WO2021006793A1

WO2021006793A1 - Optimized first-path detection using beamforming for positioning

Info

Publication number: WO2021006793A1
Application number: PCT/SE2020/050627
Authority: WO
Inventors: Satyam Dwivedi; Erik Stare; Niklas WERNERSSON
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2019-07-09
Filing date: 2020-06-16
Publication date: 2021-01-14

Abstract

Systems and methods are disclosed herein for first arrived path detection optimized for positioning using beamforming. Embodiments of a method performed by a wireless device and corresponding embodiments of a wireless are disclosed. In one embodiment, a method performed by a wireless device comprises, for each receive beam of a plurality of receive beams, receiving a signal on the receive beam via one or more signal propagation paths, detecting a first arrived path for the signal on the receive beam, and determining a Time of Arrival (TOA) of the signal on the receive beam via the first arrived path on the receive beam. The method further comprises determining a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

Description

OPTIMIZED FIRST- PA TH DETECTION USING BEAMFORMING FOR

POSI TIONING

Related Applications

This application claims the benefit of provisional patent application serial number 62/871 ,986, filed July 9, 2019, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Reid

The present disclosure relates to identifying a position (i.e., positioning) of a wireless device, such as a User Equipment (UE).

Background

User Equipment (UE) positioning is recognized as an important feature for Long Term Evolution (LTE) networks due to its potential for massive commercial applications such as, for example, intelligent transportation, entertainment, industry automation, robotics, remote operation, healthcare, smart parking, and so on, as well as its relevance to United States (US) Federal Communications Commission (FCC) Emergency 91 1 (E91 1 ) requirements.

Positioning in LTE is supported by the architecture in Figure 1 , with direct interactions between a UE and a location server (i.e., the Evolved Serving Mobile Location Center (E-SMLC)) via the LTE Positioning Protocol (LPP) . Moreover, there are also interactions between the E-SMLC and a base station (i.e., the enhanced or evolved Node B (eNB)) serving the UE via the LPP annex (LPPa) protocol, to some extent supported by interactions between the eNB and the UE via the Radio Resource Control (RRC) protocol.

The following positioning techniques are considered in LTE:

• Enhanced Cell Identity (ID)\ Essentially cell I D information to associate the UE to the serving area of a serving cell, and then additional information to determine a finer granularity position.

• Assisted Gobai Navigation Satellite System (GNSS)\ GNSS information retrieved by the UE, supported by assistance information provided to the UE from the E- SMLC. • Observed Time Difference Of Arrival (OTDOA)·. The UE estimates the time difference of reference signals from different base stations and sends the estimate to the E-SMLC for multilateration.

• Uplink Time Difference Of Arrival (UTDOA)\ The UE is requested to transmit a specific waveform that is detected by multiple location measurement units (e.g., an eNB) at known positions. These measurements are forwarded to the E-SMLC for multilateration.

One class of positioning methods is based on the principle of OTDOA, where a UE, for example, receives signals from at least three Base Stations (BSs) with known geographical locations. By pairwise determination of the OTDOA between received BS signals, the UE may estimate its position via so-called triangulation. The OTDOA between two BS signals is typically performed by comparing the estimated Channel I mpulse Response (CI R) of each received BS signal. The results of the OTDOA measurements may either be used by the UE or the network for estimation of the UE’s position.

For the UE to be able to estimate the OTDOA between two BSs, e.g. by estimating the CI R of each transmitted BS signal, the signals transmitted from the respective BSs may include a Positioning Reference Signal (PRS) that is a priori known to the UE, e.g. specified in the standard being used or by using demodulated and re modulated data instead of, or as a complement to, dedicated PRS signals.

By comparing the received PRS with a local version, e.g. via correlation, the UE may estimate the Cl R of the received PRS signal from a particular BS. By using the estimated CI Rs from at least three BSs, the UE (or network) may pairwise compare the OTDOAs between these BSs and use these estimates as a basis for an estimation of its position. The quality of this estimation is however affected by the Signal to

I nterference plus Noise Ratio (SI NR) of the received PRSs. A potential source of interference, when estimating a CI R from one BS, is the received PRSs from other BSs.

One way of reducing such interference is to allow different, especially adjacent, BSs to transmit orthogonal PRSs. I n Orthogonal Frequency Division Multiplexing (OFDM), such orthogonality may naturally be achieved by using different (non overlapping) sets of Resource Elements (REs) in an OFDM symbol for the PRSs originating from different BSs. To keep latency and/or overhead limited, some BSs in a network may, however, need to use overlapping sets of REs such that some REs are used by more than one BS. This introduces a degree of interference when a UE receives signals from several BSs on the same REs. Therefore, there is a trade-off between latency and overhead on the one hand and the degree of interference on the other hand. Overlapping REs are typically introduced in a systematic way by applying a frequency reuse technique, e.g. reuse-6 for LTE PRS. This means that, e.g., adjacent BSs are received with orthogonal PRSs, but BSs that are farther away, where the same REs are reused, are received with interference since they are non-orthogonal. To reduce the negative impact of such interference, some form of coding may be applied on non-orthogonal PRSs so that, e.g., the effect of the interferer is noise-like.

Summary

Systems and methods are disclosed herein for first arrived path detection optimized for positioning using beamforming. Embodiments of a method performed by a wireless device. I n one embodiment, a method performed by a wireless device comprises, for each receive beam of a plurality of receive beams, receiving a signal on the receive beam via one or more signal propagation paths, detecting a first arrived path for the signal on the receive beam where the first arrived path is a signal propagation path by which the signal is first received at the wireless device on the receive beam, and determining a Time of Arrival (TOA) of the signal on the receive beam via the first arrived path on the receive beam. The method further comprises determining a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams, wherein the minimum TOA is used in relation to positioning of the wireless device. I n this manner, accuracy of the estimated TOA is improved as compared to TOA estimation using a path determined in a manner that is optimized for data transmission.

I n one embodiment, the method further comprises setting an estimated TOA to the minimum TOA and reporting or employing the estimated TOA for positioning the wireless device.

I n one embodiment, the method further comprises fixing a receive beam of the wireless device to a receive beam from among the plurality of receive beams that corresponds to the minimum TOA. The method further comprises, for each transmit beam of one or more transmit beams detected at the wireless device on the fixed receive beam, receiving a signal for the transmit beam on the fixed receive beam via one or more signal propagation paths, determining a first arrived path for the signal for the transmit beam received at the wireless device on the fixed receive beam where the first arrived path is a signal propagation path by which the signal for the transmit beam is first received at the wireless device on the fixed receive beam, and determining a TOA of the signal for the transmit beam received at the wireless device on the fixed receive beam via the first arrived path for the signal for the transmit beam. The method further comprises determining a second minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the fixed receive beam on the determined first arrived paths for the one or more transmit beams, setting an estimated TOA to the second minimum TOA, and reporting or employing the estimated TOA for positioning the wireless device. I n one embodiment, the method further comprises, for each transmit beam of the one or more transmit beams, calculating a Channel I mpulse Response (CI R) for the transmit beam based on the signal for the transmit beam received at the wireless device on the fixed receive beam via one or more signal propagation paths. Further, for each transmit beam of the one or more transmit beams, detecting the first arrived path for the transmit beam comprises detecting the first arrived path for the transmit beam based on the calculated CI R for the transmit beam. I n one embodiment, for each transmit beam of the one or more transmit beams, the signal for the transmit beam comprises a reference signal, data, or a combination of a reference signal and data.

I n one embodiment, the method further comprises, for each receive beam of the plurality of receive beams, calculating a CI R for the receive beam based on the signal received on the receive beam via the one or more signal propagation paths. Further, for each receive beam of the plurality of receive beams, detecting the first arrived path on the receive beam comprises detecting the first arrived path on the receive beam based on the calculated CI R for the receive beam.

I n one embodiment, for each receive beam of the plurality of receive beams, the signal received on the receive beam comprises a reference signal, data, or a

combination of a reference signal and data.

I n one embodiment, the method is iteratively performed wherein, for each iteration, a base station transmits signals using a narrower transmit beam. I n one embodiment, the method further comprises estimating an angle of arrival of the first arrived path corresponding to each of the plurality of receive beams, and setting directions of the plurality of receive beams based on the angle of arrival. I n one embodiment, the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas. I n one embodiment, the angle of arrival, phi, is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light,

T = time difference of arrival at the two receiving antennas, and

a = antenna separation.

Corresponding embodiments of a wireless device are also disclosed. I n one embodiment, a wireless device for positioning in a wireless communication system is adapted to, for each receive beam of a plurality of receive beams, receive a signal on the receive beam via one or more signal propagation paths, detect a first arrived path for the signal on the receive beam where the first arrived path is a signal propagation path by which the signal is first received at the wireless device on the receive beam, and determine a TOA of the signal on the receive beam via the first arrived path on the receive beam. The wireless device is further adapted to determine a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

I n one embodiment, a wireless device for positioning in a wireless communication system comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless device to, for each receive beam of a plurality of receive beams, receive a signal on the receive beam via one or more signal propagation paths, detect a first arrived path for the signal on the receive beam where the first arrived path is a signal propagation path by which the signal is first received at the wireless device on the receive beam, and determine a TOA of the signal on the receive beam via the first arrived path on the receive beam. The processing circuitry is further configured to cause the wireless device to determine a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

I n one embodiment, a method performed by a wireless device comprises, for each transmit beam of one or more transmit beams detected at the wireless device, receiving a signal for the transmit beam via one or more signal propagation paths, determining a first arrived path of the signal for the transmit beam received at the wireless device where the first arrived path is a signal propagation path by which the signal for the transmit beam is first received at the wireless device, and determining a TOA of the signal for the transmit beam received at the wireless device via the first arrived path of the signal for the transmit beam. The method further comprises determining a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

I n one embodiment, the method further comprises setting an estimated TOA to the minimum TOA, and reporting or employing the estimated TOA for positioning the wireless device.

I n one embodiment, the method further comprises, for each receive beam of a plurality of receive beams, receiving a signal on the receive beam via one or more signal propagation paths, detecting a first arrived path for the signal on the receive beam where the first arrived path is a signal propagation path by which the signal is first received at the wireless device on the receive beam, and determining a TOA of the signal on the receive beam via the first arrived path on the receive beam. The method further comprises determining a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams, setting a second estimated TOA to the minimum TOA, and reporting or employing the second estimated TOA for positioning the wireless device. I n one embodiment, the method further comprises, for each receive beam of the plurality of receive beams, calculating a Cl R for the receive beam based on the signal received on the receive beam via the one or more signal propagation paths. Further, for each receive beam of the plurality of receive beams, detecting the first arrived path on the receive beam comprises detecting the first arrived path on the receive beam based on the calculated Cl R for the receive beam. I n one embodiment, for each receive beam of the plurality of receive beams, the signal received on the receive beam comprises a reference signal, data, or a

combination of a reference signal and data.

I n one embodiment, the method further comprises, for each transmit beam of the one or more transmit beams, calculating a Cl R for the transmit beam based on the signal for the transmit beam received at the wireless device via one or more signal propagation paths. Further, for each transmit beam of the one or more transmit beams, detecting the first arrived path for the transmit beam comprises detecting the first arrived path for the transmit beam based on the calculated Cl R for the transmit beam.

I n one embodiment, for each transmit beam of the one or more transmit beams, the signal for the transmit beam comprises a reference signal, data, or a combination of a reference signal and data.

I n one embodiment, the method is iteratively performed wherein, for each iteration, the wireless device receives signals using a narrower receive beam.

I n one embodiment, the method further comprises estimating an angle of arrival of the first arrived path corresponding to each of the plurality of receive beams, and setting directions of the plurality of receive beams based on the angle of arrival. I n one embodiment, the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas. I n one embodiment, the angle of arrival, phi, is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light,

T = time difference of arrival at the two receiving antennas, and

a = antenna separation.

Corresponding embodiments of a wireless device are also disclosed. I n one embodiment, a wireless device for positioning in a wireless communication system is adapted to, for each transmit beam of one or more transmit beams detected at the wireless device, receive a signal for the transmit beam via one or more signal propagation paths, determine a first arrived path of the signal for the transmit beam received at the wireless device where the first arrived path is a signal propagation path by which the signal for the transmit beam is first received at the wireless device, and determine a TOA of the signal for the transmit beam received at the wireless device via the first arrived path of the signal for the transmit beam. The wireless device is further adapted to determine a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

I n one embodiment, a wireless device for positioning in a wireless communication system comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless device to, for each transmit beam of one or more transmit beams detected at the wireless device, receive a signal for the transmit beam via one or more signal propagation paths, determine a first arrived path of the signal for the transmit beam received at the wireless device where the first arrived path is a signal propagation path by which the signal for the transmit beam is first received at the wireless device, and determine a TOA of the signal for the transmit beam received at the wireless device via the first arrived path of the signal for the transmit beam. The processing circuitry is further configured to cause the wireless device to determine a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams, wherein the minimum TOA is used in relation to positioning of the wireless device.

Brief Description of the Drawings

The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the

description serve to explain the principles of the disclosure.

Figure 1 illustrates the positioning architecture in Long Term Evolution (LTE) ;

Figure 2 illustrates one example of a cellular communications system in which embodiments of the present disclosure may be implemented;

Figure 3 illustrates an example of User Equipment (UE) based beamforming;

Figure 4 illustrates an example of Base Station (BS) based beamforming; Figure 5 illustrates an example of combined UE-based and BS-based beamforming;

Figure 6 illustrates a procedure performed by a UE for the case of UE-based beamforming in accordance with one embodiment of the present disclosure;

Figure 7 illustrates a procedure performed by a UE for the case of BS-based beamforming in accordance with one embodiment of the present disclosure;

Figures 8A and 8B illustrate a procedure performed by a UE for the case of combined UE-based beamforming and BS-based beamforming in accordance with one embodiment of the present disclosure;

Figures 9 through 1 1 are schematic block diagrams of a radio access node in accordance with embodiments of the present disclosure; and

Figures 12 and 13 are schematic block diagrams of a UE in accordance with embodiments of the present disclosure.

Detailed Description

The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

Radio Node: As used herein, a“radio node” is either a radio access node or a wireless device.

Radio Access Node: As used herein, a“radio access node” or“radio network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth

Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like) , and a relay node. Core Network Node: As used herein, a“core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF) , a Home Subscriber Server (HSS) , or the like. Some other examples of a core network node include a node implementing an Access and Mobility Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF) , a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.

Wireless Device: As used herein, a“wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting and/or receiving signals to a radio access node(s). Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

Network Node: As used herein, a“network node” is any node that is either part of the RAN or the core network of a cellular communications network/ system.

As used herein, the terminology“spatial filtering weights,”“spatial filtering configuration,”“spatial domain filtering weights,”“spatial domain filtering

configuration,” and“spatial domain transmission filter” refer to the set of antenna weights that are applied at the transmitter (e.g., at the base station such as, e.g., at the gNB for downlink or at the wireless communication device such as, e.g., at the UE for uplink) and/or the receiver (e.g., at the wireless communication device such as, e.g., at the UE for downlink or at the base station such as, e.g., at the gNB for uplink) for data/ control transmission/reception. The spatial filtering weights may not always result in a beam in a strict sense; however, the term“beam” is used herein when referring to said set of antenna weights.

Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

Note that, in the description herein, reference may be made to the term“cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

There currently exist certain challenge(s) related to conventional positioning schemes. For data communication, Base Station (BS)- based and UE-based

beamforming may be used separately, or in combination, to maximize the Signal to I nterference plus Noise Ratio (SI NR) of the received signal. The target in data communications is normally to maximize the overall SI NR, including all signal

propagation paths of the received signal. Note that signal propagation paths are referred to herein simply as“paths”. For positioning, especially Time of Arrival (TOA) based positioning, the target is rather to maximize the SI NR of the first received path to allow the TOA of a Line of Sight (LOS) path to be estimated as accurately as possible, where the estimated TOA of the LOS path is used for positioning. For positioning, paths other than the LOS path are non-important. Maximizing the overall SI NR as is done for data communication may, however, be catastrophic for TOA-based positioning since the resulting beams may point in totally wrong directions, and the estimated TOA may be based on a heavily delayed path, resulting in a poor TOA estimation and corresponding poor positioning.

Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. I n some embodiments,

beamforming is performed at the BS and/or at the UE in such a way that the power of the first received path at the UE is maximized, which will directly improve TOA

estimation accuracy and indirectly improve positioning accuracy. I n the general case, this may imply pointing the respective BS and/or UE beams in a completely different direction compared to the optimum direction for data communication. To find the optimum beam direction at the BS and UE sides, beam sweeping schemes may be used, as described below, as well as various side information.

Aspects disclosed herein include using BS beamforming, UE beamforming, or both to increase the power of the first received path at the UE and thereby increase TOA and positioning accuracy. I n another aspect disclosed herein, beam sweeping techniques may be used, initiated either on the BS side or on the UE side, in a first step and with the counterpart in a second step to find the best BS and/or UE beam.

Certain embodiments may provide one or more of the following technical advantage(s). The LOS path (or quasi-LOS path) may be detected with higher probability, i.e. the risk is reduced that a totally different path is mistakenly detected as the first path. Assuming the first path has been roughly identified in a correct way, a higher received power of the first path allows the first path to be detected with higher time accuracy, since the SI NR is higher. The better accuracy positively affects positioning performance.

Systems and methods are disclosed herein for improving wireless positioning using beamforming. I n this regard, Figure 2 illustrates one example of a cellular communications system 200 in which embodiments of the present disclosure may be implemented. I n the embodiments described herein, the cellular communications system 200 is a 5G System (5GS) including a NR RAN or an Evolved Packet System (EPS) including a LTE RAN. I n this example, the RAN includes base stations 202-1 and 202-2, which in LTE are referred to as eNBs and in 5G NR are referred to as gNBs, controlling corresponding (macro) cells 204-1 and 204-2. The base stations 202-1 and 202-2 are generally referred to herein collectively as base stations 202 and individually as base station 202. Likewise, the (macro) cells 204-1 and 204-2 are generally referred to herein collectively as (macro) cells 204 and individually as (macro) cell 204. The RAN may also include a number of low power nodes 206-1 through 206-4 controlling corresponding small cells 208-1 through 208-4. The low power nodes 206-1 through 206-4 can be small base stations (such as pico or femto base stations) or Remote Radio Heads (RRHs), or the like. Notably, while not illustrated, one or more of the small cells 208-1 through 208-4 may alternatively be provided by the base stations 202. The low power nodes 206-1 through 206-4 are generally referred to herein collectively as low power nodes 206 and individually as low power node 206. Likewise, the small cells 208- 1 through 208-4 are generally referred to herein collectively as small cells 208 and individually as small cell 208. The cellular communications system 200 also includes a core network 210, which in the 5GS is referred to as the 5G Core (5GC). The base stations 202 (and optionally the low power nodes 206) are connected to the core network 210.

The base stations 202 and the low power nodes 206 provide service to wireless devices 212-1 through 212-5 in the corresponding cells 204 and 208. The wireless devices 212-1 through 212-5 are generally referred to herein collectively as wireless devices 212 and individually as wireless device 212. The wireless devices 212 are also sometimes referred to herein as UEs. Beamforming for data communication may be applied at the BSs 202, at the wireless devices 212, or both. I n the following description, the wireless devices 212 are oftentimes referred to as UEs or UEs 212.

The effect of applying beamforming on the BS side and/or the UE side is that the received power/SI NR at the UE 212 may increase. The best beamforming for data communication purposes is, however, not necessarily the best for positioning because only the overall SI NR of the received signal matters for data communication, whereas only the SI NR of the first arrived path, e.g. a path by which a signal is first received by the UE, matters for positioning. Beamforming adapted to maximize the overall SI NR may, however, be very different from beamforming adapted to maximize the SI NR of the first arrived path. Note that a signal may be received by a UE via multiple paths (e.g., a LOS path and multiple reflected paths). As used herein, the“first arrived path” is the path by which the signal is first received (in time) by the UE. I n some scenarios, the first arrived path is the LOS path. However, in some environments, a true LOS path may not exist, in which case the first arrived path is a reflected path by which the signal is first received by the UE (e.g., a reflected path that is closest to a LOS path). The first arrived path may also be referred to herein as the first received path or the first path.

Beamforming for positioning a wireless device by the methods of the present disclosure are now disclosed.

UE-based beamforming: An example of a case with UE-based beamforming is shown in Figure 3. As shown in Figure 3, a UE receives a reflected signal from the BS on Beam # 1 , and receives a diffracted signal on Beam # 2. The reflected signal on Beam # 1 may travel a longer path than a signal on Beam # 2, but the signal via Beam # 1 may be stronger than the signal via Beam # 2. Therefore, Beam # 1 would be used to maximize the overall SI NR for purposes of data communication, but this could imply missing the actually-f irst path and falsely detecting the reflected signal as the first path. By instead using Beam # 2, which is actually received first, the power/SI NR of the actually-first path is maximized, which allows the first path to be detected and therefore allows for a much better TOA estimate of the first received path. Although Beam # 2 is not, in this example, a perfect LOS path, it may still be a nearly-LOS path, with only a small additional delay due to the diffraction.

BS-based beamforming: An example of a case with BS-based beamforming is shown in Figure 4. As shown in Figure 4, a BS transmits a reflected signal to the UE on Beam # 1 , and a diffracted signal on Beam # 2. Beam # 1 would be used to maximize the overall SI NR, but this could imply missing the actually-f irst path and falsely detecting the reflected signal as the first path. By instead using Beam # 2 the

power/SI NR of the actually-f irst path is maximized, which allows the first path to be detected and therefore allows for a much better TOA estimate of the first received path. Although Beam # 2 is not, in this example, a perfect LOS path, it may still be a nearly- LOS path, with only a small additional delay due to the diffraction.

Combined UE-based and BS-based beamforming·. An example with beamforming on both the BS and the UE sides is shown in Figure 5. I n this case the positive effects of UE-based and BS-based beamforming are combined so that the first path is even more amplified, which means that the risk of missing the true first path is further reduced and a corrected detected first path may be detected with even higher TOA accuracy.

Below, various methods for UE positioning are disclosed. Each of these methods includes the UE detecting the first arrived path for each respective beam (i.e., UE receive beam or BS transmit beam). I n the methods disclosed herein, the Channel I mpulse Response (CI R) for the respective paths may be used to determine the first arrived path on a beam. The CI R can be estimated by correlating the received signal with a corresponding known transmitted signal, or by estimating the channel in the frequency domain by dividing received Resource Element (RE) positions with their a priori-known transmitted values followed by an I nverse Discrete Fourier Transform (I DFT) (e.g., an I nverse Fast Fourier Transform (I FFT)), which gives the CI R. To increase the accuracy of the estimated CI R, it may be interpolated using, e.g., well- known interpolation methods such as, e.g., an appropriately designed Finite I mpulse Response (FI R) filter.

Also, since the optimum beam directions for either the BS or UE side are not a priori-known, this needs to be found. For this, beam sweeping schemes may be used by the communication system including the UE and the BS. These beam sweeping schemes may use side information to assist in the determination of the best beams for the BS and UE sides.

I n regarding to a method for the UE beam case (with a wide BS beam), as discussed above with respect to Figure 3, in some embodiments the UE utilizes receive beams with a wide BS transmit beam. I n this regard, the UE may perform the following procedure for positioning the UE:

1 . For one or more received Orthogonal Frequency Division Multiplexing (OFDM) symbols, the UE may use beam sweeping and apply a number of pre-coders for beams (i.e., receive beams) in different directions.

• With analog UE beamforming, different UE beams are applied in a sequence, with one beam after the other in time. Each beam is associated with an integer number of received symbols on which the corresponding beamforming is applied.

• With digital beamforming the UE creates, in parallel, a number of different receive beams based on the same received symbol(s) .

2. Based on received reference signals, demodulated data, or a combination of these, the UE calculates the Cl R for each applied UE beam direction.

3. The UE detects the first arrived path in each Cl R and estimates its TOA, TOAi.

Thus, for each applied UE beam direction, the UE detects the first arrived path in the Cl R for that UE beam direction and estimates the TOA of the first arrived path in the Cl R for that UE beam direction. This TOA is denoted as TOAi, where“i" denotes the i-th UE beam direction.

4. The UE compares the estimated TOAs from all Cl Rs (i.e., from all the applied UE beam directions) and chooses the lowest TOA value of the set of TOAs as the estimated TOA for the received signal. That is, the estimated TOA for the received signal is:

Estimated TOA = min{ TOAi}

5. The UE applies the found beam and uses it for estimating the TOA of the first received path. The“found beam” is the UE beam that corresponds to the estimated TOA for the received signal. I n addition, the UE may report the mentioned TOA value itself to allow the network to perform positioning.

Note, in regard to estimating the TOA of the first received path, the value calculated in step 4 may be sufficient. Flowever, in some scenarios, it may be desirable to improve the accuracy of the estimated TOA of the first received path, in which case the found beam may be used for further TOA estimation to improve the accuracy of the estimated TOA. Figure 6 illustrates as least some aspects of the procedure described above.

Note that while these actions are referred to as“steps”, these actions may be

performed in any suitable order and are not limited to the order in which they are presented here, unless otherwise stated or required. Further, optional steps are represented in Figure 6 by dashed lines. The BS here is denoted as the BS 202 and the UE is denoted as the UE 212.

Step 600-0 : The BS 202 transmits a signal(s) to the UE 212 via a wide transmit beam. The signal(s) may include a reference signal(s) (e.g., Positioning Reference Signal (PRS)) in one or more OFDM symbols, modulated data, or both a reference signal(s) and modulated data.

Step 600 (Optional) : The UE 212 receives a signal(s) from the BS 202 via each of a plurality of receive beams. Flere, for each receive beam, the corresponding received signal includes one or more instances of the signal transmitted by the BS 202 received via one or more respective paths (see, e.g., the instance of the signal received at the UE via Beam # 1 in Figure 3 and the instance of the signal received at the UE via Beam # 2 in Figure 3). I n some embodiments, using beam sweeping or some similar mechanism, the UE 212 receives a signal(s) (e.g., one or more OFDM symbols comprising one or more signals received via one or more paths) using a plurality of ( Rx) beams in different directions (e.g. , by applying a plurality of precoders for beams in different directions). Employing analog beamforming, different UE beams are applied, one beam after the other, in a sequence. Employing digital beamforming, the UE 212 creates, in parallel, a number of different receive beams based on the same received symbol(s).

Step 602 (Optional) : The UE 212 calculates a Cl R of the signal received via each of the receive beams based on the received reference signals, demodulated data, or a combination thereof. I n other words, for each receive beam, the UE 212 calculates a Cl R for the receive beam based on the signal received on that receive beam. As discussed above, for each receive beam, the Cl R can be estimated by correlating the received signal on that receive beam with a corresponding known transmitted signal, or by estimating the channel in the frequency domain by dividing received RE positions with their a priori-known transmitted values followed by an I DFT (e.g., I FFT), which gives the CI R. To increase the accuracy of the estimated CI R, it may be interpolated using, e.g., well-known interpolation methods such as, e.g., an appropriately designed FI R filter.

Step 604 : The UE 212 detects a first arrived path, which is a path by which the transmitted signal is first received at the UE 212, for each of the plurality of receive beams. The receive beams are also referred to herein as UE beams. As discussed above, for each receive beam, the UE 212 detects the first arrived path of the

transmitted signal in the Cl R for that receive beam.

Step 606 : The UE determines a TOA of the signal received via the first arrived path on each receive beam. As discussed above, for each receive beam, the UE 212 estimates the TOA of the transmitted signal via the first arrived path in the Cl R for that receive beam. This TOA is denoted as TOAi, where“i" denotes the i-th receive beam.

Step 608 : The UE 212 determines a minimum TOA of the determined TOAs (e.g., compares the determined TOAs for the first arrived paths of all of the receive beams and chooses the lowest value) .

Step 61 0 (Optional) : The UE 212 sets an estimated TOA to the minimum TOA.

Step 61 2 (Optional) : The UE 212 reports or employs the estimated TOA for positioning the UE 212.

I n regard to a method for the BS beam case with wide UE beam, as discussed above with respect to Figure 4, in some embodiments the BS utilizes a plurality of transmit beams with a wide UE receive beam. I n this regard, the UE may perform the following procedure for positioning the UE:

1 . For one or more transmitted OFDM symbols, the BS may use beam sweeping and apply a number of precoders for beams in different directions. Each beam is associated with a beam index and the signal transmitted in each beam is encoded in such a way that the beam index may be identified by the UE directly or indirectly.

• With analog BS beamforming, different BS beams are applied in a sequence, with one beam after the other in time. Each beam is associated with an integer number of transmitted symbols on which the corresponding beamforming is applied.

• With digital beamforming, the BS creates, in parallel, a number of different transmit beams based on the same transmitted symbol(s). 2. Based on received reference signals, demodulated data, or a combination of these, the UE detects the beam identifier and calculates the Cl R for each received BS beam direction.

3. The UE detects the first arrived path in each Cl R and estimates its TOA, TOAi. Thus, for each received BS beam direction, the UE detects the first arrived path of the transmitted signal in the Cl R for that BS beam direction and estimates the TOA of the transmitted signal via the first arrived path in the Cl R for that BS beam direction. This TOA is denoted as TOAi, where“i" denotes the i-th BS beam direction.

4. The UE compares the estimated TOAs from all Cl Rs (i.e., from all the

received BS beam directions) and chooses the lowest TOA value of the set of TOAs as the estimated TOA for the received signal. That is, the estimated TOA for the received signal is:

Estimated TOA = min{ TOAi}

5. The UE reports to the network the beam index of the estimated TOA

found in step (4) above. I n addition, the UE may report the mentioned TOA value itself to allow the network to perform positioning.

Figure 7 illustrates as least some aspects of the procedure described above.

performed in any suitable order and are not limited to the order in which they are presented here, unless otherwise stated or required. Further, optional steps are represented in Figure 7 by dashed lines. The BS here is denoted as the BS 202 and the UE is denoted as the UE 212.

Step 700-0 : The BS 202 transmits a signal(s) to the UE 212 via each of a plurality of transmit beams. The transmit beams are also referred to herein as BS beams. I n some embodiments, using beam sweeping or some similar mechanism, the BS 202 transmits a signal(s) (e.g., one or more OFDM symbols comprising one or more signals) using a plurality of (Tx) beams in different directions (e.g., by applying a plurality of precoders for beams in different directions). Employing analog

beamforming, different transmit beams are applied, one beam after the other, in a sequence. Employing digital beamforming, the BS 202 creates, in parallel, a number of different transmit beams based on the same transmit symbol(s). Step 700 (Optional) : The UE 212 receives the signals via each of the transmit beams. I n other words, for each of at least some of the transmit beams that can be received at the UE 212, the UE 212 receives the signal transmitted by the BS 202 on that transmit beam.

Step 702 (Optional) : The UE 212 calculates a Cl R of the signal received via each of the transmit beams based on the received reference signals, demodulated data, or a combination thereof. I n other words, for each transmit beam for which the UE 212 has received the respective signal, the UE 212 calculates a Cl R for the transmit beam based on the signal received for that transmit beam (e.g., based on reference signal(s) comprised in the received signal, based on demodulated data from the received signal, or a combination thereof) , as described above.

Step 704 : The UE 212 detects a first arrived path, which is a path by which the signal is first received, for each of the transmit beams received at the UE 212.

Step 706 : The UE 212 determines a TOA of the signal received via the respective first arrived path on each of the transmit beams received at the UE 212.

Step 708 : The UE 212 determines a minimum TOA of the determined TOAs (e.g., compares the determined TOAs for the first arrived paths of all of the transmit beams received at the UE 212 and chooses the lowest value).

Step 71 0 (Optional) : The UE 212 sets an estimated TOA to the minimum TOA.

Step 71 2 (Optional) : The UE 212 reports or employs the estimated TOA for positioning the UE 212.

I n regard to a combined BS beam and UE beam case, as discussed above with respect to Figure 5, in some embodiments the UE utilizes receive beams and the BS utilizes transmit beams. I n this regard, the UE may perform the following procedure for positioning the UE. For combined BS and UE beam sweeping, either BS- or UE-based beam sweeping, as above, is used in a first step, followed by beam sweeping for the counterpart, also as above, except that the non-beam sweeping part then uses a fixed beam, as found in the first step. I n other words, beam sweeping is performed by a first one of the BS and the UE while the other applies a wide beam. Subsequently, the other one of the BS and the UE performs beam sweeping while the first one uses the beam determined to result in the minimum TOA in the first step. Thus, in one example, the procedure of Figure 6 is first performed and then the procedure of Figure 7 is performed using the UE beam that corresponds to the minimum TOA found in the procedure of Figure 6. I n another example, the procedure of Figure 7 is first performed and then the procedure of Figure 6 is performed using the BS beam that corresponds to the minimum TOA found in the procedure of Figure 7.

Figures 8A and 8B illustrate as least some aspects of an example of the procedure described above for positioning a wireless device (e.g., a UE) by a

communication system using beamforming. I n the example in Figures 8A and 8B, UE beam sweeping is performed first, followed by the BS beam sweeping. I n a second example, not shown, the BS beam sweeping may be performed first, followed by UE beam sweeping. I n the second example, after the BS beam sweeping is performed, the BS fixes the transmit beam based on the transmit beam with the minimum TOA. Note that while these actions are referred to as“steps”, these actions may be performed in any suitable order and are not limited to the order in which they are presented here, unless otherwise stated or required. Further, optional steps are represented in Figures 8A and 8B by dashed lines. The BS here is denoted as the BS 202 and the UE is denoted as the UE 212.

Step 800-0 : The BS 202 transmits a signal(s) to the UE 212 via a wide transmit beam.

Step 800 (Optional) : The UE 212 receives a signal from the BS 202 via each of a plurality of receive beams. Flere, for each receive beam, the corresponding received signal includes one or more instances of the signal transmitted by the BS 202 received via one or more respective paths (see, e.g., the instance of the signal received at the UE via Beam # 1 in Figure 3 and the instance of the signal received at the UE via Beam # 2 in Figure 3) .

Step 802 (Optional) : The UE 212 calculates a Cl R of the signal received via each of the receive beams. I n other words, for each receive beam, the UE 212 calculates a Cl R for the receive beam based on the signal received on that receive beam. As discussed above, for each receive beam, the Cl R can be estimated by correlating the received signal on that receive beam with a corresponding known transmitted signal, or by estimating the channel in the frequency domain by dividing received RE positions with their a priori-known transmitted values followed by an I DFT (e.g. , I FFT), which gives the CI R. To increase the accuracy of the estimated CI R, it may be interpolated using, e.g., well-known interpolation methods such as, e.g., an appropriately designed FI R filter. Step 804 : The UE 212 detects a first arrived path, which is a path by which the transmitted signal is first received, on each of a plurality of receive beams. As discussed above, for each receive beam, the UE 212 detects the first arrived path in the Cl R for that receive beam.

Step 806 : The UE determines a TOA of the signal received via the first arrived path on each receive beam. As discussed above, for each receive beam, the UE 212 estimates the TOA of the first arrived path in the Cl R for that receive beam. This TOA is denoted as TOAi, where“i" denotes the i-th receive beam.

Step 808 : The UE 212 determines a minimum TOA of the determined TOAs (e.g., compares the determined TOAs for the first arrived paths of all of the receive beams and chooses the lowest value) .

Step 81 0 (Optional) : The UE 212 sets an estimated TOA to the minimum TOA.

Step 81 2 (Optional) : The UE reports or employs the estimated TOA for positioning the UE 212.

Step 81 4 : The UE fixes the receive beam to the receive beam on which the first arrived path had the minimum TOA of all the determined TOAs found in step 808.

Step 81 6-0 : The BS 212 transmits a signal(s) to the UE 212 via each of a plurality of transmit beams.

Step 81 6 (Optional) : The UE 212 receives the signal from the BS 202 via at least some of a plurality of transmit beams, e.g., using the fixed receive beam (as fixed in step 814). I n other words, for each of at least some of the transmit beams that can be received at the UE 212 via the fixed receive beam, the UE 212 receives the signal transmitted by the BS 202 on that transmit beam.

Step 81 8 (Optional) : The UE 212 calculates a Cl R of the signal received for each of the transmit beams via the fixed receive beam at the UE 212. I n other words, for each transmit beam for which the UE 212 has received the respective signal via the fixed receive beam, the UE 212 calculates a Cl R for the transmit beam based on the signal received for that transmit beam (e.g., based on reference signal(s) comprised in the received signal, based on demodulated data from the received signal, or a

combination thereof), as described above.

Step 820 : The UE 212 detects a first arrived path in each of the calculated Cl Rs. I n other words, the UE 212 uses the calculated Cl Rs to detect the first arrived path for each of the transmit beams for which the corresponding signal is received at the UE 212.

Step 822 : The UE 212 determines a TOA of the signal received via the respective first arrived path for each transmit beam received at the UE 212.

Step 824 : The UE 212 determines a minimum TOA of the determined TOAs from step 822 (e.g., compares the determined TOAs for the first arrived paths of all of the transmit beams received at the UE 212 and chooses the lowest value).

Step 826 (Optional) : The UE 212 sets an estimated TOA to the minimum TOA from among those determined in step 824.

Step 828 (Optional) : The UE 22 reports or employs the estimated TOA for positioning the UE 212.

I n some embodiments, the BS and/or the UE may use an iterative/ successive procedure for beam sweeping so that the beam angle is gradually narrowed down in several steps instead of immediately going from a wide beam to a narrow beam. When, e.g., a reliable first path cannot be detected as part of a first step, where one side (BS or UE) uses a wide beam, several somewhat narrower (“intermediate-narrow”) beams could be tested to find out if any of these will allow a reliable first path to be found. If this is the case the procedure could continue, and the best of the narrower beams could be further subdivided into more narrow beams. This subdivision approach could in principle be extended to allow all combinations of BS and UE beam combinations to be tested, although the complexity would increase by this.

I n one embodiment, the UE and/or the BS may estimate the Angle of Arrival (AoA) of the first path in one or more stages of the process. The UE and/or the BS may then use this estimated AoA information in the beam selection procedure by pointing the antenna beam in the same direction as the estimated AoA indicates.

The AoA of the first path may, e.g. , be estimated by measuring the Time

Difference of Arrival (TDOA) between the first path of two (or more) of the receiving antennas and use the a priori-information of the antenna separation and the speed of light to deduce the AoA. This may, e.g., be done in the following way.

With two antennas, an antenna separation = a, time difference T between the first paths from the two antennas and with AoA = phi we have a geometrical difference in overall path length of d, such that:

d = a x sin(phi) Further noticing that d = T x c we have

phi = arcsin(T x c/a),

with c being the speed of light and phi the AoA relative to the normal against a line between the two antennas.

A corresponding measurement may also be performed by measuring the phase difference between corresponding frequency domain REs from two or more antennas, provided other components than the first path have first been removed from the CI R.

I n connection with, e.g., Time Division Duplexing (TDD) communication, where the downlink and the uplink are operating in the same bandwidth, the downlink and uplink channels may often be assumed to be the same (i.e., using channel reciprocity). I n such conditions the UE and/or the BS may use the received PRS signal to estimate the channel on each receiving antenna separately.

I n a further embodiment, the UE and/or the BS may then apply a precoder in the uplink (UE) or downlink (BS) in such a way that, for each antenna, a precoding weight is applied, where the precoding weight is the complex conjugate of the estimated channel (of the first received path) on the corresponding antenna. I n this way, a transmitting beam is formed that is directed in the same direction as the received first path. This assumes that other components than the first path have first been removed from the CI R.

I n some embodiments, the UE and/or the network use side information to assist in the determination of the best beam or best beam combinations. I n some

embodiments, the UE could use, e.g., two-dimensional (2D) or three-dimensional (3D) map information, magnetic compass, barometer pressure, Global Navigation Satellite System (GNSS) positioning, or a coarse positioning based on Radio Access Technology (RAT) or non-RAT positioning methods to assist in finding the best beams. For 5G/NR, the network may in addition use Channel State I nformation (CSI) feedback, e.g. of Type I I , which would give information about the propagation environment. For beam management all the configured beam pair links would also be natural candidates to sweep.

The BS may use all or a subset of such side information, whatever is appropriate.

I n some embodiments, the UE may send one or more messages to one or more entities of the network, e.g. a positioning server, to inform about the best BS beam found and/or the best UE beam found. The UE may alternatively, or in addition, send information about the estimated CI Rs to the network to let the network perform the decision of which BS and/or UE beams to use. Examples of such messages from the UE to the network are beam identifier and earliest found TOA value.

Figure 9 is a schematic block diagram of a radio access node 900 according to some embodiments of the present disclosure. The radio access node 900 may be, for example, a base station 202 or 206. As illustrated, the radio access node 900 includes a control system 902 that includes one or more processors 904 (e.g., Central Processing Units (CPUs), Application Specific I ntegrated Circuits (ASI Cs), Reid Programmable Gate Arrays (FPGAs) , and/or the like), memory 906, and a network interface 908. The one or more processors 904 are also referred to herein as processing circuitry. I n addition, the radio access node 900 includes one or more radio units 910 that each includes one or more transmitters 912 and one or more receivers 914 coupled to one or more antennas 916. The radio units 910 may be referred to or be part of radio interface circuitry. I n some embodiments, the radio unit(s) 910 is external to the control system 902 and connected to the control system 902 via, e.g., a wired connection (e.g., an optical cable). Plowever, in some other embodiments, the radio unit(s) 910 and potentially the antenna(s) 916 are integrated together with the control system 902. The one or more processors 904 operate to provide one or more functions of a radio access node 900 as described herein (e.g., one or more functions of a BS as described herein). I n some embodiments, the function(s) are implemented in software that is stored, e.g. , in the memory 906 and executed by the one or more processors 904.

Rgure 10 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 900 according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures.

As used herein, a“virtualized” radio access node is an implementation of the radio access node 900 in which at least a portion of the functionality of the radio access node 900 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 900 includes the control system 902 that includes the one or more processors 904 (e.g., CPUs, ASI Cs, FPGAs, and/or the like), the memory 906, and the network interface 908 and the one or more radio units 910 that each includes the one or more transmitters 912 and the one or more receivers 914 coupled to the one or more antennas 916, as described above. The control system 902 is connected to the radio unit(s) 910 via, for example, an optical cable or the like. The control system 902 is connected to one or more processing nodes 1000 coupled to or included as part of a network(s) 1002 via the network interface 908. Each processing node 1000 includes one or more processors 1004 (e.g., CPUs, ASI Cs, FPGAs, and/or the like), memory 1006, and a network interface 1008.

I n this example, functions 1010 of the radio access node 900 described herein are implemented at the one or more processing nodes 1000 or distributed across the control system 902 and the one or more processing nodes 1000 in any desired manner. I n some particular embodiments, some or all of the functions 1010 of the radio access node 900 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the

processing node(s) 1000. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1000 and the control system 902 is used in order to carry out at least some of the desired functions 1010. Notably, in some embodiments, the control system 902 may not be included, in which case the radio unit(s) 910 communicate directly with the processing node(s) 1000 via an appropriate network interface(s).

I n some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 900 or a node (e.g., a processing node 1000) implementing one or more of the functions 1010 of the radio access node 900 in a virtual environment according to any of the embodiments described herein is provided.

I n some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g. , a non-transitory computer readable medium such as memory).

Figure 1 1 is a schematic block diagram of the radio access node 900 according to some other embodiments of the present disclosure. The radio access node 900 includes one or more modules 1 100, each of which is implemented in software. The module(s) 1 100 provide the functionality of the radio access node 900 described herein. This discussion is equally applicable to the processing node 1000 of Figure 10 where the modules 1 100 may be implemented at one of the processing nodes 1000 or distributed across multiple processing nodes 1000 and/or distributed across the processing node(s) 1000 and the control system 902.

Figure 12 is a schematic block diagram of a UE 1200 according to some embodiments of the present disclosure. As illustrated, the UE 1200 includes one or more processors 1202 (e.g., CPUs, ASI Cs, FPGAs, and/or the like), memory 1204, and one or more transceivers 1206 each including one or more transmitters 1208 and one or more receivers 1210 coupled to one or more antennas 1212. The transceiver(s) 1206 includes radio-front end circuitry connected to the antenna(s) 1212 that is configured to condition signals communicated between the antenna(s) 1212 and the processor(s) 1202, as will be appreciated by on of ordinary skill in the art. The processors 1202 are also referred to herein as processing circuitry. The transceivers 1206 are also referred to herein as radio circuitry. I n some embodiments, the functionality of the UE 1200 described above may be fully or partially implemented in software that is, e.g. , stored in the memory 1204 and executed by the processor(s) 1202. Note that the UE 1200 may include additional components not illustrated in Figure 12 such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other

components for allowing input of information into the UE 1200 and/or allowing output of information from the UE 1200), a power supply (e.g. , a battery and associated power circuitry), etc.

I n some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the UE 1200 according to any of the embodiments described herein is provided. I n some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

Figure 13 is a schematic block diagram of the UE 1200 according to some other embodiments of the present disclosure. The UE 1200 includes one or more modules 1300, each of which is implemented in software. The module(s) 1300 provide the functionality of the UE 1200 described herein.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory ( RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. I n some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g. , alternative embodiments may perform the

operations in a different order, combine certain operations, overlap certain operations, etc.).

Some example embodiments of the present disclosure are as follows:

Embodiment 1 : A method performed by a wireless device, the method comprising: receiving (600) a signal from a network node via each of a plurality of receive beams; detecting (604, 704) a first arrived path on each receive beam, the first arrive path comprising a path by which the signal is first received; determining (606, 706) a Time of Arrival, TOA, of the signal received on each receive beam via the first arrived path on each receive beam; determining (608,) a minimum TOA of the determined TOAs; setting (610) an estimated TOA to the minimum TOA; and reporting or employing (612) the estimated TOA for positioning the wireless device.

Embodiment 2: The method of embodiment 1 , further comprising: calculating (602) a Channel I mpulse Response, CI R, of the signal received via each of the receive beams, wherein detecting (604, 704) the first arrived path on each received beam is based on the calculated CI R of the signal received on each receive beam. Embodiment 3: The method of embodiment 1 or 2, wherein receiving (600) the signal from a network node via each of the plurality of receive beams further comprises receiving signals sequentially from respective ones of the plurality of receive beams.

Embodiment 4: The method of embodiment 3, wherein each beam is associated with an integer number of received symbols.

Embodiment 5: The method of embodiment 1 , wherein receiving the signal from a network node via each of the plurality of receive beams further comprises receiving signals in parallel on the plurality of receive beams.

Embodiment 6: The method of embodiment 1 , wherein the signals received in parallel are each based on a same at least one symbol.

Embodiment 7: The method of embodiment 1 , wherein each of the received signals comprises one of a reference signal, demodulated data, or a combination of a reference signal and demodulated data.

Embodiment 8: The method of embodiment 1 , further comprising iteratively receiving signals from a network node via each of a plurality of receive beams, each receive beam corresponding to a direction, wherein a range of directions of the plurality of receive beams narrows with each iteration.

Embodiment 9: The method of embodiment 1 , further comprising estimating an angle of arrival of the first arrived path corresponding to each of the received beams; and setting directions of the plurality of receive beams based on the angle of arrival.

Embodiment 10: The method of embodiment 9, wherein the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas.

Embodiment 1 1 : The method of embodiment 10, wherein the angle of arrival, phi, is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light;

T = time difference of arrival at the two receiving antennas; and

a = antenna separation.

Embodiment 12: A method performed by a wireless node, the method comprising: receiving (700) a signal from a base station via a plurality of transmit beams, each transmit beam corresponding to one of a plurality of beam directions; detecting (704) a first arrived path for each transmit beam, the first arrive path comprising a path by which the signal is first received; determining (706) a Time of Arrival, TOA, of the first signal via the first arrived path on each transmit beam;

determining (708) a minimum TOA of the determined TOAs; setting (710) an estimated TOA of the first signal, for positioning the wireless device, to the minimum TOA; and reporting or employing (712) the estimated TOA for positioning the wireless device.

Embodiment 13: The method of embodiment 12, further comprising calculating (602) a Channel I mpulse Response, CI R, of the signal received via each of the transmit beams, wherein detecting (604, 704) the first arrived path on each transmit beam is based on the calculated CI R of the signal received on each transmit beam.

Embodiment 14: The method of embodiment 12, wherein receiving (700) the signal from a network node via each of the plurality of transmit beams further comprises receiving signals sequentially on respective ones of the plurality of transmit beams.

Embodiment 15: The method of embodiment 14, wherein each beam is associated with an integer number of received symbols.

Embodiment 16: The method of embodiment 12, wherein receiving the signal from a network node via each of the plurality of transmit beams further comprises receiving signals in parallel on the plurality of transmit beams.

Embodiment 17: The method of embodiment 16, wherein the signals received in parallel are each based on a same at least one symbol.

Embodiment 18: The method of embodiment 12, wherein each of the received signals comprises one of a reference signal, demodulated data, or a combination of a reference signal and demodulated data.

Embodiment 19: The method of embodiment 12, further comprising iteratively receiving signals from a network node via each of a plurality of transmit beams, each transmit beam corresponding to a direction, wherein a range of directions of the plurality of transmit beams narrows with each iteration.

Embodiment 20: The method of embodiment 12, further comprising: estimating an angle of arrival of the first arrived path corresponding to each of the transmit beams; and informing the network node to set directions of the plurality of transmit beams based on the angle of arrival. Embodiment 21 : The method of embodiment 20, wherein the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas.

Embodiment 22: The method of embodiment 21 , wherein the angle of arrival (phi) is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light;

T = time difference of arrival at the two receiving antennas; and

a = antenna separation.

Embodiment 23: A wireless device, the wireless device adapted to perform the method of any one of claims 1 to 22.

Embodiment 24: A wireless device comprising: one or more receivers; and processing circuitry associated with the one or more receivers, the processing circuitry configured to cause the wireless device to perform the method of any one of claims 1 to

23.

At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s) .

2D Two-Dimensional

3D Three-Dimensional

3GPP Third Generation Partnership Project

5G Fifth Generation

5GC Fifth Generation Core

5GS Fifth Generation System

AMF Access and Mobility Function

AoA Angle of Arrival

ASIC Application Specific I ntegrated Circuit

AUSF Authentication Server Function

BS Base Station

CI R Channel I mpulse Response

CPU Central Processing Unit • CSI Channel State I nformation

• DSP Digital Signal Processor

• E91 1 Emergency 91 1

• eNB Enhanced or Evolved Node B

• EPS Evolved Packet System

• E-SMLC Evolved Serving Mobile Location Center

• FCC Federal Communications Commission

• FI R Finite I mpulse Response

• FPGA Reid Programmable Gate Array

. gNB New Radio Base Station

• GNSS Global Navigation Satellite System

• HSS Flome Subscriber Server

• I D Identity

• I DFT I nverse Discrete Fourier Transform

• I FFT I nverse Fast Fourier Transform

• LOS Line of Sight

• LPP Long Term Evolution Positioning Protocol

• LPPa Long Term Evolution Positioning Protocol Annex

• LTE Long Term Evolution

• MME Mobility Management Entity

• MTC Machine Type Communication

• NEF Network Exposure Function

• NF Network Function

• NR New Radio

• NRF Network Function Repository Function

• NSSF Network Slice Selection Function

• OFDM Orthogonal Frequency Division Multiplexing

• OTDOA Observed Time Difference of Arrival

• PCF Policy Control Function

• P-GW Packet Data Network Gateway

• PRS Positioning Reference Signal

• RAM Random Access Memory

• RAN Radio Access Network RAT Radio Access Technology

RE Resource Element

ROM Read Only Memory

RRC Radio Resource Control

· RRH Remote Radio Head

SCEF Service Capability Exposure Function

SI NR Signal to I nterference plus Noise Ratio

SMF Session Management Function

TDD Time Division Duplexing

· TDOA Time Difference of Arrival

TOA Time of Arrival

UDM Unified Data Management

UE User Equipment

UPF User Plane Function

· US United States

UTDOA Uplink Time Difference of Arrival

Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Qaims What is claimed is:

1 . A method performed by a wireless device (212), the method comprising:

• for each receive beam of a plurality of receive beams:

o receiving (600; 800) a signal on the receive beam via one or more signal propagation paths;

o detecting (604, 804) a first arrived path for the signal on the receive

beam, the first arrived path being a signal propagation path by which the signal is first received at the wireless device (212) on the receive beam; o determining (606, 806) a Time of Arrival, TOA, of the signal on the receive beam via the first arrived path on the receive beam; and

• determining (608, 808) a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams;

• wherein the minimum TOA is used in relation to positioning of the wireless device (212).

2. The method of claim 1 further comprising:

setting (610) an estimated TOA to the minimum TOA; and

reporting or employing (612) the estimated TOA for positioning the wireless device (212).

3. The method of claim 1 , further comprising:

• fixing (814) a receive beam of the wireless device (212) to a receive beam from among the plurality of receive beams that corresponds to the minimum TOA;

• for each transmit beam of one or more transmit beams detected at the

wireless device (212) on the fixed receive beam:

o receiving (816) a signal for the transmit beam on the fixed receive beam via one or more signal propagation paths;

o determining (820) a first arrived path for the signal for the transmit beam received at the wireless device (212) on the fixed receive beam, the first arrived path being a signal propagation path by which the signal for the transmit beam is first received at the wireless device (212) on the fixed receive beam; and

o determining (822) a TOA of the signal for the transmit beam received at the wireless device (212) on the fixed receive beam via the first arrived path for the signal for the transmit beam;

• determining (824) a second minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the fixed receive beam on the determined first arrived paths for the one or more transmit beams;

• setting (826) an estimated TOA to the second minimum TOA; and

• reporting or employing (828) the estimated TOA for positioning the wireless device (212).

4. The method of claim 3, further comprising:

for each transmit beam of the one or more transmit beams, calculating (818) a Channel I mpulse Response, CI R, for the transmit beam based on the signal for the transmit beam received at the wireless device (212) on the fixed receive beam via one or more signal propagation paths;

wherein, for each transmit beam of the one or more transmit beams, detecting (820) the first arrived path for the transmit beam comprises detecting (820) the first arrived path for the transmit beam based on the calculated CI R for the transmit beam.

5. The method of claim 3 or 4, wherein, for each transmit beam of the one or more transmit beams, the signal for the transmit beam comprises a reference signal, data, or a combination of a reference signal and data.

6. The method of any one of claims 1 to 5, further comprising:

for each receive beam of the plurality of receive beams, calculating (602) a CI R for the receive beam based on the signal received on the receive beam via the one or more signal propagation paths;

wherein, for each receive beam of the plurality of receive beams, detecting (604, 804) the first arrived path on the receive beam comprises detecting (604; 804) the first arrived path on the receive beam based on the calculated CI R for the receive beam.

7. The method of claim 1 to 6, wherein, for each receive beam of the plurality of receive beams, the signal received on the receive beam comprises a reference signal, data, or a combination of a reference signal and data.

8. The method of claim 1 or 2 wherein the method is iteratively performed wherein, for each iteration, a base station transmits signals using a narrower transmit beam.

9. The method of claim 1 , further comprising:

estimating an angle of arrival of the first arrived path corresponding to each of the plurality of receive beams; and

setting directions of the plurality of receive beams based on the angle of arrival.

10. The method of claim 9, wherein the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas.

1 1 . The method of claim 10, wherein the angle of arrival, phi, is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light,

T = time difference of arrival at the two receiving antennas, and

a = antenna separation.

12. A wireless device (212) for positioning in a wireless communication system, the wireless device (212) adapted to:

• for each receive beam of a plurality of receive beams:

o receive (600; 800) a signal on the receive beam via one or more signal propagation paths;

o detect (604, 804) a first arrived path for the signal on the receive beam, the first arrived path being a signal propagation path by which the signal is first received at the wireless device (212) on the receive beam; o determine (606, 806) a Time of Arrival, TOA, of the signal on the receive beam via the first arrived path on the receive beam; and

• determine (608, 808) a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams;

13. The wireless device (212) of claim 12 wherein the wireless device (212) is further adapted to perform the method of any one of claims 2 to 1 1 .

14. A wireless device (212; 1200) for positioning in a wireless communication system, the wireless device (212; 1200) comprising:

one or more transmitters (1208) ;

one or more receivers (1210) ; and

processing circuitry (1202) associated with the one or more transmitters (1208) and the one or more receivers (1210) , the processing circuitry (1202) configured to cause the wireless device (212; 1200) to:

• for each receive beam of a plurality of receive beams:

o detect (604, 804) a first arrived path for the signal on the receive beam, the first arrived path being a signal propagation path by which the signal is first received at the wireless device (212; 1200) on the receive beam; o determine (606, 806) a Time of Arrival, TOA, of the signal on the receive beam via the first arrived path on the receive beam; and

• wherein the minimum TOA is used in relation to positioning of the wireless device (212; 1200).

15. A method performed by a wireless device (212), the method comprising:

• for each transmit beam of one or more transmit beams detected at the

wireless device (212) : o receiving (700) a signal for the transmit beam via one or more signal propagation paths;

o determining (704) a first arrived path of the signal for the transmit beam received at the wireless device (212), the first arrived path being a signal propagation path by which the signal for the transmit beam is first received at the wireless device (212) ; and

o determining (706) a Time of Arrival, TOA, of the signal for the transmit beam received at the wireless device (212) via the first arrived path of the signal for the transmit beam; and

• determining (708) a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams;

16. The method of claim 15 further comprising:

setting (710) an estimated TOA to the minimum TOA; and

reporting or employing (712) the estimated TOA for positioning the wireless device (212).

17. The method of claim 15 or 16, further comprising:

• for each receive beam of a plurality of receive beams:

o receiving (600) a signal on the receive beam via one or more signal

propagation paths;

o detecting (604) a first arrived path for the signal on the receive beam, the first arrived path being a signal propagation path by which the signal is first received at the wireless device (212) on the receive beam; and o determining (606) a TOA of the signal on the receive beam via the first arrived path on the receive beam;

• determining (608) a minimum TOA from among the determined TOAs for the determined first arrived paths on the plurality of receive beams;

• setting (610) a second estimated TOA to the minimum TOA; and • reporting or employing (612) the second estimated TOA for positioning the wireless device (212).

18. The method of claim 17 comprising:

for each receive beam of the plurality of receive beams, calculating (602) a Channel I mpulse Response, CI R, for the receive beam based on the signal received on the receive beam via the one or more signal propagation paths;

wherein, for each receive beam of the plurality of receive beams, detecting (604) the first arrived path on the receive beam comprises detecting (604) the first arrived path on the receive beam based on the calculated CI R for the receive beam.

19. The method of claim 17 or 18, wherein, for each receive beam of the plurality of receive beams, the signal received on the receive beam comprises a reference signal, data, or a combination of a reference signal and data.

20. The method of any one of claims 15 to 19, further comprising:

for each transmit beam of the one or more transmit beams, calculating (818) a CI R for the transmit beam based on the signal for the transmit beam received at the wireless device (212) via one or more signal propagation paths;

21 . The method of any one of claims 15 to 20, wherein, for each transmit beam of the one or more transmit beams, the signal for the transmit beam comprises a reference signal, data, or a combination of a reference signal and data.

22. The method of claim 15 or 16 wherein the method is iteratively performed wherein, for each iteration, the wireless device (212) receives signals using a narrower receive beam.

23. The method of any one of claims 17 to 19, further comprising: estimating an angle of arrival of the first arrived path corresponding to each of the plurality of receive beams; and

24. The method of claim 23, wherein the angle of arrival is determined by a time difference of arrival at two receiving antennas and a priori information of separation of the two receiving antennas.

25. The method of claim 24, wherein the angle of arrival, phi, is determined according to the following equation:

phi = arcsin(T x c/a),

wherein:

c = speed of light,

T = time difference of arrival at the two receiving antennas, and

a = antenna separation.

26. A wireless device (212) for positioning in a wireless communication system, the wireless device (212) adapted to:

• for each transmit beam of one or more transmit beams detected at the

wireless device (212) :

o receive (700) a signal for the transmit beam via one or more signal

propagation paths;

o determine (704) a first arrived path of the signal for the transmit beam received at the wireless device (212), the first arrived path being a signal propagation path by which the signal for the transmit beam is first received at the wireless device (212) ; and

o determine (706) a Time of Arrival, TOA, of the signal for the transmit beam received at the wireless device (212) via the first arrived path of the signal for the transmit beam; and

• determine (708) a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams; • wherein the minimum TOA is used in relation to positioning of the wireless device (212).

27. The wireless device (212) of claim 26 wherein the wireless device (212) is further adapted to perform the method of any one of claims 16 to 25.

28. A wireless device (212; 1200) for positioning in a wireless communication system, the wireless device (212; 1200) comprising:

one or more transmitters (1208) ;

one or more receivers (1210) ; and

• for each transmit beam of one or more transmit beams detected at the

wireless device (212; 1200) :

o receive (700) a signal for the transmit beam via one or more signal

propagation paths;

o determine (704) a first arrived path of the signal for the transmit beam received at the wireless device (212; 1200) , the first arrived path being a signal propagation path by which the signal for the transmit beam is first received at the wireless device (212; 1200) ; and

o determine (706) a Time of Arrival, TOA, of the signal for the transmit

beam received at the wireless device (212; 1200) via the first arrived path of the signal for the transmit beam; and

• determine (708) a minimum TOA from among the determined TOAs of the signals received for the one or more transmit beams on the determined first arrived paths for the one or more transmit beams;