WO2023033835A1

WO2023033835A1 - Apparatus and method of beam parameter estimation for line-of-sight determination

Info

Publication number: WO2023033835A1
Application number: PCT/US2021/049088
Authority: WO
Inventors: Arkady Molev-Shteiman; Yi-Hsiu Wang
Original assignee: Zeku, Inc.
Priority date: 2021-09-03
Filing date: 2021-09-03
Publication date: 2023-03-09

Abstract

According to one aspect of the present disclosure, an apparatus of wireless communication is provided. The apparatus may include a radio. The radio may perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The radio may estimate, based on the set of beam parameters, a plurality of amplitudes associated with the plurality of beams. The radio may identify a maximum amplitude of the plurality of amplitudes. The radio may identify a line-of-sight (LOS) beam based on the maximum amplitude. The radio may input the set of beam parameters associated with the LOS beam into a navigation function.

Description

APPARATUS AND METHOD OF BEAM PARAMETER ESTIMATION FOR LINE-OF-SIGHT DETERMINATION

BACKGROUND

[0001] Embodiments of the present disclosure relate to apparatus and method for wireless communication.

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. In wireless local area network (WLAN) communication (e.g., such as Wi-Fi) and in cellular communication (e.g., such as the 4th-generation (4G) Long Term Evolution (LTE) and the 5th-generation (5G) New Radio (NR)), the Institute of Electrical and Electronics Engineers (IEEE) and the 3rd Generation Partnership Project (3 GPP) define various operations for determining a line-of-sight (LOS) beam in a multipath scenario.

SUMMARY

[0003] Embodiments of apparatus and method for antenna array calibration are disclosed herein.

[0004] According to one aspect of the present disclosure, an apparatus of wireless communication is provided. The apparatus may include an antenna array configured to receive a signal comprising a plurality of beams. The apparatus may include a radio. The radio may include a set of beam parameter estimation circuits configured to perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The radio may include an amplitude estimation circuit configured to estimate, based on the set of beam parameters, a plurality of amplitudes associated with the plurality of beams. The amplitude estimation circuit may be further configured to identify a maximum amplitude from the plurality of amplitudes. The radio may include an LOS circuit configured to identify an LOS beam based on the maximum amplitude. The LOS circuit may input the set of beam parameters associated with the LOS beam into a navigation function.

[0005] According to another aspect of the disclosure, a radio is provided. The radio may include a set of beam parameter estimation circuits configured to perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The radio may include an amplitude estimation circuit configured to estimate, based on the set of beam parameters, a plurality of amplitudes associated with the plurality of beams. The amplitude estimation circuit may be further configured to identify a maximum amplitude from the plurality of amplitudes. The radio may include an LOS circuit configured to identify an LOS beam based on the maximum amplitude. The LOS circuit may input the set of beam parameters associated with the LOS beam into a navigation function.

[0006] According to yet another aspect of the disclosure, a method of wireless communication is provided. The method may include receiving, by an antenna array, a signal comprising a plurality of beams. The method may include performing, by a set of beam parameter estimation circuits, a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The method may include estimating, by an amplitude estimation circuit, a plurality of amplitudes associated the plurality of beams based on the set of beam parameters. The method may include identifying, by the amplitude estimation circuit, a maximum amplitude from the plurality of amplitudes. The method may include identifying, by an LOS circuit, an LOS beam based on the maximum amplitude. The method may include inputting the set of beam parameters associated with the LOS beam into a navigation function.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the pertinent art to make and use the present disclosure.

[0008] FIG. 1 illustrates an exemplary wireless network, according to some embodiments of the present disclosure.

[0009] FIG. 2 illustrates a block diagram of an apparatus including a radio, a wireless network interface, and a host chip, according to some embodiments of the present disclosure.

[0010] FIG. 3 A illustrates a graphical representation of a time autocorrelation function that set of beam parameters estimation circuits of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure.

[0011] FIG. 3B illustrates a graphical representation of an angular autocorrelation function that set of beam parameters estimation circuits of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure. [0012] FIG. 3C illustrates a graphical representation of a time-angular autocorrelation function that set of beam parameters estimation circuits of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure.

[0013] FIG. 3D illustrates a diagram of an acquisition correlation and zoom-in procedure that may be implemented by a set of beam parameter estimation circuits of FIG. 2, according to some embodiments of the present disclosure.

[0014] FIG. 3E illustrates a diagram of a beam cluster that includes a superposition of beams, according to some embodiments of the present disclosure.

[0015] FIG. 3F illustrates a diagram of a correlation cluster identified using the acquisition correlation and zoom-in procedure, according to some embodiments of the present disclosure.

[0016] FIG. 4 illustrates a flowchart of a method for wireless communication, according to some embodiments of the present disclosure.

[0017] FIG. 5 illustrates a block diagram of an exemplary node, according to some embodiments of the present disclosure.

[0018] FIG. 6 illustrates an antenna array receiving a plurality of beams.

[0019] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION

[0020] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present disclosure. It will be apparent to a person skilled in the pertinent art that the present disclosure can also be employed in a variety of other applications.

[0021] It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “some embodiments,” “certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of a person skilled in the pertinent art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0022] In general, terminology may be understood at least in part from usage in context. For example, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0023] Various aspects of wireless communication systems will now be described with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0024] The techniques described herein may be used for various wireless communication networks, such as code division multiple access (CDMA) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, orthogonal frequency division multiple access (OFDMA) system, single-carrier frequency division multiple access (SC- FDMA) system, wireless local area network (WLAN) system, a global navigation satellites system (GNSS), and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio access technology (RAT), such as Universal Terrestrial Radio Access (UTRA), evolved UTRA (E-UTRA), CDMA 2000, etc. A TDMA network may implement a RAT, such as the Global System for Mobile Communications (GSM). An OFDMA network may implement a RAT, such as LTE or NR. A WLAN system may implement a RAT, such as Wi-Fi. The techniques described herein may be used for the wireless networks and RATs mentioned above, as well as other wireless networks and RATs.

[0025] GNSS is frequently used for positioning services in various applications, such as pedestrian and vehicular navigation. To accurately determine its position, a user equipment (UE) or station (STA) is generally equipped with a GNSS receiver. The GNSS receiver uses the time difference between the time a signal is received versus when the signal was broadcast by a satellite vehicle (SV) to determine the receiver’s distance from the SV. A GNSS receiver that receives signals from four SVs can determine its position in three-dimensions (3D). Three of the SVs are used to determine latitude, longitude, and height, while a fourth SV is set to synchronize the receiver’s internal clock.

[0026] In recent years, research into Angle-of-Arrival (AoA) estimation has attracted significant attention for applications such as radar, sonar, mobile communications, and position estimation. GNSS AoA techniques typically utilize arrays of multiple antennas to measure the direction of incoming signals from several locations. Multipath and interference are the main sources of errors in positions estimated by GNSS signals. The interfering signals reduce the signal- to-noise ratio (SNR) and can cause receiver failure to detect SV signals. On the other hand, multipath distorts correlation peaks and affects discriminators.

[0027] Similar issues may arise when multiple-input multiple-output (MIMO) and/or multi-use-MIMO (MU-MIMO) are used for position estimation. MIMO facilitates parallel delivery of multiple spatially multiplexed data signals, which are referred to as multiple spatial streams. Further, in multi-user MIMO (MU-MIMO), an access point (AP) may simultaneously transmit to multiple client user equipments (UEs), and beamforming may be used for directional signal transmission or reception. In MU-MIMO, the term “downlink” refers to communication, which may occur in parallel, from an AP (e.g., transmitted by the AP) to one or more stations (STAs), while the term “uplink” refers to communication, which may occur in parallel, to an AP (received by the AP) from one or more STAs.

[0028] AoA refers to a direction of propagation of a radio-frequency wave incident on an antenna array relative to the orientation of the antenna array. As one example, AoA may be determined based on the Time Difference of Arrival (TDOA) or phase difference measurements of a radio wave received at individual elements (also referred to herein as “antenna systems”) of an antenna array. In some embodiments, AoA may be determined by an STA (e.g., user equipment) based on signals exchanged with another STA (e.g., an access point (AP)). For example, an STA, such as a receiver, may resolve AoA based on signals exchanged with another STA.

[0029] The term “Fine Timing Measurement” (FTM) refers to a message exchange protocol that may be used for positioning. FTM involves the exchange of FTM frames for range determination. For example, an initiating STA (e.g., non-AP STA) may start an FTM session and exchange FTM frames with a responding STA (e.g., an AP STA). The initiating STA may measure the time-of-fhght (TOF), which is given by half the round trip delay. The initiating STA may determine its range based on exchanged frames, which may include timestamps corresponding to (a) the departure time of the FTM frame from the initiating STA and (b) the arrival time of the FTM frames at the responding station (e.g., an AP) during an FTM session. In some embodiments, such as MIMO/MU-MIMO, parameters such as Angle of Arrival (AoA), doppler speed, and delay may also be used to determine STA position. FTM frames (e.g., from an initiator) may use a dialog token to identify a corresponding FTM/FTM Acknowledgment (e.g., from a responder). FTM frames may include timestamp measurements at the AP and/or at an STA. The timestamp measurements may be used for range calculation and/or position determination.

[0030] One or more frame structure and/or fields (OE/IE/data) in frames, broadcast messages, and/or message exchange protocols may be leveraged to determine one or more of (a) whether STA-AP positioning is available and/or whether an AP supports STA-AP positioning; and/or (b) whether AP-AP positioning is available and/or c) whether an AP is currently performing AP-AP positioning. In some embodiments, the disclosed techniques may be embodied in an application on an STA (e.g., an AP STA or a non-STA) as appropriate. The example message flows, frame formats, and/or information elements described herein may be compatible, in some respects, with specifications, diagrams, and guidelines found in some IEEE 802.11 standards.

[0031] The AoA, doppler speed, and delay (e.g., beam parameters) can be estimated using an antenna array of a STA. However, accurate determinations of these beam parameters require accurate knowledge of the received signal. An example of an antenna array 600 receiving multiple signals 601 from multiple directions is illustrated in FIG. 6. These signals may be received from one or more SVs, APs, and/or base stations, depending on the type of positioning determination performed.

[0032] As shown in FIG. 6, antenna array 600 includes a plurality of antennas 602. Although depicted as a linear array, antenna array 600 may include a planar rectangular array with spacing between antennas equal to half-wavelength. The number of vertical antennas may beM_α , while the number of horizontal antennas may be M_β . Thus, the total antennas number is A received signal may include Q bands, where the carrier frequency of each band q

is denoted as f . Moreover, a received signal may include K beams, where each of the K beams has complex amplitude A_k , a two-dimensional electronics angle or AoA

, speed v_k , and delay T_k .

[0033] The connection between AoA

and the two-dimensional physical angle is described by the following expressions (1.1): α = cos (e/) - cos (az), β = cos (e/) . sin (az) (0 1), where az is the azimuth and el is the elevation.

[0034] The signal received by an antenna 602 with index

in band q at time t is equal to a superposition of K beams, as described below in expression (1.2):

where (t) is additive noise at antenna(mα ,mβ

) at band q at time t.

[0035] Moreover, each beam k in antenna (m_α, mβ) , band q at time t can be described according to expression (1.3):

where pn_q (t) is the pseudo-random number (PN) sequence of band q, BW is the signal bandwidth, and str_{mα ,mβ}(α_k, β_k) is the steering function.

[0036] An example of steering function str_{mα ,mβ}(α_k, β_k) is shown below in expression

(1.4):

where exp(j . 2 . π (m_α . α + mβ.β is the doppler shift, j is

m_α is the antenna

row number, mβ is the antenna column number, M_α is the total number of rows in antenna array 600, and Mβ is the total number of columns in antenna array 600.

[0037] For simplicity, the PN sequence bandwidth of each band q may be considered identical. For a direct sequence spread spectrum, the PN sequence is a quadrature phase shift keying (QPSK) signal. For OFDM, the PN sequence signal has a Gaussian distribution. In both cases, the autocorrelation function of the PN code may be described according to expression (1.5):

where (□) denotes a conjugate operation, E is the energy, t is time, and T is delay.

[0038] In urban environments, however, GNSS positioning using antenna array 600 may perform unreliably. GNSS positioning is greatly affected by multipath and non-LOS (NLOS) reception scenarios, which occur when an SV signal is blocked and/or reflected by a building, for example. In other words, the denser the urban canyon, the more challenging it is to determine beam parameters from an LOS beam, and hence, to estimate parameters accurately for use in navigation. For example, a superposition of the K beams of received signal 601 may complicate the estimation of beam parameters.

[0039] Thus, there exists an unmet need for a technique to estimate beam parameters and identify an LOS beam for use in navigation in scenarios in which multipath or beam superposition occurs.

[0040] To overcome these and other challenges, the present disclosure provides a joint estimation procedure that jointly estimates a set of beam parameters for each k beam of a received signal. The jointly estimated beam parameters may include, e.g., AoA (angle speed

, and delay . Using the estimated set of beam parameters, the first arriving beam may be identified: (0.6).

[0041] Then, it may be verified that the first arriving beam has the maximum energy: (0.7),

by estimating complex amplitude /( for each k beam. The present disclosure identifies the LOS beam as the beam associated with the maximum complex amplitude. Then, the set of beam parameters associated with the LOS beam may be input into a navigation function. Thus, using the present techniques, the set of beam parameters use in navigation can be estimated with a high- degree of accuracy even in multipath and/or beam superposition scenarios. Additional details of these and other techniques are provided below in connection with FIGs. 1-5.

[0042] Although some embodiments are described herein in connection with a WLAN or GNSS communication system, the same or similar techniques may be applied to a cellular communication system, as well. For example, a UE that receives a signal from a 5G NR base station via beamforming and/or millimeter-wave (mmW) signaling may experience multipath issues as these beams may reflect off nearby objects, which can deteriorate the accuracy of positioning determination using these signals. Thus, the techniques described below may apply to estimating a set of beam parameters for use in positioning determination by a UE in a cellular communication system without departing from the scope of the present disclosure.

[0043] FIG. 1 shows a simplified architecture of a wireless communication system 100 in accordance with certain embodiments presented herein. System 100 may include non-access point (AP) stations (STAs) such as UEs 120-1 through 120-n (collectively referred to as UEs 120), and AP STAs such as APs 140-1 through 140-4 (collectively referred to as APs 140), which may communicate over a wireless communication network 130. Examples of UEs 120 may include, e.g., smartphones, vehicles, wearable devices, laptops, or any other device that can provide a navigation function to a user. In some embodiments, wireless communication network 130 may take the form of and/or may include one or more wireless local area networks (WLANs) or the internet. In some embodiments, UEs 120 and/or APs 140 may communicate with server 150 via wireless communication network 130. While system 100 illustrates some UEs 120 and APs 140, the number of UEs 120 and APs 140 in a wireless communication network (e.g., a WLAN) may be varied in accordance with various system parameters. In general, system 100 may include a smaller or larger number of UEs 120 and/or APs 140.

[0044] In some embodiments, as outlined above, UE 120 may receive, measure and decode signals from one or more satellite vehicles (SVs) 180-1 through 180-4 and thereby, as is well known in the art, obtain a position fix, an accurate absolute time reference (such as global positioning system (GPS) time, Coordinated Universal Time (UTC) or a time for another GNSS which may be accurate to 50 nanoseconds (ns) or better in some embodiments) and a timing reference uncertainty. In some embodiments, the GNSS position fix, absolute time reference and/or absolute time synchronization information (e.g., GPS time, GNSS time, or UTC time) and timing reference uncertainty may be provided (e.g., by one or more UEs 120) to APs 140 by sending signaling information to APs 140 that includes a time reference such as using, for example, the Internet Network Time Protocol (NTP), IEEE 1588 Precision Time Protocol (PTP) and/or ITU- T Synchronous Ethernet. In some embodiments, APs 140, which receive the position fix, absolute time reference, and time reference uncertainty information, may optionally, modify the time reference uncertainty information to account for other inaccuracies and/or processing delays. In some embodiments, the absolute time and time reference uncertainty information may be modified by APs 140 based on the distance of UE 120 from AP 140, which may be determined from the position fix. For example, APs 140 may modify time reference uncertainty to adjust for Short Interframe Spacing (SIFS) delays, if appropriate. The terms “SIFS interval” or “SIFS delay” may refer to the amount of time (e.g., in microseconds) it takes for a wireless interface to process a received frame and to respond with a response frame. A SIFS interval may consist of the time delay arising from receiver radio frequency (RF) processing, Physical Layer Convergence Procedure (PLCP) delay, and the Medium Access Control (MAC) processing delay, which may depend on the physical layer used.

[0045] In some embodiments, APs 140 and/or UEs 120 that are synchronized to or have access to a common time reference may transmit or re-transmit (unicast, multicast, or broadcast) the common time reference and time reference uncertainty to other STAs or devices on network 130. For example, an AP 140 synchronized to an absolute timing reference may transmit the timing reference and timing uncertainty information to other devices. As another example, a UE 120 may demodulate the Time-Of-Week (TOW) header to obtain an absolute (e.g., GNSS) time reference. In some embodiments, UE 120 may send the absolute time reference and timing reference uncertainty to one or more APs 140. Further, the timing reference and timing uncertainty may be requested by and/or provided to one or more UEs 120 that do not have access to the absolute timing reference source.

[0046] In instances where one or more APs 140 experience clock degradation, maintaining timing synchronization by APs 140 may be facilitated by the timing information received by the APs 140 from UEs 120. In some embodiments, APs 140 may use the absolute time reference (e.g., GNSS time) for measurements and/or time stamps. For example, packets or frames sent or received by APs 140 may be timestamped using the absolute time reference. In some embodiments, multiple APs 140 on network 130 may be synchronized to a common absolute time reference (e.g., to GNSS time) via timing information received from UEs 120 to obtain a quasi-synchronous network.

[0047] In some embodiments (e.g., in quasi -synchronized networks), APs 140 may estimate one-way delay for packets received from another device based on the timestamp indicating the time the packet was sent and the time that the packet was received at AP 140. In embodiments where one or more UEs 120 may also be synchronized to the absolute time reference (bounded by the timing reference uncertainty), then, APs 140 that are also synchronized to the absolute time reference may estimate one-way delay for packets (with the timing uncertainty) received from synchronized UEs 120 based on the timestamp indicating the time the packet was sent and time that the packet was received at AP 140. Conversely, a UE 120 may also estimate one-way delay for packets received from APs 140 that are synchronized to the common absolute time reference.

[0048] In some embodiments, one or more UEs 120 and/or APs 140 in system 100 may comprise multiple antennas and may support multiple-input multiple-output (MIMO) and/or multiuser MIMO (MU-MIMO). UE 120 may receive and measure signals from APs 140, which may be used for position determination. In some embodiments, APs 140 may form part of a wireless communication network 130, such as a WLAN. For example, a WLAN may be an IEEE 802.1 lx network (e.g., such as IEEE 802.1 lax, 802. Hay, or later version). Further, system 100 may comprise or take the form of an Extended Service Set (ESS) network, which may comprise a plurality of appropriately configured basic service set (BSS) networks, an Independent Basic Service Set (IBSS) network, an ad-hoc network, or a peer-to-peer (P2P) network (e.g., operating according to Wi-Fi Direct or similar protocols).

[0049] In some embodiments, system 100 may support orthogonal frequency -division multiple access (OFDMA) communications, namely, conforming to the IEEE 802.1 lax specification or variants thereof. OFDMA may facilitate multiple STAs to transmit and receive data on a shared wireless medium at the same time. For a wireless network using OFDMA, the available frequency spectrum may be divided into a plurality of resource units (RUs) each with a number of different frequency subcarriers, and distinct RUs may be assigned (e.g., by AP 140) to various wireless devices (e.g., UEs 120) at a given point in time. Accordingly, OFDMA may facilitate the concurrent transmission of wireless data by multiple wireless devices over the wireless medium using their assigned RUs. In some implementations, an AP may use a specific type of frame (such as a “trigger frame”) to allocate specific RUs to a number of wireless devices identified in the trigger frame. The trigger frame may indicate the RU size and location, power level, and other parameters to be used by identified wireless devices for uplink (UL) transmissions. In some embodiments, the AP may also use a trigger frame to solicit uplink (UL) multi-user (MU) data transmissions from wireless devices identified in the trigger frame. In some instances, the trigger frame may indicate or specify an order for identified wireless devices are to transmit UL data to the AP.

[0050] In some embodiments, one or more UEs 120 and APs 140 may communicate over wireless communication network 130, which may be based on IEEE 802.11 or compatible standards. In some embodiments, UEs 120 and APs 140 may communicate using variants of the IEEE 802.11 standards. For example, UEs 120 and APs 140 may communicate using 802.1 lac on the 5 GHz band, which may support multiple spatial streams including MIMO and MU-MIMO and. In some embodiments, UEs 120 and APs 140 may communicate using some of the above standards, which may further support one or more of Very High Throughput (VHT) (as described in the above standards) and High Efficiency WLAN (HEW), and/or beamforming with standardized sounding and feedback mechanisms. In some embodiments, UEs 120 and or APs 140 may additionally support legacy standards for communication with legacy devices.

[0051] In some embodiments, an AP 140 may determine its availability for positioning at a first time and may transmit, based on the determination, information indicative of the AP’s availability for positioning. The information indicative of the AP’s availability for positioning may comprise at least one of AP availability for STA-AP location determination, or STA-AP location determination capability, or whether AP-AP AP positioning is being performed; or the next scheduled passive AP-AP ranging session; or some combination thereof.

[0052] In some embodiments, the availability of AP 140 for positioning at a first time may be determined based on AP load or network load or channel load. For example, APs 140, which may form part of wireless communication network 130, may transmit management frames, which may include network related information. APs 140 may transmit (broadcast) management (e.g., beacon) frames periodically (e.g., every 120 ms) to announce the WLAN. For example, management frames, such as beacon frames, may include capability information, supported data rates, identification of network type (e.g., as an infrastructure network), a service set identifier (SSID) and/or a basic service set identifier (BSSID). In some embodiments, APs 140 may transmit a BSS Load element frame (e.g., with information related to the number of stations currently associated with an AP, channel utilization for available channels, available admission capacity, etc.), which may provide information on parameters related to AP load. In some embodiments, the BSS Load Element or similar information element (IE) may be transmitted by an AP 140 as part of a probe response frame or another WLAN management frame.

[0053] Conventionally, network congestion may detrimentally affect STA positioning. For example, network congestion may cause an AP 140 to reject positioning requests from one or more UEs 120. When STA positioning requests are rejected, one or more UEs 120 may retry the positioning request, thereby potentially aggravating existing congestion. In other instances, the response to STA/UE 120 positioning requests may be delayed (e.g., by a responding STA/AP 140), thereby limiting the utility of the response. In addition, as the number of STAs associated with an AP increases, the ranging (RTT/FTM) measurements may consume significant system and network resources. For an AP with a high load relative to capacity, additional STA-AP positioning requests from UEs may aggravate congestion and detrimentally affect performance.

[0054] Accordingly, in some embodiments, the availability of AP 140 for positioning at a first time may be determined based on AP load or network load or channel load. As one example, one or more APs 140 may transmit information indicative of AP load, network load, or channel load. For example, an AP 140 may provide information indicative of AP load in a BSS Load Element and/or another Field (e.g., in a management frame) field. As another example, an AP 140 may implicitly indicate higher AP load by disabling STA-AP positioning. As a further example, AP 140 may implicitly indicate lower AP load by signaling availability for STA-AP positioning. AP load, and/or network load and/or channel load-related information may also be implicitly indicated by temporarily indicating that AP 140 lacks support for STA-AP positioning or lacks STA-AP positioning capability. For example, capability information transmitted by APs 140 may be temporarily altered to indicate a lack of support STA-AP positioning. Further, the capability information may (additionally or alternatively) indicate support for AP-AP positioning and/or indicate performance (e.g., at a current time or some scheduled time) of AP-AP positioning.

[0055] In some embodiments, UE 120 may initiate a location determination method to determine a location of UE 120 based on indications of availability for positioning received from one or more APs communicatively coupled to the STA. Each indication of availability may correspond to a distinct AP, and the location determination method may include either active UE- AP/STA-AP location determination by UE 120, or passive location determination. For example, in passive location determination, UE 120 may determine its location by sniffing AP-AP positioning session message exchanges, or by sniffing STA-AP positioning session message exchanges for other STAs/UEs. In some embodiments, the indication of availability (of an AP) for positioning may include information indicative of: (i) availability of an STA-AP positioning mode on the AP, or (ii) support for an STA-AP positioning capability on the AP, or availability of an AP-AP positioning mode on the AP, or (iii) support for an AP-AP positioning capability on the AP, or (iv) a current performance of AP-AP positioning by the AP, or (v) a scheduled performance of AP-AP positioning on the AP, or some combination thereof. In some embodiments, the information indicative of support for the STA-AP positioning capability on an AP, or the information indicative of support for the AP-AP positioning capability on the AP may be comprised in a capabilities field specifying the corresponding AP’s capabilities.

[0056] In some embodiments, UEs 120 may determine or infer a network load and/or AP load and/or channel load based on (i)-(v) above. In some embodiments, UE 120 may determine a network load and/or AP load and/or channel load based, in part, on (i) parameters in a BSS Load Element and/or in other fields transmitted by the AP (e.g., in a management frame). Further, based on the AP positioning availability information and/or inferred/determined network/ AP/channel load, one or more UEs 120 may request AP-AP positioning, or STA-AP positioning. For example, when the network load (e.g., as determined by UEs 120) is high or exceeds some threshold, or one or more APs signal unavailability or a lack of support for STA-AP positioning, then, UEs 120 may determine their respective position based on passive positioning. In some embodiments, UEs 120 may determine position by requesting and performing STA-AP positioning when AP/network/channel load is low, or APs 140 indicate support for STA-AP positioning and/or availability of STA-AP positioning at a current time (or at some specified time). For example, if the AP load or network load (e.g., as determined by UEs 120) indicates that AP load is low or does not exceed the threshold, or, if one or more APs 140 signal availability or support for STA-AP positioning, then STAs/UEs 120 may request STA-AP positioning and determine their respective positions actively by requesting STA-AP positioning.

[0057] In some embodiments, UEs 120 and/or APs 140 may be coupled to one or more additional networks, such as a cellular carrier network, a satellite positioning network (shown in FIG. 1), wireless personal area network (WPAN) access points, and the like (not shown in FIG. 1). In some embodiments, UEs 120 and/or APs 140 may be coupled to a wireless wide area network (WWAN) (not shown in FIG. 1), A WWAN may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) network, Long Term Evolution (LTE), WiMax, and so on.

[0058] A CDMA network may implement one or more radio access technologies (RATs) such as CDMA1000, Wideband-CDMA (W-CDMA), and so on. CDMA1000 includes IS-95, IS- 1000, and IS-856 standards. A TDMA network may implement Global System for Mobile Communications (GSM), Digital Advanced Mobile Phone System (D-AMPS), or some other RAT. GSM, W-CDMA, LTE, 5GNR are described in documents from 3GPP. CDMA1000 is described in documents from a consortium named “3rd Generation Partnership Project 2” (3GPP2). 3GPP and 3GPP2 documents are publicly available.

[0059] As illustrated in FIG. 1, UE 120 may also communicate with server 150 through wireless communication network 130 and APs 140, which may be associated with wireless communication network 130. In some embodiments, APs 140 and/or UE 120 may receive location assistance, network traffic, network load, and/or other network related information from server 150, which, in some instances, may be relayed to UEs 120 through one or more APs 140. In some embodiments, server 150 may serve as a system controller and may interface with other less and/or wired networks, and/or facilitate communication between devices coupled to system 100 and devices on another work.

[0060] Each element in FIG. 1 may be considered a node of wireless communication system 100. More detail regarding the possible implementation of a node is provided by way of example in the description of a node 500 in FIG. 5. Node 500 may be configured as UE 120, AP 140, or server 150 in FIG. 1. As shown in FIG. 5 , node 500 may include a processor 502, a memory 504, and a transceiver 506. These components are shown as connected to one another by a bus, but other connection types are also permitted. When node 500 is UE 120, additional components may also be included, such as a user interface (UI), sensors, and the like. Similarly, node 500 may be implemented as a blade in a server system when node 500 is configured as server 150. Other implementations are also possible.

[0061] Transceiver 506 may include any suitable device for sending and/or receiving data. Node 500 may include one or more transceivers, although only one transceiver 506 is shown for simplicity of illustration. An antenna 508 is shown as a possible communication mechanism for node 500. Multiple antennas and/or arrays of antennas may be utilized for receiving multiple spatially multiplex data streams. Additionally, examples of node 500 may communicate using wired techniques rather than (or in addition to) wireless techniques. For example, AP 140 may communicate wirelessly to UE 120 and may communicate by a wired connection (for example, by optical or coaxial cable) to server 150. Other communication hardware, such as a network interface card (NIC), may be included as well.

[0062] As shown in FIG. 5, node 500 may include processor 502. Although only one processor is shown, it is understood that multiple processors can be included. Processor 502 may include microprocessors, microcontroller units (MCUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. Processor 502 may be a hardware device having one or more processing cores. Processor 502 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software can include computer instructions written in an interpreted language, a compiled language, or machine code. Other techniques for instructing hardware are also permitted under the broad category of software. [0063] As shown in FIG. 5, node 500 may also include memory 504. Although only one memory is shown, it is understood that multiple memories can be included. Memory 504 can broadly include both memory and storage. For example, memory 504 may include random-access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferroelectric RAM (FRAM), electrically erasable programmable ROM (EEPROM), compact disc read only memory (CD-ROM) or other optical disk storage, hard disk drive (HDD), such as magnetic disk storage or other magnetic storage devices, Flash drive, solid-state drive (SSD), or any other medium that can be used to carry or store desired program code in the form of instructions that can be accessed and executed by processor 502. Broadly, memory 504 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0064] Processor 502, memory 504, and transceiver 506 may be implemented in various forms in node 500 for performing wireless communication functions. In some embodiments, processor 502, memory 504, and transceiver 506 of node 500 are implemented (e.g., integrated) on one or more system-on-chips (SoCs). In one example, processor 502 and memory 504 may be integrated on an application processor (AP) SoC (sometimes known as a “host,” referred to herein as a “host chip”) that handles application processing in an operating system (OS) environment, including generating raw data to be transmitted. In another example, processor 502 and memory 504 may be integrated on a baseband processor (BP) SoC (sometimes known as a “modem,” referred to herein as a “radio”) that converts the raw data, e.g., from the host chip, to signals that can be used to modulate the carrier frequency for transmission, and vice versa, which can run a real-time operating system (RTOS). In still another example, processor 502 and transceiver 506 (and memory 504 in some cases) may be integrated on an RF SoC (sometimes known as a “transceiver,” referred to herein as a “wireless network interface”) that transmits and receives RF signals with antenna 508. It is understood that in some examples, some or all of the host chip, radio, and wireless network interface may be integrated as a single SoC. For example, a radio and a wireless network interface may be integrated into a single SoC that manages all the radio functions for GPSS communication, WLAN communication, WPAN communication, and/or cellular communication.

[0065] Referring back to FIG. 1, in some embodiments, any suitable node of wireless communication system 100 (e.g., UE 120) may include a receiver with an antenna array configured to receive a signal, and a radio configured to estimate positioning information based on the received signal. In some scenarios, the received signal may include multipath beams and/or a superposition of beams received from different transmitters (e.g., APs 140 and/or SVs 180). UE 120 may apply a joint estimation procedure to the received signal to jointly estimate a set of beam parameters for each of the K beams. The jointly estimated beam parameters may include, e.g., AoA (angle speed , and delay Using the estimated set of beam parameters, UE 120 may

estimate a set of complex amplitudes of the received signal, where each amplitude is associated

with a k beam. Moreover, UE 120 may identify the first arriving beam of the received signal and whether the first arriving beam is associated with the maximum amplitude from the set of complex amplitudes In response to the first arriving beam having the maximum amplitude, UE 120 may input the set of beam parameters estimated for the first beam into a navigation function. Otherwise, UE 120 checks the other beams to determine which has the maximum amplitude. The beam with the maximum amplitude is identified as the LOS beam, and the associated set of beam parameters may be input into a navigation function. Using these techniques, UE 120 may estimate a set of beam parameters with a high degree of accuracy even in scenarios of multipath and/or beam superposition. Additional details of these and other techniques are provided below in connection with FIGs. 2, 3A, 3B, 3C, 3D, 3E, 3F, and 4.

[0066] FIG. 2 illustrates a block diagram of an apparatus 200 including a radio 202, a wireless network interface 204, and a host chip 206, according to some embodiments of the present disclosure. Apparatus 200 may be implemented as UE 120 of wireless communication system 100 in FIG. 1. In some embodiments, radio 202 is implemented by processor 502 and memory 504, and wireless network interface 204 is implemented by processor 502, memory 504, and transceiver 506, as described above with respect to FIG. 5. When used for positioning determination within a WLAN communication system, radio 202 may be implemented as a WLAN radio or communication chip. On the other hand, when used for positioning determination within a GNSS communication system, radio 202 may be implemented as a GNSS receiver radio. Still further, when used for positioning determination within a cellular communication system, radio 202 may be implemented as a baseband chip and wireless network interface 204 may be implemented as an RF chip.

[0067] Besides the on-chip memory 218 (also known as “internal memory,” e.g., registers, buffers, or caches) on radio 202, wireless network interface 204, or host chip 206, apparatus 200 may further include an external memory 208 (e.g., the system memory or main memory) that can be shared by radio 202, wireless network interface 204, or host chip 206 through the system/main bus. Although radio 202 is illustrated as a standalone SoC in FIG. 2, it is understood that in one example, radio 202 and wireless network interface 204 may be integrated as one SoC; in another example, radio 202 and host chip 206 may be integrated as one SoC; in still another example, radio 202, wireless network interface 204, and host chip 206 may be integrated as one SoC, as described above.

[0068] In the uplink, host chip 206 may generate raw data and send it to radio 202 for encoding, modulation, and mapping. Interface 214 of radio 202 may receive the data from host chip 206. Radio 202 may also access the raw data generated by host chip 206 and stored in external memory 208, for example, using the direct memory access (DMA). Radio 202 may first encode (e.g., by source coding and/or channel coding) the raw data and modulate the coded data using any suitable modulation techniques, such as multi-phase shift keying (MPSK) modulation or quadrature amplitude modulation (QAM). Radio 202 may perform any other functions, such as symbol or layer mapping, to convert the raw data into a signal that can be used to modulate the carrier frequency for transmission. In the uplink, radio 202 may send the modulated signal to wireless network interface 204 via interface 214. Wireless network interface 204, through TX 250, may convert the modulated signal in the digital form into analog signals, i.e., RF signals, and perform any suitable front-end RF functions, such as filtering, digital pre-distortion, up-conversion, or sample-rate conversion. Antenna array 210 may transmit the RF signals provided by TX 250 of wireless network interface 204.

[0069] In the downlink, antenna array 210 may receive RF signals from an access node or other wireless device. An RF signal may include K beams. The RF signals may be passed to RX 240 of wireless network interface 204. Wireless network interface 204 may perform any suitable front-end RF functions, such as filtering, IQ imbalance compensation, down-paging conversion, or sample-rate conversion, and convert the RF signals (e.g., transmission) into low-frequency digital signals (baseband signals) that can be processed by radio 202.

[0070] As seen in FIG. 2, radio 202 may include beam parameter estimation circuit(s) 260 configured to perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. In some embodiments, beam parameter estimation circuit(s) 260 may include an autocorrelation circuit configured to perform autocorrelation of the received signal, an acquisition circuit configured to perform an acquisition procedure, a zoom-in circuit configured to perform a zoom-in procedure, and a beam cluster circuit configured to estimate the set of beam parameters for each beam in the cluster. However, in some embodiments, beam parameter estimation circuit(s) 260 may include a single circuit configured to perform the joint estimation procedure to estimate the set of beam parameters.

[0071] Further, radio 202 may include an amplitude estimation circuit 270 configured to estimate, based on the set of beam parameters and a minimum mean square error (MMSE) function, a plurality of amplitudes associated with the plurality of beams. Amplitude estimation circuit 270 further may be configured to identify a maximum amplitude from the plurality of amplitudes. Further, radio 202 may include an LOS circuit 280 configured to determine an LOS beam as the beam associated with the maximum amplitude. LOS circuit 280 or beam parameter estimation circuit(s) 260 may input the set of beam parameters associated with the LOS beam into navigation circuit 290. Navigation circuit 290 may use the set of beam parameters of the LOS beam to provide navigation services to apparatus 200. Additional details of the operations performed by each of the beam parameter estimation circuit(s) 260, amplitude estimation circuit 270, and LOS circuit 280 are described below in connection with FIGs. 3A, 3B, 3C, 3D, 3E, 3F, and 4.

[0072] FIG. 3 A illustrates a graphical representation 300 of a time autocorrelation function that beam parameter estimation circuit(s) 260 of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure. FIG. 3B illustrates a graphical representation 301 of an angular autocorrelation function that beam parameter estimation circuit(s) 260 of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure. FIG. 3C illustrates a graphical representation 303 of a time-angular autocorrelation function that beam parameter estimation circuit(s) 260 of FIG. 2 may apply to a received signal, according to some embodiments of the present disclosure. FIG. 3D illustrates a diagram 305 of an acquisition correlation and zoom-in procedure that may be implemented by beam parameter estimation circuit(s) 260 of FIG. 2, according to some embodiments of the present disclosure. FIG. 3E illustrates a diagram 307 of a beam cluster that includes a superposition of K beams, according to some embodiments of the present disclosure. FIG. 3F illustrates a diagram 307 of a correlation cluster identified using the acquisition correlation and zoom-in procedure, according to some embodiments of the present disclosure. FIGs. 3 A-3F will be described together.

[0073] Referring to FIGs. 2 and 3A, the process may begin when a signal including K beams is received by antenna array 210. Antenna array 210 may send the signal to RX 240, which may perform RF processing (as described above in connection with FIG. 2) before sending the signal to beam parameter estimation circuit(s) 260. Beam parameter estimation circuit(s) 260 may perform a joint estimation procedure as described below to estimate a set of beam parameters for each of the K beams of the received signal. To begin, beam parameter estimation circuit(s) 260 may generate a set of correlation samples by applying an autocorrelation function to the signal received from RX 240. For example, the correlation function Cor_q between the received signal and beam k with angle (a, β), speed v, and delay r at band q may be defined according to expression (1.8):

where S_q,mα,mβ are the samples of an antenna at band q, row m_α, and column m_β, N_A is the accumulation length, Tc is the chip duration, Mv is the number of vertical antennas, M_H is the number of horizontal antennas, and BW is the bandwidth.

[0074] From expressions (0.2), (0.3), (0.4) and (0.5) described above, it follows that the correlation function Cor_q is related to a sum of the amplitudes Ak of the K beams, as shown below in expression (1.9):

where N_A is the accumulation length, C (α, β , v, t) is the single beam autocorrelation, α, β , v, and T are the set of parameters associated with the received signal, ak, fik, Vk, and tk and are the set of beam parameters associated with beam k, N_q (α, β , v, t) is the resulting noise, which may be defined according to expression (1.10):

[0075] Meanwhile, C (a, fl, v, T) may be defined according to expression (1.11):

[0076] Moreover, from expressions (0.3), (0.4) and (0.5), it follows that:

[0077] Examples of the beam autocorrelation function, where

C_q (Δα = 0, Δβ = 0, Δv = 0, Δt) , are depicted in FIGs. 3A-3C.

[0078] Once autocorrelation is performed, beam parameter estimation circuit(s) 260 may identify a search interval for an acquisition procedure. For example, from (0.1) it follows that initial angular ambiguity may be defined according to expression (1.14):

0 ≤ α < 1 and 0 ≤ β < 1 (0- 14).

[0079] From (0.13) it follows that beam parameter estimation circuit(s) 260 may check angular ambiguity with step (Δ_α /OS} and (A_β/OS) . Thus, beam parameter estimation circuit(s) 260 may estimate the angular ambiguity based on a first angular offset Δ_α , a second angular offsetA_β, and an oversampling (OS) value. Here, Δ_α and A_β may be defined according to expression (1.15):

[0080] The initial speed ambiguity interval may be defined by expression (1.16):

- max (v) ≤ v < max (v) (0.16). [0081] Moreover, from expression (0.13) it follows that beam parameter estimation circuit(s) 260 may check velocity/speed ambiguity with step (ΔΤ/OS) . Thus, beam parameter estimation circuit(s) 260 may estimate the speed ambiguity based on a speed offset Δ_v and the OS value. Here, Δ_v may be defined according to expression (1.17):

[0082] Further, the initial delay ambiguity interval may be defined according to expression

(1.18):

0 < T < max(t) (0.18).

[0083] From expression (0.13) it also follows that beam parameter estimation circuit(s) 260 may check delay ambiguity with step (ΔΤ/OS) . Thus, beam parameter estimation circuit(s) 260 may estimate the delay ambiguity based on a delay offset A_r and the OS value. Here, Δ_t may be defined according to expression (1.19):

Δ_t = 1//BW (0.19)

[0084] The oversampling value OS may be chosen according to a tradeoff between the number of correlation samples and computation complexity. To limit computation complexity, beam parameter estimation circuit(s) 260 may set OS to 2, in some embodiments.

[0085] Thus, using the intervals described above, it follows that the overall initial acquisition search interval used by beam parameter estimation circuit(s) 260 may be defined according to expression (1.20):

[0086] The total number of correlation points NACQ in this interval may be defined according to expression (1.21):

N_ACQ = N_α - N_β - N_v - N_T (0.21), where N_α is the number of a correlation points in the interval, N_β is the number of β correlation points in the interval, N_v is the number of v correlation points in the interval, and N_T is the number of T correlation points in the interval.

[0087] Referring to FIG. 3D, during the initial acquisition procedure (also referred to herein as “the acquisition procedure”), beam parameter estimation circuit(s) 260 may check all N_ACQ points and identify one or more correlation sample clusters 302a, 302b, 302c that exceed a thermal noise threshold, as defined by expression (1.22):

[0088] Still referring to FIG. 3D, beam parameter estimation circuit(s) 260 may select first cluster 302a and verify that this cluster has the maximum energy of all clusters. Then, beam parameter estimation circuit(s) 260 may apply a zoom-in procedure to find the location of the main beam within this cluster.

[0089] From autocorrelation expression (0.12), it follows that if first cluster 302a includes a single beam, the location of cluster maximum may be defined according to expression (1.23):

(0.23).

[0090] However, multipath and/or a superposition of beams within first cluster 302a may insert errors in the beam parameters estimation

[0091] FIG. 3E illustrates an example cluster 302d in which there is a superposition of two beams, namely beam k_x 306a and beam k_y 306b. The condition for beam k_x 306a and beam k_y 306b overlapping within cluster 302d may be defined according to expression (1.24):

where a_kx is the first electronic angle of beam k_x, a_ky is the first electronic angle of beam k_y, (3_kx is the second electronic angle of beam k_x, (3_ky is the second electronic angle of beam k_y, v_kx is the speed of beam k_x, v_ky is the speed of beam k_y, T_kx is the delay of beam k_x, T_ky is the delay of beam k_y, and intervals Δ_β , Δ_v, Δ_t are defined above according to expression (0.15), (0.17) and

(0.19).

[0092] Referring to FIG. 3F, after the zoom-in procedure, beam parameter estimation circuit(s) 260 may measure a plurality of correlation samples 304 (also referred to herein as “plurality of correlation points”) within first cluster 302a to estimate the set of beam parameters. Still referring to FIG. 3F, it may be assumed that first cluster 302a is defined on the interval defined by expression (1.25):

(0.25).

[0093] Thus, first cluster 302a may be described as a superposition of K beams 308 within the interval defined by expression (1.26):

where intervals 3 l 0 are defined above by (0.15), (0.17) and (0.19).

[0094] Here, beam parameter estimation circuit(s) 260 may select an oversampling coefficient OS (e.g., OS = 256) that is much larger than the initial acquisition oversampling coefficient (e.g., OS = 2). Then, within first cluster 302a, beam parameter estimation circuit(s) 260 we can measure N correlation samples 304 as defined by expression (1.27):

Cor (n ) (0.27),

where n is the collective set of beam parameters associated with beam k at band q and defined by expressions (1.28) and (1.29):

[0095] Thus, the correlation points are the product of K beams within first cluster 302a with the set of beam parameters defined by expression (1.32), (1.33) (1.34), (1.35), and (1.36):

where:

[0096] From expression (0.9) it follows that:

where A_k is the complex amplitude of beam k and:

where n is defined by expression (0.28) and k is defined by expression (0.33).

[0097] Expression (0.38) may be rewritten in matrix form as seen below in expressions (1.39) and (1.40):

VectorCor = MatrixC . Vector A+VectorNoise (0.40).

[0098] Thus, amplitude estimation circuit 270 may apply an MMSE function to expression (1.40) to estimate a set of complex amplitude vectors Vector Aestim associated with the K beams of first cluster 302a, as shown below in expression (1.41):

[0099] To estimate the set of complex amplitudes for each of the K beams

of first cluster 302a, amplitude estimation circuit 270 may select the amplitude vectors that are larger than a noise floor, as shown below in expression (1.42):

[0100] From the set of complex amplitudes, amplitude estimation circuit 270 may identify the beam ko with the maximum energy, as shown below in expression (1.43): ko = arg (0.43).

[0101] LOS circuit 280 may identify the beam ko with the maximum energy in the cluster as the LOS beam. Then, the set of beam parameters estimated for the LOS beam may be input into navigation circuit 290. Thus, using the techniques described above in connection with FIGs. 2 and 3A-3F, an estimation of beam parameters for an LOS beam can be achieved with the high degree of accuracy even in multipath or beam superposition scenarios.

[0102] FIG. 4 illustrates a flowchart of an exemplary method 400 of wireless communication, according to embodiments of the disclosure. Exemplary method 400 may be performed by an apparatus for wireless communication, e.g., such as UE 120, apparatus 200, radio 202, beam parameter estimation circuit(s) 260, amplitude estimation circuit 270, LOS circuit 280, navigation circuit 290, and/or node 500. Method 400 may include steps 402-412 as described below. It is to be appreciated that some of the steps may be optional, and some of the steps may be performed simultaneously, or in a different order than shown in FIG. 4.

[0103] At 402, the radio may receive a signal comprising a plurality of beams. For example, referring to FIG. 2, radio 202 may receive a signal with multiple beams from RX 240.

[0104] At 404, the radio may perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. For example, referring to FIGs. 2 and 3A-3F, beam parameter estimation circuit(s) 260 may be configured to jointly estimate a set of beam parameters for each of the K beams as described above in connection with expressions (1.8)-( 1.36).

[0105] At 406, the radio may estimate a plurality of amplitudes associated with the plurality of beams based on the set of beam parameters. For example, referring to FIGs. 2 and 3 A-3F, amplitude estimation circuit 270 may estimate a set of complex amplitudes as described above in connection with expressions (1.37)-(l .42).

[0106] At 408, the radio may estimate a maximum amplitude from the plurality of amplitudes. For example, referring to FIGs. 2 and 3A-3F, amplitude estimation circuit 270 may estimate the maximum amplitude as described above in connection with expression (1.43).

[0107] At 410, the radio may identify an LOS beam based on the maximum amplitude. For example, referring to FIGs. 2 and 3A-3F, LOS circuit 280 may identify the beam ko with the maximum energy in the cluster as the LOS beam.

[0108] At 412, the radio may input the set of beam parameters associated with the LOS beam into a navigation function. For example, referring to FIGs. 2 and 3A-3F, the set of beam parameters estimated for the LOS beam may be input into navigation circuit 290.

[0109] In various aspects of the present disclosure, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as instructions or code on a non-transitory computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computing device, such as node 500 in FIG. 5. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, HDD, such as magnetic disk storage or other magnetic storage devices, Flash drive, SSD, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a processing system, such as a mobile device or a computer. Disk and disc, as used herein, includes CD, laser disc, optical disc, digital video disc (DVD), and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. [0110] According to one aspect of the present disclosure, an apparatus of wireless communication is provided. The apparatus may include an antenna array configured to receive a signal comprising a plurality of beams. The apparatus may include a radio. The radio may include a set of beam parameter estimation circuits configured to perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The radio may include an amplitude estimation circuit configured to estimate, based on the set of beam parameters, a plurality of amplitudes associated with the plurality of beams. The amplitude estimation circuit may be further configured to identify a maximum amplitude from the plurality of amplitudes. The radio may include an LOS circuit configured to identify an LOS beam based on the maximum amplitude. The LOS circuit may input the set of beam parameters associated with the LOS beam into a navigation function.

[0111] In some embodiments, the set of beam parameters includes an AoA, a speed, and a delay.

[0112] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by generating a set of correlation samples by applying an autocorrelation function to the signal. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by performing an acquisition procedure based on the search interval and the set of correlation samples. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

[0113] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the angular ambiguity associated with the set of correlation samples based on a first angular offset, a second angular offset, and an oversampling value. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the speed ambiguity associated with the set of correlation samples based on a speed offset and the oversampling value. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the delay ambiguity associated with the set of correlation samples based on a delay offset and the oversampling value. [0114] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by selecting a first cluster of the one or more clusters that exceed the thermal noise threshold. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by applying a zooming procedure to the first cluster. In some embodiments, the first cluster may include a superposition of the plurality of beams.

[0115] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

[0116] In some embodiments, the amplitude estimation circuit may be configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by applying a MMSE function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams. In some embodiments, the amplitude estimation circuit may be configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.

[0117] According to another aspect of the disclosure, a radio chip (e.g., radio 202) is provided. The radio chip (referred to hereinafter as “radio”) may include a set of beam parameter estimation circuits configured to perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The radio may include an amplitude estimation circuit configured to estimate, based on the set of beam parameters, a plurality of amplitudes associated with the plurality of beams. The amplitude estimation circuit may be further configured to identify a maximum amplitude from the plurality of amplitudes. The radio may include an LOS circuit configured to identify an LOS beam based on the maximum amplitude. The LOS circuit may input the set of beam parameters associated with the LOS beam into a navigation function.

[0118] In some embodiments, the set of beam parameters includes an AoA, a speed, and a delay.

[0119] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by generating a set of correlation samples by applying an autocorrelation function to the signal. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by performing an acquisition procedure based on the search interval and the set of correlation samples. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

[0120] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the angular ambiguity associated with the set of correlation samples based on a first angular offset, a second angular offset, and an oversampling value. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the speed ambiguity associated with the set of correlation samples based on a speed offset and the oversampling value. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by estimating the delay ambiguity associated with the set of correlation samples based on a delay offset and the oversampling value.

[0121] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by selecting a first cluster of the one or more clusters that exceed the thermal noise threshold. In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by applying a zooming procedure to the first cluster. In some embodiments, the first cluster may include a superposition of the plurality of beams.

[0122] In some embodiments, the set of beam parameter estimation circuits may be configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

[0123] In some embodiments, the amplitude estimation circuit may be configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by applying a MMSE function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams. In some embodiments, the amplitude estimation circuit may be configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.

[0124] According to yet another aspect of the disclosure, a method of wireless communication is provided. The method may include receiving, by an antenna array, a signal comprising a plurality of beams. The method may include performing, by a set of beam parameter estimation circuits, a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams. The method may include estimating, by an amplitude estimation circuit, a plurality of amplitudes associated the plurality of beams based on the set of beam parameters. The method may include identifying, by the amplitude estimation circuit, a maximum amplitude from the plurality of amplitudes. The method may include identifying, by an LOS circuit, an LOS beam based on the maximum amplitude. The method may include inputting the set of beam parameters associated with the LOS beam into a navigation function.

[0125] In some embodiments, the set of beam parameters may include an AoA, a speed, and a delay.

[0126] In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include generating a set of correlation samples by applying an autocorrelation function to the signal. In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples. In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include performing an acquisition procedure based on the search interval and the set of correlation samples. In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

[0127] In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include selecting a first cluster of the one or more clusters that exceed the thermal noise threshold. In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include applying a zooming procedure to the first cluster. In some embodiments, the first cluster may include a superposition of the plurality of beams.

[0128] In some embodiments, the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams may include measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

[0129] In some embodiments, the estimating the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters may include applying an MMSE function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams. In some embodiments, the estimating the plurality of amplitudes associated the plurality of beams based on the set of beam parameters may include identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.

[0130] The foregoing description of the specific embodiments will so reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0131] Embodiments of the present disclosure have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0132] The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0133] Various functional blocks, modules, and steps are disclosed above. The particular arrangements provided are illustrative and without limitation. Accordingly, the functional blocks, modules, and steps may be re-ordered or combined in different ways than in the examples provided above. Likewise, certain embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permitted.

[0134] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

- 34 - WHAT IS CLAIMED IS:

1. An apparatus of wireless communication, comprising: an antenna array configured to receive a signal comprising a plurality of beams; a radio comprising: a set of beam parameter estimation circuits configured to: perform a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams; an amplitude estimation circuit configured to: estimate, based on the set of beam parameters, a plurality of amplitudes associated the plurality of beams; and identify a maximum amplitude from the plurality of amplitudes; and a line-of-sight (LOS) circuit configured to: identify an LOS beam based on the maximum amplitude; and input the set of beam parameters associated with the LOS beam into a navigation function.

2. The apparatus of claim 1, wherein the set of beam parameters includes an angle-of-arrival (AoA), a speed, and a delay.

3. The apparatus of claim 1, wherein the set of beam parameter estimation circuits is configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: generating a set of correlation samples by applying an autocorrelation function to the signal; identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples; performing an acquisition procedure based on the search interval and the set of correlation samples; and identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

4. The apparatus of claim 3, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for - 35 - each of the plurality of beams by: estimating the angular ambiguity associated with the set of correlation samples based on a first angular offset, a second angular offset, and an oversampling value; estimating the speed ambiguity associated with the set of correlation samples based on a speed offset and the oversampling value; and estimating the delay ambiguity associated with the set of correlation samples based on a delay offset and the oversampling value.

5. The apparatus of claim 3, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: selecting a first cluster of the one or more clusters that exceed the thermal noise threshold; and applying a zooming procedure to the first cluster, wherein the first cluster includes a superposition of the plurality of beams.

6. The apparatus of claim 5, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

7. The apparatus of claim 6, wherein the amplitude estimation circuit is configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by: applying a minimum mean square error (MMSE) function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams; and identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.

8. A radio chip, comprising: a set of beam parameter estimation circuits configured to: perform a joint estimation procedure to estimate a set of beam parameters for each of a plurality of beams associated with a signal received by an antenna array; an amplitude estimation circuit configured to: estimate, based on the set of beam parameters, a plurality of amplitudes associated the plurality of beams; and identify a maximum amplitude from the plurality of amplitudes; and a line-of-sight (LOS) circuit configured to: identify an LOS beam based on the maximum amplitude; and input the set of beam parameters associated with the LOS beam into a navigation function.

9. The radio chip of claim 8, wherein the set of beam parameters includes an angle-of-arrival (AoA), a speed, and a delay.

10. The radio chip of claim 8, wherein the set of beam parameter estimation circuits is configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: generating a set of correlation samples by applying an autocorrelation function to the signal; identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples; performing an acquisition procedure based on the search interval and the set of correlation samples; and identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

11. The radio chip of claim 10, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: estimating the angular ambiguity associated with the set of correlation samples based on a first angular offset, a second angular offset, and an oversampling value; estimating the speed ambiguity associated with the set of correlation samples based on a speed offset and the oversampling value; and estimating the delay ambiguity associated with the set of correlation samples based on a delay offset and the oversampling value.

12. The radio chip of claim 10, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: selecting a first cluster of the one or more clusters that exceed the thermal noise threshold; and applying a zooming procedure to the first cluster, wherein the first cluster includes a superposition of the plurality of beams.

13. The radio chip of claim 12, wherein the set of beam parameter estimation circuits is further configured to perform the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams by: measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

14. The radio chip of claim 13, wherein the amplitude estimation circuit is configured to estimate the plurality of amplitudes associated with the plurality of beams based on the set of beam parameters by: applying a minimum mean square error (MMSE) function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams; and identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.

15. A method of wireless communication, comprising: receiving, by an antenna array, a signal comprising a plurality of beams; performing, by a set of beam parameter estimation circuits, a joint estimation procedure to estimate a set of beam parameters for each of the plurality of beams; estimating, by an amplitude estimation circuit, a plurality of amplitudes associated the plurality of beams based on the set of beam parameters; identifying, by the amplitude estimation circuit, a maximum amplitude of the plurality of - 38 - amplitudes; identifying, by a line-of-sight (LOS) circuit, an LOS beam based on the maximum amplitude; and inputting, by the LOS circuit, the set of beam parameters associated with the LOS beam into a navigation function.

16. The method of claim 15, wherein the set of beam parameters includes an angle-of-arrival (AoA), a speed, and a delay.

17. The method of claim 15, wherein the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams comprises: generating a set of correlation samples by applying an autocorrelation function to the signal; identifying a search interval based on an angular ambiguity, a speed ambiguity, and a delay ambiguity associated with the set of correlation samples; performing an acquisition procedure based on the search interval and the set of correlation samples; and identifying, based on the acquisition procedure, one or more clusters in the set of correlation samples that exceed a thermal noise threshold.

18. The method of claim 17, wherein the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams further comprises: selecting a first cluster of the one or more clusters that exceed the thermal noise threshold; and applying a zooming procedure to the first cluster, wherein the first cluster includes a superposition of the plurality of beams.

19. The method of claim 18, wherein the performing the joint estimation procedure to estimate the set of beam parameters for each of the plurality of beams further comprises: measuring a plurality of correlation points within the first cluster to estimate the set of beam parameters.

20. The method of claim 19, wherein the estimating the plurality of amplitudes associated the - 39 - plurality of beams based on the set of beam parameters comprises: applying a minimum mean square error (MMSE) function to the set of beam parameters to estimate a plurality of amplitude vectors associated with the plurality of beams; and identifying the plurality of amplitudes as a subset of the plurality of amplitude vectors that exceed a noise floor threshold.