round trip time (RTT) is another technique for determining the location of a mobile device. RTT is a two-way messaging technique (from a network node to a mobile device, and from a mobile device to a network node), where both the mobile device and the network node report their receive-to-transmit (Rx-Tx) time difference to a positioning entity (e.g., a location server or location management function (LMF)), which calculates the location of the mobile device. This allows the round-trip flight time between the mobile device and the network node to be calculated. It is then known that the location of the mobile device is located on a circle (for two-dimensional positioning) or sphere (for three-dimensional positioning) centered on the location of the network node. Using multiple network nodes to report RTT allows the positioning entity to resolve the location of the mobile device as the intersection of a circle or sphere. Summary of the invention

[0011] The present disclosure identifies features of some example aspects and is not an exclusive or exhaustive description of the disclosed subject matter. Whether a feature or aspect is included in or omitted from the present disclosure is not intended to indicate the relative importance of such features. Additional features and aspects are described and will become apparent to those skilled in the art upon reading the following detailed description and viewing the accompanying drawings which form a part hereof.

[0012] An exemplary method performed by a network node is disclosed. The method includes collecting a plurality of RTTs between a user equipment (UE) and a plurality of base stations (BSs). Each RTT of the plurality of RTTs is associated with a BS of the plurality of BSs. In addition, each RTT represents a total flight time of a round-trip RTT signal between the UE and the associated BS. The method also includes performing a differential RTT-based positioning procedure to determine a position of the UE based on a difference in the RTTs between the plurality of RTTs.

[0013] An exemplary method performed by a wireless device is disclosed. The method includes providing one or more group delay parameters of the wireless device to a positioning entity. The one or more group delay parameters may include an RTT type parameter that indicates whether the RTT reported by the wireless device is a measured RTT or an actual RTT. When the RTT type parameter indicates that the reported RTT is a measured RTT, it may be determined that the group delay of the wireless device is included in the reported RTT.

[0014] An exemplary network node is disclosed. The network node includes at least one transceiver, at least one memory component, and at least one processor. The at least one transceiver, the at least one memory component, and the at least one processor are configured to collect multiple RTTs between a UE and multiple BSs. Each of the multiple RTTs is associated with a BS in the multiple BSs. In addition, each RTT represents the total flight time of the RTT signal between the UE and the associated BS. The at least one transceiver, the at least one memory component, and the at least one processor are also configured to perform a positioning procedure based on differential RTT to determine the position of the UE based on the difference in RTT between the multiple RTTs.

[0015] An exemplary wireless device is disclosed. The wireless device includes at least one transceiver, at least one memory component, and at least one processor. The at least one transceiver, at least one memory component, and at least one processor are configured to provide one or more group delay parameters of the wireless device to a positioning entity. The one or more group delay parameters may include an RTT type parameter, which indicates whether the RTT reported by the wireless device is a measured RTT or an actual RTT. When the RTT type parameter indicates that the reported RTT is a measured RTT, it may be determined that the group delay of the wireless device is included in the reported RTT.

[0016] Another exemplary network node is disclosed. The network node includes a component for collecting multiple RTTs between a UE and multiple BSs. Each RTT in the multiple RTTs is associated with a BS in the multiple BSs. In addition, each RTT represents a total flight time of RTT signals traveling back and forth between the UE and the associated BS. The network node also includes a component for performing a differential RTT-based positioning procedure to determine the location of the UE based on the difference in RTT between the multiple RTTs.

[0017] Another exemplary wireless device is disclosed. The wireless device includes a component for providing one or more group delay parameters of the wireless device to a positioning entity. The one or more group delay parameters may include an RTT type parameter that indicates whether the RTT reported by the wireless device is a measured RTT or an actual RTT. When the RTT type parameter indicates that the reported RTT is a measured RTT, it may be determined that the group delay of the wireless device is included in the reported RTT.

[0018] An exemplary non-transitory computer-readable medium storing computer-executable instructions for a network node is disclosed. The computer-executable instructions include one or more instructions for causing the network node to collect multiple RTTs between a UE and multiple BSs. Each of the multiple RTTs is associated with a BS in the multiple BSs. In addition, each RTT represents the total flight time of the RTT signal between the UE and the associated BS. The computer-executable instructions also include one or more instructions for causing the network node to perform a differential RTT-based positioning procedure to determine the location of the UE based on the difference in RTT between the multiple RTTs.

[0019] An exemplary non-transitory computer-readable medium storing computer-executable instructions for a wireless device is disclosed. The computer-executable instructions include one or more instructions for causing the wireless device to provide one or more group delay parameters of the wireless device to a positioning entity. The one or more group delay parameters may include an RTT type parameter indicating whether the RTT reported by the wireless device is a measured RTT or an actual RTT. When the RTT type parameter indicates that the reported RTT is a measured RTT, it may be determined that the group delay of the wireless device is included in the reported RTT.

[0020] 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

[0021] The accompanying drawings are presented to aid in describing examples of one or more aspects of the disclosed subject matter and are provided solely for purposes of illustration and not limitation of the examples:

[0022] Figure 1 A high-level system architecture of a wireless communication system according to one aspect of the present disclosure is shown;

[0023] Figure 2A and Figure 2B An example wireless network structure according to various aspects is shown;

[0024] Figures 3A to 3C is a simplified block diagram of several example aspects of components that may be used in a wireless communication node and configured to support communications as taught herein;

[0025] Figure 4 An exemplary technique for determining a UE location is shown;

[0026] Figure 5A shows a scenario for determining the RTT between a transmitter and a receiver, and Figure 5B is a graph showing the time during wireless probe request and response. Figure 5A A diagram of exemplary timing within RTT occurring in a scenario of;

[0027] Figure 6 An exemplary method performed by a network node to determine a UE location according to one aspect of the present disclosure is shown;

[0028] Figure 7 An exemplary process performed by a network node to determine a UE position by absolute RTT-based positioning according to one aspect of the present disclosure is shown;

[0029] Figure 8An exemplary process performed by a network node to determine a UE position through differential RTT-based positioning according to one aspect of the present disclosure is shown;

[0030] Fig. 9 An exemplary method performed by a UE to determine a UE location according to one aspect of the present disclosure is shown. DETAILED DESCRIPTION

[0031] Various aspects of the subject matter are provided in the following description of specific examples of the disclosed subject matter and the related drawings. Alternatives may be envisioned without departing from the scope of the disclosed subject matter. In addition, well-known elements will not be described in detail or will be omitted to avoid obscuring the relevant details.

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

[0033] The terms used herein describe only specific aspects and should not be construed as limiting any aspect disclosed herein. As used herein, unless the context otherwise clearly indicates, the singular forms "a", "an" and "the" are intended to include the plural forms as well. It will be further understood by those skilled in the art that the terms "include" and / or "comprise" as used herein specify the presence of stated features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof.

[0034] In addition, various aspects can be described in terms of a sequence of actions to be performed by, for example, an element of a computing device. Those skilled in the art will recognize that the various actions described herein can 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, these action sequences described herein can be considered to be fully embodied in any form of non-transitory computer-readable medium, which has a corresponding computer instruction set stored thereon, which, when executed, will cause the associated processor to perform the functions described herein. Therefore, the various aspects described herein can be embodied in several different forms, all of which are contemplated to be within the scope of the subject matter claimed. In addition, for each aspect described herein, the corresponding form of any such aspect can be described herein as, for example, "logically configured to" and / or configured to perform other structural components of the described actions.

[0035] As used herein, unless otherwise noted, the terms "user equipment" (UE) and "base station" are not intended to be specific 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, a laptop, a tracking device, a wearable device (e.g., a smart watch, glasses, augmented reality (AR) / virtual reality (VR) headsets, etc.), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate via a wireless communication network. A UE may be mobile or may be (e.g., at certain times) stationary and may communicate with a radio access network (RAN). As used herein, the term "UE" may be interchangeably referred to as an "access terminal" or "AT", "client device", "wireless device", "subscriber equipment", "subscriber terminal", "subscriber station", "user terminal" or UT, "mobile terminal", "mobile station" or variants thereof. In general, a UE may communicate with a core network via a RAN, and through the core network, the UE may connect to external networks such as the Internet and to other UEs. Of course, other mechanisms are also possible for the UE to connect to the core network and / or the Internet, such as through a wired access network, a wireless local area network (WLAN) (eg, based on IEEE 802.11, etc.), and so on.

[0036] A base station may operate in communication with a UE according to one of several RATs, depending on the network in which it is deployed, and may alternatively be referred to as an access point (AP), a network node, a Node B, an evolved Node B (eNB), a new radio (NR) Node B (also referred to as a gNB or gNodeB), etc. In addition, in some systems a base station may provide only edge node signaling functionality, while in other systems it may provide additional control and / or network management functionality. 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 of the UL / reverse or DL / forward traffic channels.

[0037] The term "base station" may refer to a single physical transmit-receive point (TRP), or multiple physical TRPs that may or may not be located at the same location. For example, where the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to the cell of the base station. Where the term "base station" refers to multiple co-located physical TRPs, the physical TRP may be an antenna array of the base station (for example, 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 TRP may be a serving base station that receives measurement reports from a UE and a neighbor base station whose reference RF signal the UE is measuring. As used herein, since the TRP is the point at which a base station transmits and receives wireless signals, transmission from a base station or reception at a base station should be understood to refer to a specific TRP of the base station.

[0038] An "RF signal" includes an electromagnetic wave of a given frequency that transmits 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.

[0039] According to various aspects, Figure 1 An example wireless communication system 100 is shown. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 10 and various UEs 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macrocell base stations may include eNBs, where the wireless communication system 100 corresponds to an LTE network, or gNBs, 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 femtocells, picocells, microcells, etc.

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

[0041] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. In one aspect, one or more cells can be supported by base station 102 in each coverage area 110. A "cell" is a logical communication entity used to communicate with a base station (e.g., through some frequency resources, called carrier frequency, component carrier, carrier, frequency band, etc.), and can be associated with an identifier (e.g., physical cell identifier (PCID)), virtual cell identifier (VCID)) used to distinguish cells operating through the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB) or others) that can provide access to different types of UEs. Since a cell is supported by a specific base station, depending on the context, the term "cell" can refer to either or both of the logical communication entity and the base station supporting it. In some cases, the term "cell" may also refer to a geographic coverage area (eg, a sector) of a base station, so long as a carrier frequency can be detected and used for communication within certain portions of the geographic coverage area 110.

[0042] Although the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., within a handoff region), some of the geographic coverage areas 110 may be substantially overlapped by 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 coverage area 110 of one or more macrocell base stations 102. A network that includes both small cells and macrocells may be referred to as a heterogeneous network. A heterogeneous network may also include a home eNB (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG).

[0043] The communication link 120 between the base station 102 and the UE 104 may include UL (also referred to as a reverse link) transmissions from the UE 104 to the base station 102 and / or downlink (DL) (also referred to as a 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 for DL ​​and UL (e.g., more or fewer carriers may be allocated to DL than to UL).

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

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

[0046] The wireless communication system 100 may also include a millimeter wave (mmW) base station 180, which may operate at mmW frequencies and / or near mmW frequencies to communicate with UE 182. Extremely high frequency (EHF) is a portion of RF in the electromagnetic spectrum. The range of EHF is 30 GHz to 300 GHz, with a wavelength between 1 mm and 10 mm. The radio waves in this band may be referred to as millimeter waves. Near mmW may extend down to a frequency of 3 GHz, with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter waves. Communications using mmW / near mmW radio frequency bands have high path loss and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (transmitting and / or receiving) through the mmW communication link 184 to compensate for extremely high path loss and short distances. In addition, it should be understood that in an alternative configuration, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Therefore, it should be understood that the foregoing description is only exemplary, and should not be construed as limiting the various aspects disclosed herein.

[0047] 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 the location of a given target device (e.g., UE) (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 direction of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, the network node can use an antenna array (called a "phased array" or "antenna array") that produces an RF beam that can be "guided" to point in different directions without actually moving the antenna. Specifically, the RF current from the transmitter is fed to each antenna in the correct phase relationship so that the radio waves from the individual antennas can be added together to increase the radiation in the desired direction while canceling to suppress the radiation in the undesired direction.

[0048] The transmit beams can be quasi-colocated, which means that the transmit beams appear to have the same parameters to the receiver (e.g., UE) regardless of whether the transmit antennas of the network nodes themselves are physically colocated. In NR, there are four types of quasi-colocated (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 transmitted 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 transmitted on the same channel. Therefore, 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 transmitted on the same channel. If the source reference RF signal is QCL type D, the receiver may use the source reference RF signal to estimate spatial reception parameters of a second reference RF signal transmitted on the same channel.

[0049] 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 the gain level of the RF signal). Thus, when a receiver is referred to as beamforming in a certain direction, it means that the beam gain in that direction is higher relative to beam gains along other directions, or the beam gain in that direction is highest compared to the beam gains of all other receive beams available to the receiver in that direction. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signal received from that direction.

[0050] The 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 a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station using a specific receive beam. The UE may then form a transmit beam for sending an uplink reference signal (e.g., a sounding reference signal (SRS)) to the base station based on the parameters of the receive beam.

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

[0052] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system such as 5G, one of the carrier frequencies is called the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell", and the remaining carrier frequencies are called "secondary carriers" or "secondary serving cells" or "SCells". In carrier aggregation, the anchor carrier is a carrier operating on the primary frequency (e.g., FR1) used by the UE 104 / 182, and is 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 control channels and UE-specific control channels, and can be a carrier in a licensed frequency (but this is not always the case). A secondary carrier is a carrier operating on a second frequency (e.g., FR2) that is configured once an RRC connection is established between the UE 104 and the anchor carrier, and can be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, such as those UE-specific signaling information and signals that may not be present in the secondary carrier, because both the primary uplink carrier and the primary downlink carrier are typically UE-specific. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same applies to 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. Since a "serving cell" (whether PCell or SCell) corresponds to a carrier frequency / component carrier (some base stations are communicating through it), the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. are used interchangeably.

[0053] 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 the data rate obtained with a single 20 MHz carrier.

[0054] The wireless communication system 100 may also include one or more UEs (eg, 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 WLAN STA 152 connected to WLAN AP 150 (through which UE 190 can indirectly obtain WLAN-based Internet connectivity). In one example, D2D P2P links 192 and 194 can be provided by any well-known D2D RAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), etc.) support.

[0055] 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.

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

[0057] According to various aspects, Figure 2BAnother example wireless network structure 250 is shown. For example, the NGC 260 (also referred to as "5GC") can be functionally viewed as a control plane function provided by an access and mobility management function (AMF) / user plane function (UPF) 264, and a user plane function provided by a session management function (SMF) 262, which operate in conjunction to form a core network (i.e., NGC 260). The user plane interface 263 and the control plane interface 265 connect the eNB 224 to the NGC 260, specifically to the SMF 262 and the AMF / UPF 264, respectively. In an additional configuration, the gNB 222 can also be connected to the NGC 260 via a control plane interface 265 to the AMF / UPF 264 and a user plane interface 263 to the SMF 262. In addition, the eNB 224 can communicate directly with the gNB 222 via the backhaul connection 223, regardless of whether the gNB is directly connected to the NGC 260. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of the eNBs 224 and the gNBs 222. Either the gNB 222 or the eNB 224 may communicate with the UE 204 (e.g., Figure 1 The base station of the new RAN 220 communicates with the AMF side of the AMF / UPF 264 through the N2 interface, and communicates with the UPF side of the AMF / UPF 264 through the N3 interface.

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

[0059] The functions of the UPF include acting as an anchor point for intra-RAT / inter-RAT mobility (where applicable), acting as an external protocol data unit (PDU) session point for interconnection 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, user plane quality of service (QoS) processing (e.g., UL / DL rate enforcement, reflective QoS marking in DL), UL traffic verification (service data flow (SDF) to QoS flow mapping), transport layer packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node.

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

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

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

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

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

[0065] In some embodiments, the transceiver circuit including the transmitter and the receiver may include an integrated device (e.g., a transmitter circuit and a receiver circuit implemented as a single communication device), may include 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, as described herein, the transmitter may include or be coupled to multiple antennas such as an antenna array (e.g., antennas 316, 336, and 376), which allows each device to perform transmit "beamforming". Similarly, as described herein, the receiver may include or be coupled to multiple antennas such as an antenna array (e.g., antennas 316, 336, and 376), which allows each device to perform receive beamforming. In one aspect, the transmitter and receiver may share the same multiple antennas (e.g., antennas 316, 336, and 376) so that each device can only receive or transmit at a given time, but not simultaneously. The wireless communication device of apparatus 302 and / or 304 (eg, one or both of transceivers 310 and 320 and / or 350 and 360) may also include a network listening module (NLM) or the like for performing various measurements.

[0066] At least in some cases, devices 302 and 304 also include global positioning system (GPS) receivers 330 and 370. GPS receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, for receiving GPS signals 338 and 378, respectively. GPS receivers 330 and 370 may include any suitable hardware and / or software for receiving and processing GPS signals 338 and 378, respectively. GPS receivers 330 and 370 request appropriate information and operations from other systems and perform calculations necessary to determine the location of devices 302 and 304 using measurements obtained through any suitable GPS algorithm.

[0067] The base station 304 and the network entity 306 each include at least one network interface 380 and 390 for communicating with other network entities. For example, the network interfaces 380 and 390 (e.g., one or more network access ports) may 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 may be implemented as transceivers configured to support wired or wireless signal communications. Such communications may involve, for example, sending and receiving: messages, parameters, or other types of information.

[0068] The devices 302, 304, and 306 also include other components that can be used in conjunction with the operations disclosed herein. The UE 302 includes a processor circuit that implements a processing system 332, which is used to provide functions related to RTT measurements in licensed or unlicensed bands, such as disclosed herein, and to provide other processing functions. The base station 304 includes a processing system 384, which is used to provide functions related to RTT measurements in licensed or unlicensed bands, such as disclosed herein, and to provide other processing functions. The network entity 306 includes a processing system 394, which is used to provide functions related to RTT measurements in licensed or unlicensed bands, such as disclosed herein, and to provide other processing functions. In one aspect, the processing systems 332, 384, and 394 may include, for example, one or more general-purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), or other programmable logic devices or processing circuits.

[0069] The apparatuses 302, 304, and 306 include memory circuitry implementing memory components 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). In some cases, the apparatuses 302, 304, and 306 may include RTT positioning modules 342, 388, and 398, respectively. The RTT positioning modules 342, 388, and 398 may be hardware circuitry that is part of or coupled to the processing systems 332, 384, and 394, respectively, and that, when executed, causes the apparatuses 302, 304, and 306 to perform the functions described herein. Alternatively, the RTT positioning modules 342, 388, and 398 may be memory modules (e.g., memory devices) stored in the memory components 340, 386, and 396, respectively. FIG. 3A to FIG. 3C ), which, when executed by processing systems 332, 384, and 394, causes devices 302, 304, and 306 to perform the functions described herein.

[0070] UE 302 may include one or more sensors 344 coupled to processing system 332 to provide motion and / or orientation information independent of motion data derived from signals received by WWAN transceiver 310, WLAN transceiver 320, and / or GPS 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. In addition, 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 position in a 2D and / or 3D coordinate system.

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

[0072] Referring to the processing system 384 in more detail, in the downlink, IP packets from the network entity 306 may be provided to the processing system 384. The processing system 384 may implement the functions of 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 can provide RRC layer functions 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 functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel priority.

[0073] The transmitter 354 and the receiver 352 may implement layer-1 functions associated with various signal processing functions. Layer-1, including the physical (PHY) layer, may include error detection on transport channels, forward error correction (FEC) encoding / decoding of transport channels, interleaving, rate matching, mapping to physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The transmitter 354 handles 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 separated into parallel streams. Each stream can be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator can be used to determine the coding and modulation schemes and for spatial processing. The channel estimate can be derived from a reference signal and / or channel condition feedback sent by the UE 302. Each spatial stream can then be provided to one or more different antennas 356. The transmitter 354 can modulate an RF carrier with a corresponding spatial stream for transmission.

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

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

[0076] Similar to the functions described in conjunction with DL transmissions performed by the base station 304, the processing system 332 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with 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 functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel priority.

[0077] 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.

[0078] At base station 304, UL transmissions are processed in a manner similar to that described in conjunction with the receiver functionality at UE 302. Receiver 352 receives the signal through its respective antenna 356. Receiver 352 recovers the information modulated onto the RF carrier and provides the information to processing system 384.

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

[0080] For convenience, devices 302, 304 and / or 306 are FIG. 3A to FIG. 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 understood that the blocks shown may have different functions in different designs.

[0081] The various components of devices 302, 304, and 306 may communicate with each other via data buses 334, 382, ​​and 392, respectively. FIG. 3A to FIG. 3C The components of can be implemented in various ways. In some implementations, FIG. 3A to FIG. 3CThe components may be implemented in one or more circuits, such as one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or include at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functions represented by blocks 310 to 346 may be implemented by the processor and memory components of UE 302 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functions represented by blocks 350-388 may be implemented by the processor and memory components of base station 304 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). In addition, some or all of the functions represented by blocks 390 to 398 may be implemented by the processor and memory components of network entity 306 (e.g., by executing 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, it will be appreciated that 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; RTT positioning modules 342, 388 and 398, etc.

[0082] Figure 4 A simplified environment for illustrating an exemplary technique for determining the location of a UE 104 is shown in FIG. UE 104 may wirelessly communicate with a plurality of gNodeBs 402-406 using radio frequency (RF) signals and standardized protocols for RF signal modulation and information packet exchange. By extracting different types of information from the exchanged signals and utilizing the layout of the network (i.e., network geometry), UE 104 or any of gNodeBs 402-406 may determine the location of UE 104 in a predefined reference coordinate system. Figure 4 As shown, a two-dimensional coordinate system can be used to specify the location (x, y) of UE 104; however, the aspects disclosed herein are not limited thereto and may also be adapted to use a three-dimensional coordinate system to determine location where additional dimensions are required. Figure 4 Three gNodeBs 402-406 are shown in FIG. 1 , but aspects may utilize additional gNodeBs.

[0083] If UE 104 wants to determine its location (x, y), UE 104 may first need to determine the network geometry. The network geometry may include the location ((x, y) of each of gNodeBs 402-406 in a reference coordinate system. k ,yk ), where k=1, 2, 3). The network geometry may be provided to the UE 104 in any manner, for example, providing the information in a beacon signal, using a dedicated external server on an external network, providing the information using a uniform resource identifier, providing the information through a base station almanac (BSA), etc.

[0084] In determining the location of UE 104, whether by UE 104 (UE-based) or by the network (UE-assisted), the distance (d k , where k=1, 2, 3). As will be described in more detail below, there are many different ways to estimate these distances (d k ). As described below, these characteristics may include the round-trip transit time of the signal.

[0085] In other aspects, the distance (d k ) may be determined or refined in part using other information sources not associated with the gNodeBs 402 to 406. For example, other positioning systems such as GPS may be used to provide d k (Note that in the expected operating environment (indoors, in large cities, etc.), GPS may not have sufficient signal to provide d k However, GPS signals may be combined with other information to assist in the location determination process.) Other relative positioning equipment may reside in the UE 104, which may be used as a basis for providing a rough estimate of relative position and / or direction (e.g., an onboard accelerometer).

[0086] Once each distance d k Once determined, the location (x, y) of UE 104 can then be solved using various known geometric techniques (e.g., trilateration). Figure 4 It can be seen that the location of UE 104 is ideally located at the intersection of the circles (or spheres) drawn using dashed lines. Each circle (or sphere) passes through a radius d k and center (x k ,y k ) where k = 1, 2, 3. In practice, due to noise and other errors in the network connection system, the intersection of these circles (or spheres) may not be at a single point.

[0087] Determining the distance between the UE 104 and each gNodeB 402-406 may involve using the timing information of the RF signal. In one aspect, determining the RTT of the signals exchanged between the UE 104 and the gNodeBs 402-406 and converting it into a distance (d k ). RTT techniques measure the time between sending a data packet and receiving a response. These methods use calibration to eliminate any processing delays. In some environments, it can be assumed that the processing delays of UE 104 and gNodeB 402-406 are the same. However, such an assumption may not actually hold true.

[0088] A position estimate (e.g., for a UE 104) may be referred to by other names, such as a position estimate, a position, a location, a position fix, a fix, etc. The position estimate may be geodetic and include coordinates (e.g., latitude, longitude, and possibly altitude), or may be urban and include a street address, a postal address, or some other verbal description of the location. The position estimate may also be defined relative to some other known location, or in absolute terms (e.g., using latitude, longitude, and possibly altitude). The position estimate may include expected errors or uncertainties (e.g., by including an area or volume where the location is expected to be included with some specific or default confidence level).

[0089] As mentioned above, OTDOA and RTT are techniques for determining the position of a UE. However, both have their limitations. In OTDOA, synchronization timing between gNodeBs on their Tx antennas is an important factor for positioning accuracy. Unfortunately, this can be complex to maintain. Otherwise, the frame boundaries identified by the UE from different gNodeBs may have arbitrary timing relationships, which in turn may result in compromising the accuracy of the UE's position determination. It should be noted that maintaining synchronization at the gNodeB Tx antennas involves measuring the delays between the digital domain and the physical transmission, or ensuring that they are the same for different gNodeBs.

[0090] Another factor in achieving positioning accuracy in OTDOA is that the group delay from the physical signal reception at the UE Rx antenna to the conversion to the digital domain (where TDOA is measured) is the same for all measuring gNodeBs. Alternatively, differences in group delays can be allowed, but these differences should be compensated to achieve the required positioning accuracy. The quantity of interest is the flight time between the Tx antenna and the Rx antenna, which should not include this group delay. However, since TDOA is used, only the difference in group delay is meaningful, not the absolute group delay.

[0091] On the other hand, when using RTT, position determination does not require maintaining time synchronization between gNodeBs. This is because the UE can follow an independent ranging procedure for each gNodeB. However, in order to avoid overestimating the range, it can be very beneficial to determine the absolute value of the group delay.

[0092] Will refer to Figure 5A and Figure 5B Describe the concept of group delay. Figure 5A shows an RTT scenario between a transmitter 502 and a receiver 504, Figure 5B 5 is a diagram illustrating an exemplary timing that occurs within an RTT during a wireless probe request and response between a transmitter 502 and a receiver 504. For network-centric (UE-assisted) RTT determination, the transmitter 502 may correspond to a network node (e.g., any of the base stations described herein) and the receiver 504 may correspond to a UE (e.g., any of the UEs described herein). For UE-centric RTT determination, the transmitter 502 may correspond to a UE and the receiver 504 may correspond to a network node.

[0093] To determine the RTT (and thus the distance) between the transmitter 502 and the receiver 504, the transmitter 502 sends an RTT measurement (RTTM) signal at a first time (referred to as “t1”). After a period of transmission time, the receiver 504 detects that the RTTM signal is received at a second time (referred to as “t2”). Subsequently, the receiver 504 requires some turnaround time “Δ” to process the received RTTM signal before sending an RTT response (RTTR) signal at a third time (referred to as “t3”). After the propagation time, the transmitter 502 detects that the RTTR signal is received at a fourth time (referred to as “t4”). Therefore, the measured flight time or RTT (referred to as “tp” for “transmission time”) can be calculated as:

[0094] Measured RTT = (t4-t1)-(t3-t2), (1)

[0095] Where (t4-t1) is the measured total time, and (t3-t2) is the measured turnaround time at the receiver 504.

[0096] Times t1, t2, t3, and t4 are times measured in the digital domain by the transmitter 502 and the receiver 504. However, in reality, the RTTM signal actually leaves the transmitter 502 at some time after t1 (referred to as "t1'") and arrives at the receiver 504 at some time before t2 (referred to as "t2'"). Additionally, the RTTR signal actually leaves the receiver 504 at some time after t3 (referred to as "t3'") and arrives at the transmitter 502 at some time before t4 (referred to as "t4'"). This means that the actual flight time or RTT (referred to as "tp'") is as follows:

[0097] Actual RTT = (t4'-t1')-(t3'-t2')(2)

[0098] Where (t4′−t1′) is the actual total time, and (t3′−t2′) is the actual turnaround time at the receiver 504 .

[0099] The difference between the measured time (e.g., t1, t2, t3, t4) and the actual time (e.g., t1', t2', t3', t4') is explained as follows. In wireless communication, a source device (or simply "source") sends a signal to a destination device (referred to as "destination"). In order to transmit a digital signal, the Tx RF chain at the source (also referred to as the RF front end (RFFE)) performs processing to convert the digital signal into an RF signal. For example, the Tx RF chain (or simply "Tx chain") of the source may include: a digital-to-analog converter (DAC) that converts the digital signal into a baseband analog signal, an upconverter that upconverts the baseband signal to an RF signal, and a power amplifier (PA) that amplifies the RF signal, which is then radiated from the antenna of the source.

[0100] The destination may include an Rx RF chain (or simply "Rx chain") to perform reverse processing to retrieve the original digital signal from the arriving RF signal. For example, the Rx RF chain (or simply "Rx chain") of the destination may include: a filter (e.g., low pass, high pass, band pass) to filter the RF signal received by the antenna of the destination, a low noise amplifier (LNA) to amplify the filtered RF signal, a down converter to down-convert the filtered RF signal to a baseband signal, and an analog-to-digital (ADC) converter to recover the digital signal from the baseband signal.

[0101] The process performed by the Tx chain of the source to convert the digital signal to an RF signal requires a finite time (generally referred to as the "Tx group delay"). The Tx group delay can be said to represent the delay between the measured transmission time of the signal and the actual time the signal leaves the source (e.g., t1'-t1). The reverse process performed by the Rx chain of the destination to recover the digital signal from the RF signal also requires a finite time (generally referred to as the "Rx group delay"). The Rx group delay can be said to represent the delay between the actual time the signal arrives at the destination and the measured arrival time of the signal (e.g., t2-t2').

[0102] The term “group delay” is used to emphasize that the delay is caused by elements in the above-mentioned Tx / Rx chain, which may include filters and may cause delays due to frequency, RAT, carrier aggregation (CA), component carrier (CC), etc.

[0103] Continue to refer Figure 5A and Figure 5B , it can be seen that each of the transmitter 502 and the receiver 504 includes a Tx group delay and an Rx group delay. The total group delay (or simply "group delay") of each device can be determined by summing the corresponding Tx group delay and Rx group delay. Subsequently, the group delay (GD) of the transmitter 502 can be expressed as:

[0104] GD = (t1' - t1) + (t4 - t4') (3)

[0105] Furthermore, the GD of the receiver 504 may be expressed as:

[0106] GD = (t3' - t3) + (t2 - t2') (4)

[0107] From equations (1) and (2), it can be understood that if the RTT measurement is based only on the measured time, the estimate of the distance between the transmitter 502 and the receiver 504 may be overestimated. However, if the group delay can be taken into account, the actual RTT can be determined. This shows that accurately determining the group delay is critical to RTT.

[0108] As mentioned above, inter-gNodeB timing synchronization and group delay are factors that affect the positioning accuracy of OTDOA technology and RTT technology. But as mentioned above, for OTDOA, although strict inter-gNodeB timing synchronization is critical, loose group delay can be tolerated. But for RTT, the situation is just the opposite. That is, strict group delay is critical, but loose inter-gNodeB timing synchronization can be tolerated. Neither requirement should limit positioning accuracy. With stricter accuracy targets in NR (for example, centimeter-level for factory automation scenarios), these requirements also need to be stricter.

[0109] In order to address these problems, it is proposed to perform a differential RTT-based positioning procedure to determine the location of the UE. Broadly speaking, the differential RTT-based positioning procedure can be regarded as a technique for determining the location of the UE (UE location) based on the difference in RTT between multiple RTTs. Relative to traditional OTDOA techniques, the proposed differential RTT-based positioning allows for looser inter-gNodeB synchronization. At the same time, relative to traditional RTT techniques, the proposed differential RTT-based positioning procedure allows for looser group delay. In other words, the differential RTT-based positioning procedure described in this article has the advantages of both known OTDOA and RTT techniques without their disadvantages. This can also result in lower complexity and equipment cost.

[0110] Figure 6 An example method 600 performed by a network node to determine a UE location according to aspects of the present disclosure is shown. In one aspect, the network node may be a location server (e.g., location server 230, LMF 270) or other positioning entity, and may be located in a core network (e.g., NGC 260), in a RAN (e.g., in a serving base station), or at a UE (e.g., for UE-based positioning).

[0111] At 610, the network node may collect a plurality of RTTs between the UE and a plurality of base stations (e.g., gNodeBs). Each RTT may be associated with a single BS in the plurality of BSs. Each RTT may represent a total round-trip flight time of an RTT signal between the UE and the associated BS. For example, each RTT may represent a RTTM and RTTR signal (see Figure 5A , Figure 5B )The flight time between the UE and the associated BS.

[0112] In one aspect, where the network node is a network entity, operation 610 may be performed by network interface 390, processing system 394, memory 396, and / or RTT positioning module 398, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a base station, operation 610 may be performed by WWAN transceiver 350, network interface 380, processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 610 may be performed by WWAN transceiver 310, processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0113] In one aspect, collecting multiple RTTs may involve receiving one or more RTT reports from the UE, wherein the one or more RTT reports include multiple RTTs. In this regard, it may be assumed that the UE determines the RTT. For example, the UE may determine the RTT between itself and the BS. If the BS serving the UE (e.g., a serving gNodeB) is a network node, the network node may directly receive the one or more RTT reports. On the other hand, if the serving BS is not a network node, the one or more RTT reports may be received from the UE via the serving BS.

[0114] In another aspect, collecting multiple RTTs may involve receiving one or more RTT reports from a serving BS. In this regard, it may be assumed that the RTT is determined on the network side. For example, each BS may determine the RTT between itself and the UE and report the RTT to the serving BS. The serving BS may then collect the RTTs from the BS into one or more RTT reports and provide the one or more RTT reports to the UE. The serving BS may determine the RTT between itself and the UE, which may be included in the multiple RTTs of the one or more RTT reports.

[0115] On the other hand, if the serving BS is a network node and the RTT is determined on the network side, collecting multiple RTTs may involve collecting RTTs from the BS (including itself). In general, calculating each RTT involves measurements made by two nodes (e.g., a UE and a gNB) between which an RTT procedure is performed. The positioning engine or location server that calculates the final position receives these measurements for multiple RTT procedures between the UE and multiple base stations, or directly receives the RTT, in which case each RTT is calculated by another node that receives the two required measurements. The positioning engine may be physically located in the UE, base station, or elsewhere in the network. The node involved in calculating the RTT, transmitting RTT-related measurements, or the RTT may also be a UE, base station, or other network node. Such special examples (e.g., where the location server is located in the base station) have been described previously, but it should be understood that the present disclosure is not limited to these examples.

[0116] At 620, the network node may receive group delay parameters. These are parameters related to multiple RTTs. If multiple RTTs are received from the UE, group delay parameters may also be received from the UE. For example, the group delay parameters may be included in one or more positioning protocol signals from the UE. Examples of positioning protocol signals include LTE Positioning Protocol (LPP) signals. As another example, the group delay parameters may be received from the UE separately from the multiple RTTs, such as in the UE's capability information.

[0117] In one aspect, where the network node is a network entity, operation 620 may be performed by network interface 390, processing system 394, memory 396, and / or RTT positioning module 398, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a base station, operation 620 may be performed by WWAN transceiver 350, network interface 380, processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 620 may be performed by WWAN transceiver 310, processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0118] If multiple RTTs are received from the network (e.g., from a serving BS), a group delay parameter may also be received from the serving BS. For example, the group delay parameter may be included in one or more positioning protocol annex signals from the serving BS. Examples of positioning protocol annex signals include LTE Positioning Protocol Annex (LPPa) signaling and New Radio Positioning Protocol Annex (NR-PPa) signaling.

[0119] If the serving BS is a network node and the RTT is determined on the network side, information related to the group delay parameters may be collected from other BSs (eg, via one or more backhaul links / interfaces).

[0120] At 630, the network node may determine whether the UE and / or BS group delay is included in the multiple RTTs. In one aspect, the group delay parameter received from the UE or serving BS at 620 may include an RTT type parameter, which indicates whether the multiple RTTs are multiple measured RTTs or actual RTTs. As mentioned above, the measured RTT (e.g., (t4-t1)-(t3-t2)) is in the digital domain, which does not exclude group delay. Therefore, if the RTT type parameter indicates that the multiple RTTs are multiple measured RTTs, it can be determined that the group delay is included in the multiple RTTs. On the other hand, if the RTT type parameter indicates that the multiple RTTs are multiple actual RTTs, this means that the group delay has been excluded.

[0121] In one aspect, where the network node is a network entity, operation 630 may be performed by processing system 394, memory 396, and / or RTT positioning module 398, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a base station, operation 630 may be performed by processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 630 may be performed by processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0122] If it is determined at 630 that the multiple RTTs do not include the UE group delay and do not include the BS group delay (the "N" branch from 630), the method 600 can proceed to 640 to determine the UE position via an absolute RTT-based positioning procedure. When the multiple RTTs do not include the group delay, this means that each RTT is an actual RTT (e.g., (t4'-t1')-(t3'-t2')). In other words, when the RTT does not include the group delay, the group delay has been taken into account.

[0123] Figure 7 An example process is shown at 640 performed by a network node to implement a positioning technique based on absolute RTT. It should be noted that if the RTT is an actual RTT, the concern about overestimation of the actual distance is reduced. Therefore, at 710, the network node may determine an absolute RTT set based on multiple RTTs. The absolute RTT set may include one or more absolute members. Each absolute member may correspond to one of the RTTs, i.e., one of the BSs. Each absolute member may represent an absolute distance between the UE and the corresponding BS calculated based on the RTT associated with the corresponding BS.

[0124] In one aspect, where the network node is a network entity, operation 710 may be performed by processing system 394, memory 396, and / or RTT positioning module 398, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a base station, operation 710 may be performed by processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 710 may be performed by processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0125] At 720, the network node may determine the UE location based on the absolute RTT set. For example, assuming that the physical location of the BS is known, each absolute distance may be converted into a circle (or sphere) of appropriate size centered at the associated BS. The UE location may then be determined based on the intersection of the circles (or spheres). It should be noted that many different procedures may be used to calculate the location of the intersection. For example, the location may be determined by involving the base station location coordinates ri and the corresponding UE-to-base station distance D between the UE and the i-th base station estimated by the RTT procedure i In another example, an iterative scheme can be used to find the position coordinate vector r that minimizes ||rr over all base stations 'i'. i |-D i |or||rr i | 2 -D i 2 |x| represents the distance of a point with coordinate vector x from the origin of the coordinate system used to describe the coordinate vector. The scope of the step described as "determining the intersection point of the circle (or sphere)" includes any such procedure.

[0126] In one aspect, where the network node is a network entity, operation 720 may be performed by processing system 394, memory 396, and / or RTT positioning module 398, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a base station, operation 720 may be performed by processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 720 may be performed by processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0127] It should be noted that the number of absolute members in the absolute RTT set need not equal the number of RTTs in the multiple RTTs. In most cases, three RTTs (producing three circles or spheres) may be required to narrow the UE position to a single position in two dimensions, and four RTTs (to produce four spheres) may be required to narrow the UE position to a single position in three dimensions. Although not absolutely necessary, additional RTTs can improve positioning accuracy.

[0128] Return to reference Figure 6, if it is determined that the multiple RTTs include UE group delay and / or BS group delay (from the middle "Y" branch of 630), then in one aspect, method 600 can proceed to 650 to determine the UE position by differential RTT-based positioning. Unlike absolute RTT-based positioning techniques, differential RTT-based positioning techniques are less sensitive to the presence of group delays. This is because the effect of the group delay of one RTT is at least partially offset by the group delay of another RTT.

[0129] Figure 8 An example process is shown performed by a network node to implement a differential RTT based positioning technique at 650. Broadly, differential RTT based positioning can be described as determining a UE location based on differences in RTTs between multiple RTTs.

[0130] At 810, the network node may determine a reference BS among the plurality of BSs. In one aspect, where the network node is a network entity, operation 810 may be performed by the processing system 394, the memory 396, and / or the RTT positioning module 398, any or all of which may be considered as a means for performing the operation. In one aspect, where the network node is a base station, operation 810 may be performed by the processing system 384, the memory 386, and / or the RTT positioning module 388, any or all of which may be considered as a means for performing the operation. In one aspect, where the network node is a UE, operation 810 may be performed by the processing system 332, the memory 340, and / or the RTT positioning module 342, any or all of which may be considered as a means for performing the operation.

[0131] At 820, the network node may determine a differential RTT set based on multiple RTTs. The differential RTT set may include one or more differential members. Each differential member may correspond to one of the RTTs, that is, one of the BSs other than the reference BS. Each differential member may represent a differential distance calculated based on the difference between the RTT associated with the reference BS and the RTT associated with the corresponding BS. More specifically, "differential member" represents the amount of d(UE, node 1)-d(UE, node 2), where d(UE, node N) is the distance between the UE and node N (e.g., a base station). One of node 1 and node 2 may be a reference node, which means that it is selected as one of the two nodes of all differential members. In one aspect, where the network node is a network entity, operation 820 may be performed by the processing system 394, the memory 396, and / or the RTT positioning module 398, any or all of which may be considered as a component for performing the operation. In one aspect, where the network node is a base station, operation 820 may be performed by processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 820 may be performed by processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0132] At 830, the network node may determine the UE position based on the differential RTT set. For example, assuming that the physical location of the BS is known, each differential distance based on a pair of BSs means that for the case of two-dimensional positioning, the UE is located on a hyperbola with the locations of the two BSs as the focus. Subsequently, the UE position on the two-dimensional plane can be determined from the intersection of the hyperbolas. In the case of three-dimensional positioning, the hyperbola is replaced by a hyperbolic surface obtained by rotating the hyperbola around an axis passing through the focus, and the UE position is obtained as the intersection of these hyperbolas. As described above for the case of the intersection of a circle (or sphere) when using absolute RTT, many different programs can be used to calculate the intersection of hyperbolas (hyperboloids), and the scope of the present disclosure includes any such program. In one aspect, where the network node is a network entity, operation 830 may be performed by a processing system 394, a memory 396, and / or an RTT positioning module 398, any or all of which may be considered as a component for performing the operation. In one aspect, where the network node is a base station, operation 830 may be performed by processing system 384, memory 386, and / or RTT positioning module 388, any or all of which may be considered as means for performing the operation. In one aspect, where the network node is a UE, operation 830 may be performed by processing system 332, memory 340, and / or RTT positioning module 342, any or all of which may be considered as means for performing the operation.

[0133] It should be noted that the number of differential members in the differential RTT set does not need to be equal to the number of RTTs in the multiple RTTs. In most cases, four RTTs (generating three hyperbolas) may be required to narrow the UE position to a single position in two dimensions, and five RTTs (generating four hyperbolas) may be required to narrow the UE position to a single position in three dimensions. Although not absolutely necessary, additional RTTs can improve accuracy. More specifically, in the case of only two hyperbolas on a plane, there may be two intersections. The third hyperbola can eliminate the ambiguity between these two points. The number of hyperbolas is one less than the number of RTTs because each hyperbola corresponds to the difference between two RTTs. It should be noted that the hyperbola to be used should correspond to an independent differential member, that is, in the case of three nodes, there are three RTTs (e.g., a, b, c), and three differential members, ab, ac, and bc, can be formed. However, only two of them are useful because the third is derived from the other two, for example, bc=(ac)-(ab).

[0134] Recall that differential RTT based positioning is advantageous because the inter-gNodeB synchronization and group delay requirements can be relaxed. The trade-off is that one of the observations (the RTT of the reference BS) is lost in differential RTT based positioning techniques. However, the trade-off cost can be minimal when the RTT exceeds the required minimum.

[0135] As mentioned above, positioning techniques based on differential RTT are less sensitive to the presence of group delay than techniques based on absolute RTT. Figure 6 , the middle Y branch from 630 to 650 indicates an aspect in which a differential RTT-based positioning technique is used whenever the multiple RTTs include a group delay (ie, the measured RTT).

[0136] Although the differential RTT based positioning procedure is less sensitive to group delay, it may not be completely insensitive. When there is a difference in group delay among multiple RTTs, inaccuracies are introduced in calculating the UE position. It should be noted that the UE group delay in the RTT may not matter. This is because the UE group delay in the RTT is cancelled out when differential is employed. However, the BS group delay may cause some concern because different BSs may have different BS group delays.

[0137] Therefore, in another aspect, if the multiple RTTs include UE group delay and / or BS group delay (from the left "Y" branch of 630), the method 600 can proceed to 660 to determine whether the group delays in the multiple RTTs are "similar enough" so that the inaccuracy introduced due to the difference in group delays is tolerable. If it is determined in 660 that the group delays (and especially the BS delays) are similar enough, the network node can proceed to 650 to perform differential RTT-based positioning.

[0138] Box 660 includes decision boxes 662, 664, and 666. The network node may perform any combination of these boxes (in conjunction or separately) to determine whether to proceed to 650. In one aspect, the group delay parameter received from the UE or serving BS at 620 may include a group delay difference parameter indicating the difference in group delays between multiple BSs. More specifically, the required parameter is the difference between the group delays included in different RTT reports (corresponding to different base stations). Each group delay includes a component from the UE and a component from the base station. The UE may indicate the UE component. If the UE uses a similar configuration (such as similar beams, antenna panels, bandwidth, etc.), the difference in the UE component is likely to be small / ignorable for two RTT measurements. For the base station component, comparisons need to be made between different base stations, so reporting its group delay is more challenging. One way is for each base station to indicate its own parameters, such as its maximum group delay and the expected variance / uncertainty of the group delay, which is then converted into a group delay difference parameter by the positioning entity. The indicated parameters may be, for example, a brand and model type indication of the base station, because the group delay may be similar for two base stations of the same brand and model. Another option for the base stations is to exchange these parameters between them (eg, over an X2 or Xn interface), and one base station combines, calculates and reports these group delay difference parameters to the positioning entities of itself and one or more of its neighbors.

[0139] At 662, the network node may determine whether the difference indicated by the group delay difference parameter is within a threshold difference, which may represent a maximum tolerable group delay difference. The threshold difference may be predetermined and / or dynamically set during operation based on, for example, a requested positioning accuracy. If 662 is applied, it can be said that when the UE and / or BS group delay is included in a plurality of RTTs, and when the difference is within the threshold difference, a differential RTT-based positioning procedure is performed.

[0140] In another aspect, the group delay parameters or RTT-related measurements (such as Rx-Tx timing differences) received from the UE or serving BS at 620 may include a group delay uncertainty parameter indicating the level of uncertainty in the group delay between the multiple BSs. This value may be based on internal details of how the RF front end of the base station is implemented. For example, a base station that calibrates its group delay (as part of a factory manufacturing process or in flight) is likely to have less group delay uncertainty, and the uncertainty may depend on how long ago the calibration was performed.

[0141] At 664, the network node may determine whether the uncertainty indicated by the group delay uncertainty parameter is within a threshold uncertainty, which may represent a maximum tolerable group delay uncertainty. The threshold uncertainty may be predetermined and / or dynamically set during operation based on, for example, a requested positioning accuracy. If 664 is applied, it may be said that when the UE and / or BS group delay is included in a plurality of RTTs, and when the uncertainty is within the threshold uncertainty, a differential RTT-based positioning procedure is performed.

[0142] In another aspect, the group delay parameters received from the UE or serving BS at 620 may include one or more Tx / Rx configurations. Each Tx / Rx configuration may correspond to one of the multiple BSs and may include link parameters associated with a communication link established between the UE and the corresponding BS for determining the RTT therebetween. The link parameters may include any one or more of the Tx / Rx beam, the Tx power used, the bandwidth, the component carrier index, the frequency band, the RAT (e.g., LTE or NR), etc. Similar configurations may be associated with similar group delays. The configuration parameters may also include details such as the brand and / or model of the BS, e.g., the same model may be expected to have similar group delays. It should be noted that some parameters such as bandwidth may be known to the network and therefore do not need to be reported.

[0143] At 666, the network node may determine whether the difference between the Tx / Rx configurations (i.e., the difference between different RTT measurements) is within a threshold Tx / Rx configuration difference, which may represent a maximum tolerable configuration difference. The threshold Tx / Rx configuration difference may be predetermined and / or dynamically set during operation based on, for example, a requested positioning accuracy. If 666 is applied, it may be said that differential RTT-based positioning is performed when the UE and / or BS group delay is included in multiple RTTs and when the configuration difference between the Tx / Rx configurations is within the threshold Tx / Rx configuration difference.

[0144] In one aspect, where the network node is a network entity, operations 662, 664, and 666 may be performed by the processing system 394, the memory 396, and / or the RTT positioning module 398, any or all of which may be considered as means for performing the operations. In one aspect, where the network node is a base station, operations 662, 664, and 666 may be performed by the processing system 384, the memory 386, and / or the RTT positioning module 388, any or all of which may be considered as means for performing the operations. In one aspect, where the network node is a UE, operations 662, 664, and 666 may be performed by the processing system 332, the memory 340, and / or the RTT positioning module 342, any or all of which may be considered as means for performing the operations.

[0145] Fig. 9 An example method 900 performed by a UE to assist a network in determining a UE location according to aspects of the present disclosure is shown. At 910, the UE may determine a plurality of RTTs. For example, the UE may exchange RTT signals with a plurality of BSs and determine associated RTTs. If the BS provides its BS group delay, the UE may exclude the group delay from the RTT so that the plurality of RTTs are actual RTTs.

[0146] At 920, the UE may provide the multiple RTTs to the network node in an RTT report. If the UE knows the BS group delay, it may provide the actual RTT or the measured RTT and the BS group delay to the network node. Otherwise, it only provides the measured RTT. As described above, the network node may determine whether to perform a differential RTT-based positioning procedure to determine the UE position based on the difference in RTT between the multiple RTTs included in the RTT report.

[0147] At 930, based on the UE and / or BS group delay, the UE may provide a group delay parameter to the network node. The group delay parameter may indicate whether the group delay is included in the RTT reported at 920, and if so, which RTT / BS. The group delay parameter may be included in one or more positioning protocol signals to the network node. Examples of positioning protocol signals include LPP signaling. The group delay parameter may also include any one or more of an RTT type parameter, a group delay difference parameter, a group delay uncertainty parameter, and one or more Tx / Rx configurations.

[0148] It should be noted that although Fig. 9 The description is in the form of a UE, but one or more base stations may perform similar methods with a single UE.

[0149] Please note that it is not necessary to execute Figures 6 to 9 The blocks shown in the figure are not limited to the blocks shown in the figure, that is, some blocks may be optional. In addition, the numerical references of the blocks in these figures should not be considered as requiring that these blocks should be executed in a specific order. In fact, some blocks can be executed simultaneously.

[0150] In addition, although Figures 6 to 9 A network-centric (UE-assisted) approach is shown, but it is envisioned that if the UE itself has the required information for UE-based positioning (such as the location of the base station), the UE itself can implement differential RTT-based positioning to determine its own position. Similarly, the positioning calculations in the network-centric solution can be performed at the base station or core network entity.

[0151] Those skilled in the art will appreciate 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 magnetic particles, light fields or optical particles, or any combination thereof.

[0152] In addition, those skilled in the art will appreciate that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the various aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, various exemplary components, blocks, modules, circuits, and steps have been described above generally from their functional perspectives. Whether these functions are implemented in the form of hardware or software depends on the specific application and the design constraints imposed on the entire system. Those skilled in the art may implement the described functions in different ways for each specific application, but such implementation decisions should not be understood as causing a departure from the scope of this disclosure.

[0153] The various exemplary logical blocks, modules, and circuits described in conjunction with the various aspects disclosed herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination 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 in conjunction with a DSP core, or any other such configuration.

[0154] The methods, sequences and / or algorithms described in conjunction with the various aspects disclosed herein may be directly embodied 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), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disks, removable disks, CD-ROMs, 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.

[0155] In one or more exemplary aspects, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the function can be stored on a computer-readable medium or transmitted via a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, and communication media include any media that facilitates the transmission of computer programs from one place to another. Storage media can be any available media 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 any other medium that can be used to carry or store required program codes in the form of instructions or data structures and 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 technology (such as infrared, radio, and microwave), coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) are all included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, 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.

[0156] Although the foregoing disclosure illustrates exemplary 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 in the appended claims. The functions, steps, and / or actions of the methods claimed according to the various aspects of the present disclosure described herein need not be performed in any particular order. In addition, although elements of the present disclosure may be described or claimed in singular form, plural forms are also considered unless a limitation to the singular form is explicitly stated.

Claims

1. A method performed by a base station (BS), the method comprising: transmitting a first round trip time (RTT) measurement (RTTM) signal having a first transmit group delay; transmitting a second RTTM signal having a second transmit group delay; as well as Information indicative of the first transmit group delay and the second transmit group delay is sent to a receiving entity.

2. The method of claim 1 , wherein sending the information to the receiving entity comprises sending the information via a Long Term Evolution (LTE) Positioning Protocol (LPP) or a New Radio (NR) Positioning Protocol Annex (NRPPa) signal.

3. The method of claim 1, wherein sending the information to the receiving entity comprises sending the information to a location server (LS) or a location management function (LMF).

4. The method of claim 1, wherein sending the information to the receiving entity comprises sending information to a user equipment (UE).

5. A method performed by a base station (BS), the method comprising: measuring a first round trip time (RTT) response (RTTR) signal from a user equipment (UE); as well as A measurement of the first RTTR signal and information indicative of a receive group delay are sent to a network entity.

6. The method of claim 5, wherein sending the measurement of the first RTTR signal and the information indicating the reception group delay of the first RTTR signal to the network entity comprises sending the measurement value of the first RTTR signal and the information indicating the reception group delay of the first RTTR signal to a location server (LS) or a location management function (LMF).

7. A method performed by a user equipment (UE), the method comprising: measuring a first round trip time (RTT) measurement (RTTM) signal having a first transmit group delay; measuring a second RTTM signal having a second transmit group delay; receiving information indicating the first transmit group delay and the second transmit group delay from a base station; as well as A position is calculated based on the first RTTM signal, the second RTTM signal, the first transmit group delay, and the second transmit group delay.

8. The method of claim 7, wherein calculating the position comprises calculating the position based on the first RTTM signal, the second RTTM signal, the first transmit group delay, the second transmit group delay, a receive group delay of the first RTTM signal, and a receive group delay of the second RTTM signal.

9. A method performed by a user equipment (UE), the method comprising: measuring a first round trip time (RTT) measurement (RTTM) signal having a first receive group delay; measuring a second RTTM signal having a second receive group delay; as well as Measurements of the first RTTM signal and the second RTTM signal and information indicative of the first receive group delay and the second receive group delay are sent to a network entity.

10. The method according to claim 9, wherein sending the measurement of the first RTTM signal and the second RTTM signal, the information indicating the first reception group delay, and the information indicating the second reception group delay to the network entity includes sending the measurement of the first RTTM signal and the second RTTM signal, the information indicating the first reception group delay, and the information indicating the second reception group delay to a base station (BS), a location server (LS), or a location management function (LMF).

11. A method performed by a user equipment (UE), the method comprising: transmitting a first round trip time (RTT) measurement (RTTM) or RTT response (RTTR) signal having a first transmit group delay; transmitting a second RTTM or RTTR signal having a second transmit group delay; and Information indicative of the first transmit group delay and the second transmit group delay is sent to a network entity.

12. The method of claim 11, wherein sending information indicating the first transmit group delay and the second transmit group delay to the network entity comprises sending information indicating the first transmit group delay and the second transmit group delay to a location server (LS) or a location management function (LMF).

13. A method performed by a network entity, the method comprising: receiving, from a user equipment (UE), a measurement of a first round trip time (RTT) measurement (RTTM) signal and a measurement of a second RTTM signal; receiving an indication from a base station (BS) that a difference between a transmit group delay of the first RTTM signal and a transmit group delay of the second RTTM signal is within a group delay difference threshold; as well as The position of the UE is calculated based on the measurement of the first RTTM signal and the measurement of the second RTTM signal.

14. The method of claim 13, wherein the network entity comprises a location server (LS) or a location management function (LMF).

15. A method performed by a network entity, the method comprising: receiving, from a user equipment (UE), a measurement of a first round trip time (RTT) measurement (RTTM) signal and a measurement of a second RTTM signal; receiving, from the UE, an indication that a difference between a received group delay of the first RTTM signal and a received group delay of the second RTTM signal is within a group delay difference threshold; as well as The position of the UE is calculated based on the measurement of the first RTTM signal and the measurement of the second RTTM signal.

16. The method of claim 15, wherein the network entity comprises a location server (LS) or a location management function (LMF).

17. A method performed by a network entity, the method comprising: receiving a measurement of a round trip time (RTT) measurement (RTTM) signal transmitted by a base station (BS) from a user equipment (UE); receiving, from the BS, a measurement of an RTT response (RTTR) signal transmitted by the UE; receiving, from the UE, information indicating a transmit group delay of the RTTR signal and information indicating a receive group delay of the RTTM signal; receiving, from the BS, information indicating a transmit group delay of the RTTM signal and information indicating a receive group delay of the RTTR signal; and The position of the UE is calculated based on the measurement of the RTTM signal, the measurement of the RTTR signal, the transmit group delay of the RTTM signal, the receive group delay of the RTTM signal, the transmit group delay of the RTTR signal and the receive group delay of the RTTR signal.

18. The method of claim 17, wherein at least one of the following: receiving information indicating a transmit group delay of the RTTM signal, receiving information indicating a receive group delay of the RTTM signal, receiving information indicating a transmit group delay of the RTTR signal, or receiving information indicating a receive group delay of the RTTR signal, This includes receiving the indication via a Long Term Evolution (LTE) Positioning Protocol (LPP) or a New Radio (NR) Positioning Protocol Annex (NRPPa) signal.

19. A base station (BS), comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: transmitting, via the at least one transceiver, a first round trip time (RTT) measurement (RTTM) signal having a first transmit group delay; transmitting, via the at least one transceiver, a second RTTM signal having a second transmit group delay; as well as Information indicative of the first transmit group delay and the second transmit group delay is transmitted to a receiving entity via the at least one transceiver.

20. The BS according to claim 19, wherein: To send the information to the receiving entity, the at least one processor is configured to send the information via a Long Term Evolution (LTE) Positioning Protocol (LPP) or a New Radio (NR) Positioning Protocol Annex (NRPPa) signal.

21. The BS according to claim 19, wherein: In order to send the information to the receiving entity, the at least one processor is configured to send the information to a location server (LS) or a location management function (LMF).

22. The BS according to claim 19, wherein: To send the information to the receiving entity, the at least one processor is configured to send the information to a user equipment (UE).

23. A base station (BS), comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: measuring a first round trip time (RTT) response (RTTR) signal from a user equipment (UE); and A measurement of the first RTTR signal and information indicative of a receive group delay are sent to a network entity via the at least one transceiver.

24. The BS according to claim 23, wherein: In order to send the measurement of the first RTTR signal and the information indicating the reception group delay of the first RTTR signal to the network entity, the at least one processor is configured to send the measurement of the first RTTR signal and the information indicating the reception group delay of the first RTTR signal to a location server (LS) or a location management function (LMF).

25. A user equipment (UE), comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: measuring a first round trip time (RTT) measurement (RTTM) signal having a first transmit group delay; measuring a second RTTM signal having a second transmit group delay; receiving, via the at least one transceiver, information indicative of the first transmit group delay and the second transmit group delay from a base station; as well as A position is calculated based on the first RTTM signal, the second RTTM signal, the first transmit group delay, and the second transmit group delay.

26. The UE according to claim 25, wherein: In order to calculate the position, the at least one processor is configured to calculate the position based on the first RTTM signal, the second RTTM signal, the first transmit group delay, the second transmit group delay, the receive group delay of the first RTTM signal and the receive group delay of the second RTTM signal.

27. A user equipment (UE), comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: measuring a first round trip time (RTT) measurement (RTTM) signal having a first receive group delay; measuring a second RTTM signal having a second receive group delay; as well as The measurement of the first RTTM signal and the second RTTM signal, the first receive group delay, and the second receive group delay are sent to a network entity via the at least one transceiver.

28. The UE according to claim 27, wherein: In order to send measurements of the first RTTM signal and the second RTTM signal, the first reception group delay, and the second reception group delay to the network entity, the at least one processor is configured to send measurements of the first RTTM signal and the second RTTM signal, the first reception group delay, and the second reception group delay to a base station (BS), a location server (LS), or a location management function (LMF).

29. A user equipment (UE), comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: transmitting, via the at least one transceiver, a first round trip time (RTT) response (RTTR) signal having a first transmit group delay; transmitting, via the at least one transceiver, a second RTTR signal having a second transmit group delay; and Information indicative of the first transmit group delay and the second transmit group delay is sent to a network entity via the at least one transceiver.

30. The UE according to claim 29, wherein: In order to send information indicating the first transmit group delay and the second transmit group delay to the network entity, the at least one processor is configured to send information indicating the first transmit group delay and the second transmit group delay to a location server (LS) or a location management function (LMF).

31. A network entity comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receiving, via the at least one transceiver, from a user equipment (UE) a measurement of a first round trip time (RTT) measurement (RTTM) signal and a measurement of a second RTTM signal; receiving, via the at least one transceiver, from a base station (BS), an indication that a difference between a transmit group delay of the first RTTM signal and a transmit group delay of the second RTTM signal is within a group delay difference threshold; as well as The position of the UE is calculated based on the measurement of the first RTTM signal and the measurement of the second RTTM signal.

32. The network entity according to claim 31, wherein: The network entity includes a location server (LS) or a location management function (LMF).

33. A network entity comprising: Memory; at least one transceiver; as well as at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Receiving a first round trip time (RTT) from a user equipment (UE) via the at least one transceiver Measurement of the (RTTM) signal and measurement of the second RTTM signal; receiving, from the UE via the at least one transceiver, an indication that a difference between a received group delay of the first RTTM signal and a received group delay of the second RTTM signal is within a group delay difference threshold; as well as The position of the UE is calculated based on the measurement of the first RTTM signal and the measurement of the second RTTM signal.

34. The network entity according to claim 33, wherein: The network entity includes a location server (LS) or a location management function (LMF).

35. A network entity comprising: Memory; at least one transceiver; and at least one processor, the at least one processor being communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receiving, via the at least one transceiver, from a user equipment (UE) a measurement of a round trip time (RTT) measurement (RTTM) signal transmitted by a base station (BS); receiving, from the BS via the at least one transceiver, a measurement of a round trip time (RTT) response (RTTR) signal transmitted by the UE; receiving, from the UE via the at least one transceiver, information indicating a transmit group delay of the RTTR signal and information indicating a receive group delay of the RTTM signal; receiving, from the BS via the at least one transceiver, information indicating a transmit group delay of the RTTM signal and information indicating a receive group delay of the RTTR signal; as well as The position of the UE is calculated based on the measurement of the RTTM signal, the measurement of the RTTR signal, the transmit group delay of the RTTM signal, the receive group delay of the RTTM signal, the transmit group delay of the RTTR signal and the receive group delay of the RTTR signal.

36. The network entity according to claim 35, wherein: receiving information indicating a transmit group delay of the RTTM signal, receiving information indicating a receive group delay of the RTTM signal, receiving information indicating a transmit group delay of the RTTR signal, or receiving information indicating a receive group delay of the RTTR signal, This includes receiving the indication via a Long Term Evolution (LTE) Positioning Protocol (LPP) or a New Radio (NR) Positioning Protocol Annex (NRPPa) signal.

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