Ranging based on movement of first device and based on wireless signaling with second device

Abstract

A ranging method for locating a second device in relation to a first device. The first device moves from a first position to a second position in a coordinate system. At each position, the first device uses wireless signaling with the second device to estimate distance and direction between the second device and the position of the first device, the direction having a range of uncertainty. For each position of the first device, the first device defines a respective arc having a center at the position, a radius based on the estimated distance between the second device and the position, and an angle centered on the estimated direction between the second device and the position and having an angular width based on the range of uncertainty. The first device then estimates a location of the second device in the coordinate system as a point of intersection of those arcs.

Description

Ranging Based on Movement of First Device and Based on Wireless Signaling with Second DeviceBACKGROUND

[0001] A first electronic device, such as a phone, tablet, gaming device, wearable device and / or other device, may be equipped with ranging technology that enables the first electronic device to determine a relative location of a second electronic device (e.g., a position of the second electronic device within a coordinate system defined around or with respect to a position of the first electronic device), such as the distance and direction between the second electronic device and the first electronic device. This ranging technology may help facilitate various useful features.

[0002] For example, the ranging technology may help facilitate person-to-person meetups, such as guiding users toward each other. For instance, a first user’s device may apply ranging to determine relative location of a second user’s device, the first user’s device could then conveniently present a graphical user interface (GUI) that depicts that relative location (e.g., both distance and direction, and the first user may use that graphical depiction as a basis to move closer to the second user. Further, being able to determine both distance and direction of another device may likewise support other tag-finding applications as well.

[0003] Further, the ranging technology may help to facilitate proximity and distance based sharing of photos or other content with select nearby devices, and proximity and distance based unlocking of secure systems such as a car or house for instance, among other possibilities.

[0004] Other examples are possible as well.SUMMARY

[0005] Disclosed is a ranging method and system for locating a second device in relation to a first device. The first device moves from a first position to a second position in a coordinate system and uses one or more sensors to track its distance and direction of movement between those positions. Further, at each position, the first device uses wireless signaling with the second device to estimate distance and direction between the second device and the position of the first device, with the direction having a range of uncertainty. Still further, for each position, the first device defines a respective arc having (i) a center at the position, (ii) a radius being based on the estimated distance between the second device and the position, and (iii) an angle centered on the estimated direction between the second device and the position and having a width based on the range of uncertainty. The first device then estimates a location of the second device in the coordinate system as being a point of overlap of those arcs.

[0006] These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that the disclosure provided here and elsewhere in this document is provided by way of example only and that numerous variations and other examples may be possible as well.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a timing diagram illustrating signaling in example Bluetooth Channel Sounding.

[0008] Figure 2 is an illustration of an angle of arrival method according to the Bluetooth specification.

[0009] Figure 3 is an illustration of measuring angle of arrival according to the Bluetooth specification.

[0010] Figure 4 is an illustration of a geometric analysis that is applicable in an example implementation.

[0011] Figure 5 is a flow chart illustrating an example ranging method.

[0012] Figure 6 is a simplified block diagram of an example device.DETAILED DESCRIPTION

[0013] This description will discuss example implementation in relation to distance and direction estimation. It should be understood, however, that the arrangements and processes described could take various other forms. For instance, the disclosed principles could extend to apply with respect to other wireless technologies and / or other types of distance and / or direction estimation. Further, disclosed elements and operations could be re-ordered, distributed, replicated, combined, omitted, added, or otherwise modified. Still further, elements described as functional entities could be implemented as discrete or distributed components or in conjunction with other components / modules, and in any suitable combination and location. In addition, various operations described as being carried out by one or more components or other entities could be implemented by and / or on behalf of those entities, through hardware, firmware, and / or software, such as by one or more processing units executing program instructions stored in memory, among other possibilities.1. Example Ranging Technology

[0014] One type of ranging technology that is particular interest makes use of the Bluetooth radio found in many devices today, specifically the Bluetooth Low Energy (BLE) protocol, an example of which is defined by the Bluetooth Core Specification v. 5.1, published by the Bluetooth Special Interest Group (BT SIG) in January 2019. Namely, based on BLE signaling between a first device and a second device, the first device may estimate a relative location of the second device, which may facilitate location-based various services such as those noted above. a. High-Accuracy Distance Determination

[0015] BLE signaling can support highly accurate determination of distance between the first device and second device, using a procedure known as Bluetooth Channel Sounding (CS) or more particularly High Accuracy Distance Measurement (HADM).

[0016] HADM itself makes use of a procedure called Multi -Carrier Phase Difference (MCPD), which involves measuring the phase shift respectively of each of multiple predefined Bluetooth tones transmitted between “initiator” and “reflector” devices (e.g., the first and second devices) and determining the distance between the devices based on a difference between those phase shifts.

[0017] For instance, as to each of multiple Bluetooth channels (i.e., predefined Bluetooth frequency channels), (i) the initiator may generate and transmit to the reflector a constant tone signal at the center frequency of the channel, (ii) the reflector may responsivelygenerate and transmit to the initiator a constant tone signal also at the center frequency of the channel, and (iii) the initiator may determine a phase shift (or phase rotation) of the channel based on a mathematical combination of the initiator’s receive phase of the reflector- transmitted constant tone signal and the reflector’s receive phase of the initiator-transmitted constant tone signal. Using a mathematical relationship between distance and difference in phase shifts computed at various frequencies, the initiator may then compute the distance between it and the reflector with a high degree of accuracy based on a comparison of its determined phase shifts at various Bluetooth channels.

[0018] To facilitate HADM, the devices may first engage in a discovery process to learn that they are in close enough proximity to each other, and the devices may then establish and maintain a BLE connection with each other through which they can share information related to the ranging process.

[0019] For instance, the reflector may advertise its presence by repeatedly broadcasting a BLE advertisement message on certain predefined BLE channels, and the initiator may scan those channels and thereby determine based on the received strength of the advertisement message (e.g., received signal strength indicator (RSSI)) that the reflector is close enough to facilitate ranging. Upon determining that the reflector is close enough to facilitate ranging, the initiator and reflector may then exchange directed advertisement messaging with each other to establish a BLE connection. With this BLE connection established, the initiator and reflector may then engage in the HADM process, possibly using their BLE connection as a basis to agree with each other on parameters of the HADM process and to share measurements and possible results of the HADM process.

[0020] As noted above, the HADM process may involve generating and transmitting constant tone signals between the devices at various BLE channels and using the difference in phase shift of those signals on those various channels as a basis to determine distance. The specifics of this process may vary from implementation to implementation.

[0021] Without limitation, in one example implementation, the devices may conduct this process across the entire set of available BLE channels. For instance, if there are 40 BLE channels, with three reserved as advertising channels, the devices may conduct the process across the remaining 37 BLE channels. Further, the devices may divide those channels into groups and conduct the HADM process separately per group to compute a respective distance determination per group, and the initiator may combine (e.g., average) those distance determination to establish a representative distance determination.

[0022] As to each group of BLE channels, the initiator may cycle through the channels, engaging ping-pong signaling with the reflector and computing an associated phase shift. For instance, on each BLE channel, (i) the initiator may use a local oscillator to generate a constant tone signal at the center frequency of the channel and may transmit that constant tone signal as a “ping” signal to the reflector, (ii) the reflector may then report to the initiator the reflector’s receive phase of that ping signal, (iii) the reflector may further use a local oscillator to generate a constant tone signal at the same center frequency and may transmit that constant tone signal as a “pong” signal to the initiator, (iv) the initiator may determine the initiator’s receive phase of that pong signal, and (v) the initiator may compute a phase shift of the BLE channel based on the reflector’s receive phase of the ping signal and the initiator’s receive phase of the pong signal.

[0023] The initiator and reflector may carry out this process with closely coordinated timing to hop from BLE channel to BLE channel so that they can exchange constant tone signals respectively on each channel and the initiator can compute phase shift respectively per channel. As shown in Figure 1, for instance, at each BLE channel in a sequence, the initiator may generate and send to the initiator a Mode-2 tone 100 (namely, a constant tone signal at the center of the BLE channel) and the reflector may respond by generating and sending to the initiator a Mode-2 tone 102 (also a constant tone signal at the center of the BLE channel). As to each BLE channel, the reflector may also report to the initiator the reflector’s receive phase information of the initiator’s constant tone signal, the initiator may determine the initiator’ s receive phase information of the reflector’ s constant tone signal, and the initiator may use the initiator’s receive phase information and the reflector’s receive phase information to compute a phase shift of the BLE channel.

[0024] Carrying out this process successively for each BLE channel of the group, the initiator may then compute a difference in phase shift as to pairs of the BLE channels. And based on the computed differences in phase shift, the initiator may compute a distance between the devices with high accuracy. b. Low-Accuracy Direction Determination

[0025] BLE signaling can also support determination of the direction of one device from another, based on an evaluation of the angle at which BLE signaling transmitted from one device arrives at the other device.

[0026] In particular, the Bluetooth Core Specification noted above states that a BLE-enabled device can make its direction available to a peer device by transmitting direction-finding-enabled packets that enable the peer device to estimate an angle of arrival (AoA) of those packets and thus a direction of the BLE-enabled device from the peer device. These direction-finding enabled packets may be BLE packets that are modified to have an appended “Constant Tone Extension” (CTE) as a constant tone signal that the peer device could evaluate in order to estimate AoA.

[0027] In particular, as shown in Figure 2, the Bluetooth specification provides that a transmitting device could transmit direction-finding-enabled packets using a single transmit antenna 200, and that a receiving device could use a radio frequency (RF) switch 202 to selectively receive those packets at different antennas of an antenna array 204. With this arrangement, as the receiving device switches from antenna to antenna, the receiving device could determine the receive phase of the CTE respectively per antenna. The receiving device could then calculate a difference in phase of the CTE as received at its different receive antennas and could use that calculated phase difference as a basis to estimate AoA, representing the angular orientation of the transmitting device (e.g., in relation to an antenna plane of the receiving device). Specifically, as shown in Figure 3, the Bluetooth specification explains that, if the signal wavelength is X, the distance between the two antennas is d, and the determined phase difference of the signal arriving at the two antennas is y, then the angle of arrival 0 of the signal at the receiving device can be estimated as 9 = arccos((\| ) / (27td)).

[0028] Unlike HADM-determined distance, however, this AoA determined based on receive phase per receive antenna has relatively low accuracy. For instance, the AoA determined by the receiving device through this process may have an accuracy of just about + / - 45° and thus a range of uncertainty of just about 90°. While this level of inaccuracy may be fine for some applications, it may be impractical for various ranging applications such as the person-to-person meetup or tag-finding applications noted above.2. Use of Movement of First Device and Wireless Signaling with Second Device Cooperatively as Improved Basis to Estimate Location of Second Device

[0029] Disclosed herein is an improved ranging mechanism that can use relatively high-accuracy distance determination and relatively low-accuracy direction determination, along with information about movement of the first device from position to position, as a basis to better estimate the relative location of the second device.

[0030] In particular, the first device may make use of one or more cameras and / or other sensors to track its own movement from a first position to a second position in a coordinate system, and at each of those positions respectively, the first device may carry outthe high-accuracy distance determination and low-accuracy direction determination with respect to the second device.

[0031] This information will cooperatively enable the first device to establish two arcs in the coordinate system, (a) one centered at the first position of the first device, having a radius based on the estimated distance between the second device and the first position, and having an angle that is centered on the estimated direction between the second device and the first position and that has an angular width based on the range of uncertainty of the direction estimate, and (b) the other centered at the second position of the first device, having a radius based on the estimated distance between the second device and the second position, and having an angle that is centered on the estimated direction between the second device and the second position and that has an angular width based on the range of uncertainty of the direction estimate.

[0032] (In this process, a radius being based on a distance may mean that the radius is equal to the distance or is an approximation or other representation of the distance, among other possibilities. Likewise, an angular width being based on the range of uncertainty may mean that the angular width is equal to the range of uncertainty or is an approximation or other representation of the range of uncertainty, among other possibilities.)

[0033] Optimally, the first device may then deem a point of intersection of those two arcs to be the location of the second device in the coordinate system, e.g., the location of the second device relative to a latest tracked position of the first device in the coordinate system.

[0034] This point of intersection of the two arcs should reasonably represent the relative location of the second device, given that the two arcs were based on determinations of distance and direction established respectively at the first and second positions of the first device.

[0035] Further, the range of uncertainty of each direction determination interestingly helps focus this analysis by defining the angular width respectively of each arc and thus limiting the issue to just where those two arcs intersect each other. If the first device were to consider the intersection of two circles, one centered at the first position of the first device and having a radius based on the estimated distance between the second device and the first position, and the other centered at the second position of the first device and having a radius based on to the estimated distance between the second device and the second position, the first device may find two points of intersection of those circles, which would be anambiguous result. Using the range of uncertainty of the two direction determinations to define the arcs at issue (e.g., as proper sub-sections of the circumferences of those circles), the first device may optimally limit its analysis to the intersection of just those arcs, which may eliminate the ambiguity.

[0036] Figure 4 is an illustration of a geometric analysis that the first device could carry out in an example implementation of this process. This process could be initiated in response to various trigger events. For instance, the first device may start the process in response to a user of the first device invoking a friend-finder or other tag-finder application on the first device, among other possibilities.

[0037] Figure 4 depicts the geometric analysis in an example coordinate system, shown as an x-y Cartesian coordinate system. The first device could programmatically define this coordinate system in relation to the position of the first device. For instance, when the first device carries out the present process, the first device could initially deem point 400 to be its current position, i.e., its first position as discussed above. The first device could then define other points in the coordinate system in relation to that position.

[0038] Figure 4 further shows an example second device that happens to be located at position 402 in this coordinate system. At issue for the first device in the present process is where position 402 is, i.e., where the second device is located in relation to the first device.

[0039] In accordance with the present process, when the first device is at position 400, i.e., at the start of the process, the first device could engage in wireless signaling with the second device to perform both high-accuracy distance determination and low-accuracy direction determination. To facilitate this in an example implementation using the Bluetooth processes discussed above, the first device and second device could first establish a Bluetooth connection with each other, possibly through the advertisement and discovery process noted above.

[0040] In line with the discussion above, the high-accuracy distance determination could involve the Bluetooth Channel Sounding process described above. Namely, the first and second devices could engage this process with each other, with the first device functioning as the initiator and the second device functioning as the reflector. And through this process, the first device could determine with relatively high accuracy the distance DI between the first device and the second device, i.e., the distance between positions 400 and 402.

[0041] Further, the low-accuracy direction determination could involve the Bluetooth AoA-determination process described above. Namely, the first device could use tworeceive antennas to receive Bluetooth signaling from the second device (e.g., the Bluetooth Channel-Sounding signaling from the second device and / or other Bluetooth signaling from the second device), and as discussed above the first device could determine the AoA of that signaling. Thus, the first device could determine with relatively low accuracy the direction Al° of the signaling from the second device to the first device, which the first device may consider to be the direction between position 400 and 402, with respect to a plane of the two antennas. In line with the discussion above, this determined direction could have a range of uncertainty of + / - U°, thus totaling 2U°. This range of uncertainty could be predetermined by engineering analysis considering Bluetooth radio and processing features of the first device and / or other factors.

[0042] Given these determinations, the first device could programmatically establish a first arc 404 in the coordinate system. In particular, in line with the discussion above, the first device could establish this first arc 404 such that (i) the first arc 404 is centered on the first position 400 of the first device (i.e., that a representative circle of whose circumference the first arc 404 would be a part would be centered at that first position 400), (ii) the first arc 404 has a radius based on the estimated distance DI between the first device and the second device (i.e., the representative circle would have that radius), and (iii) the first arc 404 has an angle that is centered on the estimated direction Al° from the second device to the first device and that has an angular width based on the range of uncertainty 2U°.

[0043] As further above, the first device may then move from the first position 400 to a second position 406, and the first device may track this movement to determine both the distance and direction of the movement so that the first device could effectively plot the second position 406 in relation to the first position in the coordinate system. The tracking of movement of the first device from the first position 400 to the second position 406 need not establish intervening positions of the first device.

[0044] The first device may track its distance of movement from first the position 400 to the second position 406 using one or more sensors. For instance, if the first device is equipped with camera technology and associated program logic, the first device may use those cameras and associated program logic as a basis to measure distance of the first device’s movement, based on an evaluation of angles and positions of one or more objects in one or more fields of view, i.e., in the environment of the first device. Alternatively or additionally, if the first device is equipped with an accelerometer and associated program logic, the first device may use the accelerometer and associated program logic as a basis to measure distance of thefirst device’s movement. Still alternatively or additionally, if the first device is equipped with lidar, radar, sonar, and / or one or more other sensors and associated program logic, the first device may use such sensor technology and associated program logic likewise as a basis to measure distance of the first device’s movement.

[0045] The first device may further track its direction of movement from the first position 400 to the second position 406 using one or more sensors. For instance, if the first device is equipped with a gyroscope and associated program logic, possibly calibrated in relation to a reference direction such as the antenna plane of the first device, among other possibilities, the first device may use that gyroscope and associated program logic as a basis to determine the first device’s rotational orientation as the first device moves from position to position and thus the direction of movement of the first device. Alternatively or additionally, if the first device is equipped with a compass and associated program logic, also possibly calibrated in relation to a reference direction, the first device may likewise use that compass and associated program logic as a basis to determine the first device’s direction of movement. Still alternatively, the first device may use one or more cameras and / or other sensors and associated program logic to track its direction of movement similarly based on analysis of one or more objects in the its environment.

[0046] In an example implementation, the first device may instruct a user of the first device to move the first device from the first position 400 to the second position 406 to facilitate the present process. For instance, once a user of the first device initiates a friendfinder or other tag-finder application on the first device and the first device generates the first arc 404 with respect to the second device, the first device may then present on a display screen of the first device a GUI providing directional guidance such as an arrow that directs the user to move the first device in a particular direction. As the user moves the first device in the indicated direction, the first device may then track its distance of movement and notify the user when the user could stop moving the device, at the second position 406.

[0047] The first device could use its determined direction Al° as a basis to determine what direction to direct the user to move the first device. For instance, the first device could select a direction of movement based on the selected direction of movement being perpendicular to the determined direction Al° or otherwise in order to avoid the selected direction being parallel to the determined direction Al°. Directing the user to move the first device in a direction that is not parallel to the determined direction Al° may help to ensure success of the present process.

[0048] In an alternative implementation, the first device may not instruct a user of the first device to move the first device from the first position 400 to the second position 406 but may instead simply track its movement as the user moves the first device. For instance, once the user initiates a friend-finder or other tag-finder application on the first device and the first device generates the first arc 404 with respect to the second device, the first device may then track movement of the first device and the user moves the first device from the first position 400 to the second position 406.

[0049] Once the first device is at the second position 406, the first device may repeat the high-accuracy location determination and low-accuracy distance determination processes with respect to the second device. Thus, the first device may determine with relatively high accuracy the distance D2 between the first device and the second device, i.e., the distance between positions 406 and 402, and the first device may determine with a range of uncertainty of 2U° the direction A2° between positions 406 and 402.

[0050] Given these determinations, the first device may then programmatically establish a second arc 408 as shown in Figure 4. Namely, the first device could establish this second arc 408 such that (i) the second arc 408 is centered on the second position 406 of the first device, (ii) the second arc 408 has a radius based on to the estimated distance D2 between the second device and the second device, and (iii) the second arc 408 has an angle that is centered on the estimated direction A2° from the second device to the first device and that has an angular width based on the range of uncertainty 2U°.

[0051] Once the first device has programmatically established these two arcs 404 and 408, the first device could then determine a point of intersection of the two arcs. As shown in Figure 4, in an ideal implementation, this point of intersection would be precisely at position 402, i.e., precisely where the second device is located in the coordinate system. In practice, the determined point of intersection may not be exactly at the position 402 of the second device but may be a good estimate of that position. In any event, the first device may deem the determined point of intersection to be the location of the second device in the coordinate system and thus the location of the second device in relation to the location of the first device. Alternatively, the first device may use the determined point of intersection as a basis to then further analyze and determine the relative location of the second device.

[0052] Once the first device has determined the location of the second device, the first device may then present on a display of the first device a GUI that indicates the determined location of the second device. For instance, the first device may present a GUI providingdirectional guidance such as an arrow pointing in a direction of the determined location of the second device, to help guide a user of the first device to move toward the second device. Further, the first device could repeat this process periodically or otherwise from time to time as the user moves the first device toward the second device, and the first device could update this directional guidance accordingly.

[0053] Note that numerous variations from this example process could be possible as well.

[0054] For example, while the above discussion focuses on use of Bluetooth signaling for distance and direction determination, one or more other wireless protocols could be used instead or in addition for the distance determination and / or for the direction determination. Without limitation, another example wireless protocol is Ultra Wideband (UWB).

[0055] Further, while the above discussion addresses use of two example positions of the first device and therefore the generation and intersection of two associated arcs 404 and 408, the process could alternatively involve use of more than two example positions of the first device, and the first device could determine points of intersection between pairs of the generated arcs and could average those points to find a representative location of the second device.

[0056] Still further, while the above discussion addresses an analysis conducted in an example x-y plane such as a horizontal plane, the process could alternatively be carried out in another plane and / or could be carried out in in each of multiple planes such as in an x-y plane (e.g., horizontal plane) and in a y-z plane (e.g., vertical plane), among other possibilities.

[0057] Yet further, while the above discussion addresses an analysis based on AoA determination, the AoA could effectively be determined based on an angle-of-departure analysis as well, whether conducted by the first device or conducted by the second device and reported to the first device.

[0058] In addition, while the above discussion characterizes the distance determination as being high accuracy and the direction determination as being low accuracy, the process could just as well be carried out with a distance determination process that is low accuracy as well. Carrying out the process with relatively low-accuracy distance determination and relatively low-accuracy direction determination may of course result in a less accurate result, but the disclosed principles could still apply.

[0059] Figure 5 is a flow chart illustrating an example ranging method that could be carried out in accordance with the present disclosure for locating a second device in relation to a first device.

[0060] As shown in Figure 5, at block 500, the method includes the first device estimating first and second positions of the first device in a coordinate system, starting at the first position and applying one or more sensors to track distance and direction of movement of the first device from the first position to the second position. At block 502, the method further includes, respectively at each position of the first and second positions of the first device, the first device using wireless signaling between the first device and the second device as a basis to estimate both distance and direction between the second device and the position of the first device, with the estimated direction having a range of uncertainty.

[0061] Further, at block 504, the method includes the first device estimating a location of the second device in the coordinate system as a point of intersection of first and second arcs, (a) the first arc having a center at the first position, a radius based on the estimated distance between the second device and the first position, and an angle centered on the estimated direction between the second device and the first position and having an angular width based on the range of uncertainty, and (b) the second arc having a center at the second position, a radius based on the estimated distance between the second device and the second position, and an angle centered on the estimated direction between the second device and the second position and having an angular width based on the range of uncertainty.

[0062] Still further, at block 506, the method includes the first device presenting a user-interface indication of the estimated location of the second device in the coordinate system, as navigation guidance toward the second device.

[0063] In this process, the act of the first device estimating the first and second positions of the first device could involve the first device deeming its current location to be the first position and then using its tracking of distance and direction from the first position to the second position as a basis to establish the second position.

[0064] In line with the discussion above, the act of applying the one or more sensors to track distance and direction of movement of the first device from the first position to the second position could involve (i) tracking the distance of movement using at least one sensor such as a camera and / or an accelerometer and (ii) tracking the direction of movement using at least one sensor such as a camera, a gyroscope, and / or a compass.

[0065] As further discussed above, the act of using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device (i.e., respectively at the first position and the second position) could involve (i) using wireless MCPD to estimate the distance between the second device and the position of the first device and (ii) using wireless AoA analysis to estimate the direction between the second device and the position of the first device.

[0066] In addition, as discussed above, the act of using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device could involve (i) using BLE Channel Sounding as a basis to estimate distance between the second device and the position of the first device and (ii) using BLE AoA analysis as a basis to estimate the direction between the second device and the position of the first device.

[0067] Further, as discussed above, the example method could involve the first device coordinating the movement of the first device from the first position to the second position, to facilitate the ranging. For instance, this coordinating could be configured specifically to avoid having the movement be parallel to the estimated direction between the second device and the first position of the first device.

[0068] Figure 6 is a simplified block diagram of an example electronic device that could function as the first device in this method. As shown in Figure 6, the example electronic device includes a Bluetooth communication interface 600, a display 602, at least one movement sensor 604, at least one processor 606, and non-transitory data storage 608, all of which may be communicatively linked together by a system bus or other connection mechanism 610 and / or may be integrated with each other wholly or partly. As an example integration of these components, for instance, the at least one processor 606 and data storage 608 may be part of the Bluetooth communication interface 600. Other arrangements could be possible as well.

[0069] As shown, the Bluetooth communication interface 600 of the example device may include a Bluetooth radio 612 and an associated antenna structure 614. The Bluetooth radio 612 may facilitate short-range wireless communication in accordance with the Bluetooth specification noted above, including BLE communications such as Bluetooth Channel sounding and Bluetooth AoA determination for instance. Further, the antenna structure 614 may be an antenna array supporting air-interface transmission and reception of such Bluetoothcommunications, including at least two spaced apart antennas in an antenna plane, suitable for receiving Bluetooth signaling from another device to facilitate AoA determination.

[0070] The display 602 could comprise a user interface display panel configured to present visual content, such as GUIs, to a user of the device. The display 702 may incorporate light emitting diode (LED) technology such as organic LED (OLED) technology for instance, among other possibilities. Further, the display 602 may incorporate a touch panel, to facilitate user input to the device as well. The example device may also or alternatively include other forms of user interface components as well.

[0071] The at least one movement sensor 604 could comprise one or more sensors such as those noted above, including for instance, camera sensors, lidar sensors, radar sensors, sonar sensors, accelerometers, gyroscopes, and compasses, among other possibilities. These sensors could operate as discussed above to facilitate the tracking movement of the device from position to position.

[0072] The at least one processor 606 may comprise one or more general purpose processors (e.g., microprocessors, central processing units, application processors, and / or one or more other processors) and / or one or more special purpose processors (e.g., digital signal processors, application specific integrated circuits, etc.) Further, the non-transitory data storage 608 may comprise one or more volatile and / or non-volatile, removable and / or permanently situated storage components (such as magnetic, optical, flash, RAM, ROM, EPROM, EEPROM, etc.) and may be integrated in whole or in part with the at least one processor 606. Further, as shown, the data storage 608 may embody, encode, hold, or otherwise store program instructions 616, which could be executable by the at least one processor 606 to carry out various device operations such as those described above for instance.

[0073] The present disclosure contemplates at least one non-transitory computer- readable medium (e.g., one or more volatile and / or non-volatile storage components, such as magnetic, optical, flash, RAM, ROM, EPROM, EEPROM, etc.) having stored thereon program instructions executable by at least one processor of a device to cause the device to carry out operations such as those discussed above.

[0074] Example embodiments have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to these embodiments without departing from the true scope and spirit of the invention.

Claims

CLAIMSWhat is claimed is:

1. A ranging method for locating a second device in relation to a first device: estimating, by the first device, first and second positions of the first device in a coordinate system, starting at the first position and applying one or more sensors to track distance and direction of movement of the first device from the first position to the second position; respectively at each position of the first and second positions of the first device, using by the first device wireless signaling between the first device and the second device as a basis to estimate both distance and direction between the second device and the position of the first device, wherein the estimated direction has a range of uncertainty; and estimating by the first device a location of the second device in the coordinate system as a point of intersection of first and second arcs, (a) the first arc having a center at the first position, a radius based on the estimated distance between the second device and the first position, and an angle centered on the estimated direction between the second device and the first position and having an angular width based on the range of uncertainty, and (b) the second arc having a center at the second position, a radius based on the estimated distance between the second device and the second position, and an angle centered on the estimated direction between the second device and the second position and having an angular width based on the range of uncertainty.

2. The ranging method of claim 1 , further comprising presenting by the first device a user-interface indication of the estimated location of the second device in the coordinate system, as navigation guidance toward the second device.

3. The ranging method of claim 1, wherein applying the one or more sensors to track distance and direction of movement of the first device from the first position to the second position comprises: tracking the distance of movement using at least one sensor selected from the group consisting of a camera and an accelerometer; andtracking the direction of movement using at least one sensor selected from the group consisting of a camera, a gyroscope, and a compass.

4. The ranging method of claim 1, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using wireless Multi-Carrier Phase Difference (MCPD) to estimate the distance between the second device and the position of the first device; and using wireless angle-of-arrival analysis to estimate the direction between the second device and the position of the first device.

5. The ranging method of claim 1, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using Bluetooth Low Energy (BLE) Channel Sounding as a basis to estimate distance between the second device and the position of the first device; and using BLE angle-of-arrival analysis as a basis to estimate the direction between the second device and the position of the first device.

6. The ranging method of claim 1, further comprising: coordinating by the first device the movement of the first device from the first position to the second position, to facilitate the ranging.

7. The ranging method of claim 6, wherein the coordinating by the first device of the movement of the first device from the first position to the second position is configured to avoid having the movement be parallel to the estimated direction between the second device and the first position of the first device.

8. A first device comprising: at least one wireless communication interface; at least one processor; at least one non-transitory data storage; andprogram instructions stored in the at least one non-transitory data storage and executable by the at least one processor to cause the first device to carry out operations for locating a second device in relation to a first device, the operations including: estimating first and second positions of the first device in a coordinate system, starting at the first position and applying one or more sensors to track distance and direction of movement of the first device from the first position to the second position, respectively at each position of the first and second positions of the first device, using wireless signaling between the first device and the second device as a basis to estimate both distance and direction between the second device and the position of the first device, wherein the estimated direction has a range of uncertainty, and estimating a location of the second device in the coordinate system as a point of intersection of first and second arcs, (a) the first arc having a center at the first position, a radius based on the estimated distance between the second device and the first position, and an angle centered on the estimated direction between the second device and the first position and having an angular width based on the range of uncertainty, and (b) the second arc having a center at the second position, a radius based on the estimated distance between the second device and the second position, and an angle centered on the estimated direction between the second device and the second position and having an angular width based on the range of uncertainty.

9. The first device of claim 8, wherein the operations additionally include presenting a user-interface indication of the estimated location of the second device in the coordinate system, as navigation guidance toward the second device.

10. The first device of claim 8, wherein applying the one or more sensors to track distance and direction of movement of the first device from the first position to the second position comprises: tracking the distance of movement using at least one sensor selected from the group consisting of a camera and an accelerometer; and tracking the direction of movement using at least one sensor selected from the group consisting of a camera, a gyroscope, and a compass.

11. The first device of claim 8, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using wireless Multi-Carrier Phase Difference (MCPD) to estimate the distance between the second device and the position of the first device; and using wireless angle-of-arrival analysis to estimate the direction between the second device and the position of the first device.

12. The first device claim 8, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using Bluetooth Low Energy (BLE) Channel Sounding as a basis to estimate distance between the second device and the position of the first device; and using BLE angle-of-arrival analysis as a basis to estimate the direction between the second device and the position of the first device.

13. The first device of claim 8, wherein the operations additionally include: coordinating the movement of the first device from the first position to the second position, to facilitate the ranging.

14. The first device of claim 13, wherein the coordinating of the movement of the first device from the first position to the second position is configured to avoid having the movement be parallel to the estimated direction between the second device and the first position of the first device.

15. At least one non-transitory computer-readable medium having stored thereon program instructions executable by at least one processor of a first device to cause the first device to carry out operations for locating a second device in relation to a first device, the operations including: estimating first and second positions of the first device in a coordinate system, starting at the first position and applying one or more sensors to track distance and direction of movement of the first device from the first position to the second position,respectively at each position of the first and second positions of the first device, using wireless signaling between the first device and the second device as a basis to estimate both distance and direction between the second device and the position of the first device, wherein the estimated direction has a range of uncertainty, and estimating a location of the second device in the coordinate system as a point of intersection of first and second arcs, (a) the first arc having a center at the first position, a radius based on the estimated distance between the second device and the first position, and an angle centered on the estimated direction between the second device and the first position and having an angular width based on the range of uncertainty, and (b) the second arc having a center at the second position, a radius based on the estimated distance between the second device and the second position, and an angle centered on the estimated direction between the second device and the second position and having an angular width based on the range of uncertainty.

16. The at least one non-transitory computer-readable medium of claim 15, wherein the operations additionally include presenting a user-interface indication of the estimated location of the second device in the coordinate system, as navigation guidance toward the second device.

17. The at least one non-transitory computer-readable medium of claim 15, wherein applying the one or more sensors to track distance and direction of movement of the first device from the first position to the second position comprises: tracking the distance of movement using at least one sensor selected from the group consisting of a camera and an accelerometer; and tracking the direction of movement using at least one sensor selected from the group consisting of a camera, a gyroscope, and a compass.

18. The at least one non-transitory computer-readable medium of claim 15, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using wireless Multi-Carrier Phase Difference (MCPD) to estimate the distance of the second device from the position of the first device; andusing wireless angle-of-arrival analysis to estimate the direction of the second device from the position of the first device.

19. The at least one non-transitory computer-readable medium of claim 15, wherein using the wireless signaling between the first device and the second device as the basis to estimate both distance and direction between the second device and the position of the first device comprises: using Bluetooth Low Energy (BLE) Channel Sounding as a basis to estimate distance between the second device and the position of the first device; and using BLE angle-of-arrival analysis as a basis to estimate the direction between the second device and the position of the first device.

20. The at least one non-transitory computer-readable medium of claim 15, wherein the operations additionally include: coordinating the movement of the first device from the first position to the second position, to facilitate the ranging, wherein the coordinating of the movement of the first device from the first position to the second position is configured to avoid having the movement be parallel to the estimated direction of the second device from the first position of the first device.

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