Method and apparatus for demand-based processing of radio signals

Abstract

A method, apparatus, and system for providing demand-based enhanced signal processing in a radio signal receiver include receiving, at the radio receiver, at least one radio signal from at least one transmitter, monitoring the received at least one radio signal to determine if enhanced signal processing is needed, if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques, if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signals to generate motion compensated correlation results, and determining a position for the radio receiver using the motion compensated correlation results. In some instances, the motion compensated correlation technique includes a SUPERCORRELATION™ technique.

Description

METHOD AND APPARATUS FOR DEMAND-BASED PROCESSING OF RADIO SIGNALSBACKGROUNDField

[0001] Embodiments of the present invention generally relate to radio signal receivers and, in particular, to methods, apparatuses and systems for processing radio signals when required.Description of the Related Art

[0002] Positioning signal receivers such as receivers for global satellite navigation systems (GNSS) signals have become ubiquitous in mobile devices. 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 a typical mobile device, 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 can be improved to about 20cm. However, that additional accuracy comes with a substantial cost of the IMU sensors and additional computational complexity.

[0003] It can also be advantageous to signal reception to know the receiver’s motion such that the received signals can be motion compensated (i.e., have the frequency and / or phase error caused by the relative motion between the receiver and transmitter removed from the signal correlation process). Compensating for the receiver motion improves receiver signal reception and / or lowers the cost of receiver components. The improvement in signal reception enables the receiver to determine accurate receiver position when confronted with an urban environment with highsignal multipath and when confronted with an environment containing GNSS signal spoofers.

[0004] Receivers capable of motion compensation can use a signal processing technique known as SUPERCORRELATION™ for improving radio signal reception using receiver motion compensated signal processing. The SUPERCORRELATION™ technique 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; US patent publication 2020 / 0319347, published 8 October 2020; and US patent publication 2024 / 0045077, published 8 February 2024, which are hereby incorporated herein by reference in their entireties.

[0005] The SUPERCORRELATION™ technique is used to correct for the effects of reflections and multipath interference on signals received by a receiver. SUPERCORRELATION™ can also be used for determining a clock offset (error) of a receiver by using motion compensated signal processing of a plurality of received signals (e.g., GNSS signals) and finding a common receiver clock error for all the received signals. When using the SUPERCORRELATION™ technique to process GNSS signals, the signal errors are removed such that a very accurate position can be computed.

[0006] GNSS receivers have many applications in which very accurate positioning is not required at all times. For example, when operating in an open space (e.g., a flat plain with open sky), conventional GNSS signal processing can create a sufficiently accurate position result. However, when the receiver is in an urban environment or confronted with signal spoofers or other electromagnetic interference, the position will be insufficient for navigation and other applications in which the receiver position needs to be accurately known.

[0007] Therefore, there is a need in the art for methods, apparatuses and systems for demand-based signal processing of radio signals to improve receiver position when the need arises.SUMMARY

[0008] Embodiments of the present principles generally relate to methods, apparatuses and systems for demand-based radio signal processing as shown in and / or described in connection with at least one of the figures included herewith.

[0009] Various features and advantages of the present principles can be appreciated from a review of the following detailed description of the present principles along with the accompanying figures in which like reference numerals refer to like parts throughout.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the features of the present principles can be understood in detail, a particular description of the invention, can 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 invention and are therefore not to be considered limiting of its scope, for the invention can admit to other equally effective embodiments.

[0011] FIG. 1 depicts a block diagram of a communication environment in which a receiver of the present principles can be applied in accordance with at least one embodiment of the present principles;

[0012] FIG. 2 is a functional block diagram of a radio signal receiver in accordance with at least one embodiment of the present principles; and

[0013] FIG. 3 is a flow diagram of a method of performing demand-based signal processing in accordance with at least one embodiment of the present principles.

[0014] 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

[0015] Embodiments of the present principles comprise methods, apparatuses and systems of demand-based signal processing in a radio signal receiver that uses motion compensated signal processing. 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 any receivers, transmitters and combinations thereof.

[0016] Such receivers include positioning systems (e.g., GNSS receivers).

[0017] In some embodiments, a radio signal receiver of the present principles temporarily stores or buffers data related to the received signals or partially processed received signals (collectively, referred to as a representation of the received signals). Such representations can include, but are not limited to, downconverted signals, sampled signals, filtered signals, correlation outputs and the like. In general, the data can be any data from which motion compensated correlation in accordance with the present principles can be performed. The data also includes receiver antenna motion information. In at least some embodiments, the receiver uses the SUPERCORRELATION™ technique (i.e., motion compensated correlation) to process the buffered data signals only when required. Events that can trigger a processing of the buffered data in accordance with the present principles can include but are not limited to entering an urban environment having high multipath and blocked satellite views and / or entering an environment having signal spoofers or other electromagnetic interference that degrades signal reception. Rather than having the SUPERCORRELATION technique used at all times and, therefore, continuously using computing resources, the processing technique of the present principles isactivated only when enhanced signal processing is required to improve signal reception. That is, in some embodiments, the SUPERCORRELATION technique can be applied as required on a signal-by-signal basis.

[0018] In some instances, satellite-based positioning systems utilize encoded digital signals including a deterministic digital code (e.g., Gold codes) to facilitate signal acquisition. Such a digital code can be 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 present principles are useful to enable a receiver to improve its position computation accuracy and / or , e.g., Gold codes o improve signal reception. The technique for improving radio signal reception using receiver motion compensated signal correlation 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; US patent publication 2020 / 0319347, published 8 October 2020; and US patent publication 2024 / 0045077, published 8 February 2024, which are hereby incorporated herein by reference in their entireties. Typically, such a motion model is derived using inertial measurement unit (IMU) data, however, in embodiments of the present principles, a motion model is derived using gyroscope data, controller area network (CAN) bus data, visual odometry data, and / or a combination of data from any of these motion data sources.

[0019] In some embodiments, a GNSS receiver of the present principles can be embedded in or carried by a moving platform such as, for example, but not limited to, an automobile, motorcycle, airplane, helicopter, drone, bicycle, person (e.g., a person carrying a smartphone, tablet, computer, internet of things (loT) device, wearable device, etc.), and the like.

[0020] In operation, the at least one received signal is correlated with at least one locally generated signal to produce at least one correlation result. As is described in detail below, embodiments of the present principles perform highly accurate positiondetermination only upon the need for enhanced signal processing. The enhanced signal processing of the present principles can be applied on a signal-by-signal basis or on all the received signals. As such, signals received directly from a satellite (e.g., line of sight (LOS) signals) can be processed in a standard manner and signals that are reflected or attenuated can be processed using enhanced signal processing of the present principles. For example, in some embodiments, enhanced signal processing can be required when a receiver enters an urban environment, when the receiver is subjected to electromagnetic interference, when a receiver parameter such as the clock frequency drifts, upon request from a remote source, and / or any other internal or external cause of degraded signal reception or processing. By only using enhanced signal processing when needed in accordance with the present principles, a substantial amount of computing resources can be reserved for other tasks or extended battery life.

[0021] 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 at least one embodiment of the present principles. In the communication environment 100 of FIG. 1 , demand-based signal processing is used in a radio signal receiver in accordance with at least one embodiment of the present principles. In the embodiment of FIG. 1 , an automobile 104 carrying a GNSS receiver 106 moves along a street (arrow 110) under open sky and has an unimpeded view of many satellites (Position 1 ). At Position 1 , the receiver 106 receives satellite signals 112 directly broadcast from a plurality of satellites 102A, 102B, and 102C. Under an open sky (and assuming no sources of interference), the receiver 106 can use conventional GNSS signal processing to determine a receiver position. Upon the receiver moving to Position 2, such as moving into an urban environment in which a signal 114 is blocked by building 120, a signal 116 is reflected by building 122 and a signal 118 is directly received, the receiver 106 determines that enhanced signal processing is required to process the received signals and achieve an accurate position (e.g., within about 2 meters) for the receiver 106. One intent of using enhanced processing in accordance with the present principles is to produce a position accuracy equivalent to the position computed in an open sky scenario even when the receiver is in a complex environment (e.g., highmultipath environment, electromagnetic interference and / or attenuated signal environments that occur in, for example, urban canyons, spoofing, and / or heavy foliage). As such, in accordance with the present principles, the position accuracy found in an open sky scenario is extended to other, more complex scenarios.

[0022] In some instances, signals received over a period of time can be processed to produce a travel path for an automobile. As described above, enhanced signal processing can also be required, for example, when the receiver is subjected to electromagnetic interference, when a receiver parameter such as the clock frequency drifts, and / or any other internal or external cause of degraded signal reception or processing. In some embodiments, the enhanced signal processing of the present principles can be applied on a signal-by-signal basis or on all received signals. As such, signals received directly from a satellite (line of sight (LOS) signals) can be processed in a standard manner and signals that are reflected or attenuated can be processed using enhanced signal processing (e.g., the SUPERCORRELATION™ technique.

[0023] In some embodiments, such as the embodiment of FIG. 1 , the receiver 106 can be a component (e.g., a GNSS receiver) within user equipment such as mobile phones, tablets, laptop computers, loT devices, wearable devices, and the like. For simplicity, the device is described herein as a receiver. Those skilled in the art will understand that the receiver can be a standalone receiver or can be a portion or component within user equipment.

[0024] FIG. 2 depicts a high-level functional diagram of the radio signal receiver 106 of FIG. 1 in accordance with at least one embodiment of the present principles. In some embodiments, the receiver 106 comprises an antenna 200, a front end 202, support circuits 204, demand generator 206, motion module 208, at least one processor 210 and memory 212. When carried by a transport platform such as a vehicle, airplane, bicycle, person, etc., the receiver 106 and its antenna 200 are an indivisible unit where the antenna 200 moves with the platform. The SUPERCORRELATION™ technique operates based upon determining a component of motion of the signal receiving antenna that is in the direction of the source (e.g.,GNSS satellite) of a received signal. As such, any mention of motion herein refers to the motion of the antenna 200. In most scenarios, the motion of the transport platform is the same as the motion of the antenna 200 and, as such, the following description assumes the motion of the platform, the receiver 106 and the antenna 200 are the same.

[0025] The receiver’s front end 202 downconverts, filters, and samples (digitizes) the received signals in a manner that is well-known to those skilled in the art. The output of the receiver front end 202 is a digital signal containing data. The data of interest for performing motion compensation is a deterministic code (e.g., Gold code) used by the processor 210 to synchronize the receiver 106 to the GNSS transmission.

[0026] In the embodiment of FIG. 2, the at least one processor 210 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 204 can comprise well-known circuits and devices facilitating functionality of the processor(s). The support circuits 204 can comprise one or more of, or a combination of, power supplies, clock circuits, analog to digital converters, communications circuits, cache, displays, filters, and / or the like.

[0027] In the embodiment of FIG. 2, the memory 212 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 212 stores software and data including, for example, GNSS signals 214 (or representations of those signals), signal processing software 216, a motion model 218 and data 220. The data 220 comprises a receiver position 222, motion hypotheses 224, and various additional data used to perform the SUPERCORRELATION™ processing.

[0028] In some embodiments, the demand generator 206 of the present principles can utilize a map to determine when the receiver is in an urban environment in which signals from transmitters can reflect off of many surfaces before reaching a receiverof the present principles to trigger the need for enhanced signal processing of the present principles. Alternatively or in addition, in some embodiments, signals received at a receiver of the present principles, such as the receiver 106 of Figs 1 and 2, can further be monitored to determine if enhanced signal processing is required. For example, in some embodiments, the demand generator 206 can use a signal-to-noise ratio (SNR) monitoring circuit to know when signal interference in received signals is present / high, a clock monitoring circuit to know when the clock frequency is inaccurate, and / or any other monitoring circuit to detect internal or external parameters that degrade signal reception or processing. That is, the demand generator 206 of the receiver of the present principles of the embodiment of FIG. 2 is designed to determine when enhanced signal processing is required to overcome degraded signal reception by determining when a received signal is a non-line-of-sight (NLOS) signal and / or an attenuated signal. In some embodiments, a demand generator 206 of the present principles can further determine that enhanced signal processing is required based on a signal delay (e.g., how long it takes a signal from a transmitter to reach a receiver), which in some embodiments, can be determined using a timing circuit, and / or a need for enhanced signal processing can be determined based on a signal strength of a received signal from a transmitter, which in some embodiments can be measured using a received signal strength indicator (RSSI) sensor. In some embodiments, a threshold signal strength can be predetermined for received radio signals from transmitters and if a received radio signal has a signal strength below the predetermined threshold, the demand generator 206 of the present principles can make the determination that there is a need for enhanced signal processing in accordance with the present principles.

[0029] Upon determination of a need for enhanced processing, satellite signals received by a receiver of the present principles, such as the receiver 106 of FIG. 1 and FIG. 2, can be processed using the SUPERCORRELATION™ technique to determine improved signal reception and enable a receiver position to be determined in a location in which the position of the receiver would otherwise not be determinable. In accordance with the present principles, an accurate position can be computed even when the receiver is operating in an urban environment or an environment containingsignal interference from GNSS signal spoofers or other electromagnetic interference sources. Alternatively or in addition, in some embodiments, a remote request for an accurate position can be received by a receiver of the present principles from, for example, a fleet management system, a concerned parent device, emergency services, police, etc., to, for example, attempt to locate the receiver.

[0030] Upon receiving a demand and / or otherwise determining a need for enhanced processing of the present principles, the at least one processor 210 of the receiver 106 accesses the GNSS signals 214 (or representations of those signals) and the at least one processor 210 correlates the received code from each satellite with locally generated codes to produce correlation results. The correlation results are processed as is well-known in the art to generate position information 222 (e.g., the correlation results are used to determine pseudoranges for each satellite and the pseudoranges are processed to compute a position for the receiver 106. The at least one processor 210 performs the SUPERCORRELATION™ processing to provide signals (phasor sequences) to phase adjust the complex correlation results such that the coherent integration period is extended (e.g., extended to one or more seconds, to improve signal reception). The phasor sequence is a time sequence of phase offsets in which each phasor in the sequence adjusts the phase of a complex signal sample. In some embodiments, 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. The least computationally intensive adjustment process is implemented to adjust the phase of the complex correlation results.

[0031] In some embodiments, the motion module 208 generates receiver motion information that is used by the at least one processor 210 to generate phasor sequences that are used to motion compensate the complex correlation results. The phasor sequences can include 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 some embodiments, the motion module 208 uses the at least one processor 210 to generate motion information reflecting the motion of the receiver 106. In some embodiments, motion information can include a predictionof receiver velocity and heading (i.e. , a motion model 218). Alternatively or in addition, the motion module 208 can comprise an inertial measurement unit (IMU) to provide platform (receiver) orientation and velocity information for the motion model.

[0032] FIG. 3 is a flow diagram of a method 300 for performing demand-based signal processing in a radio signal receiver in accordance with at least one embodiment of the present principles. The method 300 of FIG. 3 can be implemented in software, hardware or a combination of both (e.g., using the at least one processor 210, the motion module 208 and the event detector 206 of FIG. 2). In some embodiments, the method 300 can operate through execution of the signal processing software (216 of FIG. 2) using the at least one processor (210 of FIG. 2) to access and perform instructions of the software.

[0033] The method 300 can begin at 302 and proceeds to 304 in which signals are received at a receiver from at least one remote source (e.g., transmitters such as the plurality of GNSS satellites 102A, 102B, 102C, . . . 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 process of downconverting the RF signal and sampling the digital code is well known in the art.

[0034] At 306, the digitized, complex GNSS signals (or representations of those signals) are stored in memory so that enhanced processing of the present principles can be performed using those signals when necessary. In some embodiments, the signals can be stored locally in the receiver and / or can be transmitted (e.g., wirelessly) to a server. The server can be a part of a system for performing enhanced signal processing in accordance with the present principles, especially for receivers of the present principles used in devices that have limited computing power. To facilitate remote processing, in addition to the signal samples, the receiver motion information and the need for enhanced signal processing are also transmitted to such a server.

[0035] In other embodiments, rather than store and process the GNSS signals themselves, the method 300 stores partially or fully processed GNSS signals. Forexample, in some embodiments, the method 300 stores for further and / or repeated processing the correlation results generated from correlating a local signal with the received GNSS signal. In addition to the GNSS signals, a receiver of the present principles can also buffer motion information (e.g., motion model and / or accelerator and gyroscope measurements of a receiver).

[0036] At 308, the method queries whether a need for enhanced processing is required. For example and as recited above, in some embodiments, the demand generator 206 of the present principles can utilize a map to determine when the receiver is in an urban environment, and / or can use a signal-to-noise ratio (SNR) monitoring circuit to know when signal interference is present / high, a clock monitoring circuit to know when the clock frequency is inaccurate, and / or any other monitoring circuit to detect internal or external parameters that degrade signal reception or processing. If demand has not been detected, the query is negatively answered and the method proceeds along path 310 to process the signals at 324 using conventional GNSS signal processing to generate the receiver position. The method 300 can then return to 304 to continue receiving GNSS signals. If demand for enhanced signal processing has occurred, the query is affirmatively answered and method 300 proceeds to 312.

[0037] In a remote processing system, the demand for enhanced processing of the present principles would be sent to the previously mentioned server and the remainder of method 300 would be performed on the server. In such embodiments, the resulting position can be transmitted to the from the server , as needed for the application, when remote processing is complete. In a local processing system (i.e., on the receiver), the remainder of method 300 is performed by the receiver’s at least one processor.

[0038] At 312, the GNSS signals (and any other data necessary for enhanced signal processing such as receiver antenna motion information) are accessed from memory. At 314, the accessed signals are processed in an enhanced manner using the SUPERCORRELATION™ technique in accordance with the present principles to motion compensate the correlation results. During this process, the SUPERCORRELATION™ procedure generates a plurality of phasor sequencehypotheses related to the motion information. 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 complex carrier phase of the local signal. Such adjustment or compensation may 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. The method applies each phase offset in the phasor sequence 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, each of the hypotheses are tested to find the hypothesis that provides the best or optimal correlation result magnitude.

[0039] The motion estimates can include typically hypotheses of the 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). In some embodiments, and as typical with GNSS receivers, the satellite positions can be known to the receiver through known ephemeris data. A comparison of correlation results over the direction hypotheses enables a receiver of the present principles to narrow the search space when processing subsequently received signals. Consequently, subsequent compensation is performed over a more narrow search space.

[0040] In some embodiments, if a signal from a given satellite was received previously, the set of hypotheses for the newly received signal can determine 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. Each received signal can be correlated with that signal’sset of hypotheses. The hypotheses can be 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), and / 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.

[0041] In accordance with the present principles, a receiver can process the correlation results to find the “best” or optimal result for each received signal. In some embodiments, the method 300 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 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.

[0042] For example, assuming all other receiver parameters are known except receiver motion direction, the hypotheses can be tested with various phasor sequences that compensate for phase changes due to each direction hypothesis. The correct phasor sequence 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.

[0043] If additional receiver parameters (e.g., clock frequency and / or frequency rate) are unknown or not accurately known, those parameter offsets can also be expressed as phasor hypotheses and tested to optimize the correlation output across multiple parameters at once. These parameter offsets can be used to correct inaccuracies in, for example, the receiver clock.

[0044] At 316, the compensated correlation results are used by a traditional positioning or navigation solution (e.g., using a pseudorange to each satellite transmitter) to generate the accurate position of the receiver. At 318, the method queries if additional signals are to be processed. By processing a sequence of signals, a path of the receiver prior to the event can be constructed. If the query is affirmatively answered, the method 300 proceeds along path 320 to access additional signals and process them. If the query is negatively answered, the method 300 proceeds to 322 and ends.

[0045] Using the method 300 enables a receiver to process GNSS signal samples using conventional GNSS signal processing until a need arises for enhanced signal processing of the present principles. Thus, computing resources are reserved for use in performing enhanced signal processing until they are truly needed.

[0046] Specifically, in some embodiments a method for performing demand-based enhanced signal processing in a radio signal receiver includes receiving, at the radio receiver, at least one radio signal from at least one transmitter, monitoring the received at least one radio signal to determine if enhanced signal processing is needed, if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques, if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signals to generate motion compensated correlation results, and determining a position for the radio receiver using the motion compensated correlation results.

[0047] In some embodiments, the received at least one radio signal is monitored using a demand generator of the radio receiver.

[0048] In some embodiments, the monitoring the received at least one radio signal to determine if enhanced signal processing is needed comprises at least one of, determining when the radio receiver is in an environment in which the at least one radio signal can reflect off of at least one surface before being received by the radioreceiver, determining when signal interference in the received at least one radio signal is present, determining when a clock frequency is inaccurate, determining when a signal strength of the received at least one radio signal is below a threshold, and / or determining when a delay exists in the received at least one radio signal.

[0049] In some embodiments, the conventional radio signal processing techniques comprise Global Navigation Satellite System (GNSS) processing techniques.

[0050] In some embodiments, the motion compensated correlation includes at least, determining a motion 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, and 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.

[0051] In some embodiments, the motion compensated correlation includes a SUPERCORRELATION™ technique.

[0052] In some embodiments, the method further includes processing a plurality of received radio signals to determine a travel path of the radio signal receiver.

[0053] In some embodiments, an apparatus for performing demand-based enhanced signal processing in a radio signal receiver includes at least one processor and at least one memory for storing programs and / or instructions. In such embodiments, when the programs and / or the instructions are executed by the at least one processor, the apparatus is configured to perform operations including receiving at least one radio signal from at least one transmitter, monitoring the received at least one radio signal to determine if enhanced signal processing is needed, if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques, if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signalsto generate motion compensated correlation results, an determining a position for the radio receiver using the motion compensated correlation results.

[0054] In some embodiments a system for performing demand-based enhanced signal processing in a radio signal receiver includes at least one transmitter for providing radio signals, and a radio signal receiver including at least one processor and at least one memory for storing programs and / or instructions. In such embodiments, when the programs and / or the instructions are executed by the at least one processor, the receiver is configured to perform operations including receiving at least one radio signal from at least one transmitter, monitoring the received at least one radio signal to determine if enhanced signal processing is needed, if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques, if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signals to generate motion compensated correlation results, and determining a position for the radio receiver using the motion compensated correlation results.

[0055] In some embodiments, the radio signal receiver further includes a demand generator and the received at least one radio signal is monitored using the demand generator of the radio receiver.

[0056] In some embodiments, the monitoring the received at least one radio signal to determine if enhanced signal processing is needed includes at least one of, using a map, determining when the radio receiver is in an environment in which the at least one radio signal can reflect off of at least one surface before being received by the radio receiver, using a signal-to-noise ratio (SNR) monitoring circuit .determining when signal interference in the received at least one radio signal is present, using a clock monitoring circuit, determining when a clock frequency is inaccurate, using an RSSI sensor, determining when a signal strength of the received at least one radio signal is below a threshold and / or using a timing circuit, determining when a delay exists in the received at least one radio signal.

[0057] 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, but capable of achieving the same. Unless otherwise stated, any one or more of the features may be combined in any order.

[0058] 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.

[0059] 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 not limiting. 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.

[0060] 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.

[0061] 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 skilledin the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly indicated.

[0062] 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 form readable 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.

[0063] 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.

[0064] 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.

[0065] 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 suchinstruction 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.

[0066] 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 demand-based enhanced signal processing in a radio signal receiver, comprising: receiving, at the radio receiver, at least one radio signal from at least one transmitter; monitoring the received at least one radio signal to determine if enhanced signal processing is needed; if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques; if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signals to generate motion compensated correlation results; and determining a position for the radio receiver using the motion compensated correlation results.

2. The method of claim 1 , wherein the received at least one radio signal is monitored using a demand generator of the radio receiver.

3. The method of claim 1 , wherein the monitoring the received at least one radio signal to determine if enhanced signal processing is needed comprises at least one of: determining when the radio receiver is in an environment in which the at least one radio signal can reflect off of at least one surface before being received by the radio receiver; determining when signal interference in the received at least one radio signal is present; determining when a clock frequency is inaccurate; determining when a signal strength of the received at least one radio signal is below a threshold; or determining when a delay exists in the received at least one radio signal.

4. The method of claim 1 , wherein the conventional radio signal processing techniques comprise Global Navigation Satellite System (GNSS) processing techniques.

5. The method of claim 1 , wherein the motion compensated correlation comprises at least: determining a motion 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; and 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.

6. The method of claim 1 , wherein the motion compensated correlation comprises a SUPERCORRELATION™ technique.

7. The method of claim 1 , further comprising: processing a plurality of received radio signals to determine a travel path of the radio signal receiver.

8. An apparatus for performing demand-based enhanced signal processing 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 least one radio signal from at least one transmitter; monitoring the received at least one radio signal to determine if enhanced signal processing is needed;if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques: if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at least one of the at least one received radio signals to generate motion compensated correlation results; and determining a position for the radio receiver using the motion compensated correlation results.

9. The apparatus of claim 8, wherein the received at least one radio signal is monitored using a demand generator of the radio receiver.

10. The apparatus of claim 8, wherein the monitoring the received at least one radio signal to determine if enhanced signal processing is needed comprises at least one of: determining when the radio receiver is in an environment in which the at least one radio signal can reflect off of at least one surface before being received by the radio receiver; determining when signal interference in the received at least one radio signal is present; determining when a clock frequency is inaccurate; determining when a signal strength of the received at least one radio signal is below a threshold; or determining when a delay exists in the received at least one radio signal.11 . The apparatus of claim 8, wherein the conventional radio signal processing techniques comprise Global Navigation Satellite System (GNSS) processing techniques.

12. The apparatus of claim 8, wherein the motion compensated correlation comprises at least:determining a motion 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; and 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.

13. The apparatus of claim 8, wherein the motion compensated correlation comprises a SUPERCORRELATION™ technique.

14. The apparatus of claim 8, wherein the apparatus further performs: processing a plurality of received radio signals to determine a travel path of the radio signal receiver.

15. A system for performing demand-based enhanced signal processing in a radio signal receiver, comprising: at least one transmitter for providing radio signals; and 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 radio signal receiver to perform operations comprising: receiving at least one radio signal from at least one transmitter; monitoring the received at least one radio signal to determine if enhanced signal processing is needed; if it is determined that enhanced signal processing is not needed, processing the received at least one radio signal using conventional radio signal processing techniques: if it is determined that enhanced signal processing is needed, performing at least a motion compensated correlation using at leastone of the at least one received radio signals to generate motion compensated correlation results; and determining a position for the radio receiver using the motion compensated correlation results.

16. The system of claim 15, wherein the radio signal receiver further comprises a demand generator and the received at least one radio signal is monitored using the demand generator of the radio receiver.

17. The system of claim 15, wherein the monitoring the received at least one radio signal to determine if enhanced signal processing is needed comprises at least one of: using a map, determining when the radio receiver is in an environment in which the at least one radio signal can reflect off of at least one surface before being received by the radio receiver; using a signal-to-noise ratio (SNR) monitoring circuit .determining when signal interference in the received at least one radio signal is present; using a clock monitoring circuit, determining when a clock frequency is inaccurate; using a received signal strength sensor, determining when a signal strength of the received at least one radio signal is below a threshold or using a timing circuit, determining when a delay exists in the received at least one radio signal.

18. The system of claim 15, wherein the conventional radio signal processing techniques comprise Global Navigation Satellite System (GNSS) processing techniques.

19. The system of claim 15, wherein the motion compensated correlation comprises at least: determining a motion 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; and 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.

20. The system of claim 15, wherein the motion compensated correlation comprises a SUPERCORRELATION™ technique.21 . The system of claim 15, wherein the receiver further performs: processing a plurality of received radio signals to determine a travel path of the radio signal receiver.

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