GB2581480A

GB2581480A - Position of user equipment

Info

Publication number: GB2581480A
Application number: GB1902051.0A
Authority: GB
Inventors: Qi Yinan
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-02-14
Filing date: 2019-02-14
Publication date: 2020-08-26
Anticipated expiration: 2039-02-14
Also published as: EP3918854A4; GB201902051D0; KR20200099500A; EP3918854A1; GB2581480B

Abstract

Determining a position of a user equipment, UE, in a network. A method comprises measuring, via a downlink, DL, and/or an uplink, UL, a first measurement of a set of measurements, and further comprises estimating, at least in part, the position of the UE using the first measurement of the set of measurements. Optionally, the measurement comprises measuring via the downlink: reference signal time difference, RSTD, between neighbour transmission / reception points, TRP, and reference TRP; a RSTD between a first beam and a reference beam; RSTD between a first positioning reference signal, PRS, and a reference PRS, or between a first PRS set and reference PRS set; and/or a PRS reference signal received power, RSRP. The measurement may also comprise measuring via the uplink: a relative time of arrival, RTOA, of sounding reference signals, SRS; a PRS RSRP; a TRP receive - transmit time difference; and/or a UE receive - transmit time difference. A quality metric for a receive – transmit time difference, RSTD or RTOA may be calculated, possibly using RSRP.

Description

Position of user equipment

Field

The present invention relates to positioning and measurement in networks, such as cellular or telecommunication networks, for example, but not exclusively, to Fifth Generation (5G) or New Radio (NR) networks.

Background to the Invention

Demand for mobile services is growing rapidly and one of the fastest growing segments is Location Based Services (LBS), primarily driven by two major requirements: emergency services and commercial applications. In response to these needs, second and third generation networks CDMA, GSM, CDMA) have added support for several positioning technologies, which vary in their accuracy and Time to First Fix (TTFF) performance. 3GPP Release 9 for LTE defines support for positioning technologies: Extended Cell ID (ECID), Assisted Global Navigation Satellite System (A-GNSS), Observed Time Different Of Arrival (OTDOA) and LTE Positioning Protocol (LPP), a new positioning protocol. A new reference signal, i.e., positioning reference signal (PRS) has been defined in LTE. Further in Release-11, Uplink Observed Time Different of Arrival (UTDOA) has been adopted using SRS measurement. 3GPP Release-15 defines support for some RAT-independent positioning techniques, such as Real Time Kinematic (RTK) GNSS, to improve the accuracy of LTE positioning.

However, there remains a need to improve an accuracy, a precision, an efficiency and/or a speed for determining the position of a user equipment, UE, to reduce a latency for determining the position of the UE and/or enable respective positions of a plurality of such UEs to be determined at higher number densities.

Summary of the Invention

It is one aim of the present invention, amongst others, to provide a method of determining a position of a user equipment, UE, in a network which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere. For example, the present invention may provide a method of determining a position of a user equipment, UE, in a network so as to improve an accuracy, a precision, an efficiency and/or a speed for determining the position, to reduce a latency for determining the position of the UE and/or enable respective positions of a plurality of such UEs to be determined at higher number densities.

According to a first aspect, there is provided a method of determining a position of a user equipment, UE, in a network, the method comprising: measuring, via a downlink, DL, and/or an uplink, UL, a first measurement of a set of measurements; and estimating, at least in part, the position of the UE using the first measurement of the set of measurements.

According to a second aspect, there is provided a user equipment, UE, or a TRP transmission / reception point, TRP arranged to implement the method according to the first aspect.

According to a third aspect, there is provided a network comprising a UE and/or a TRP according to the second aspect.

According to a fourth aspect, there is provided a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by a TRP transmission / reception point, TRP, and/or a user equipment, UE, cause the TRP and/or the UE device to perform a method according to the first aspect.

Detailed description of the Invention

According to the present invention there is provided a method of determining a position of a user equipment, UE, in a network as set forth in the appended claims. Also provided are a TRP transmission / reception point, TRP, a user equipment, UE, a network comprising a TRP and/or a UE and a computer-readable storage medium. Other features of the invention will be apparent from the dependent claims, and the description that follows.

Terms and definitions Generally, terms and definitions given in 3GPP TR 21.905 apply.

Transmission / Reception Point (TRP): A set of geographically co-located transmit antennas for one cell, part of one cell or one PRS-only TRP. TRPs can include base station (ng-eNB or gNB) antennas, remote radio heads, a remote antenna of a base station, an antenna of a PRS-only TRP, etc. One cell can be formed by one or multiple transmission points. For a homogeneous deployment, each transmission point may correspond to one cell.

PRS-only TRP: A TRP which only transmits PRS signals for PRS-based TBS positioning for EUTRA and is not associated with a cell.

Location Measurement Unit: A typical cell site will include an LMU in order to support network based location services. The LMU is responsible for taking specific radio interface measurements, typically under the control of a SMLC (Serving Mobile Location Centre).

As used in this document, the suffixes "-based" and "-assisted" refer respectively to the node that is responsible for making the positioning calculation (and which may also provide measurements) and a node that provides measurements (but which does not make the positioning calculation). Thus, an operation in which measurements are provided by the UE to the LMF to be used in the computation of a position estimate is described as "UE-assisted" (and could also be called "LMF-based"), while one in which the UE computes its own position is described as "UE-based".

Abbreviations Generally, abbreviations given in 3GPP TR 21.905 apply.

5GC 5G Core Network 5GS 5G System AoA Angle of Arrival AMF Access Management Function AP Access Point BDS BeiDou Navigation Satellite System BSSID Basic Service Set Identifier CID Cell-ID (positioning method) E-SMLC Enhanced Serving Mobile Location Centre E-CID Enhanced Cell-ID (positioning method) ECEF Earth-Centered, Earth-Fixed ECI Earth-Centered-Inertial EGNOS European Geostationary Navigation Overlay Service E-UTRAN Evolved Universal Terrestrial Radio Access Network FR1 Frequency Range 1 (450 MHz -6,000 MHz) FR2 Frequency Range 2 (24,250 MHz -52,600 MHz) GAGAN GPS Aided Geo Augmented Navigation GLONASS GLObal'naya NAvigatsionnaya Sputnikovaya Sistema (Engl.: Global Navigation Satellite System) GMLC Gateway Mobile Location Center GNSS Global Navigation Satellite System GPS Global Positioning System HESSID Homogeneous Extended Service Set Identifier LOS LoCation Services LMF Location Management Function LMU Location Measurement Unit LPP LTE Positioning Protocol MBS Metropolitan Beacon System MO-LR Mobile Originated Location Request MT-LR Mobile Terminated Location Request NG-C NG Control plane NG-AP NC Application Protocol NI-LR Network Induced Location Request NL Notification Log NRPPa NR Positioning Protocol A OTDOA Observed Time Difference Of Arrival PDU Protocol Data Unit PRS Positioning Reference Signal (for E-UTRA) QZSS Quasi-Zenith Satellite System RRM Radio Resource Management RSSI Received Signal Strength Indicator SBAS Space Based Augmentation System SET SUPL Enabled Terminal SLP SUPL Location Platform SSID Service Set Identifier SUPL Secure User Plane Location TADV Timing Advance TBS Terrestrial Beacon System TP Transmission Point TRP Transmission / Reception Point (a TRP comprises a TP) UE User Equipment WAAS Wide Area Augmentation System WGS-84 World Geodetic System 1984 Network Generally, in Universal Mobile Telecommunications System (UMTS) and 3GPP Long Term Evolution (LTE), UE devices allow users to access network services. In other words, a UE device is any device used by a user to communicate on a network. The UE device may be, for example, a device comprising a transmitter and a receiver or a transceiver, such as a mobile telephone or a laptop computer equipped with a mobile broadband adapter. The user may be a human user or a non-human user, for example a vehicle or infrastructure. The UE device may connect to or communicate with or via an access point (AP) for example a Universal Terrestrial Radio Access Network (UTRAN) access point such as a base station Node B (Node B or NB) and/or an evolved base station Node B (eNodeB or eNB and/or a gNodeB (gNB).

That is, the UE device may transmit data to and/or receive data from the access point, as described below. Furthermore, the device may connect to or communicate with or via another such UE device.

The TRP comprises and/or is an access point, for example a UTRAN access point. It should be understood that an UTRAN access point may be a conceptual point within the UTRAN performing radio transmission and reception. The UTRAN access point may be associated with one specific cell. That is, there may exist one UTRAN access point, for example a TRP, for each cell. The UTRAN access point may be the UTRAN-side end point of a radio link. In other words, the TRP may define a cell.

It should be understood that a cell may be a radio network object that may be uniquely identified by the UE device from a cell identification that is broadcast over a geographical area from one UTRAN access point. A cell may be in either Frequency Division Duplex (FDD) or Time Division Duplex (TDD) mode.

It should be understood that a sector may be a sub-area of a cell. All sectors within the cell may be served by the same access point. A radio link within the sector may be identified by a single logical identification belonging to the sector.

Reference signals NR seeks to minimize always-on transmissions to enhance network energy efficiency and ensure forward compatibility. In contrast to LTE, reference signals in NR are transmitted only when necessary. The four main reference signals are the demodulation reference signal (DMRS), phase-tracking reference signal (PTRS), sounding reference signal (SRS) and channel-state information reference signal (CSI-RS).

DMRS is used to estimate the radio channel for demodulation. DMRS is UE device-specific, may be beamformed, confined in a scheduled resource block, and transmitted only when necessary, both in downlink (DL) and uplink (UL). To support multiple-layer multiple input, multiple output (MIMO) transmission, multiple orthogonal DMRS ports may be scheduled, one for each layer. Orthogonality is achieved by frequency division multiplexing (FDM), time division multiplexing (TDM) and code division multiplexing (CDM). For low-speed scenarios, DMRS uses low density in the time domain. However, for high-speed scenarios, the time density of DMRS is increased to track fast changes in the radio channel.

As described previously, phase tracking reference signals (PTRS) were introduced in New Radio (NR) to enable compensation of oscillator phase noise. Typically, phase noise increases as a function of oscillator carrier frequency. A degradation caused by phase noise in an orthogonal frequency-division multiplexing (OFDM) signal is an identical phase rotation of all the subcarriers, known as common phase error (CPE). PTRS may be used at high carrier frequencies (such as mmWave) to mitigate phase noise. PTRS has low density in the frequency domain and high density in the time domain, since the phase rotation produced by CPE is identical for all subcarriers within an OFDM symbol. PTRS is user equipment (UE) device-specific, confined in a scheduled resource block (RB) and may be beamformed. The number of PTRS ports may be lower than the total number of DMRS ports, and orthogonality between PTRS pods is achieved by means of FDM. PTRS is configurable depending on the quality of the oscillators, allocated BW, carrier frequency, OFDM subcarrier spacing, and modulation and coding schemes used for transmission.

The SRS is transmitted in UL to perform CSI measurements mainly for scheduling and link adaptation. For NR, SRS may be used for reciprocity-based precoder design for massive MIMO and UL beam management. The approach for CSI-RS is similar.

Method of determining a position of a UE in a network According to a first aspect, there is provided a method of determining a position (i.e. a geographic position) of a user equipment, UE, in a network, the method comprising: measuring, via a downlink, DL, and/or an uplink, UL, a first measurement of a set of measurements; and estimating, at least in part, the position of the UE using the first measurement of the set of measurements.

In this way, the position of the UE may be estimated with improved accuracy, precision, efficiency and/or speed, with reduced latency and/or enable respective positions of a plurality of such UEs to be determined at higher number densities, compared with conventional methods of position determination Generally, positioning functionality provides a means a determine a geographic position and/or a velocity of the UE, based on measuring radio signals. The position information may be requested by and reported to a client (e.g. an application) associated with the UE, or by a client within or attached to the core network. The position information may be reported in standard formats, such as those for cell-based or geographical co-ordinates, together with the estimated errors (uncertainty) of the position and velocity of the UE and, if available, the positioning method (or the list of the methods) used to obtain the position estimate.

Generally, it should be possible for the majority of the UEs within a network to use the LCS feature without compromising the radio transmission or signalling capabilities of the NG-RAN.

An uncertainty of the position measurement may be network-implementation-dependent, for example at the choice of the network operator. The uncertainty may vary between networks as well as from one area within a network to another. The uncertainty may be hundreds of metres in some areas and only a few metres in others. In the event that a particular position measurement is provided through a UE-assisted process, the uncertainty may also depend on the capabilities of the UE.

The uncertainty of the position information may be dependent on the method used, the position of the UE within the coverage area and/or the activity of the UE. Several design options of the NG-RAN system (e.g., size of cell, adaptive antenna technique, pathloss estimation, timing accuracy, ng-eNB and gNB surveys) may allow the network operator to choose a suitable and cost-effective UE positioning method for their market.

There are many different possible uses for the positioning information. The positioning functions may be used internally by the 5GS, by value-added network services, by the UE itself or through the network, and by "third party" services. The feature may also be used by an emergency service (which may be mandated or "value-added"), but the location service is not exclusively for emergencies.

Generally, for UE positioning in NG-RAN, the following assumptions apply: a. both TDD and FDD will be supported; b. the provision of the UE Positioning function in NG-RAN and 5GC is optional through support of the specified method(s) in the ng-eNB, gNB and the LMF; c. UE Positioning is applicable to any target UE, whether or not the UE supports LCS, but with restrictions on the use of certain positioning methods depending on UE capability (e.g. as defined within the LPP protocol); d. the positioning information may be used for internal system operations to improve system performance; e. the UE Positioning architecture and functions shall include the option to accommodate several techniques of measurement and processing to ensure evolution to follow changing service requirements and to take advantage of advancing technology.

Generally, determining the position of the UE involves two main steps: A. signal measurement; and B. position estimation and optional velocity computation based on the measurements.

Generally, the signal measurements may be made by the UE or by the serving ng-eNB or gNB. The basic signals measured for terrestrial position methods are typically the LTE radio transmissions; however, other methods may make use of other transmissions such as general radio navigation signals including those from Global Navigation Satellites Systems (GNSSs).

Generally, the position estimation and optional velocity computation may be made by the UE and/or by the LMF, for example by the network such as a TRP in the network.

In one example, the measuring is by (i.e. performed by) the UE. In one example, the measuring is by the network, for example a TRP transmission! reception point, TRP, a gNB, or a LMU, for example co-located with the gNB, in the network. For example, if the measuring is via the DL, the measuring may be by the UE and/or the network, for example a TRP transmission / reception point, TRP, or a gNB in the network. For example, the UE may perform the measuring and provide the first measurement and/or the set of measurements to the network, tor example a TRP or a gNB, for the estimating thereby. Additionally and/or alternatively, the UE may perform the measuring and the estimating. Subsequently, the UE may provide the estimated position to the network, for example a TRP or a gNB. For example, if the measuring is via the UL, the measuring may be performed by the network, for example a TRP transmission / reception point, TRP, a gNB and/or a LMU, for example co-located with the gNB, in the network. The network may provide the first measurement and/or the set of measurements thereto and/or to the UE.

In one example, the estimating is by (i.e. performed by) the UE. In one example, the estimating is by the network, for example a TRP transmission / reception point, TRP, or a gNB in the network. In one example, the estimating is by the UE and by the network, for example a TRP transmission / reception point, TRP, or a gNB in the network.

Described herein are specific methods of measuring via the DL and the UL, as itemized here and as listed below: Measuring via DL 1. RSTD between a neighbour TRX and a reference TRP 2. RSTD between a first beam and a reference beam 3. RSTD between a first PRS resource and a reference PRS resource 4. RSRP 5. SINR Measuring via UL 6. RTOA of SRS 7. PRS-RSRP 8. gNB Rx-Tx time difference 9. UE Rx-Rx time difference It should be understood that these specific methods of measuring are not mutually exclusive. That is, one or more of these specific methods of measuring may be performed, for example simultaneously and/or successively, by the UE and/or by the network, for example a TRP or gNB therein. In other words, hybrid positioning using multiple of these methods is supported.

Particularly, any two or more of these specific methods of measuring may be combined. For example, measuring may be via the DL and/or via the UL, while two or more of the specific methods of measuring via the DL and/or via the UL may also be combined. Furthermore, measuring the first measurement of the set of measurements for these specific methods may be measuring the Nth measurement of the set of measurements, where N refers respectively to the respective specific methods ito 9 above, notwithstanding that the specific methods may be ordered in any order. In this way, an accuracy, a precision, an efficiency and/or a speed for determining the position may be further improved, a latency for determining the position of the UE further reduced and/or respective positions of a plurality of such UEs to be determined at higher number densities further enabled. Furthermore, these specific methods may be additionally and/or alternatively combined with conventional methods of position determination, such as network-assisted GNSS methods, observed time difference of arrival (OTDOA) positioning, enhanced cell ID methods, barometric pressure sensor positioning, WLAN positioning, Bluetooth (RTM) positioning and/or terrestrial beacon system (TBS) positioning, thereby further supporting hybrid methods of positioning.

Measuring via DL 1. RSTD between a neighbour TRX and a reference TRP In one example, measuring the first measurement comprises measuring, via the DL, a first reference signal time difference, RSTD, between a neighbour TRP transmission / reception point, TRP, and a reference TRP.

That is, the first RSTD may be defined with respect to TRPs/gNBs.

It should be understood that the first measurement is thus the first RSTD. In one example, the neighbour TRP is the TRP most proximal to the UE. In one example, the reference TRP is a predetermined TRP, for example predetermined for the network and/or for the neighbour TRP.

It should be understood that the neighbour TRP and/or the reference TRP may be respectively a neighbour gNB and/or a reference gNB.

In one example, the relative timing difference (i.e. the first RSTD) between the neighbour gNB/TRP j and the reference gNB/TRP i is defined as: TSubframeRxj TSubframeRm where: Tsui:Eft-0.R.] is the time when the UE receives the start of one subframe from cell j; and TsubframeRxi is the time when the UE receives the corresponding start of one subframe from cell i that is closest in time to the subframe received from cell].

In one example, for frequency range 1 (FR1), a reference point for the observed subframe time difference is an antenna connector of the UE.

It should be understood that the reference point, as described generally herein, is the point in the radio frequency, RF, chain where the measurement is performed. Generally, in a radio receiver circuit, the RF front end is a generic term for all the circuitry between a receiver's antenna input up to and including the mixer stage.

In one example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on a combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver (Rx) branch.

2. RSTD between a first beam and a reference beam In one example, measuring the first measurement comprises measuring, via the DL, a second reference signal time difference, RSTD, between a first beam and a reference beam, optionally wherein the first beam and the reference beam are associated with (for example, belong to, transmitted by) the same or different TRPs.

That is, the second RSTD may be defined with respect to beams.

In one example, the relative timing difference (i.e. the second RSTD) between the first beam] and the reference beam i is defined as: TsubframeRxj TSubframeRxi where: TsubframeR>g is the time when the UE receives the start of one subframe from beam j; and TsubframeRre is the time when the UE receives the corresponding start of one subframe from beam i that is closest in time to the subframe received from beam].

In one example, for frequency range I (FR1), the reference point for the observed subframe time difference is the antenna connector of the UE.

In one example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on the combined signal from antenna elements corresponding, for example of the UE, to a given (i.e. predetermined) receiver branch.

3. RSTD between a first PRS resource and a reference PRS resource In one example, measuring the first measurement comprises measuring, via the DL, a third reference signal time difference, RSTD, between a first positioning reference signal, PRS, resource of a set of PRS resources and a reference PRS resource of a set of reference PRS resources.

In one example, measuring the first measurement comprises measuring, via the DL, a fourth reference signal time difference, RSTD, between a first positioning reference signal, PRS, resource set and a reference PRS resource set.

That is, the third RSTD may be defined with respect to PRS resources and/or resource sets.

In one example, the relative timing difference (i.e. the third RSTD) between the first PRS resource and/or resource set] and the reference PRS resource and/or resource set i is defined as: TSubframeRxj TSubframeRA where: TSubframeR>g is the time when the UE receives the start of one subframe from the first PRS resource and/or resource set]; and TSubframeRxi is the time when the UE receives the corresponding start of one subframe from the first PRS resource and/or resource set i that is closest in time to the subframe received from PRS resource and/or resource set j.

In one example, for frequency range 1 (FR1), the reference point for the observed subframe time difference is the antenna connector of the UE.

In one example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on the combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

4. RSRP In one example, measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, reference signal received power, RSRP In one example, the PRS reference signal received power (PRS-RSRP) is defined as the linear average over power contributions On [W]) of resource elements of antenna port(s) of the UE that carry PRS reference signals configured for RSRP measurements within the considered measurement frequency bandwidth in the configured PRS occasions.

In one example, PRS reference signals transmitted on a specific antenna port i are used for measuring the PRS-RSRP.

In one example, if PRS-RSRP is used for L1-RSRP, the PRS transmitted on one or more specific antenna ports i, j is used for PRS-RSRP determination.

In one example, for intra-frequency PRS-RSRP measurements, if a measurement gap is not configured, the UE constrains the measuring of the PRS resource(s) within the active downlink bandwidth part.

In one example, for frequency range 1 (FR1), the reference point for the PRS-RSRP is the antenna connector of the UE.

In one example, for frequency range 2 (FR2), the PRS-RSRP is measured based on the combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

5. SINR In one example, measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, signal-to-noise and interference ration, SINR.

In one example, the PRS signal-to-noise and interference ratio (PRS-SINR), is defined as a linear average over a power contribution On [W]) of resource elements carrying PRS reference signals divided by a linear average of a noise and interference power contribution On [W]) over the resource elements carrying PRS reference signals within the same frequency bandwidth.

In one example, PRSs transmitted on a specific antenna port shall be used for the PRS-SINR determination.

In one example, the UE constrains measuring of the PRS resource(s) within the active downlink bandwidth part.

In one example, for frequency range 1 (FR1), the reference point for the PRS-SINR is the antenna connector of the UE.

In one example, for frequency range 2 (FR2), the PRS-SINR is measured based on a combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

Measuring via UL 6. RTOA of SIRS In one example, measuring the first measurement comprises measuring, via the UL, a relative time of arrival, RTOA, of a sounding reference signal, SRS.

Generally, OTDOA positioning methods makes use of the measured timing of downlink signals received from multiple TRPs, comprising eNBs, ng-eNBs and PRS-only TRPs, at the UE. The UE measures the timing of the received signals using assistance data received from the positioning server, and the resulting measurements are used to locate the UE in relation to the neighbouring TRPs.

In contrast, in this example, the first measurement comprises measuring, via the UL, the RTOA of the SRS.

In one example, the UL Relative Time of Arrival (RTOA) TUL-RTOA is the beginning of subframe containing the SRS received in TRP/gNB/LMU j, relative to a configurable reference time, which may be configured by upper layers, for example.

In one example, the reference point for the UL relative time of arrival RTOA is the RX antenna connector of the TRP/gNB/LMU node if a location measurement unit (LMU) has a separate RX antenna or shares a RX antenna with a gNB/TRP. In one example, the reference point for the UL relative time of arrival RTOA is the gNB/TRP antenna connector if a LMU is integrated in gNB/TRP.

7. PRS-RSRP In one example, measuring the first measurement comprises measuring, via the UL, a positioning reference signal, PRS, reference signal received power, RSRP (also known as UL PRS-PSRP).

In one example, the UL PRS (for example, SRS) reference signal received power (UL PRSRSRP), is defined as the linear average over the power contributions On [W]) of the resource elements of the antenna port(s) that carry UL PRS configured for RSRP measurements within the considered measurement frequency bandwidth in the configured UL PRS occasions.

In one example, for UL PRS-RSRP determination, PRS reference signals transmitted on a specific antenna port i shall be used.

In one example, if the UL PRS-RSRP is used for L1-RSRP, the UL PRS transmitted on one or more specific antenna ports I,] is used for UL PRS-RSRP determination.

In one example, for frequency range 1 (FR1), the reference point for the UL PRS-RSRP is an antenna connector of a, for example receiving, TRP or gNB in the network.

In one example, for frequency range 2 (FR2), the UL PRS-RSRP is measured based on a combined signal from antenna elements corresponding to a given receiver branch of a, for example receiving, TRP or gNB in the network.

8. gNB Rx-Tx time difference In one example, measuring the first measurement comprises measuring, via the UL, a g node B, gNB, receive -transmit (Rx-Tx) time difference.

In one example, the gNB Rx -Tx time difference k is defined as: TOB-RX,k TgNISTX where: TgNB-RX,k is the k-th gNB received timing of uplink radio frame #i, defined by the first or the strongest detected path in time.

In one example, for frequency range 1 (FR1), the reference point for TgNB.RXk is the Rx antenna connector.

In one example, for frequency range 2 (FR2), the reference point for TgNB-RX,k is the combined signal from antenna elements corresponding to a given receiver branch.

In one example, TgNB-TX,k is the k-th gNB transmit timing of downlink radio frame #i.

In one example, for frequency range 1 (FR1), the reference point for TgmB_Tx k is the Tx antenna connector, for example of the UE.

In one example, for frequency range 2 (FR2),the reference point for TgNB-TX,k is the combined signal from antenna elements corresponding to a given transmission branch, for example of a TRP or a gNB.

9. UE Rx-Rx time difference In one example, measuring the first measurement comprises measuring, via the UL, a UE receive -transmit (Rx-Tx) time difference.

In one example, the UE Rx -Tx time difference k is defined as: TUE-RX k TUE-TX where: TuEdix k is the UE received timing of downlink radio frame #i from the k-th gNB, defined by the first or the strongest detected path in time.

In one example, for frequency range 1 (FR1), the reference point for TuE_Rx k shall be the Rx antenna connector of the UE.

In one example, for frequency range 2 (FR2), the reference point for TgNB_Rx,k shall be the combined signal from antenna elements corresponding to a given receiver branch of the UE.

In one example, TuEsrxx is the transmit timing of uplink radio frame #i to the k-th gNB.

In one example, for frequency range 1 (FR1), the reference point for TuEsix k is the Tx antenna connector of the UE.

In one example, for frequency range 2 (FR2), the reference point for TUE-TX,k is the combined signal from antenna elements corresponding to a given transmission branch of the UE.

Quality metrics In one example, the method comprises determining a quality metric for a reference signal time difference, RSTD, a UE receive -transmit time difference and/or a reference signal time difference, RTOA, optionally using a reference signal received power, RSRP.

In one example, the method comprises determining the quality metric for the reference signal time difference, RTOA, using the reference signal received power, RSRP.

In one example, the method comprises determining the quality metric for the UE receive -transmit time difference, using the reference signal received power, RSRP.

In one example, the method comprises determining the quality metric using an UL RSRP, for example for NR UL PRS.

Reporting In one example, the method comprises reporting the quality metric.

In one example, the quality metric (for example, a FRS-RSRP quality metric) is always reported.

In one example, the quality metric is derived from other signals, for example a SS-RSRP.

In one example, the quality metric is reported when necessary, for example based on a triggering mechanism, and/or configured by upper layers, for example LPP/RRC/MAC CE.

In one example, the triggering mechanism comprises and/or is a low signal reception strength and/or an accuracy error.

In one example, a periodicity of the reporting is the same or different from a PRS periodicity, for example K times the PRS periodicity, where K is configured by upper layers, for example LPP/RRC/MAC CE.

UE and TRP According to the second aspect, there is provided a user equipment, UE, or a TRP transmission / reception point, TRP (or gNB) arranged to implement the method according to the first aspect.

Network According to the third aspect, there is provided a network comprising a UE and/or a TRP according to the third aspect.

In one example, an architecture of the network is as described in ETSI TS 138 305 V15.1.0 (2018-10).

CRM

According to the fourth aspect, there is provided a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by a TRP transmission / reception point, TRP, and/or a user equipment, UE, cause the TRP and/or the UE device to perform a method according to the first aspect.

Definitions Throughout this specification, the term "comprising" or "comprises" means including the component(s), unit(s), module(s), feature(s) or integer(s) specified but not to the exclusion of the presence of other components, units, modules, features or integers.

The term "consisting or or "consists or means including the component(s), unit(s), module(s), feature(s) or integer(s) specified but excluding other components, units, modules, features or integers.

Whenever appropriate, depending upon the context, the use of the term "comprises" or "comprising" may also be taken to include the meaning "consists essentially of' or "consisting essentially of', and also may also be taken to include the meaning "consists of or "consisting of'.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

Brief description of the drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which: Figure 1 schematically depicts an example of UE positioning architecture for NG-RAN; Figure 2 schematically depicts a method of location service support for the architecture of Figure 1; and Figure 3 schematically depicts a method according to an exemplary embodiment.

Detailed Description of the Drawings

Figure 1 schematically depicts an example of UE positioning architecture for NG-RAN.

The UE may make measurements of downlink signals from NG-RAN and other sources such as E-UTRAN, different GNSS and TBS systems, WLAN access points, Bluetooth beacons, and UE barometric sensors. The measurements to be made will be determined by the chosen positioning method. Furthermore, the gNB may make such measurements of downlink and uplink signals, mutatis mutandis.

The UE may also contain LCS applications, or access an LCS application either through communication with a network accessed by the UE or through another application residing in the UE. This LCS application may include the needed measurement and calculation functions to determine the UE's position with or without network assistance. The UE may also, for example, contain an independent positioning function (e.g. GPS) and thus be able to report its position, independent of the NG-RAN transmissions. The UE with an independent positioning function may also make use of assistance information obtained from the network.

The gNB is a network element of NG-RAN that may provide measurement information for a target UE and communicates this information to an LMF.

The ng-eNB is a network element of NG-RAN that may provide measurement results for position estimation and makes measurements of radio signals for a target UE and communicates these measurements to an LMF The ng-eNB makes its measurements in response to requests from the LMF (on demand or periodically).

An ng-eNB may serve several TRPs, including for example remote radio heads and PRS-only TRPs for PRS-based TBS positioning for E-UTRA.

The LMF manages the support of different location services for target UEs, including positioning of UEs and delivery of assistance data to UEs. The LMF may interact with the serving gNB or serving ng-eNB for a target UE in order to obtain position measurements for the UE, including uplink measurements made by an ng-eNB and downlink measurements made by the UE that were provided to an ng-eNB as part of other functions such as for support of handover.

The LMF may interact with a target UE in order to deliver assistance data if requested for a particular location service, or to obtain a location estimate if that was requested.

For positioning of a target UE, the LMF decides on the position methods to be used, based on factors that may include the LCS Client type, the required QoS, UE positioning capabilities, gNB positioning capabilities and ng-eNB positioning capabilities. The LMF then invokes these positioning methods in the UE, serving gNB and/or serving ng-eNB. The positioning methods may yield a location estimate for UE-based position methods and/or positioning measurements for UE-assisted and network-based position methods. The LMF may combine all the received results and determine a single location estimate for the target UE (hybrid positioning). Additional information like accuracy of the location estimate and velocity may also be determined.

Note 1: The gNB and ng-eNB may not always both be present.

Note 2: When both the gNB and ng-eNB are present, the NG-C interface may only present for one of them.

Figure 2 schematically depicts a method of location service support for the architecture of Figure 1.

Generally, to support positioning of a target UE and delivery of location assistance data to a UE with NG-RAN access in 5GS, location related functions are distributed as shown in the architecture in Figure 1, as detailed in TS 23.501. The overall sequence of events applicable to the UE, NG-RAN and LMF for any location service is shown in Figure 2.

Note that when the AMF receives a Location Service Request in case of the UE is in CM-IDLE state, the AMF performs a network triggered service request as defined in TS 23.502 in order to establish a signalling connection with the UE and assign a specific serving gNB or ng-eNB. The UE is assumed to be in connected mode before the beginning of the flow shown in the Figure 2 that is, any signalling that might be required to bring the UE to connected mode prior to step la is not shown. The signalling connection may, however, be later released (e.g. by the NG-RAN as a result of signalling and data inactivity) while positioning is still ongoing.

la. Either: some entity in the 5GC (e.g. GMLC) requests some location service (e.g. positioning) for a target UE to the serving AMF.

1 b. Or: the serving AMF for a target UE determines the need for some location service (e.g. to locate the UE for an emergency call).

2. The AMF transfers the location service request to an LMF.

3a. The LMF instigates location procedures with the serving ng-eNB or gNB in the NG-RAN -e.g. to obtain positioning measurements or assistance data.

3b. In addition to step 3a or instead of step 3a, for downlink positioning the LMF instigates location procedures with the UE -e.g. to obtain a location estimate or positioning measurements or to transfer location assistance data to the UE.

4. The LMF provides a location service response to the AMF and includes any needed results -e.g. success or failure indication and, if requested and obtained, a location estimate for the UE.

5a. If step la was performed, the AMF returns a location service response to the 5GC entity in step la and includes any needed results -e.g. a location estimate for the UE.

5b. If step lb occurred, the AMF uses the location service response received in step 4 to assist the service that triggered this in step lb (e.g. may provide a location estimate associated with an emergency call to a GMLC).

Location procedures applicable to NG-RAN occur in steps 3a and 3b in Figure 5.2-1 and are defined in greater detail in this specification. Other steps in Figure 2 are generally applicable only to the 5GC and are described in greater detail and in TS 23.502.

Steps 3a and 3b can involve the use of different position methods to obtain location related measurements for a target UE and from these compute a location estimate and possibly additional information like velocity.

Figure 3 schematically depicts a method according to an exemplary embodiment.

The method is of determining a position of a user equipment, UE, in a network.

At 531, a first measurement of a set of measurements is measured, via a downlink, DL, and/or an uplink, UL.

At S32, the position of the UE is estimated, at least in part, using the first measurement of the set of measurements.

The measuring of the first measurement may be as described below with respect to one or more of Examples 1 to 9.

Measuring via DL Example 1: RSTD between a neighbour TRX and a reference TRP In this example, measuring the first measurement comprises measuring, via the DL, a first reference signal time difference, RSTD, between a neighbour TRP transmission / reception point, TRP, and a reference TRP.

In this example, the relative timing difference (i.e. the first RSTD) between the neighbour gNB/TRP j and the reference gNB/TRP i is defined as: TSubframeRxj TSubframeRA where: TSubframeRxj is the time when the UE receives the start of one subframe from cell j; and TSubframeRxi is the time when the UE receives the corresponding start of one subframe from cell i that is closest in time to the subframe received from cell j.

In this example, for frequency range 1 (FR1), the reference point for the observed subframe time difference is an antenna connector of the UE.

In this example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on a combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver (Rx) branch.

Example 2: RSTD between a first beam and a reference beam In this example, measuring the first measurement comprises measuring, via the DL, a second reference signal time difference, RSTD, between a first beam and a reference beam.

That is, the second RSTD may be defined with respect to beams.

In this example, the relative timing difference (i.e. the second RSTD) between the first beam j and the reference beam i is defined as: TSubframeRxr TSubframeRxi where: TsubframeRN is the time when the UE receives the start of one subframe from beam]; and TsubframeRxi is the time when the UE receives the corresponding start of one subframe from beam i that is closest in time to the subframe received from beam].

In this example, for frequency range 1 (FR1), the reference point for the observed subframe time difference is the antenna connector of the UE.

In this example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on the combined signal from antenna elements corresponding, for example of the UE, to a given (i.e. predetermined) receiver branch.

Example 3: RSTD between a first PRS resource and a reference PRS resource In this example, measuring the first measurement comprises measuring, via the DL, a third reference signal time difference, RSTD, between a first positioning reference signal, PRS, resource of a set of PRS resources and a reference PRS resource of a set of reference PRS resources That is, the third RSTD may be defined with respect to PRS resources.

In this example, the relative timing difference (i.e. the third RSTD) between the first PRS resource and/or resource set] and the reference PRS resource and/or resource set i is defined as: TsubframeRN TsubframeRm where: TsubframeRN is the time when the UE receives the start of one subframe from the first PRS resource and/or resource set]; and TsubfraMeRm is the time when the UE receives the corresponding start of one subframe from the first PRS resource and/or resource set i that is closest in time to the subframe received from PRS resource and/or resource set j.

In this example, for frequency range 2 (FR2), the reference point for the observed subframe time difference is measured based on the combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

Example 4: RSRP

In this example, measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, reference signal received power, RSRP.

In this example, the PRS reference signal received power (PRS-RSRP) is defined as the linear average over power contributions (in [W]) of resource elements of antenna port(s) of the UE that carry PRS reference signals configured for RSRP measurements within the considered measurement frequency bandwidth in the configured PRS occasions.

In this example, PRS reference signals transmitted on a specific antenna port i are used for measuring the PRS-RSRP.

In this example, if PRS-RSRP is used for L1-RSRP, the PRS transmitted on one or more specific antenna ports i, j is used for PRS-RSRP determination.

In this example, for intra-frequency PRS-RSRP measurements, if a measurement gap is not configured, the UE constrains the measuring of the PRS resource(s) within the active downlink bandwidth part.

In this example, for frequency range 1 (FR1), the reference point for the PRS-RSRP is the antenna connector of the UE.

In this example, for frequency range 2 (FR2), the PRS-RSRP is measured based on the combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

Example 5: SINR

In this example, measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, signal-to-noise and interference ration, SINR.

In this example, the PRS signal-to-noise and interference ratio (PRS-SINR), is defined as a linear average over a power contribution (in [W]) of resource elements carrying PRS reference signals divided by a linear average of a noise and interference power contribution On [W]) over the resource elements carrying PRS reference signals within the same frequency bandwidth.

In this example, PRSs transmitted on a specific antenna port shall be used for the PRS-SINR determination.

In this example, the UE constrains measuring of the PRS resource(s) within the active downlink bandwidth part.

In this example, for frequency range 1 (FR1), the reference point for the PRS-SINR is the antenna connector of the UE.

In this example, for frequency range 2 (FR2), the PRS-SINR is measured based on a combined signal from antenna elements, for example of the UE, corresponding to a given (i.e. predetermined) receiver branch.

Measuring via UL Example 6: RTOA of SRS In this example, measuring the first measurement comprises measuring, via the UL, a relative time of arrival, RTOA, of a sounding reference signal, SRS.

In this example, the UL Relative Time of Arrival (RTOA) TuL_RT0A is the beginning of subframe containing the SRS received in TRP/gNB/LMU f, relative to a configurable reference time.

In this example, the reference point for the UL relative time of arrival RTOA is the RX antenna connector of the TRP/gNB/LMU node if a location measurement unit (LMU) has a separate RX antenna or shares a RX antenna with a gNB/TRP. In this example, the reference point for the UL relative time of arrival RTOA is the gNB/TRP antenna connector if a LMU is integrated in gNB/TRP.

Example 7: PRS-RSRP

In this example, measuring the first measurement comprises measuring, via the UL, a positioning reference signal, PRS, reference signal received power, RSRP (also known as UL PRS-PSRP).

In this example, the UL PRS (for example, SRS) reference signal received power (UL PRSRSRP), is defined as the linear average over the power contributions On [WI) of the resource elements of the antenna port(s) that carry UL PRS configured for RSRP measurements within the considered measurement frequency bandwidth in the configured UL PRS occasions.

In this example, for UL PRS-RSRP determination, PRS reference signals transmitted on a specific antenna port i shall be used.

In this example, if the UL PRS-RSRP is used for L1-RSRP, the UL PRS transmitted on one or more specific antenna ports I,] is used for UL PRS-RSRP determination.

In this example, for frequency range 1 (FR1), the reference point for the UL PRS-RSRP is an antenna connector of a, for example receiving, TRP or gNB in the network.

In this example, for frequency range 2 (FR2), the UL PRS-RSRP is measured based on a combined signal from antenna elements corresponding to a given receiver branch of a, for example receiving, TRP or gNB in the network.

Example 8: g NB Rx-Tx time difference In this example, measuring the first measurement comprises measuring, via the UL, a g node B, gNB, receive -transmit (Rx-Tx) time difference.

In this example, the gNB Rx -Tx time difference k is defined as: TgNB-RX,k TgNB-TX where: TgNa RX,k is the k-th gNB received timing of uplink radio frame #i, defined by the first or the strongest detected path in time.

In this example, for frequency range 1 (FR1), the reference point for TgNB-RX,k is the Rx antenna connector.

In this example, for frequency range 2 (FR2), the reference point for TgNB_Rx,k is the combined signal from antenna elements corresponding to a given receiver branch.

In this example, TQNBTXK is the k-th gNB transmit timing of downlink radio frame #i.

In this example, for frequency range 1 (FR1), the reference point for TgNB-TX,k is the Tx antenna connector, for example of the UE.

In this example, for frequency range 2 (FR2),the reference point for TgmB_Tx k is the combined signal from antenna elements corresponding to a given transmission branch, for example of the UE, a TRP or a gNB.

Example 9: UE Rx-Rx time difference In this example, measuring the first measurement comprises measuring, via the UL, a UE receive -transmit (Rx-Tx) time difference.

In this example, the UE Rx -Tx time difference k is defined as: TUE-RX k TUE-TX where: TuE-RX k is the UE received timing of downlink radio frame #i from the k-th gNB, defined by the first or the strongest detected path in time.

In this example, for frequency range 1 (FR1), the reference point for TuEk shall be the Rx antenna connector of the UE.

In this example, for frequency range 2 (FR2), the reference point for TgNB-RX,k shall be the combined signal from antenna elements corresponding to a given receiver branch of the UE.

In this example, TuE_Tx k is the transmit timing of uplink radio frame #i to the k-th gNB.

In this example, for frequency range 1 (FR1), the reference point for TuEsix,k is the Tx antenna connector of the UE.

In this example, for frequency range 2 (FR2), the reference point for TuE_Tx k is the combined signal from antenna elements corresponding to a given transmission branch of the UE.

Quality metrics Optionally, the method comprises determining a quality metric for a reference signal time difference, RSTD, a UE receive -transmit time difference and/or a reference signal time difference, RTOA, optionally using a reference signal received power, RSRP.

Optionally, the method comprises determining the quality metric for the reference signal time difference, RTOA, using the reference signal received power, RSRP.

Optionally, the method comprises determining the quality metric for the UE receive -transmit time difference, using the reference signal received power, RSRP.

Optionally, the method comprises determining the quality metric using an UL RSRP, for example for NR UL PRS.

ReportinQ Optionally, the method comprises reporting the quality metric.

Optionally, the quality metric (for example, a PRS-RSRP quality metric) is always reported.

Optionally, the quality metric is derived from other signals, for example a SS-RSRP.

Optionally, the quality metric is reported when necessary, for example based on a triggering mechanism, and/or configured by upper layers, for example LPP/RRC/MAC CE.

Optionally, the triggering mechanism comprises and/or is a low signal reception strength and/or an accuracy error.

Optionally, a periodicity of the reporting is the same or different from a PRS periodicity, for example K times the PRS periodicity, where K is configured by upper layers, for example LPP/RRC/MAC CE.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

In summary, the invention provides a method of determining a position of a user equipment, UE, in a network so as to improve an accuracy, a precision, an efficiency and/or a speed for determining the position, to reduce a latency for determining the position of the UE and/or enable respective positions of a plurality of such UEs to be determined at higher number densities. Also provided are a UE and/or TRP, a network and a CRM.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A method of determining a position of a user equipment, UE, in a network, the method comprising: measuring, via a downlink, DL, and/or an uplink, UL, a first measurement of a set of measurements; and estimating, at least in part, the position of the UE using the first measurement of the set of measurements.
2. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a first reference signal time difference, RSTD, between a neighbour TRP transmission / reception point, TRP, and a reference TRP.
3. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a second reference signal time difference, RSTD, between a first beam and a reference beam, optionally wherein the first beam and the reference beam are associated with the same or different TRPs.
4. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a third reference signal time difference, RSTD, between a first positioning reference signal, PRS, resource of a set of PRS resources and a reference PRS resource of a set of reference PRS resources.
5. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a fourth reference signal time difference, RSTD, between a first positioning reference signal, PRS, resource set and a reference PRS resource set.
6. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, reference signal received power, RSRP.
7. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the DL, a positioning reference signal, PRS, signal-to-noise and interference ration, SINR.
8. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the UL, a relative time of arrival, RTOA, of a sounding reference signal, SRS.
9. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the UL, a positioning reference signal, PRS, reference signal received power, RSRP.
10. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the UL, a TRP transmission / reception point, TRP, a g node B, gNB, and/or a location management unit, LMU, receive -transmit time difference.
11. The method according to any previous claim, wherein measuring the first measurement comprises measuring, via the UL, a UE receive-transmit time difference.
12. The method according to any previous claim, comprising determining a quality metric for a reference signal time difference, RSTD, a UE receive -transmit time difference and/or a reference signal time difference, RTOA, optionally using a reference signal received power, 15 RSRP.
13. The method according to claim 12, comprising determining the quality metric for the reference signal time difference, RTOA, using the reference signal received power, RSRP.
14. The method according to any of claims 12 to 13, comprising determining the quality metric for the UE receive -transmit time difference, using the reference signal received power, RSRP.
15. The method according to any of claims 12 to 14, comprising reporting the quality metric.
16. A user equipment, UE, or a TRP transmission / reception point, TRP arranged to implement the method of any previous claim.
17. A network comprising a UE and/or a TRP according to claim 16.
18. A tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by a TRP transmission / reception point, TRP, and/or a user equipment, UE, cause the TRP and/or the UE device to perform a method of any of claims 1 to 15.