Method, apparatus and system for performing signal acquisition in a radio signal receiver

Abstract

A method, apparatus and system for performing signal acquisition in a radio signal receiver includes receiving, at an antenna of the radio signal receiver, a plurality of radio signals from at least one transmitter, determining motion of the antenna of the radio signal receiver, correlating at least one local signal with at least one received radio signal to produce at least one correlation result, compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result, selecting at least one of the received radio signals based on the at least one motion compensated correlation result, and determining a final position of the radio signal receiver by using the selected received radio signals in a navigation solution.

Description

METHOD, APPARATUS AND SYSTEM FOR PERFORMING SIGNAL ACQUISITION IN A RADIO SIGNAL RECEIVERBACKGROUNDField

[0001] Embodiments of the present principles generally relate to radio signal receivers and, in particular, to a method, apparatus and system for performing signal acquisition in a radio signal receiver.Description of the Related Art

[0002] 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.

[0003] 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 reacquires the 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 inparking decks or in an urban canyon where GNSS signals are readily attenuated, reflected, or blocked.

[0004] Therefore, there is a need for a method, apparatus and system for performing signal acquisition in a radio signal receiver using advanced signal processing techniques.SUMMARY

[0005] Embodiments of the present principles generally relate to a method, apparatus, and system for performing signal acquisition in a radio signal receiver as shown in and / or described in connection with at least one of the figures.

[0006] Various advantages, aspects and features of the present principles, as well as details of illustrated embodiments thereof, are more fully understood from the following description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] So that the manner in which the above recited features of the present principles can be understood in detail, a more particular description of the present principles, briefly summarized above, 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 this present principles and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0008] FIG. 1 depicts a block diagram of a communication environment in which a receiver of the present principles can be applied in accordance with an embodiment of the present principles;

[0009] FIG. 2 depicts a high-level functional block diagram of a radio signal receiver in accordance with at least one embodiment of the present principles;

[0010] FIG. 3 depicts a high-level block diagram of a computing device suitable for implementing the functions of at least one of the GNSS processor and navigationengine and the motion compensation processor within the receiver of FIGs. 1 and 2 in accordance with at least one embodiment of the present principles; and

[0011] FIG. 4 depicts a flow diagram of a method of operating the receiver to perform signal acquisition in accordance with at least one embodiment of the present principles.

[0012] 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 that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0013]

[0014] Embodiments of the present principles generally relate to a method, apparatus, and system for performing signal acquisition in a radio signal receiver. While the concepts of the present principles are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail below. It should be understood that there is no intent to limit the concepts of the present principles to the particular forms disclosed. On the contrary, the intent is to cover all modifications, equivalents, and alternatives consistent with the present principles and the appended claims. For example, although embodiments of the present principles will be described primarily with respect to specific receivers and transmitters, embodiments of the present principles can be applied to substantially and receivers, transmitters and combinations thereof.

[0015] Embodiments of the present principles include apparatuses, systems, and methods for performing signal acquisition in a radio signal receiver using motion compensated signal processing. Such receivers include positioning systems (e.g., aGNSS receiver) and / or communications receivers (e.g., WiFi, cellular, Bluetooth communications receivers).

[0016] In some embodiments, upon receiving radio signals and detecting motion of the antenna (e.g., the vehicle starts moving), 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). The selected signals are coupled to a navigation engine to rapidly and accurately determine the receiver (and vehicle) position. In such embodiments, reflected signals and highly attenuated signals are rejected and not used in the navigation solution.

[0017] 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 model of the receiver, embodiments of the invention are useful to enable a receiver to improve its position computation accuracy and / or signal reception. The technique for improving radio signal reception using receiver 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 publication 2020 / 0264317, published 20 August 2020; and US patent publication 2020 / 0319347, published 8 October 2020, which are hereby incorporated herein by reference in their entireties. The motion model is typically derived using IMU data. In addition, motion information determined by the SUPERCORRELATION™ technique can be provided as feedback to a motion module to correct and / or update the motion model.

[0018] In some embodiments, a radio receiver of the present principles can be 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 thelike. In its broadest sense, embodiments of the invention find use in any autonomous vehicle or vehicle that uses a self-driving mode.

[0019] In operation, at least one signal received by a receiver of the present principles can be correlated with at least one locally generated signal to produce at least one correlation result. In such embodiments, motion compensation can be used as part of an optimal signal acquisition process, in which determined motion information is used to motion compensate the correlation results to enable the receiver to select preferred signals to use for navigation.

[0020] FIG. 1 depicts a block diagram of a communication environment 100 in which a receiver of the present principles can be applied in accordance with an embodiment of the present principles. In the embodiment of FIG. 1 , a receiver 104 of the present principles implements a signal acquisition method in accordance with the present principles to improve signal acquisition. In the communication environment 100 of FIG. 1 , an autonomous vehicle 102 carrying a receiver 104 (position A) moves (represented by arrow 105) 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 and 114 broadcast from a plurality of satellites 108-1 , 108-2, . . . 108-N are severely attenuated. Consequently, the receiver 104 may not be able to accurately determine its position and direction of travel when the vehicle 102 begins to move. In some embodiments, an embodiment of a signal acquisition technique of the present principles can be used (as described below in greater detail) to quickly determine the vehicle’s accurate pose (position and orientation).

[0021] In an alternate scenario (position B), the vehicle 102 can be located in an urban canyon (surrounded by tall buildings 106 and 122). When the vehicle is activated, the receiver 104 can receive direct signals 112 and 116, and reflected signals 120. At position B, some signals 118 are blocked or severely attenuated before reaching the receiver. Using indirect (reflected) signals in a navigation solution results in a very inaccurate solution and, in some cases, the reflected signals can result in multipath interference so severe, a position cannot be computed. As such,embodiments of the present principles implement a signal acquisition technique to quickly determine a vehicle’s accurate pose (position and orientation) using only selected ones of received signals.

[0022] FIG. 2 depicts a high-level functional block diagram of a radio signal receiver of the present principles, 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 212. In the embodiment of FIG. 2, the motion compensation processor 208 comprises an acquisitional module 214 and the motion module comprises an inertial measurement unit (IMU) 212. The IMU 212 comprises various sensors such as, but not limited to one or more of an accelerometer, a gyroscope, a magnetometer, a barometer, and the like.

[0023] When carried by a vehicle 102, the receiver 104 and its antenna 210 are an indivisible unit where the antenna 202 moves with the vehicle 102. The SUPERCORRELATION™ technique of the present principles operates based upon determining a component of motion of the signal receiving antenna that is in the direction of the source of a received signal. Any mention of motion herein refers to the motion of the antenna 202. In most scenarios, the motion of the vehicle 102 and / or receiver 104 is the same as the motion of the antenna 202 and, as such, the following description assumes the motion of the vehicle 102, receiver 104 and antenna 202 are the same. In alternate embodiments, however, the antenna 202 can be moved independently of the vehicle 102 or receiver 104 as described in commonly assigned US patent application 18 / 218,277, filed 6 July 2023, entitled “Method and Apparatus for Processing Radio Signals,” which is hereby incorporated herein by reference in its entirety.

[0024] 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, such process will not be described in detail herein. The output of the receiver front end 204 is a digital signal containing data. The data of interest for performingmotion compensation is a deterministic code, e.g., Gold code, used by the GNSS signal processor 206 to synchronize the receiver 104 to the GNSS transmission and acquire the GNSS signals.

[0025] During GNSS signal acquisition, the GNSS signal processor 206 correlates the 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. For example, in some embodiments, the correlation results can be used to determine pseudoranges to each satellite and the pseudoranges are processed to compute the receiver position. In the embodiment of FIG. 2, the motion compensation processor 208 can perform the SUPERCORRELATION™ processing to provide signals (e.g., phasor sequences) to phase adjust the correlation results such that the coherent integration period is extended (i.e., extended to one or more seconds), such that very attenuated signals can be received and used for navigation. The phasor sequence can be a time sequence of phase offsets where each phasor in the sequence adjusts the phase of a signal sample. The adjustment can 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, the least computationally intensive adjustment process is selected to adjust the phase of the correlation results.

[0026] In the embodiment of FIG. 2, 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. In some embodiments, the phasor sequences comprise a sequence of phase offsets to be made over time (i.e., across a received signal) to compensate for phase changes that occur over time due to movement of the receiver. In some embodiments, the motion module 208 uses the GNSS signal processor and navigation engine 206 and / or an IMU 212 to generate motion information for the motion compensation processor 208. The motion information can comprise a prediction of receiver velocity and heading. Alternatively or in addition, the motion module 210 can comprise an IMU 212 to provide vehicle orientation information for the motion model. In the embodimentof FIG. 2, the motion compensation processor 208 can provide motion estimation correction information along path 216 to the motion module 210. In this manner, the motion compensation processor 208 can provide corrective feedback to the motion module 210.

[0027] The acquisition module 214 is an element of the motion compensation processor 208. As is described in detail below, the acquisition module 214 is activated when the vehicle and its receiver 104 are activated and the vehicle begins to move. Once motion is detected by the IMU 212, 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.

[0028] FIG. 3 depicts a high-level block diagram of a computing device 350 suitable for implementing the functions of at least one of 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. In the embodiment of FIG. 3, the computing device 350 comprises at least one processor 300, support circuits 302 and a memory 304. The at least one processor 300 can include any form of processor 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 of the computing device 350 can include well-known circuits and devices facilitating functionality of the processor(s). The support circuits 302 can further include one or more of, or a combination of, power supplies, clock circuits, analog to digital converters, communications circuits, cache, displays, and / or the like.

[0029] In the embodiment of FIG. 3, the memory 304 can include 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 satellite information 314, motion information, and various additional data can be used to perform the acquisition processing of the present principles.

[0030] When vehicle / receiver motion is detected, the acquisition software 306 can cause the execution of the SUPERCORRELATION™ software 308 to select GNSS signals to be processed by the navigation software 310. The selected GNSS signals are selected because they are GNSS signals that are expected to be rapidly processed by the navigation software into an accurate vehicle position in accordance with the present principles.

[0031] FIG. 4 depicts a flow diagram of a method 400 of operating a receiver of the present principles to perform signal acquisition in accordance with at least one embodiment of the present principles. The method 400 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 FIG. 2).

[0032] The method 400 begins at 402 and proceeds to 404 where 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. 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 RF signal is downconverted and the digital code is sampled. The process of downconverting the RF signal and sampling the digital code is well known in the art and will not be described in detail herein. The method 400 can proceed to 406.

[0033] At 406, the GNSS processor acquires the GNSS signals using a traditional signal acquisition procedure. The GNSS processor acquires as many signals as it is able to acquire and produces an initial receiver position and time (typically accurate to within about 1 km and within seconds of the actual time). These signals may include severely attenuated, reflected signals and direct signals resulting in an inaccurate position and time. The method 400 can proceed to 408.

[0034] At 408, it is determined if antenna motion exists (e.g., the IMU detects the vehicle / receiver is moving). In some embodiments, an autonomous vehicle uses sensors (e.g., LIDAR, RADAR, IMU, cameras, etc.) during motion to avoid collisions with surrounding objects while performing an acquisition process. In embodiments of the present principles, motion of about 1 meter / second or more is sufficient to be used in the SUPERCORRELATION™ processing of the present principles. At 408, if the query is affirmatively answered and it is determined that antenna motion exists, the SUPERCORRELATION™ processing (e.g., execute the SUPERCORRELATION™ software 308) can be executed by, for example, the acquisition module at 410. That is, the method 400 can then proceed to 410. At 408, if the query is negatively answered and it is determined that no antenna motion exists, the method 400 returns to 404 to continue receiving signals.

[0035] At 410, the SUPERCORRELATION™ processing is initiated to process the received GNSS signals. Specifically, SUPERCORRELATION™ is performed using motion hypotheses and the received signals. During the SUPERCORRELATION™ 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 this method, 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. In some embodiments, the motion estimates can be hypotheses of the motion in a direction of interest such as in the direction ofthe satellite that transmitted the received signal (e.g., along the signal propagation path).

[0036] 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. In some embodiments, 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, which produce motion compensated correlation results.

[0037] In the method 400, the correlation results are processed to find the “best” or optimal result for each received signal. In one embodiment, the method 400 produces a joint correlation output 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 can be a single value or a plurality of values that represent the parameter hypotheses (preferred hypotheses) that provide an optimal or best correlation output. In embodiments of the present principles, a cost function can be applied to each set of correlation values for each received signal to find the optimal correlation output corresponding to a preferred hypothesis or hypotheses.

[0038] For example, in some embodiments assuming all other receiver parameters are known except receiver motion direction, the method 400 tests hypotheses with various phasor sequences that compensate for phase changes due to each direction hypothesis. The correct phasor sequence hypothesis that represents the accuratedirection estimate will produce the highest correlation result magnitude (e.g., largest magnitude correlation value) 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.

[0039] That is, in embodiments of the present principles, SUPERCORRELATION™ processing is used to determine the direction of arrival of signals to facilitate identifying direct (or LOS) signals as compared to reflected (or NLOS) signals. In most cases, 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 allows for GNSS signals that are received indoors to be used in the navigation solution. The method 400 can proceed to 412.

[0040] At 412, it is determined whether the motion compensated correlation results contain signals that are sufficient to produce an accurate navigation solution (e.g., a final determination of a position of the receiver from which to begin navigation). If it is determined that the motion compensated correlation results do not contain signals that are sufficient (e.g., of sufficient quality or of sufficient numbers) to produce an accurate navigation solution, the method 400 can return, along path 422, to 404 to receive additional GNSS signals. If it is determined that the motion compensated correlation results do contain signals that are sufficient to produce an accurate navigation solution, the method 400 can proceed to 414. In some embodiments of the present principles, the sufficiency of the signals, such as sufficient quality, can be determined based on a number of direct (line of sight) satellite signals that are available / present in the correlation results. For example, if very few direct signals are available, a navigation solution of the present principles can be inaccurate. Alternatively or in addition, in some embodiments, the GNSS processor of a receiver of the present principles, such as the receiver 104 of FIGs. 1 and 2, can produce a sufficiency score based on, for example, at least one of signal noise, error ellipse, signal strength, frequency error, code phase error, etc. Once the vehicle has begunmoving, signal conditions can change and the attenuation level can be less or the multipath interference may have improved. As such, in some embodiments, a sufficiency score can be determined more than once and, in some embodiment, on a continuous basis.

[0041] At 414, at least one “best” or “preferred” signal associated with the motion compensated correlation results that was determined sufficient enough to produce an accurate navigation solution is selected to, for example, be used to calculate a final receiver position. These signals can typically include direct GNSS signals (i.e., LOS signals) that have a higher / highest signal-to-noise ratio. As such, in embodiments of the present principles, reflected signals are not used in a navigation solution of the present principles and the accuracy of the position is substantially improved. The method 400 can proceed to 416.

[0042] At 416, the at least one selected signals associated with the selected compensated correlation result(s) are used to determine a final position of the receiver. For example, in some embodiments, the selected compensated correlation result(s) are implemented in a traditional navigation solution (e.g., using a respective range / distance to each satellite transmitter from which a radio signal was received) to determine a final position of the receiver. The method 400 can proceed to 418.

[0043] At 418, once the vehicle / receiver position is determined, the autonomous driving features of an autonomous vehicle can be activated. The method 400 ends at 420.

[0044] In some embodiments of the present principles, in the method 400, the initial receiver position estimate determined by, for example, the GNSS processor, can be compared to the determined final position of the receiver to verify an accuracy of the determined final position of the radio signal receiver. That is, in some embodiments, the determined receiver positions can be compared to determine if the determined final receiver position is within a reasonable distance (e.g., a previously determined distance threshold) of the determined initial receiver position. If the initial receiver position and the final receiver position are, for example, too far apart, it canbe determined that at least one or both of the initial receiver position or the final receiver position are faulty.

[0045] In some embodiments, rather than using a largest magnitude correlation value to determine a correct phasor sequence hypothesis that represents the accurate direction estimate, other test criteria can be used. For example, in some embodiments, the 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, in such embodiments the joint correlation output can be a joint correlation value or a group of values.

[0046] In some embodiments of the present principles, a method for performing signal acquisition in a radio signal receiver includes receiving, at an antenna of the radio signal receiver, a plurality of radio signals from at least one transmitter, determining a motion of the antenna of the radio signal receiver, correlating at least one local signal with at least one received radio signal to produce at least one correlation result, compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result, selecting at least one of the received radio signals based on the at least one motion compensated correlation result, and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

[0047] In some embodiments, the method can further include performing a GNSS signal acquisition process to determine an initial estimate of a position of the radio signal receiver from the received plurality of radio signals upon receiving the plurality of radio signals.

[0048] In some embodiments, the initial estimate of a position of the radio signal receiver is compared to the determined final position of the radio signal receiver to verify an accuracy of the determined final position of the radio signal receiver.

[0049] In some embodiments, selecting at least one of the received radio signals based on the at least one motion compensated correlation result includes determining a sufficiency of the signals, associated with the at least one motion compensated correlation result, to produce an accurate position of the radio signal receiver, and selecting at least one of the signals, associated with the at least one motion compensated correlation result, having a highest determined sufficiency.

[0050] In some embodiments, a sufficiency of signals to produce an accurate position of the radio signal receiver is measured using at least one of a number of line of sight radio signals associated with a respective motion compensated correlation result, a signal noise of radio signals associated with a respective motion compensated correlation result, an error ellipse of radio signals associated with a respective motion compensated correlation result, a signal strength of radio signals associated with a respective motion compensated correlation result, a frequency error of radio signals associated with a respective motion compensated correlation result, or a code phase error of radio signals associated with a respective motion compensated correlation result.

[0051] In some embodiments, the navigation solution includes using the determined final position of the radio signal receiver to determine at least one of a range or a distance between the radio signal receiver and the at least one transmitter from which a respective radio signal was received.

[0052] In some embodiments, the radio signal receiver is located in an autonomous vehicle and the method further includes using the determined final position of the radio signal receiver to implement autonomous driving features of the autonomous vehicle.

[0053] In some embodiments, an apparatus for performing signal acquisition in a radio signal receiver includes at least one processor and at least one memory for storing programs and / or instructions. The programs and / or instructions when executed by the at least one processor, causes the apparatus to perform operations including receiving, at an antenna of the radio signal receiver, a plurality of radiosignals from at least one transmitter, determining a motion of the antenna of the radio signal receiver, correlating at least one local signal with at least one received radio signal to produce at least one correlation result, compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result, selecting at least one of the received radio signals based on the at least one motion compensated correlation result, and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

[0054] In some embodiments, a system for performing signal acquisition in a radio signal receiver includes at least one transmitter for providing radio signals, and a radio signal receiver including an antenna, at least one processor, and at least one memory for storing programs and / or instructions. In some embodiments when the programs and / or instructions are executed by the at least one processor, the radio signal receiver is caused to perform operations including receiving, at the antenna of the radio signal receiver, a plurality of radio signals from the at least one transmitter, determining motion of the antenna of the radio signal receiver, correlating at least one local signal with at least one received radio signal to produce at least one correlation result, compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result, selecting at least one of the received radio signals based on the at least one motion compensated correlation result, and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

[0055] In the present disclosure, 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, butcapable of achieving the same. Unless otherwise stated, any one or more of the features may be combined in any order.

[0056] Those skilled in the art will appreciate that, while various items are illustrated as being stored in memory or on storage while being used, these items or portions of them can be transferred between memory and other storage devices for purposes of memory management and data integrity. Alternatively, in other embodiments some or all of the software components can execute in memory on another device and communicate with the illustrated computer system via intercomputer communication. Some or all of the system components or data structures can also be stored (e.g., as instructions or structured data) on a computer-accessible medium or a portable article to be read by an appropriate drive, various examples of which are described above. In some embodiments, instructions stored on a computer- accessible medium separate from a computing device can be transmitted to the computing device via transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and / or a wireless link. Various embodiments can further include receiving, sending or storing instructions and / or data implemented in accordance with the foregoing description upon a computer-accessible medium or via a communication medium. In general, a computer-accessible medium can include a storage medium or memory medium such as magnetic or optical media, e.g., disk or DVD / CD-ROM, volatile or non-volatile media such as RAM (e.g., SDRAM, DDR, RDRAM, SRAM, and the like), ROM, and the like.

[0057] The methods and processes described herein may be implemented in software, hardware, or a combination thereof, in different embodiments. In addition, the order of methods can be changed, and various elements can be added, reordered, combined, omitted or otherwise modified. All examples described herein are presented in a non-limiting manner. Various modifications and changes can be made as would be obvious to a person skilled in the art having benefit of this disclosure. Realizations in accordance with embodiments have been described in the context of particular embodiments. These embodiments are meant to be illustrative and notlimiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances can be provided for components described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and can fall within the scope of claims that follow. Structures and functionality presented as discrete components in the example configurations can be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements can fall within the scope of embodiments as defined in the claims that follow.

[0058] In the foregoing description, numerous specific details, examples, and scenarios are set forth in order to provide a more thorough understanding of the present disclosure. It will be appreciated, however, that embodiments of the disclosure can be practiced without such specific details. Further, such examples and scenarios are provided for illustration, and are not intended to limit the disclosure in any way. Those of ordinary skill in the art, with the included descriptions, should be able to implement appropriate functionality without undue experimentation.

[0059] References in the specification to “an embodiment,” etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed to be within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly indicated.

[0060] Embodiments in accordance with the disclosure can be implemented in hardware, firmware, software, or any combination thereof. Embodiments can also be implemented as instructions stored using one or more machine-readable media, which may be read and executed by one or more processors. A machine-readable medium can include any mechanism for storing or transmitting information in a formreadable by a machine (e.g., a computing device or a “virtual machine” running on one or more computing devices). For example, a machine-readable medium can include any suitable form of volatile or non-volatile memory.

[0061] In addition, the various operations, processes, and methods disclosed herein can be embodied in a machine-readable medium and / or a machine accessible medium / storage device compatible with a data processing system (e.g., a computer system), and can be performed in any order (e.g., including using means for achieving the various operations). Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. In some embodiments, the machine-readable medium can be a non-transitory form of machine-readable medium / storage device.

[0062] Modules, data structures, and the like defined herein are defined as such for ease of discussion and are not intended to imply that any specific implementation details are required. For example, any of the described modules and / or data structures can be combined or divided into sub-modules, sub-processes or other units of computer code or data as can be required by a particular design or implementation.

[0063] In the drawings, specific arrangements or orderings of schematic elements can be shown for ease of description. However, the specific ordering or arrangement of such elements is not meant to imply that a particular order or sequence of processing, or separation of processes, is required in all embodiments. In general, schematic elements used to represent instruction blocks or modules can be implemented using any suitable form of machine-readable instruction, and each such instruction can be implemented using any suitable programming language, library, application-programming interface (API), and / or other software development tools or frameworks. Similarly, schematic elements used to represent data or information can be implemented using any suitable electronic arrangement or data structure. Further, some connections, relationships or associations between elements can be simplified or not shown in the drawings so as not to obscure the disclosure.

[0064] While the foregoing is directed to embodiments of the present principles, other and further embodiments of the invention can 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 performing signal acquisition in a radio signal receiver, comprising: receiving, at an antenna of the radio signal receiver, a plurality of radio signals from at least one transmitter; determining motion of the antenna of the radio signal receiver; correlating at least one local signal with at least one received radio signal to produce at least one correlation result; compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result; selecting at least one of the received radio signals based on the at least one motion compensated correlation result; and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

2. The method of claim 1 , further comprising: performing a GNSS signal acquisition process to determine an initial estimate of a position of the radio signal receiver from the received plurality of radio signals upon receiving the plurality of radio signals.

3. The method of claim 2, wherein the initial estimate of a position of the radio signal receiver is compared to the determined final position of the radio signal receiver to verify an accuracy of the determined final position of the radio signal receiver.

4. The method of claim 1 , wherein selecting at least one of the received radio signals based on the at least one motion compensated correlation result, comprises: determining a sufficiency of the signals, associated with the at least one motion compensated correlation result, to produce an accurate position of the radio signal receiver; andselecting at least one of the signals, associated with the at least one motion compensated correlation result, having a highest determined sufficiency.

5. The method of claim 4, wherein a sufficiency of signals to produce an accurate position of the radio signal receiver is measured using at least one of a number of line of sight radio signals associated with a respective motion compensated correlation result, a signal noise of radio signals associated with a respective motion compensated correlation result, an error ellipse of radio signals associated with a respective motion compensated correlation result, a signal strength of radio signals associated with a respective motion compensated correlation result, a frequency error of radio signals associated with a respective motion compensated correlation result, or a code phase error of radio signals associated with a respective motion compensated correlation result.

6. The method of claim 1 , wherein the navigation solution comprises: using the determined final position of the radio signal receiver to determine at least one of a range or a distance between the radio signal receiver and the at least one transmitter from which a respective radio signal was received.

7. The method of claim 1 , wherein the radio signal receiver is located in an autonomous vehicle and the method further comprises: using the determined final position of the radio signal receiver to implement autonomous driving features of the autonomous vehicle.

8. An apparatus for performing signal acquisition in a radio signal receiver, comprising: at least one processor; and at least one memory for storing programs and / or instructions that, when executed by the at least one processor, causes the apparatus to perform operations comprising:receiving, at an antenna of the radio signal receiver, a plurality of radio signals from at least one transmitter; determining motion of the antenna of the radio signal receiver; correlating at least one local signal with at least one received radio signal to produce at least one correlation result; compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result; selecting at least one of the received radio signals based on the at least one motion compensated correlation result; and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

9. The apparatus of claim 8, wherein the apparatus is further caused to perform operations comprising: performing a GNSS signal acquisition process to determine an initial estimate of a position of the radio signal receiver from the received plurality of radio signals upon receiving the plurality of radio signals.

10. The apparatus of claim 9, wherein the initial estimate of a position of the radio signal receiver is compared to the determined final position of the radio signal receiver to verify an accuracy of the determined final position of the radio signal receiver.11 . The apparatus of claim 8, wherein selecting at least one of the received radio signals based on the at least one motion compensated correlation result, comprises: determining a sufficiency of the signals, associated with the at least one motion compensated correlation result, to produce an accurate position of the radio signal receiver; and selecting at least one of the signals, associated with the at least one motion compensated correlation result, having a highest determined sufficiency.

12. The apparatus of claim 11 , wherein a sufficiency of signals to produce an accurate position of the radio signal receiver is measured using at least one of a number of line of sight radio signals associated with a respective motion compensated correlation result, a signal noise of radio signals associated with a respective motion compensated correlation result, an error ellipse of radio signals associated with a respective motion compensated correlation result, a signal strength of radio signals associated with a respective motion compensated correlation result, a frequency error of radio signals associated with a respective motion compensated correlation result, or a code phase error of radio signals associated with a respective motion compensated correlation result.

13. The apparatus of claim 8, wherein the navigation solution comprises: using the determined final position of the radio signal receiver to determine at least one of a range or a distance between the radio signal receiver and the at least one transmitter from which a respective radio signal was received.

14. The apparatus of claim 8, wherein the radio signal receiver is located in an autonomous vehicle and the apparatus is further caused to perform operations comprising: using the determined final position of the radio signal receiver to implement autonomous driving features of the autonomous vehicle.

15. A system for performing signal acquisition in a radio signal receiver, comprising: at least one transmitter for providing radio signals; and a radio signal receiver comprising: an antenna; at least one processor; andat least one memory for storing programs and / or instructions that, when executed by the at least one processor, causes the radio signal receiver to perform operations comprising: receiving, at the antenna of the radio signal receiver, a plurality of radio signals from the at least one transmitter; determining motion of the antenna of the radio signal receiver; correlating at least one local signal with at least one received radio signal to produce at least one correlation result; compensating a phase of at least one of the local signal, the at least one received radio signal or the at least one correlation result based on the determined motion to produce at least one motion compensated correlation result; selecting at least one of the received radio signals based on the at least one motion compensated correlation result; and determining a final position of the radio signal receiver by using the selected at least one of the received radio signals in a navigation solution.

16. The system of claim 15, wherein the radio signal receiver is further caused to perform operations comprising: performing a GNSS signal acquisition process to determine an initial estimate of a position of the radio signal receiver from the received plurality of radio signals upon receiving the plurality of radio signals.

17. The system of claim 16, wherein the initial estimate of a position of the radio signal receiver is compared to the determined final position of the radio signal receiver to verify an accuracy of the determined final position of the radio signal receiver.

18. The system of claim 15, wherein selecting at least one of the received radio signals based on the at least one motion compensated correlation result, comprises:determining a sufficiency of the signals, associated with the at least one motion compensated correlation result, to produce an accurate position of the radio signal receiver; and selecting at least one of the signals, associated with the at least one motion compensated correlation result, having a highest determined sufficiency.

19. The system of claim 18, wherein a sufficiency of signals to produce an accurate position of the radio signal receiver is measured using at least one of a number of line of sight radio signals associated with a respective motion compensated correlation result, a signal noise of radio signals associated with a respective motion compensated correlation result, an error ellipse of radio signals associated with a respective motion compensated correlation result, a signal strength of radio signals associated with a respective motion compensated correlation result, a frequency error of radio signals associated with a respective motion compensated correlation result, or a code phase error of radio signals associated with a respective motion compensated correlation result.

20. The system of claim 15, wherein the radio signal receiver is located in an autonomous vehicle and the radio signal receiver is further caused to perform operations comprising: using the determined final position of the radio signal receiver to implement autonomous driving features of the autonomous vehicle.

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