CN108702726B

CN108702726B - Positioning method for 5G system

Info

Publication number: CN108702726B
Application number: CN201680082560.3A
Authority: CN
Inventors: A·达维多夫
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2016-03-24
Filing date: 2016-09-08
Publication date: 2021-06-01
Anticipated expiration: 2036-09-08
Also published as: CN108702726A; WO2017164925A1

Abstract

A method of obtaining a User Equipment (UE) location with high accuracy in a cellular network is disclosed. Using both the measurement information and the new beam information, a positioning method operable within the UE performs observed time difference of arrival (OTDOA) or enhanced cell identification (E-CID) measurements using receive beamformed Positioning Reference Signals (PRS). Whether a UE or an enhanced node B base station (eNB), the new beam information includes an index of the beam, a beam pointing angle (in both the elevation domain and the azimuth domain) relative to a line of sight of the transmitting device's antenna, and a relative orientation of the device's antenna, where the relative orientation is obtained using a position sensor. The beam information and time of arrival measurements are used to determine the location of the UE or to improve its location accuracy.

Description

Positioning method for 5G system

Cross Reference to Related Applications

This application claims priority from united states provisional patent application No. 62/312,952 filed on 24/3/2016, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to beam, position location, observed time difference of arrival, sensors and other enhanced 911 issues under the third generation partnership project (3 GPP).

Background

The Evolved Packet Core (EPC) is the core network of the advanced mobile communication system. The EPC allows different Radio Access Technologies (RATs) to operate in an integrated manner. These wireless access technologies include first generation wireless Local Area Networks (LANs), second generation (2G) systems such as global system for mobile communications or GSM, third generation (3G) systems such as Universal Mobile Telecommunications System (UMTS), and fourth generation (4G) systems such as Long Term Evolution (LTE). LTE continues to evolve (e.g., LTE-advanced or LTE-a), and many new features are referred to as fifth generation (5G) technologies.

Fig. 1 is a basic architecture of an Evolved Packet System (EPS) 80. User Equipment (UE)50 (also referred to as a terminal) is connected to EPC 70 through an LTE access network referred to as E-UTRAN (short for evolved UMTS terrestrial radio access network) 44, and communicates with base stations referred to as evolved node bs (enbs) 40, which may collectively refer to one or more base stations and/or radio heads. The EPS 80 generally refers to a complete system consisting of the UE 50, the E-UTRAN 44, and the core network (EPC) 70. The EPC 70 is a packet-switched network in which the Internet Protocol (IP) is used for all transport services. The EPC is part of the third generation partnership project (3GPP) specifications.

The EPC 70 is comprised of a serving gateway (S-GW)30, a packet data network gateway (P-GW)32, a Mobility Management Entity (MME)34, and a Home Subscriber Server (HSS) 36. The EPC 70 is connected to the external network 38, which in this case comprises an internet protocol multimedia subsystem (IMS) 42. User data and signaling are independent, with user data occupying the user plane (solid line) and signaling occupying the control plane (dashed line).

In the united states and canada, "911" telephone numbers designed for emergency use were developed in 1968 and began to spread in the 1970 s and 1980 s. A person dials "911" on his/her telephone and the dispatcher provides services for the call, which may include dispatching police, fire, or other emergency personnel to the location of the caller. "enhanced 911" or "E911" refers to the feature where a 911 dispatcher automatically receives location information (if available) from a caller. Typically, for a fixed telephone, location information is available, while for a mobile device, no location information is provided to the dispatcher.

The Federal Communications Commission (FCC) requires that all mobile operators in the united states comply with the following E911 outdoor position location requirements:

67% of emergency calls should be located with an accuracy of 50 meters (m);

80% of emergency calls should be located with an accuracy of 150m (increasing to 90% in six years).

Location Based Services (LBS) involve determining the location of a device and may be useful to a 911 dispatcher. One satellite-based LBS is known as a Global Navigation Satellite System (GNSS). The Global Positioning System (GPS) and the global navigation satellite system (GLONASS) are two GNSS-based systems. Most LTE devices provide GNSS-based functionality.

However, the GNSS based LBS works well only when the line-of-sight (line-of-sight) between the UE and the satellite is good. If the satellite signals are blocked, the GNSS will not operate. Therefore, GNSS cannot work in dense urban environments and inside buildings.

The FCC now proposes to extend E911 to automatically provide location information to dispatchers when receiving calls from indoor locations. In addition, the FCC requires that vertical location information (z-axis) within 3 meters of the caller be provided for 67% of indoor locations (increasing to 80% in five years). Due to the higher received power of Radio Access Technology (RAT) signals relative to GNSS signals, RAT-based location services are beginning to receive greater attention in the industry to meet these requirements. GNSS alone is not sufficient to meet the new FCC requirements.

Therefore, a mechanism is needed to overcome the disadvantages of the prior art.

Drawings

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts throughout the several views, unless otherwise specified.

FIG. 1 is a diagram of an evolved packet system architecture under E-UTRAN access;

figure 2 illustrates mapping of position reference signals with one or two PBCH ports and with four PBCH ports for both normal and extended cyclic prefixes;

FIG. 3 illustrates an observed time difference of arrival (OTDOA) technique for determining the location of a device using three devices of known locations;

fig. 4 is a simplified diagram showing how the E-CID is improved by using multiple measurement results;

fig. 5 shows an architecture of network positioning under the long term evolution standard;

figure 6 shows a number of links established between an enhanced base station and a user equipment when beamforming is employed;

FIG. 7 is a simplified block diagram of a positioning method for facilitating user equipment position location, in accordance with some embodiments;

FIG. 8 is a diagram of calculating a difference between an elevation angle and an azimuth angle used for position location of a user equipment relative to an enhanced base station in the positioning method of FIG. 7, in accordance with some embodiments;

FIG. 9 is a diagram of a distance calculation between a user equipment and an enhanced base station used by the positioning method of FIG. 7, in accordance with some embodiments;

fig. 10 illustrates how the positioning method of fig. 7 utilizes multiple communication links and beam directions between a user equipment and a single enhanced base station, in accordance with some embodiments;

fig. 11 is a simplified block diagram of a UE capable of implementing the positioning method of fig. 7, in accordance with some embodiments.

Detailed Description

According to embodiments described herein, a method of obtaining a User Equipment (UE) location with high accuracy in a cellular network is disclosed. Positioning methods operable within a UE perform observed time difference of arrival (OTDOA) or enhanced cell identification (E-CID) measurements using receive beamformed Positioning Reference Signals (PRSs) using both measurement information and new beam information. Whether a UE or an enhanced node B base station (eNB), the new beam information includes an index of the beam, a beam pointing angle (in the elevation and azimuth domains) relative to a line of sight of the transmitting device's antenna, and a relative orientation of the device's antenna, where the relative orientation is obtained using a position sensor. The beam information and time of arrival measurements are used to determine the location of the UE or to improve its location accuracy. Measurements obtained from multiple communication links between the UE and the eNB enable more accurate location of the UE.

In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the subject matter described herein may be practiced. However, it is to be understood that other embodiments will become apparent to those of ordinary skill in the art upon reading this disclosure. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, as the scope of the subject matter is defined by the appended claims.

LTE based location services

Location Based Services (LBS) are familiar to many mobile device users, for map services, discovery of nearby friends, and other functions. LBS enables the location or position of a mobile device to be obtained by software that provides these functions.

Some LBS employ multilateration, which is a navigation technique based on measuring the difference in distance at a known time to two objects broadcasting signals at known locations. The resulting locations form a hyperbola. Additional measurements made using additional objects produce a second hyperbola that intersects the first hyperbola to enable determination of the position.

The current LTE standard supports three independent positioning technologies: assisted global navigation satellite system (A-GNSS), observed time difference of arrival (OTDOA), and enhanced cell identifier (E-CID). Combinations of these techniques may also be used.

Auxiliary global navigation satellite system (A-GNSS)

Global Navigation Satellite Systems (GNSS), such as GPS, are based on satellite-based position estimates. Most mobile devices include an integrated GNSS receiver. At least four satellites, each having an unobstructed line of sight to the UE, enable estimation of the UE's location. Using its GPS chip (GNSS receiver), the UE establishes a connection with the satellite. GPS operation is very time consuming and not available inside dense urban environments or buildings.

Assisted GNSS (a-GNSS) improves the reception of location information by the UE, since the serving eNB establishes an initial connection with the satellite and stores the obtained information. The eNB then provides the data to the GNSS receiver. The data includes almanac and/or ephemeris data. The almanac data contains coarse orbit parameters from all global navigation satellites and is not updated frequently. In contrast, ephemeris data uses clock correction to obtain very accurate position information, which is broadcast by each satellite every 30 seconds. The assistance data based position calculation may be performed by a network entity other than the UE. However, a-GNSS is problematic in-building and dense urban environments because line-of-sight satellite signals are not available at the UE.

Positioning Reference Signal (PRS)

In LTE Release 9, the positioning function is enhanced by introducing Positioning Reference Signals (PRS). Fig. 2 is a diagram of the mapping of PRSs in a resource block for both normal and extended cyclic prefixes, for one or two Physical Broadcast Channel (PBCH) antenna ports, and for four PBCH antenna ports (taken from 3GPP TS 36.211 Release 10.0.0Release 10, Section 6.10.4), respectively. In a downlink subframe configured for positioning reference signal transmission, PRS is transmitted on antenna port 6. PRS enable terminals (UEs) to perform measurements on one or more LTE cells (enbs) to estimate the geographic location of the terminal.

The PRS is defined by a bandwidth, an offset, a duration (number of consecutive subframes), and a periodicity. The PRS is configured to the UE via higher layer signaling by providing the following characteristics: a carrier index at which the PRS is transmitted, a PRS bandwidth, a number of consecutive subframes at which the PRS is transmitted, a PRS transmission periodicity/subframe offset, and a PRS muting sequence. The PRS bandwidth is smaller than the system bandwidth and the PRS is mapped around the carrier frequency. In general, PDSCH is not transmitted in a PRS configured subframe. The PRS may be muted to reduce inter-cell interference as needed.

The above-described a-GNSS is earlier than the implementation of positioning reference signals, but PRS is used for both OTDOA and E-CID location services, as described below.

Observation of time Difference of arrival (OTDOA)

OTDOA is similar to GPS and other a-GNSS based location services, but instead of obtaining measurements from satellites, a UE obtains measurements from enbs in its vicinity, including the base station with which the UE communicates (referred to as its serving eNB) and neighboring enbs.

Under OTDOA positioning techniques, a UE measures the time difference between the PRS transmitted by its serving eNB and the PRS at least two neighboring enbs. The UE calculates a Reference Signal Time Difference (RSTD) by measuring a time difference between the PRS of the neighbor cell and the PRS of its serving cell; a second time difference is measured between the PRS of a second neighboring cell and the PRS of its serving cell. Unlike GPS satellites that orbit the earth at high speed for computing position, the network knows the location of the eNB and this enables the UE position to be obtained relative to the eNB using these RSTDs.

Fig. 3 illustrates an OTDOA positioning technique. The UE 50 is closest to its serving eNB 40, but the neighboring enbs 40A and 40B are within range of the UE. UE gets from neighbor cell A (T) by measurement_{RX_NA}) And serving cell (T)_{RX_serving}) Receiving a time difference of PRS to calculate a first RSTD (RSTD)_N1) (ii) a UE slave neighbor cell B (T) by measurement_{RX_NB}) And serving cell (T)_{RX_serving}) Receiving a time difference of PRS to calculate a second RSTD (RSTD)_N2). Both measurement results are reported to the location server, which is based on the received measurement results RSTD_N1And RSTD_N2To calculate the UE position.

The network assists the UE by providing the relative transmission time difference of each neighboring cell with respect to the serving cell. A location server in the network knows the exact location of each eNB transmit antenna and can provide candidate neighbor cells to the UE, limiting the search space and increasing the speed at which measurements can be made.

Enhanced cell identifier (E-CID)

Another method for position estimation in LTE is enhanced cell ID (E-CID). Under this approach, the location of the UE is estimated based on the location of its serving eNB, which may be obtained by performing tracking area updates or by paging. Thus, the location of the UE relative to the eNB is known and is associated with the size of the cell coverage area of the eNB. To obtain more accurate information, additional measurements may be obtained as follows:

E-CID, estimating the distance to a single base station

E-CID, measuring distances to three base stations

E-CID, measuring angles of arrival (AoA) with at least two (or three) base stations.

The measurement results help to find the location of the UE within the cell with higher accuracy. The measurement may consist of Reference Signal Received Power (RSRP), time difference of arrival (TDOA), and Timing Advance (TA) or Round Trip Time (RTT) measurements from the serving eNB. RSRP is the average power of Resource Elements (REs) carrying PRSs over the entire bandwidth. TDOA is obtained by measuring the time of arrival of a synchronization signal (such as PRS) at physically separated locations. TA is the length of time it takes for a signal to arrive at the eNB from the UE. The commonly used TA measurements are: type 1, summing the eNB and UE receive-transmit time differences; and type 2, measurements made by the eNB during the UE random access procedure.

TA type 1 measurements correspond to RTT. For example, for type 1TA measurements, a summation of the receive-transmit time difference at the eNB (positive or negative) and the receive-transmit time difference at the UE (always positive) is made. The measurement results are reported to the location server, where the distance between the UE and the eNB is half the RTT multiplied by the speed of light.

In the first E-CID option, the location of the UE is obtained by estimating the distance of the UE from the serving eNB, whose location is known to the network. The estimate measures RSRP, TA, or RTT from the serving eNB. Thus, the first E-CID option obtains a circle (coarse position) around the eNB.

In the second E-CID option, RSRP, TA, or RTT is measured from each of the three enbs (where the network knows the location of each eNB). For the second E-CID option, the position accuracy is finer than a circle around the eNB and is instead a point within the cell.

The third option can be distinguished from the first two options in that the measurements are made by the eNB, not the UE. Two (or three) enbs, including the serving eNB, obtain angle of arrival (AoA) measurements to the network, where a combination of a location server, serving eNB, or eNB performs calculations, enabling the location of the UE to be obtained. Each of the two or three enbs estimates a direction in which the UE transmits using a linear array of equally spaced antenna elements. The PRS phase received from the UE at any two neighboring elements is rotated by an amount that depends on the angle of arrival, carrier frequency, and element spacing.

In the first and second options, the UE makes measurements and the measurements are based on RSRP, TA or RTT estimates. In a third option, the measurements are made directly by the eNB.

Fig. 4 is a simplified diagram showing how the E-CID is improved by using multiple measurement results. For simplicity, only one base station is shown. In case of using basic E-CID, the location of all UEs in the cell area is roughly known and it is basically a circle around the eNB; positioning the UE of the measurement distance from the eNB under the condition of E-CID plus RTT; in case of E-CID plus RTT plus AoA, the location of the UE can be obtained with the highest accuracy.

LTE architecture for location-based services

Fig. 5 illustrates an LTE-advanced location architecture 200 for location services. Many entities of the EPS 80 in fig. 1 are similarly found in the LTE location architecture 200, such as the S-GW 30, the P-GW 32, the MME 34, the eNB 40, and the UE 50. Additionally, location server 90 includes an evolved serving mobile location center (E-SMLC)52 and a secure user plane location (SULP) location platform (SLP)54 and is connected to eNB 40 through MME 34 or through serving gateway (S-GW)30 and packet data network gateway (P-GW) 32.

The UE 50 and eNB 40 may communicate with the location server 90 via the user plane (U-plane, solid line) or the control plane (C-plane, dashed line) in one of two ways. In the C-plane, LBS sessions are established and assistance data message exchanges are performed on control channels. C-plane signaling is considered more reliable and robust than U-plane signaling and can overcome network congestion in emergency situations. The LTE Positioning Protocol (LPP) is a protocol for C-plane LBS sessions. In the C-plane, the E-SMLC is a location server.

In the U-plane, the data link serves as a bearer for processing the LBS session and for transmitting the assistance data message. For example, map services use the U-plane due to large data transfers, since control channels typically do not support large amounts of data. For the U-plane, SLP 54 provides location services. SUPL is a positioning protocol defined by the open mobile alliance. The location server 90 is a physical or logical entity that collects measurement data and other location information from the UE 50 and/or eNB 40 and assists in measuring and estimating the location of the UE.

5G MIMO

A 5G Multiple Input Multiple Output (MIMO) system will rely on the beamforming concept for signal transmission and reception. Beamforming is the shaping of the entire antenna beam in the direction of the receiver. Beamforming uses multiple antennas (such as antenna arrays) to control the direction of signals by weighting the amplitude and phase of each antenna signal. The reference signals transmitted by the eNB may be beamformed using multiple antennas to provide adequate transmission coverage in a particular beam direction. Beamforming may be performed in the digital and/or analog domain.

The UE may also apply beamforming on the receive antennas and based on measurements from received reference signals, may select and indicate to the eNB the most dominant set of beams, which is preferable from a communication perspective. As a result, multiple possible communication links may be established between the UE and the eNB, where each communication link may be associated with a transmit and receive beam pair.

The most preferred communication link may correspond to a line-of-sight path or to a first order reflection path of the channel. Fig. 6 shows one case of a possible communication link between the eNB 40 and the UE 50.

Beams

1, 2 and 3 are transmitted by the eNB in the general direction of the UE, with receive beams 4, 5 and 6 at the UE for receiving PRS signals. Objects 58 and 68, which may be buildings, walls, or other physical objects that may reflect signals. Link 1 is a line of sight (LOS) path, where beam 4 at UE 50 receives PRS signals transmitted via beam 1 at eNB 40. The PRS signal transmitted via beam 2 at the eNB is reflected by object 58 such that a first order reflected path (link 2) is received via beam 5 at the UE. The PRS signal transmitted via beam 3 at the eNB is reflected by object 68, also causing a first order reflected path (link 3) to be received via beam 6 at the UE.

Positioning method 100

Fig. 7 is a simplified block diagram of a positioning method 100 for enabling a UE in a cellular network to coordinate with other entities in obtaining and transmitting location information of the UE. In some embodiments, the positioning method 100 is applicable to UEs that include new wireless features (e.g., 5G-capable mobile devices). The positioning method 100 involves processing at the serving eNB 40, UE 50, and location server 90, all of which are part of a cellular network.

Furthermore, in some embodiments, the positioning method 100 is part of a global coordinate system. The global coordinate system is a coordinate system common to the UE and all enbs involved in UE positioning. Therefore, a global coordinate system is used in the context of beam directions. This enables the beam direction and beam angle to be defined from a common coordinate system.

For example, all beam directions may be measured in the azimuth domain relative to the north direction (which is common to the relevant eNB and UE). Similarly, the elevation direction can be measured with respect to the up-down direction (this should also be common for the relevant eNB and UE). For such a global coordinate system, in order to obtain the beam orientation, the device should know the orientation of the antenna array in the global coordinate system and the orientation of the beam in the local coordinate system of the antenna array. The beam orientation of the antenna array in the local coordinate system is typically known from the beamforming weights. The antenna array orientation in the global coordinate system may be obtained from sensor measurements (at the UE) or known in advance (e.g., at fixed locations in the eNB).

The positioning method 100 begins when the eNB 40 transmits positioning reference signals using beamforming 56 on one or more communication links. The UE implementing the positioning method 100 comprises a beam information calculation unit 60 and a measurement information calculation unit 74. In some embodiments, the UE uses the receive beamformed PRS 56 and the location sensor 64 to provide beam information 62 and measurement information 72 to a location server 90.

In some embodiments, the beam information 62 includes an index of the beam, a beam pointing angle (in both the elevation and azimuth domains) of the link relative to a line of sight of an antenna of the device (UE or eNB), and a line of sight direction of the antenna in the global coordinate system. In some embodiments, the position sensor 64 provides the orientation of the antenna array in a global coordinate system.

Fig. 8 shows the difference between the elevation and the azimuth. Elevation and azimuth define the position of an object relative to another object at a particular time. Elevation (also called attitude) is a measure of the angle between an object and the horizon of the viewer's position. In fig. 8, the elevation angle is the angle between the top of the eNB 40 relative to the horizon of the UE 50. Azimuth is the angle of an object around the horizon measured clockwise around the observer's horizon relative to the north position. In fig. 8, the azimuth angle is obtained by drawing a line between the eNB 40 and the UE 50 and then measuring the angle of the line with respect to north (N). These two angles, elevation and azimuth, are part of the beam information 62 that the UE 50 provides to the location server 90.

The beam information may also include the relative orientation of the device antenna in the global coordinate system. The position sensor 64 in the UE 50 is able to obtain the relative orientation of the antennas. A position sensor is a device capable of measuring the position of an object. The position sensors (which may comprise orientation sensors and/or magnetometers) measure the physical position of the device and may therefore provide information to the position server 90 regarding the pointing direction of the beams in the global coordinate system. The magnetometer measures the direction of the magnetic field at a point in space. The beam direction information and time of arrival measurements may be used to determine or improve the location accuracy of the UE. The orientation of the antennas of the eNB is typically fixed and may be determined during deployment.

The physical location of the device and the beam direction relative to the device corresponding to the link may be used to improve positioning accuracy in various ways. For example, by taking into account the beam angle of the link, the estimation of the distance to the transmitting device can be improved.

The simplified diagram of fig. 9 illustrates this improvement, consisting of the UE 50 and eNB 40, as previously described. The communication link d (where d ═ a + b) is a first order reflection path (see fig. 6) due to the presence of a physical object, and is indicated by a thick black line. For simplicity, consider the two-dimensional case. However, the positioning method 100 as described herein may be extended to three dimensions.

Based on time of arrival measurements using reference signals transmitted over the link, the propagation length d of the link can be estimated. By using the beam pointing angles β and γ corresponding to the link, the actual distance x between the UE and the eNB can be estimated as follows:

thus, with the beam directions at the eNB 40 and the UE 50 known, the distance x between the UE and the eNB can be calculated more accurately despite the presence of channel path reflections.

In other embodiments, multiple communication links and beam directions may also be used to constructively increase the effective number of measurement sources. Thus, each communication link may be considered an additional transmission source. Three communication links are shown in fig. 10, a line-of-sight link (link 1), a first order reflected path caused by object 58 (link 2), and a second first order reflected path caused by object 68 (link 3). The positioning method 100 treats the three links as coming from three transmitting base stations, which are called active enbs or virtual enbs. In some embodiments, the location of each active base station (eNB 40A and eNB 40B) is obtained from time of arrival measurements and beam angle information.

The utilization of the first order reflection path by the positioning method 100 is particularly useful in rural environments where the deployment of base stations is expensive and thus the distance between base stations may be long, so that the cells tend to be larger and the UE may not be able to detect neighboring cells.

Thus, the positioning method 100 enables the location server 90 to obtain the location of the UE 50 using PRS transmissions from a single transmission point over multiple communication links.

Operating environment

The various techniques, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, non-transitory computer-readable storage medium, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. The non-transitory computer-readable storage medium may be a computer-readable storage medium that does not include a signal. In the case of program code execution on programmable computers, the computing device may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and nonvolatile memory and/or storage elements can be RAM, EPROM, flash drives, optical drives, magnetic hard drives, solid state drives, or other media for storing electronic data. The nodes and wireless devices may also include transceiver modules, computer modules, processing modules, and/or clock modules or timer modules. One or more programs that may implement or utilize the various techniques described herein may use an Application Programming Interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.

It should be appreciated that many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays/programmable array logic/programmable logic devices or the like.

Modules may also be implemented in software for execution by various types of processors. An identifiable module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. These modules may be passive or active, including agents operable to implement the desired functionality.

Reference throughout this specification to "an example" or "an example" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in an example" or "in some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no element in such list should be construed as a de facto equivalent of any other element in the same list solely based on their presentation in a common group without any representation to the contrary. Additionally, various embodiments and examples of the present invention may be referenced herein along with alternatives to the various components thereof. It should be understood that these embodiments, examples, and alternatives are not to be construed as being virtually equivalent to one another, but are to be considered as separate and autonomous representations of the invention. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used herein, the term "circuitry" may refer to, be part of, or include: an ASIC, an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with, one or more software or firmware modules. In some embodiments, the circuitry may comprise logic that operates, at least in part, in hardware.

The embodiments described herein may be implemented into a system using suitably configured hardware and/or software. Fig. 11 illustrates exemplary components of a User Equipment (UE) device 800 for one embodiment that may implement the positioning method 100 described above. In some embodiments, UE device 800 may include application circuitry 802, baseband circuitry 804, Radio Frequency (RF) circuitry 806, front-end module (FEM) circuitry 808, and one or more antennas 810 coupled together at least as shown.

The application circuitry 802 may include one or more application processors. For example, the application circuitry 802 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to and/or may include a storage medium 812 or other type of memory/storage, and may be configured to: instructions stored in the memory/storage are executed to enable various applications and/or operating systems to run on the system.

The baseband circuitry 804 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Baseband circuitry 804 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of RF circuitry 806 and to generate baseband signals for the transmit signal path of RF circuitry 806. Baseband circuitry 804 may be connected with the application circuitry 802 for generating and processing baseband signals and controlling the operation of the RF circuitry 806. For example, in some embodiments, the baseband circuitry 804 may include a second generation (2G) baseband processor 804A, a third generation (3G) baseband processor 804B, a fourth generation (4G) baseband processor 804C, and/or other baseband processors 804D for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 7G, etc.). Baseband circuitry 804 (e.g., one or more of baseband processors 804A-D) may process various wireless control functions that enable communication with one or more wireless networks via RF circuitry 806. Wireless control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency offset, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 804 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 804 may include convolution, tail-biting convolution, turbo, viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments.

In some embodiments, the baseband circuitry 804 may include elements of a protocol stack, such as, for example, elements of the EUTRAN protocol, including, for example, Physical (PHY) elements, Medium Access Control (MAC) elements, Radio Link Control (RLC) elements, Packet Data Convergence Protocol (PDCP) elements, and/or Radio Resource Control (RRC) elements. A Central Processing Unit (CPU)804E of the baseband circuitry 804 may be configured to: elements of the protocol stack are run for signaling at the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 804F. The audio DSP 804F may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. In some embodiments, components of the baseband circuitry may be combined as appropriate in a single chip, a single chipset, or disposed on the same circuit board. In some embodiments, some or all of the constituent components of the baseband circuitry 804 and the application circuitry 802 may be implemented together, such as, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 804 may provide communications compatible with one or more wireless technologies. For example, in some embodiments, baseband circuitry 804 may support communication with E-UTRAN and/or other Wireless Metropolitan Area Networks (WMANs), Wireless Local Area Networks (WLANs), or Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry 804 is configured to support wireless communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 806 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 806 may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 806 may include a receive signal path that may include circuitry to down-convert RF signals received from FEM circuitry 808 and provide baseband signals to baseband circuitry 804. RF circuitry 806 may also include a transmit signal path that may include circuitry to upconvert baseband signals provided by baseband circuitry 804 and provide an RF output signal to FEM circuitry 808 for transmission.

In some embodiments, RF circuitry 806 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 806 may include a mixer circuit 806A, an amplifier circuit 806B, and a filter circuit 806C. The transmit signal path of RF circuitry 806 may include filter circuitry 806C and mixer circuitry 806A. RF circuitry 806 may further include synthesizer circuitry 806D for synthesizing the frequencies used by mixer circuitry 806A of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 806A of the receive signal path may be configured to: the RF signal received from FEM circuitry 808 is downconverted based on a synthesized frequency provided by synthesizer circuitry 806D. The amplifier circuit 806B may be configured to: the downconverted signal is amplified, and the filter circuit 806C may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to: unwanted signals are removed from the down-converted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 804 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, but this is not required. In some embodiments, mixer circuit 806A of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 806A of the transmit signal path may be configured to: the input baseband signal is upconverted based on a synthesized frequency provided by synthesizer circuit 806D to generate an RF output signal for FEM circuit 808. The baseband signal may be provided by baseband circuitry 804 and may be filtered by filter circuitry 806C. Filter circuit 806C may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, mixer circuit 806A of the receive signal path and mixer circuit 806A of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, mixer circuit 806A of the receive signal path and mixer circuit 806A of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, mixer circuit 806A of the receive signal path and mixer circuit 806A of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, mixer circuit 806A of the receive signal path and mixer circuit 806A of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuitry 806 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 804 may include a digital baseband interface to communicate with the RF circuitry 806.

In some dual-mode embodiments, separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 806D may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuit 806D may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.

Synthesizer circuit 806D may be configured to: the output frequency used by mixer circuit 806A of RF circuit 806 is synthesized based on the frequency input and the divider control input. In some embodiments, synthesizer circuit 806D may be a fractional N/N +1 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), but this is not required. The divider control input may be provided by the baseband circuitry 804 or the application processor 802, depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by the application processor 802.

Synthesizer circuit 806D of RF circuit 806 may include a divider, a Delay Locked Loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the divider may be a dual-mode divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to: the input signal is divided by N or N +1 (e.g., based on a carry) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay element may be configured to decompose the VCO period into N_dAn equal phase grouping, wherein N_dIs the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuit 806D may be configured to: the carrier frequency is generated as the output frequency, while in other embodiments the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and divider circuit to generate the carrier frequency relative to each other at the carrier frequencyThe signal has a plurality of signals with different phases. In some embodiments, the output frequency may be the LO frequency (f)_LO). In some embodiments, the RF circuitry 806 may include an IQ/polar converter.

FEM circuitry 808 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 810, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 806 for further processing. FEM circuitry 808 may further include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 806 for transmission by one or more of the one or more antennas 810.

In some embodiments, FEM circuitry 808 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a Low Noise Amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to RF circuitry 806). The transmit signal path of the FEM circuitry 808 may include: a Power Amplifier (PA) to amplify an input RF signal (e.g., provided by RF circuitry 806); and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 810).

In some embodiments, the UE device 800 may include additional elements, such as memory/storage, a display, a camera, sensors, and/or an input/output (I/O) interface.

In summary, the positioning method 100 of fig. 7 may be implemented in a first example by a computer-readable medium comprising instructions that, when executed by one or more processors of a User Equipment (UE), cause the UE to: establishing one or more communication links between a UE and an enhanced node b (eNB), wherein each link is associated with a beam pair at the UE and the eNB; receive beamformed Positioning Reference Signals (PRSs) over one or more established communication links; estimating a beam direction of the UE and the eNB for each of the one or more established communication links; obtaining time-of-arrival measurements of beamformed PRSs for each of one or more established communication links; and transmitting the beam direction and time of arrival measurements to a location server.

Further to the first example or any other example discussed herein, in a second example, the beam direction estimation comprises estimating an orientation of the UE in a global coordinate system.

Further to the second example or any other example discussed herein, in a third example, the beam direction estimation comprises estimating an orientation of the eNB in a global coordinate system.

Further to the second example or any other example discussed herein, in a fourth example, the orientation is obtained using a sensor disposed on the UE.

Further to the fourth example or any other example discussed herein, in a fifth example, the orientation comprises azimuth and elevation orientation information of the beam obtained at a time interval at which time of arrival measurements for the location are performed.

Further to the first, second, or third examples, or any other example discussed herein, in a sixth example, the beam direction estimation comprises estimating a beam orientation relative to the UE.

Further to any of the first to sixth examples or any other example discussed herein, in a seventh example, the beam direction includes an azimuth and an elevation of the beam of each communication link in the global coordinate system.

Further to the first example or any other example discussed herein, in an eighth example, wherein the time of arrival measurements are selected from the group consisting of: observed time difference of arrival (OTDOA), Timing Advance (TA), Round Trip Time (RTT), OTDOA plus TA, OTDOA plus RTT, TA plus RTT, and OTDOA plus TA plus RTT.

Moreover, the positioning method 100 of fig. 7 may be implemented in a ninth example by an apparatus of a User Equipment (UE) capable of processing beamformed Positioning Reference Signals (PRSs), the apparatus comprising: one or more antennas to receive beamformed PRSs over one or more communication links; a beam information calculation unit for estimating beam information including a beam direction of each of the one or more communication links and transmitting the beam information to the location server; a measurement information calculation unit to calculate measurement information including arrival times of the beamformed PRSs for each of the one or more communication links, and to transmit the measurement information to a location server, wherein the UE receives from the location server a UE location based on the beam information and the measurement information.

Further to the ninth example or any other example discussed herein, in a tenth example, the beam information includes a beam index for each of the one or more communication links.

Further to the ninth or tenth example or any other example discussed herein, in an eleventh example, the beam information includes a beam pointing angle in an azimuth direction.

Further to any of the ninth through eleventh examples or any other example discussed herein, in a twelfth example, the beam information includes a beam pointing angle in an elevation direction.

Further with respect to any of the ninth-twelfth examples or any other example discussed herein, in a thirteenth example, the beam information includes a relative orientation of the one or more antennas for each of the one or more communication links.

Further to the ninth example or any other example discussed herein, in a fourteenth example, the apparatus of the UE includes one or more location sensors for calculating the beam information.

Further to the fourteenth example or any other example discussed herein, in a fifteenth example, the position sensor comprises an orientation sensor.

Further to the fourteenth example or any other example discussed herein, in a sixteenth example, the position sensor comprises a magnetometer.

Further to the ninth example or any other example discussed herein, in a seventeenth example, the one or more communication links comprise a line-of-sight communication path, a first order reflected communication path, and a second first order reflected communication path.

Further to the thirteenth example or any other example discussed herein, in an eighteenth example, the one or more communication links comprise a first order reflection communication path, wherein the distance x between the UE and the enhanced node B is calculated using the following formula:

where the beam pointing angles β and γ correspond to the communication link and d is the first order reflection path of the communication link.

Furthermore, the positioning method 100 of fig. 7 may be implemented in a nineteenth example by machine readable memory comprising machine readable instructions to implement an apparatus as in any of the ninth through eighteenth examples or any other example discussed herein.

Furthermore, the positioning method 100 of fig. 7 may be implemented in a twentieth example by machine-readable memory comprising machine-readable instructions that, when executed, implement a method or apparatus as claimed in any of the examples discussed herein.

Further, the positioning method 100 of fig. 7 may be implemented in a twenty-first example by a computer-readable medium comprising instructions that, when executed by one or more processors of an enhanced node b (eNB), cause the eNB to: establishing one or more communication links between a User Equipment (UE) and an eNB, wherein each link is associated with a beam pair at the UE and the eNB; receiving beamformed positioning reference signals over one or more established communication links; estimating a beam direction of the UE and the eNB for each of the one or more established communication links; measuring a time of arrival (ToA) of a beamformed positioning reference signal for each of one or more established communication links; and transmitting the beam direction and ToA measurements to a location server.

Further to the twenty-first example or any other example discussed herein, in a twenty-second example, the instructions cause the eNB to estimate an orientation of the UE transmitting the beamformed positioning reference signal.

Further to the twenty-second example or any other example discussed herein, in a twenty-third example, the instructions cause the eNB to estimate an orientation in an azimuth domain and an elevation domain.

Further to the twenty-third example or any other example discussed herein, in a twenty-fourth example, the instructions cause the eNB to measure the ToA using one or more of: time difference of arrival (OTDOA), Timing Advance (TA), and Round Trip Time (RTT) are observed.

While the foregoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and that numerous modifications and variations will be apparent therefrom without departing from the principles and concepts of the invention. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

Claims

1. A method of User Equipment (UE) positioning using beamformed Positioning Reference Signals (PRSs), the method comprising:

establishing a plurality of communication links between the UE and a base station, wherein each of the plurality of communication links established is associated with a beam pair at the UE and the base station;

receive a beamformed PRS over the established plurality of communication links;

estimating a beam direction of the UE and the base station for each of the plurality of established communication links;

making time-of-arrival measurements of the beamformed PRS for each of the plurality of established communication links; and

transmitting the beam direction and time of arrival measurements to a location server, wherein the UE receives a UE location from the location server based on the beam direction and the time of arrival measurements.

2. The method of claim 1, wherein beam direction estimation comprises estimating an orientation of the UE in a global coordinate system.

3. The method of claim 1, wherein beam direction estimation comprises estimating an orientation of the base station in a global coordinate system.

4. The method of claim 2, wherein the orientation is obtained using a sensor disposed on the UE.

5. The method of claim 4, wherein the orientation comprises azimuth and elevation orientation information of beams obtained at time intervals at which time-of-arrival measurements for a location are performed.

6. The method of claim 1, 2 or 3, wherein beam direction estimation comprises estimating a beam orientation relative to the UE.

7. The method of any of claims 1-3, wherein the beam direction comprises an azimuth and an elevation of a beam of each of the established plurality of communication links in a global coordinate system.

8. The method of claim 1, wherein the time of arrival measurements are selected from the group consisting of: and observing the arrival time difference OTDOA, the timing advance TA, the round trip time RTT, the OTDOA plus TA, the OTDOA plus RTT, the TA plus RTT and the OTDOA plus TA plus RTT.

9. An apparatus of a user equipment, UE, capable of processing beamformed positioning reference signals, PRSs, the apparatus comprising:

one or more antennas to receive beamformed PRSs over a plurality of communication links between the UE and a base station, wherein each of the plurality of communication links is associated with a beam pair at the UE and the base station;

a beam information calculation unit for:

estimating beam information comprising a beam direction for each of the plurality of communication links; and is

Transmitting the beam information to a location server;

a measurement information calculation unit for:

calculating measurement information comprising a time of arrival of a beamformed PRS for each of the plurality of communication links; and is

Sending the measurement information to the location server;

wherein the UE receives a UE location based on the beam information and the measurement information from the location server.

10. The apparatus of the UE of claim 9, wherein the beam information comprises a beam index for each of the plurality of communication links.

11. The apparatus of the UE of claim 9 or 10, wherein the beam information comprises a beam pointing angle in an azimuth direction.

12. The apparatus of the UE of any of claims 9-10, wherein the beam information comprises a beam pointing angle in an elevation direction.

13. The apparatus of the UE of any of claims 9-10, wherein the beam information comprises a relative orientation of the one or more antennas for each of the plurality of communication links.

14. The apparatus of the UE of claim 9, further comprising:

one or more position sensors for calculating beam information.

15. The apparatus of the UE of claim 14, wherein the one or more location sensors comprise an orientation sensor.

16. The apparatus of the UE of claim 14, wherein the one or more location sensors comprise a magnetometer.

17. The apparatus of the UE of claim 9, wherein the plurality of communication links comprise:

a line-of-sight communication path;

a first order reflected communication path; and

the second first order reflects the communication path.

18. The apparatus of the UE of claim 13, wherein the plurality of communication links comprise:

a first order reflected communication path;

wherein the distance x between the UE and the base station is calculated using the following formula:

where the beam pointing angles β and γ correspond to the communication link and d is the first order reflected communication path of the communication link.

19. A machine-readable memory comprising machine-readable instructions that when executed perform operations performed by the apparatus of any of claims 9-18.

20. A machine readable memory comprising machine readable instructions which, when executed, implement the method of any of claims 1-8.