Method and apparatus for acquiring a position in a radio signal receiver located in a vehicle

Abstract

A method, apparatus, and system for determining an accurate position and / or orientation of a radio signal receiver located in a stationary vehicle and having an antenna mounted on a moveable component of the vehicle include moving the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna, performing a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal, determining motion of the antenna of the radio signal receiver, compensating a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results, selecting specific received signals, based on the motion compensated correlation results, and determining a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

Description

METHOD AND APPARATUS FOR ACQUIRING A POSITION IN A RADIO SIGNAL RECEIVER LOCATED IN A VEHICLECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims benefit of and priority to U.S. Provisional Patent Application Serial No. 63 / 738,015 filed December 23, 2024, which is herein incorporated by reference in its entirety.BACKGROUNDField

[0002] Embodiments of the present principles generally relate to radio signal receivers and, in particular, to a method and apparatus for acquiring a position in a radio signal receiver located in a vehicle.Description of the Related Art

[0003] Positioning signal receivers such as receivers for global satellite navigation systems (GNSS) signals are used in the operation of autonomous vehicles and vehicles with self-driving modes to determine the location of the vehicle. A GNSS receiver (e.g., receivers for GPS, GLONASS, GALILEO, BEIDOU, etc. satellite signals or a combination thereof) receive signals from satellites, process the received signals and determine the position of the receiver from information contained in the received signals. The typical accuracy of a consumer receiver without the assistance of an inertial measurement unit (IMU) can range from 5 to 50m. To provide inertial navigation in an autonomous vehicle, an IMU typically comprises a magnetometer, a gyroscope and an accelerometer, i.e. , traditional IMU sensors. The signals from these three sensors (typically, MEMS-based sensors) are used to augment the GNSS receiver’s positioning computation such that the receiver accuracy may be improved to about 20cm and enable the vehicle's orientation to be known and tracked.

[0004] When an autonomous vehicle is deactivated (e.g., parked), the various sensors and receivers are also deactivated. Upon reactivation, the vehicle cannot operate autonomously or in a self-driving mode until the GNSS receiver reacquiresthe GNSS satellite signals and determines the pose (position and orientation) of the vehicle. The result is a delay in the start of autonomous or self-driving modes. In the worst case, the autonomous vehicle may not be able to acquire weak GNSS signals and may never move unless driven in manual mode. This problem is especially acute when autonomous vehicles and / or vehicles with self-driving modes are parked in parking decks or in an urban canyon where GNSS signals are readily attenuated, reflected, or blocked.

[0005] Therefore, there is a need for a method, apparatus, and system for acquiring an accurate position and / or orientation in a radio signal receiver located in a vehicle using advanced signal processing techniques.SUMMARY

[0006] Embodiments of the present principles generally relate to and provide methods, apparatuses and systems for acquiring a position in a radio signal receiver located, for example, in a vehicle.

[0007] Various features and advantages of the present principles may be appreciated from a review of the following detailed description of the present disclosure, along with the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] So that the manner in which the features of the present principles can be understood in detail, a particular description of the present principles may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present principles and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0009] FIG. 1 depicts a communication environment in which an embodiment of a radio signal receiver of the present principles can be applied for acquiring an accurateposition of a vehicle in which the receiver is located in accordance with at least one embodiment of the present principles;

[0010] FIG. 2 depicts a functional block diagram of a radio signal receiver in accordance with at least one embodiment of the present principles;

[0011] FIG. 3 depicts a block diagram of a computing device, which can be a component of and / or can be configured to operate with a receiver of the present principles in accordance with at least one embodiment of the present principles;

[0012] FIG. 4 depicts a flow diagram of a method for determining an initial position of a stationary vehicle including a receiver having an antenna mounted on a moveable component of the vehicle in accordance with at least one embodiment of the present principles; and

[0013] FIG. 5A depicts an exemplary moveable component that may be used to move the antenna in accordance with at least one embodiment of the present principles.

[0014] FIG. 5B depicts an exemplary moveable component that may be used to move the antenna in accordance with at least one alternate embodiment of the present principles.

[0015] FIG. 5C depicts an exemplary moveable component that may be used to move the antenna in accordance with at least another alternate embodiment of the present principles.

[0016] FIG. 5D depicts an exemplary moveable component that may be used to move the antenna in accordance with at least another alternate embodiment of the present principles.

[0017] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. It is contemplated thatelements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0018] Embodiments of the present principles comprise apparatus and methods for acquiring a position and / or orientation in a vehicle-based radio signal receiver using motion compensated signal processing in challenging signal environments. Such receivers include positioning systems (e.g., a GNSS receiver) and / or communications receivers (e.g., WiFi, cellular, Bluetooth communications receivers).

[0019] Satellite-based positioning systems and communications receivers utilize encoded digital signals including a deterministic digital code to facilitate signal acquisition, e.g., Gold codes. Such a digital code is determined by the receiver and repeatedly broadcast by the transmitter to enable receivers to acquire and process transmitted signals. Using such deterministic codes combined with an accurate motion estimation of the receiver antenna, embodiments of the present principles are useful to enable a receiver to improve its position computation accuracy and / or signal reception. The technique for improving radio signal reception using antenna motion compensated signal processing is known as SUPERCORRELATION™ and is described in commonly assigned US patent 9,780,829, issued 3 October 2017; US patent 10,321,430, issued 11 June 2019; US patent 10,816,672, issued 27 October 2020; US patent 11 / 474,258, issued 28 September 2022; US patent 11 / 474,258, issued 28 September 2022, and US Patent Publication No. US20240014549A1, published 11 January 2024, which are hereby incorporated herein by reference in their entireties. A GNSS receiver that uses the SUPERCORRELATION™ technique is referred to as an S-GNSS® receiver. SUPERCORRELATION™ and S-GNSS® are trademarks of Focal Point Positioning Ltd. For the SUPERCORRELATION™ technique to function properly, the receiver antenna must be moving relative to the transmitter as the transmitted signals are received.

[0020] In an embodiment of the present principles, to ensure accurate position and / or orientation initialization, the receiver antenna is mounted to a moveable component of the vehicle. The moveable component is automatically moved, for example, but not limited to, when a person approaches the vehicle, when a driver unlocks and / or opens a driver’s door, when a signal is sent to the vehicle to begin initialization, and the like. For accurate results, the antenna movement should be through a distance of at least a quarter to a half wavelength or more of the received signal, e.g., for GNSS signals - the wavelength ranges from 19 cm to 25 cm depending on the system and signal frequency used by the system. Such movement may be imparted to the antenna by mounting the antenna to a door such that, when the door is opened, the antenna is moved while signals are being received. In other embodiments, the antenna may be mounted to, for example, but not limited to, one or more of windshield (windscreen) and / or rear window wiper(s), moveable side mirror(s), and the like. In other embodiments, the entire vehicle may be automatically rocked (moved) back and forth a short distance while receiving signals.

[0021] Upon receiving radio signals from the moving antenna, the radio signal receiver uses motion compensated signal processing (known as SUPERCORRELATION™ processing) to select the “best” GNSS signals to use for navigation. The “best” signals are typically line-of-sight (LOS) or direct signals from the transmitter (e.g., GNSS satellite), while reflected, non-line-of-sight (NLOS) signals and / or severely attenuated signals are rejected for use in the position computation. The SUPERCORRELATION™ processing is capable of discriminating between the angle-of-arrival of received signals, for example, between the direct LOS signal and the reflected NLOS signals which arrive at the receiver antenna from different directions. The SUPERCORRELATION™ processing is also capable of differentiating between legitimate GNSS signals from GNSS satellites and spoofing GNSS signals sent from unauthorized transmitters. Furthermore, the SUPERCORRELATION™ processing is capable of boosting the sensitivity of the receiver towards LOS signals, and can increase the signal-to-noise ratio (SNR) of attenuated LOS signals enabling these to be selected and used for positioning. The selected signals are coupled to anavigation engine to rapidly and accurately determine the receiver (and vehicle) position. In this manner, reflected signals and spoofer signals are rejected and not used in the navigation solution.

[0022] In an embodiment, the radio receiver is embedded in, attached to or carried by, a moving platform such as, for example, but not limited to, an automobile, motorcycle, airplane, helicopter, drone, bicycle, and the like. In its broadest sense, embodiments of the present principles find use in any autonomous vehicle, a vehicle that uses a self-driving mode or any vehicle that requires knowledge of its initial position and / or orientation - especially within a challenging signal environment such as, but not limited to, urban canyons, under dense foliage, proximate one or more spoofers, in a parking garage, and the like.

[0023] The technical effect of embodiments of the present principles is to improve signal reception and / or positioning / orientation of the receiver when the receiver is located in a challenging signal environment. By attaching the antenna to a moveable component of a vehicle, an additional platform for moving the antenna is not necessary to facilitate the use of motion compensated correlation (e.g., a SUPERCORRELATION™ technique). Consequently, embodiments of the present principles reduce system cost and complexity.

[0024] FIG. 1 depicts a communication environment in which an embodiment of a radio signal receiver of the present principles can be applied for acquiring an accurate position of a vehicle in which the receiver is located in accordance with at least one embodiment of the present principles. More specifically, in the communication environment 100 of FIG. 1, a receiver of the present principles implements a processing method to improve the accuracy of a calculated position and / or orientation of a radio signal receiver located in, for example, a vehicle in accordance with at least one embodiment. In the communication environment 100 of FIG. 1 , a vehicle 102 that requires accurate initial knowledge of its position (i.e. less than approximately 5-10 meters of error) carrying a receiver 104 (position A) is parked within a building 106(e.g., a car park or garage) after being deactivated. While within the building 106, the receiver 104 does not have a clear view of the sky and the satellite signals 110, 114, and 118 broadcast from a plurality of satellites 108-1, 108-2, . . . 108-N, which are severely attenuated and can be reflected (e.g., signal 123). In the embodiment of FIG.1 , the radio receiver 104 can be in a ‘multi-path’ environment, including a complex mix of signals reflected, refracted, or diffracted from the plurality of structures around, for example, the vehicle. In some embodiments, the radio receiver can also receive signals directly along the line of sight (LOS) path from the transmitter to the receiver. As such, the receiver 104, in some instances, may not be able to accurately determine its initial position. In such instances, an embodiment of a signal processing technique of the present principles, described in greater detail below, is used to quickly determine the vehicle’s position accurately.

[0025] In the embodiment of FIG. 1, in another instance (position B), the vehicle 102 can be parked in an urban canyon (surrounded by tall buildings 106 and 122) and, when the vehicle is activated, the receiver receives direct signals 112 and 116, reflected signals 120, and some signals 118 can blocked or severely attenuated. Using such indirect (reflected) signals in navigation solutions results in a very inaccurate solution and, in some cases, the reflected signals may result in multipath interference so severe that a position cannot be accurately determined. In such instances, an embodiment of a signal processing technique of the present principles, described in greater detail below, is used to quickly determine the vehicle’s position accurately.

[0026] FIG. 2 depicts a functional block diagram of a radio signal receiver, such as the radio signal receiver 104 of FIG. 1, in accordance with at least one embodiment of the present principles. In the embodiment of FIG. 2, the receiver 104 comprises an antenna 202, a front end 204, a GNSS signal processor and navigation engine 206, a motion compensation processor 208, and a motion module 210. In the embodiment of FIG. 2, the motion compensation processor 208 comprises an acquisition module 214 and the motion module 210 comprises an inertial measurement unit (IMU) 212.The IMU 212 comprises one or more sensors such as, but not limited to an accelerometer, a gyroscope, a magnetometer, a barometer, and the like (not shown). In some embodiments, an IMU is not necessary.

[0027] In the embodiment of FIG. 2, the receiver’s front end 204 downconverts, filters, and samples (digitizes) the received signals in a manner that is well-known to those skilled in the art and, as such, will not be described in greater detail herein. The output of the receiver front end 204 is a digital signal containing data. In some embodiments, the data of interest for performing motion compensation in accordance with the present principles includes a deterministic code (e.g., Gold code) received in a signal received from a transmitter and used by the GNSS signal processor 206 to synchronize the receiver 104 to the GNSS transmission to acquire the GNSS signals.

[0028] More specifically, in some embodiments, during GNSS signal acquisition, the GNSS signal processor 206 correlates a received code from each satellite with locally generated codes to produce correlation results. The correlation results are processed by the navigation engine 206 as is well-known in the art to generate position information. That is, in some embodiments the correlation results are used to determine pseudoranges to each satellite and the pseudoranges are processed to compute the receiver position. To do so, in some embodiments, the motion compensation processor 208 performs SUPERCORRELATION™ processing to provide signals (phasor sequences) to phase adjust the correlation results such that the coherent integration period is extended (e.g., extended to one or more seconds) such that very attenuated signals may be received and used for navigation. In some embodiments, the phasor sequence comprises a time sequence of phase offsets where each phasor in the sequence adjusts the phase of a signal sample. The adjustment may be performed by adjusting the phase of each sample of the received signals, the locally generated signals or the correlation results themselves. In some embodiments, a least computationally intensive adjustment process adjusts the phase of the correlation results.

[0029] In some embodiments, the motion module 210 generates receiver motion information that is used by the motion compensation processor 208 to generate phasor sequences that are used to motion compensate the correlation results. The phasor sequences comprise a sequence of phase offsets to be made over time (e.g., across a received signal) to compensate for phase changes that occur over time due to movement of the receiver. In one embodiment, the motion module 210 can use a known model of antenna motion (e.g., a known model of the motion of the vehicle component on which the antenna is mounted) and / or an IMU 212 to generate motion information for the motion compensation processor 208. In one embodiment, motion information can include a prediction of antenna motion. Alternatively or in addition, in some embodiments the motion module 210 can implement the IMU 212 to provide vehicle orientation information and / or measurements of the vehicle component motion (e.g. the motion of a door being opened and / or closed) which can optionally be combined with a motion model to generate accurate antenna motion information. In the embodiment of FIG. 2, the motion compensation processor 208 provides motion estimation correction information along path 216 to the motion module 210. In this manner, the motion compensation processor 208 provides corrective feedback to the motion module 210 in accordance with the present principles.

[0030] In the embodiment of FIG. 2, the acquisition module 214 is an element of the motion compensation processor 208. As is described in further detail below, the acquisition module 214 is activated when the vehicle and its receiver 104 are activated and an initial position is required. In some embodiments, activation may be instigated by, one or more of, the approach of an authorized vehicle operator (e.g., a person carrying a key and / or a key fob for the vehicle, a door being unlocked, a door handle being manipulated, an activation signal being transmitted from a remote location (e.g., an auto-start signal or an autonomous vehicle activation command), a start command for the vehicle (e.g., the ‘start’ button of the vehicle being operated or key being turned), and the like. In accordance with embodiments of the present principles, any such activation indicates a need for a vehicle position to be computed. In some embodiments, once a need for a position is detected, the antenna is moved using amoveable component of the vehicle while signals are received and buffered. The acquisition module 214 initializes the motion compensation processor 208 to motion compensate any received GNSS signals. Such processing enables the acquisition module 214 to select the “best” signals for processing by the GNSS processor and navigation engine 206 and rapidly generate an accurate vehicle position.

[0031] In embodiments of the present principles, to ensure accurate position initialization, the receiver antenna is mounted on a moveable component of the vehicle. The moveable component is automatically or manually moved, for example, but not limited to, when a person approaches the vehicle, when a driver unlocks and / or opens a driver’s door, when a signal is sent to the vehicle to begin initialization, when the vehicle ‘start’ button is operated, and the like. In some embodiments, to ensure accurate results, the antenna of a receiver of the present principles is moved a distance of a quarter to a half wavelength or more of the received signal. For example, for GNSS signals, the wavelength ranges from 19 cm to 25 cm depending on the system and signal frequency used by the system.

[0032] FIGs. 5A, 5B, 5C, and 5D depict examples of moveable components of a vehicle 499 that may be used to move the antenna 202 of the receiver 104 in accordance with various embodiments of the present principles. In some embodiments, the antenna 202 can include a patch antenna or dipole antenna that is embedded into the moveable component. Movement can then be imparted to the antenna 202 by mounting the antenna 202 to, for example, a door 500 (FIG. 5A) such that, when the door is opened (position B) from a closed position (position A), the antenna 202 is moved along path 502 while signals are being received. Alternatively or in addition, in some embodiments, the antenna 202 can be mounted to, for example, but not limited to, one or more of windshield (windscreen) (FIG. 5B) and / or rear window wiper(s) 504, moveable side mirror(s) 506 (FIG. 5C), and the like. Alternatively or in addition, in some embodiments (FIG. 5D), the entire vehicle 499 can be automatically rocked (moved) back and forth a short distance (path 508 between positions A and B) while receiving signals through an antenna 202 mountedon the vehicle 499. In such embodiments, the vehicle 499 can use various sensors (e.g., RADAR, LIDAR, acoustic, etc.) to detect any obstacles proximate the vehicle 499 to avoid collisions.

[0033] The motion of moveable components such as the wipers and / or mirrors can be known by, for example, measuring such motion in advance and including such motion as, for example, a motion model without a need to measure the movement using an IMU sensor. In such embodiments, the motion of, for example, the wiper and / or the mirror carrying the antenna need only move as the GNSS signals are being received. A motion of the moveable component of the present principles can be activated upon a determination of the need for an initial receiver position, such as, for example, by unlocking of a door of the vehicle, sitting in the driver’s seat, a pressing of the start button, a turning of the start key, and the like.

[0034] In some instances, a motion of an antenna of a receiver may not be definitively determinable when a mobile component of a vehicle is moved during use. For example, if a door of a vehicle is the mobile component, a driver may vary the distance the door is opened and / or the velocity used to open the door. In such situations, an IMU sensor may be attached to the mobile component (door) to indicate movement of the door in all instances. Alternatively or in addition, in some embodiments a single axis gyroscope and / or an accelerometer may be coupled / attached to the door to sense / indicate motion.

[0035] FIG. 3 depicts a block diagram of a computing device 350, which, in some embodiments, can be a component of and / or can be configured to operate with a receiver of the present principles, such as the receiver 104 of FIG.1 and FIG. 2, to perform the functions of at least the GNSS processor and navigation engine 206 and the motion compensation processor 208 within the receiver 104 of FIGs. 1 and 2 in accordance with at least one embodiment of the present principles. The computing device 350 of FIG. 3 illustratively comprises at least one processor 300, support circuits 302 and memory 304. The at least one processor 300 can be any form ofprocessor or combination of processors including, but not limited to, central processing units, microprocessors, microcontrollers, field programmable gate arrays, graphics processing units, digital signal processors, and the like. The support circuits 302 can include well-known circuits and devices facilitating functionality of the processor(s). The support circuits 302 can include one or more of, or a combination of, power supplies, clock circuits, analog to digital converters, communications circuits, memory cache, displays, and / or the like.

[0036] In the embodiment of FIG. 3, the memory 304 comprises one or more forms of non-transitory computer readable media including one or more of, or any combination of, read-only memory or random-access memory. The memory 304 can store software and data including, for example, acquisition software 306, SUPERCORRELATION™ software 308, navigation software 310 and data 312. The data 312 can include satellite information 314, motion information, and various additional data used to perform the acquisition processing of the present principles.

[0037] In accordance with embodiments of the present principles, when the antenna motion is detected, the acquisition software 306 causes the execution of the SUPERCORRELATION™ software 308 and causes the receiver 104 to begin to receive GNSS signals to be processed according to the navigation software 310. The selected GNSS signals are rapidly processed by the navigation software 310 to determine a vehicle position.

[0038] FIG. 4 depicts a flow diagram of a method 400 for determining an initial position of a stationary vehicle including a receiver having an antenna mounted on a moveable component of the vehicle in accordance with at least one embodiment of the present principles. The method 400 of FIG. 4 can be implemented in software, hardware or a combination of both (e.g., using the GNSS processor and navigation engine 206, the motion compensation processor 208 and the acquisition module 214 of the receiver 104 of FIG. 2).

[0039] The method 400 can begin at optional 402 during which a need for the determination of an initial position is detected. For example, in some embodiments and as described above, a need for the determination of an initial position can be triggered when an authorized operator (e.g., a person carrying the vehicle’s key and / or key fob approaches the vehicle, when a driver unlocks and / or opens a driver’s door, when a signal is sent to the vehicle to begin initialization, and the like. The method 400 can proceed to 404.

[0040] At 404, the antenna / receiver in the vehicle is moved using a moveable component of the vehicle while signals are received at the receiver from at least one remote source (e.g., transmitters such as the GNSS satellites 108 of FIG. 1) in a manner as described with respect to FIG. 1. The method 400 can proceed to optional 406.

[0041] At optional 406, the received signals can be stored. In some embodiments and as described above, each received signal comprises a synchronization or acquisition code (e.g., a Gold code) extracted from the radio frequency (RF) signal received at the antenna. The method 400 can proceed to 408.

[0042] At 408, the GNSS processor processes the GNSS signals using a traditional signal acquisition procedure. For example, in some embodiments, each received RF signal is downconverted and the digital code is sampled as is well known in the art. The buffered signals can include representations of the received signals such as, but not limited to, digitized RF signals, digitized, downconverted signals, baseband signals, extracted code, correlation results and the like. In some embodiments, the GNSS processor acquires / processes as many signals as the processor is able to acquire / process and produces an initial receiver position and / or time (typically accurate to within about 1km and within seconds of the actual time). These signals can include severely attenuated, reflected signals and direct signals resulting in an inaccurate position and time. As such, in accordance with the present principles, the GNSS processor can make use of externally provided data, such aslocal time, approximate location (e.g. from local cellular tower) and satellite ephemeris data in order to target acquisition of signals from satellites that are currently above the local horizon. Alternatively, or in addition, in some embodiments the position already known inside the vehicle driver’s mobile phone can be transmitted to the vehicle’s GNSS receiver for use as the approximate starting position. The method 400 can proceed to 410.

[0043] At 410, the method 400 initiates the SUPERCORRELATION™ processing to process the received GNSS signals. In some embodiments, a stationary SUPERCORRELATION™ technique is used as described in commonly assigned US Patent Publication No. US20240014549A1 , published 11 January 2024, entitled “Method and Apparatus for Processing Radio Signals,” which is herein incorporated by reference herein in its entirety.

[0044] Specifically, in the embodiment of the method 400, SUPERCORRELATION™ is performed using motion hypotheses and the received signals. During this process, the SUPERCORRELATION™ procedure generates a plurality of phasor sequence hypotheses related to the motion information. These hypotheses comprise a plurality of local signals representing code phase estimates. Each phasor sequence hypothesis comprises a phase estimate that varies with motion parameters of the receiver. The signal processing correlates a local code encoded in a local signal with a code encoded in the received RF signal. The phasor sequence hypotheses are used to adjust, at a sub-wavelength accuracy, the carrier phase of the local code. Such adjustment or compensation can be performed by adjusting a local oscillator signal, the received signal(s), or the correlation result. The signals and / or correlation results comprise complex signal samples having in-phase (I) and quadrature phase (Q) components. In the method 400, each phase offset in the phasor sequence is applied to a corresponding complex sample in the signals and / or correlation results. For each received signal, the process correlates the received signals with a set (plurality) of phasor sequence hypotheses containing estimates of a phase offset necessary to accurately correlate the received signals.

[0045] In some embodiments, the motion estimates are typically hypotheses of a component of motion in a direction of interest such as in the direction of the satellite that transmitted the received signal (e.g., along the signal propagation path).

[0046] In some embodiments, if a signal from a given satellite was received previously, the set of hypotheses for the newly received signal include a group of phasor sequence hypotheses using the expected Doppler and Doppler rate and / or last Doppler and last Doppler rate used in receiving the prior signal from that particular satellite. The hypotheses values can be centered around the last values used or the last values used additionally offset by a prediction of further offset based on the expected receiver motion. In the method 400, each received signal is correlated with that signal’s set of hypotheses. The hypotheses are used as parameters to form the phase-compensated phasors to phase compensate the correlation process. As such, the phase compensation can be applied to the received signals, the local frequency source (e.g., an oscillator), or the correlation result values. The result of the correlation process is a plurality of phase-compensated correlation results - one phase-compensated correlation result value for each hypothesis for each received signal.

[0047] The correlation results are processed to find the “best” or optimal result for each received signal. In one embodiment, a joint correlation output is produced as a function (e.g., summation) of the plurality of correlation results resulting from all the hypotheses and received transmitter signals. The joint correlation output may be a single value or a plurality of values that represent the parameter hypotheses that provide an optimal or best correlation output. In general, in some embodiments, a cost function is applied to each set of correlation values for each received signal to find the optimal correlation output corresponding to a preferred hypothesis or hypotheses.

[0048] For example, assuming all other receiver parameters are known except receiver motion direction, hypotheses are tested with various phasor sequences that compensate for phase changes due to each direction hypothesis. The correct phasorsequence hypothesis that represents the accurate direction estimate will produce the highest correlation result magnitude for a given received signal. By processing the received signals from different satellites, the correlation results will converge upon hypotheses representing the true receiver motion direction.

[0049] In accordance with some embodiments of the present principles, SUPERCORRELATION™ processing can be used to determine the direction of arrival of signals to facilitate identifying direct (or line-of-sight (LOS)) signals as compared to reflected (or non-line-of-sight (NLOS)) signals. In most instances, direct signals are better to use in a navigation solution and provide a more accurate position. Furthermore, SUPERCORRELATION™ processing enables extended coherent integration periods to be used on the GNSS signals resulting in an ability to receive and use very attenuated signals. This enables GNSS signals that are received indoors to be used in a navigation solution.

[0050] Because the receiver knows the location of each GNSS satellite from the satellite ephemeris information received from each satellite, an anomalous direction from which a signal is received can be an indication that the signal is a NLOS signal or a spoofer. These signals can then be rejected for use in the navigation solution. The method 400 can proceed to 412.

[0051] At 412, it is determined whether the correlation results represent signals that have sufficient quality to produce an accurate position solution. If the method 400 determines that none or not enough of the received signals are of sufficient quality to compute an accurate position solution, the method 400 returns, along path 422, to 404 to receive additional GNSS signals while moving the antenna. In some embodiments, a sufficiency of the quality of the signals can be measured by the number of direct satellite signals that are available (i.e. , if very few direct signals are available, the navigation solution could be considered inaccurate). Alternatively or in addition, in some embodiments, the GNSS processor can produce a sufficiency score in a standard manner based on signal noise, error ellipse, signal strength, frequencyerror, code phase error, etc., and a sufficiency of the signal can be based on a respective score. Alternatively or in addition in some embodiments, a period during which GNSS signals are received at the moving antenna and coherently integrated using SUPERCORRELATION™ processing can be dynamically increased in order to boost further the signal-to-noise ratio of the line-of-sight signals. This is of particular importance where the line-of-sight signals are heavily attenuated, for example when the vehicle is positioned in a covered car park or parking garage. If the correlation results are determined to be sufficient, the method 400 can proceed to 414.

[0052] At 414, the “best” or “preferred” signals are selected to be used to calculate a receiver position. These signals are typically direct GNSS signals (i.e. , LOS signals) that have the highest signal-to-noise ratio. In this manner, reflected signals which contain unknown ranging errors are not used in the navigation solution and the accuracy of the position is substantially improved. The method 400 can proceed to 416.

[0053] At 416, the selected compensated correlation results are used in a traditional navigation solution (e.g., using range to each satellite transmitter) to generate the position of the receiver. In some embodiments, the selected LOS signals can be used to determine an orientation of the vehicle in the East-North frame using knowledge of the azimuths of the GNSS satellites. SUPERCORRELATION™ processing can be used to determine the angle of arrival of each LOS signal relative to the path of antenna motion, which in turn can be related to the body frame of the vehicle thereby allowing the East-North orientation of the vehicle to be estimated from the known azimuths of GNSS satellite that transmitted the LOS signals. The method 400 can proceed to optional 418.

[0054] At optional 418, once the vehicle position is determined, autonomous driving features of the vehicle can be activated. That is, in some embodiments, the determined vehicle position can be used for providing autonomous driving solutions for the vehicle. For example, an accurate starting position / orientation of the vehicle,together with a map of the area containing the position, and inputs from local sensors such as cameras and the like, can enable calculation of an accurate and safe route for the vehicle such that the vehicle can leave the local environment and navigate autonomously to a destination. The method 400 ends at 420.

[0055] Alternatively or in addition in some embodiments, rather than using the largest magnitude correlation value, other test criteria can be used. For example, a progression of correlations can be monitored as hypotheses are tested and a cost function can be applied that indicates the preferred hypotheses when the cost function reaches a minimum. As such, the joint correlation output can be a joint correlation value or a group of values.In some embodiments, a method for determining an accurate position and / or orientation of a radio signal receiver located in a stationary vehicle and having an antenna mounted on a moveable component of the vehicle includes moving the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna, performing a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal, determining motion of the antenna of the radio signal receiver, compensating a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results, selecting specific received signals, based on the motion compensated correlation results, and determining a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

[0056] In some embodiments, the method can further include sensing a need for moving the moveable component of the vehicle to determine a position of the vehicle before the moving of the moveable component of the vehicle.

[0057] In some embodiments, sensing the need for moving the moveable component includes at least one of sensing an approach of an authorized operator ofthe vehicle, sensing a door being unlocked, sensing a door handle being manipulated, sensing an activation signal being transmitted from a remote location, or sensing a vehicle start command for the vehicle.

[0058] In some embodiments, the method can further include implementing the determined vehicle position for providing autonomous driving solutions for the vehicle.

[0059] In some embodiments, the moveable component of the vehicle comprises at least one of a door of the vehicle, a wiper of the vehicle, a moveable mirror of the vehicle, or the vehicle itself.

[0060] In some embodiments, a motion of the moveable component and the antenna is determined using a predetermined model.

[0061] In some embodiments, the specific received signals comprise line-of-sight signals.

[0062] In some embodiments, an apparatus in a stationary vehicle, for determining an accurate position and / or orientation of the vehicle and mounted on a moveable component of the vehicle includes an antenna, at least one processor, and a memory accessible to the processor, the memory having stored therein at least one of programs or instructions. In some embodiments when the programs or instructions are executed by the processor, the apparatus is configured to move the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna, perform a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal, determine motion of the antenna of the apparatus, compensate a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results, select specific received signals, based on the motion compensated correlation results, and determine a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

[0063] In some embodiments a system for determining an accurate position and / or orientation of a stationary vehicle includes a vehicle including a moveable component, an a radio signal receiver including an antenna mounted on the moveable component of the vehicle, at least one processor, and a memory accessible to the processor, the memory having stored therein at least one of programs or instructions. In some embodiments, when the programs or instructions are executed by the processor, the radio signal receiver is configured to move the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna, perform a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal, determine motion of the antenna of the apparatus, compensate a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results, select specific received signals, based on the motion compensated correlation results, and determine a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

[0064] Here multiple examples have been given to illustrate various features and are not intended to be so limiting. Any one or more of the features may not be limited to the particular examples presented herein, regardless of any order, combination, or connections described. In fact, it should be understood that any combination of the features and / or elements described by way of example above are contemplated, including any variation or modification which is not enumerated, but capable of achieving the same. Unless otherwise stated, any one or more of the features may be combined in any order.

[0065] As above, figures are presented herein for illustrative purposes and are not meant to impose any structural limitations, unless otherwise specified. Various modifications to any of the structures shown in the figures are contemplated to be within the scope of the present principles presented herein. The invention is not intended to be limited to any scope of claim language.

[0066] Where “coupling” or “connection” is used, unless otherwise specified, no limitation is implied that the coupling or connection be restricted to a physical coupling or connection and, instead, should be read to include communicative couplings, including wireless transmissions and protocols.

[0067] Any block, step, module, or otherwise described herein may represent one or more instructions which can be stored on a non-transitory computer readable media as software and / or performed by hardware. Any such block, module, step, or otherwise can be performed by various software and / or hardware combinations in a manner which may be automated, including the use of specialized hardware designed to achieve such a purpose. As above, any number of blocks, steps, or modules may be performed in any order or not at all, including substantially simultaneously, i.e., within tolerances of the systems executing the block, step, or module.

[0068] Where conditional language is used, including, but not limited to, “can,” “could,” “may” or “might,” it should be understood that the associated features or elements are not required. As such, where conditional language is used, the elements and / or features should be understood as being optionally present in at least some examples, and not necessarily conditioned upon anything, unless otherwise specified.

[0069] Where lists are enumerated in the alternative or conjunctive (e.g., one or more of A, B, and / or C), unless stated otherwise, it is understood to include one or more of each element, including any one or more combinations of any number of the enumerated elements (e.g. A, AB, AC, ABC, ABB, etc.). When “and / or” is used, it should be understood that the elements may be joined in the alternative or conjunctive.

[0070] While the foregoing is directed to embodiments of the present principles, other and further embodiments of the present principles may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

Claims:

1. A method for determining an accurate position and / or orientation of a radio signal receiver located in a stationary vehicle and having an antenna mounted on a moveable component of the vehicle, comprising:moving the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna;performing a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal;determining motion of the antenna of the radio signal receiver; compensating a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results;selecting specific received signals, based on the motion compensated correlation results; anddetermining a position and / or orientation of the receiverand of the vehicle using the selected, specific received signals.

2. The method of claim 1 , further comprising:sensing a need for moving the moveable component of the vehicle to determine a position of the vehicle before the moving of the moveable component of the vehicle.

3. The method of claim 2, wherein sensing the need for moving the moveable component comprises at least one of sensing an approach of an authorized operator of the vehicle, sensing a door being unlocked, sensing a door handle being manipulated, sensing an activation signal being transmitted from a remote location, or sensing a vehicle start command for the vehicle4. The method according to any of claims 1 to 3, further comprising:implementing the determined vehicle position for providing autonomous driving solutions for the vehicle.

5. The method according to any of claims 1 to 3, wherein the moveable component of the vehicle comprises at least one of a door of the vehicle, a wiper of the vehicle, a moveable mirror of the vehicle, or the vehicle itself.

6. The method according to any of claims 1 to 3, wherein a motion of the moveable component and the antenna is determined using a predetermined model.

7. The method according to any of claims 1 to 3, wherein the specific received signals comprise line-of-sight signals.

8. An apparatus, in a stationary vehicle, for determining an accurate position and / or orientation of the vehicle and mounted on a moveable component of the vehicle, comprising:an antenna;at least one processor; anda memory accessible to the processor, the memory having stored therein at least one of programs or instructions executable by the processor to configure the apparatus to:move the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna;perform a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal;determine motion of the antenna of the apparatus;compensate a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results;select specific received signals, based on the motion compensated correlation results; anddetermine a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

9. The apparatus of claim 8, wherein the apparatus is further configured to:sense a need for moving the moveable component of the vehicle to determine a position of the vehicle before the moving of the moveable component of the vehicle.

10. The apparatus of claim 9, wherein the apparatus is configured to sense the need for moving the moveable component by at least one of sensing an approach of an authorized operator of the vehicle, sensing a door being unlocked, sensing a door handle being manipulated, sensing an activation signal being transmitted from a remote location, or sensing a vehicle start command for the vehicle.

11. The apparatus according to any of claims 8 to 10, wherein the apparatus is further configured to:implement the determined vehicle position for providing autonomous driving solutions for the vehicle.

12. The apparatus according to any of claims 8 to 10, wherein the moveable component of the vehicle comprises at least one of a door of the vehicle, a wiper of the vehicle, a moveable mirror of the vehicle, or the vehicle itself.

13. The apparatus according to any of claims 8 to 10, wherein a motion of the moveable component and the antenna is determined using a predetermined model.

14. The apparatus according to any of claims 8 to 10, wherein the specific received signals comprise line-of-sight signals.

15. A system for determining an accurate position and / or orientation of a stationary vehicle, comprising:a vehicle including a moveable component; anda radio signal receiver; comprising;an antenna mounted on the moveable component of the vehicle; at least one processor; anda memory accessible to the processor, the memory having stored therein at least one of programs or instructions executable by the processor to configure the radio signal receiver to:move the moveable component of the vehicle while receiving radio signals from a plurality of transmitters using the antenna;perform a GNSS signal acquisition process resulting in a correlation result between a respective received radio signal and a corresponding local signal;determine motion of the antenna of the apparatus; compensate a phase of at least one of the local signal, the plurality of received signals, or at least one correlation result based on the determined antenna motion to produce motion compensated correlation results;select specific received signals, based on the motion compensated correlation results; anddetermine a position and / or orientation of the receiver and of the vehicle using the selected, specific received signals.

16. The system of claim 15, wherein the radio signal receiver is further configured to:sense a need for moving the moveable component of the vehicle to determine a position of the vehicle before the moving of the moveable component of the vehicle.

17. The system of claim 16, wherein the radio signal receiver is configured to sense the need for moving the moveable component by at least one of sensing an approach of an authorized operator of the vehicle, sensing a door being unlocked, sensing a door handle being manipulated, sensing an activation signal being transmitted from a remote location, or sensing a vehicle start command for the vehicle.

18. The system according to any of claims 15 to 17, wherein the radio signal receiver is further configured to:implement the determined vehicle position for providing autonomous driving solutions for the vehicle.

19. The system according to any of claims 15 to 17, wherein the moveable component of the vehicle comprises at least one of a door of the vehicle, a wiper of the vehicle, a moveable mirror of the vehicle, or the vehicle itself.

20. The system according to any of claims 15 to 17, wherein a motion of the moveable component and the antenna is determined using a predetermined model.

21. The system according to any of claims 15 to 17, wherein the specific received signals comprise line-of-sight signals.

Images