Method and apparatus for coherently combining pilot and data signals

Abstract

A method and receiver architecture for coherently combining pilot and data signals in a Global Navigation Satellite System (GNSS) receiver to improve sensitivity and tracking performance is disclosed. The method includes receiving a pilot signal and a corresponding data signal from a common GNSS source and demodulating data bits in the data signal using the pilot signal as a phase reference. The demodulated bits are cancelled or remodulated for alignment, enabling coherent combination of the pilot and data signals into a single combined signal. The system can remove a constant phase offset via a phase rotator, perform quadratic code cancellation, and dynamically adjust the combining gain based on an estimated bit error rate. An intervention control enables or disables combining based on a carrier-to-noise density ratio and a signal power threshold.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 728,221, filed December 5, 2024, and U.S. Application No. 19 / 354,111, filed October 9, 2025, the disclosures of which are incorporated herein by reference in their entirety as if fully set forth herein. Technical Field

[0003] This disclosure generally relates to receivers for Global Navigation Satellite Systems (GNSS). More specifically, the subject matter disclosed herein relates to signal processing for GNSS receivers that improve tracking and acquisition performance by coherently combining pilot and data signals in real time without external assistance. Background Technology

[0004] Improving the signal-to-noise ratio (SNR) is important for fully utilizing the benefits of L5 signals in GNSS products. In some L5 tracking systems, only pilot or data signals are processed.

[0005] Figure 1 The baseline architecture of a Global Navigation Satellite System (GNSS) receiver is shown.

[0006] refer to Figure 1The baseline architecture of a GNSS receiver 100 is shown, illustrating the signal tracking loop used in a GNSS receiver such as a Global Positioning System (GPS) to estimate the carrier phase, frequency, and code phase of a satellite signal using pilot and data channels. An input signal y[n] is received at receiver 100. The received GNSS signal y[n] (e.g., a digitized I / Q sample after downconversion) is split into two branches: pilot channel 102 and data channel 104. Pilot channel 102 multiplies y[n] by a locally generated pilot code Cp(.) 106. After multiplication, the signal is coherently integrated 108 (summed over a fixed time interval) to produce a pilot correlator output Pp,i (without navigation data). Data channel 104 multiplies y[n] by a data code Cd(.) (110) and performs a coherent integration 112 to produce a data correlator output Pd,i (including navigation data bits). Then, the signal Pd,i is provided to the carrier tracking loop 114 to employ a carrier phase discriminator (phase-locked loop or Costas loop) 116 to track the frequency and phase of the signal carrier. The carrier phase discriminator 116 uses the output from the pilot channel or data channel to estimate the carrier phase error. A phase loop filter 118 filters the discriminator's output to smooth the phase estimate. A frequency discriminator 120 measures the Doppler shift (i.e., frequency error), and a frequency loop filter 122 filters the frequency error signal. It should be understood that in the GNSS receiver 100, the tracking loop is a feedback system that keeps the receiver's locally generated signal aligned with the satellite signal after acquisition. It continuously estimates and corrects errors in code phase, carrier frequency, and carrier phase caused by Doppler shift, oscillator drift, and noise. A numerically controlled oscillator (NCO) 124 uses this information to generate a locally reconstructed carrier to match the phase and frequency of the incoming signal. Furthermore, the code tracking loop 126 uses a code phase discriminator 128, a code phase loop filter 130, and a code NCO 132 to estimate the code phase (timing) of the signal. The code NCO 132 generates a locally reconstructed code sequence synchronized with the incoming signal. The receiver uses the estimated carrier phase output 134 and the estimated code phase output 136 to maintain a lock on the satellite signal to decode navigation data and calculate position.

[0007] However, since the power of the input signal is typically separated between the data signal and the pilot signal, the receiver only has half the signal energy when using only the data signal. This leads to degraded performance in low SNR environments; for example, the data signal alone may be too weak or unstable to maintain lock. To recover the lost signal power, combining the pilot and data signals has been proposed; however, this cannot be done without knowing the data bits in the data signal.

[0008] The efficient combination of pilot and data signals in a tracking loop has recently attracted considerable interest in the industry. For example, a service has been proposed to stream Nav (navigation) data bits to a GNSS receiver via cellular or Wi-Fi to allow for 3dB coherent combining gain. Figure 2 An example of this proposed architecture 200 is shown in the figure.

[0009] Figure 2 The GNSS architecture employing an external data stream service is shown.

[0010] refer to Figure 2 The proposed technical requirement is that Nav bits 201 are transmitted from server 203 to GNSS receiver via a communication link (such as cellular or Wi-Fi). The GNSS receiver does not demodulate the Nav bits; instead, it uses the data bits received from server 203 to coherently combine the pilot and data signals. Once combined, the output of combiner 205 is sent to carrier tracking loop 214 and code tracking loop 226, and functions similarly to the... Figure 1 The described functionality.

[0011] One problem with the above method is that it requires an external Nav data streaming service and communication link. Summary of the Invention

[0012] To overcome these types of problems, this document describes a system and method for coherently combining pilot and data signals in real time without external assistance, i.e., without relying on external Nav bit assistance. This disclosure provides the following: demodulating the data bits of the data signal in real time (using the pilot signal as a reference) before sending the pilot / data signal to the tracking loop; using the demodulated data bits to coherently combine the pilot and data signals, and then sending the combined signal to the tracking loop; and operating the existing frequency, carrier phase, and code cycle without any changes.

[0013] The methods described above improve upon previous methods because they are easier to implement (i.e., without external assistance) and more energy efficient. For tracking, a considerable gain (~1.5 to 3 dB) can be achieved across the full range of carrier-to-noise ratio (C / N0) levels (>=12 dBHz) compared to existing baseline (uncombined) algorithms. More specifically, a 3 dB gain can be achieved over a wide range of C / N0 levels (>=21 dBHz), which is the theoretical limit for coherent combination of two signals. For acquisition, the sensitivity gain can be 1.5 dB because a higher detection threshold can be used to maintain the same false alarm probability.

[0014] In an embodiment, a method for coherently combining pilot signals and data signals in a GNSS receiver includes: receiving pilot signals and data signals from the same GNSS signal source; using the pilot signals as a phase reference to demodulate data bits in the data signals in real time; wiping off the demodulated data bits from the data signals; and coherently combining the pilot signals and data signals to generate a combined signal for one or more tracking loops.

[0015] In an embodiment, the GNSS receiver includes at least one processing unit; and a memory storing instructions that, when executed by the processing unit, cause the GNSS receiver to: receive pilot signals and data signals from the same GNSS signal source; demodulate data bits in the data signals in real time using the pilot signals as a phase reference; cancel or clear the demodulated data bits from the data signals; and coherently combine the pilot signals and data signals to generate a combined signal for one or more tracking loops. Attached Figure Description

[0016] In the following sections, aspects of the subject matter disclosed herein will be described with reference to exemplary embodiments shown in the accompanying drawings, wherein:

[0017] Figure 1 The baseline architecture of the GNSS receiver is shown.

[0018] Figure 2 The GNSS architecture employing an external data stream service is shown.

[0019] Figure 3 This is the architecture of a GNSS receiver according to an embodiment of the present disclosure.

[0020] Figure 4 This is a flowchart illustrating a method for coherently combining pilot signals and data signals according to an embodiment of the present disclosure.

[0021] Figure 5This is the architecture of a GNSS receiver according to another embodiment of the present disclosure.

[0022] Figure 6 This is a flowchart illustrating a method for coherently combining pilot signals and data signals according to another embodiment of the present disclosure.

[0023] Figure 7 This is a block diagram of an electronic device in a network environment according to an embodiment.

[0024] Figure 8 The system shown includes user equipment (UE) and gNB communicating with each other. Detailed Implementation

[0025] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of this disclosure. However, those skilled in the art will understand that the disclosed aspects can be practiced without these specific details. In other instances, well-known methods, processes, components, and circuits have not been described in detail so as not to obscure the subject matter of this disclosure.

[0026] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment may include in at least one embodiment disclosed herein. Therefore, the phrases "in one embodiment," "in an embodiment," or "according to an embodiment" (or other phrases with similar meanings) appearing in various places throughout this specification may not necessarily refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In this regard, as used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" should not be construed as necessarily preferred or advantageous over other embodiments. Moreover, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. And, depending on the context discussed herein, singular terms may include corresponding plural forms, and plural terms may include corresponding singular forms. Similarly, hyphenated terms (e.g., "two-dimensional", "pre-determined", "pixel-specific", etc.) may occasionally be used interchangeably with their corresponding unhyphenated versions (e.g., "two-dimensional", "pre-determined", "pixel specific", etc.), and uppercase entries (e.g., "counter clock", "row select", "pixout", etc.) may be used interchangeably with their corresponding non-uppercase versions (e.g., "counter clock", "row select", "pixout", etc.). This occasional interchangeability should not be considered inconsistent with each other.

[0027] Furthermore, depending on the context discussed herein, singular terms may include their corresponding plural forms, and plural terms may include their corresponding singular forms. It should also be noted that the various figures shown and discussed herein (including component diagrams) are for illustrative purposes only and are not drawn to scale. For example, the dimensions of some elements may be enlarged relative to others for clarity. Additionally, reference numerals are repeated in the figures where appropriate to indicate corresponding and / or similar elements.

[0028] The terminology used herein is for the purpose of describing some exemplary embodiments only and is not intended to limit the claimed subject matter. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, numbers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and / or combinations thereof.

[0029] It will be understood that when an element or layer is referred to as being on, "connected to," or "coupled to" another element or layer, the element or layer may be directly on, directly connected to, or directly coupled to the other element or layer, or there may be intermediate elements or layers. Conversely, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intermediate elements or layers. The same reference numerals always denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] As used herein, the terms “first,” “second,” etc., serve as labels for nouns that follow them and do not imply any kind of ordering (e.g., spatial, temporal, logical, etc.) unless explicitly defined as such. Furthermore, the same reference numerals may be used in two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functions. However, this usage is merely for simplicity of description and ease of discussion; it does not imply that the construction or architectural details of such components or units are identical in all embodiments, or that these commonly referenced parts / modules are the only way to implement some of the exemplary embodiments disclosed herein.

[0031] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the same meaning as their meaning in the context of the relevant field, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0032] As used herein, the term "module" means any combination of software, firmware, and / or hardware configured to provide the functionality described herein in conjunction with modules. For example, software may be embodied as a software package, code, and / or instruction set or instructions, and the term "hardware" as used in any implementation described herein may, for example, individually or in any combination, include assemblies, hardwired circuitry, programmable circuitry, state machine circuitry, and / or firmware storing instructions executed by programmable circuitry. Modules may be embodied collectively or individually as circuitry forming part of a larger system, such as, but not limited to, integrated circuits (ICs), system-on-a-chip (SoCs), assemblies, etc.

[0033] This disclosure provides a GNSS signal processing algorithm that improves tracking and acquisition performance by coherently combining pilot and data signals in real time without external assistance. GNSS receivers typically use only pilot signals for tracking because the data signal contains navigation bits that flip every bit cycle, preventing coherent combination. This limits the SNR gain to the gain provided by the pilot alone.

[0034] This disclosure provides a real-time pilot-assisted demodulation method that allows data signals to be used for tracking. The method includes demodulating data bits from the data signal using a pilot signal as a phase reference, removing the demodulated data bits from the data signal (or equivalently modulating them onto the pilot signal), coherently combining the pilot and data signals (i.e., aligning the pilot and data signals so that they constructively enhance each other), doubling the available signal power and improving the SNR, and feeding the combined signal into the receiver's existing tracking loop without modifying the loop design. The algorithm also includes real-time engagement decision logic based on the average carrier-to-noise ratio (C / N0) and signal power to ensure that the combination is performed only when it is likely to be beneficial.

[0035] Figure 3 An example signal processing architecture 300 for a GNSS receiver that uses both the pilot and data components of the received signal to achieve real-time demodulation is shown. Figure 4 This is a flowchart illustrating a real-time demodulation and coherent combination method 400 for an architecture 300 used to improve tracking, combining pilot and data signals. It should be understood that in wireless communication, the pilot signal is the transmitted signal component that does not contain data bit information. Without the need for demodulation or decoding of data bits, the pilot signal assists the receiver in performing synchronization, frequency / phase estimation, channel estimation, etc.

[0036] In step 402, an incoming signal y[n] comprising a pilot signal and a data signal from the same GNSS source is received. The incoming sampled signal y[n] is received at the first multiplier 302 and subsequently processed through two parallel branches: one for the pilot signal and one for the data signal. In the pilot branch, the signal is multiplied by a locally generated pilot code in the second multiplier 306. In the data branch, the signal is similarly mixed with the locally generated data code in multiplier 310. mix.

[0037] In step 404, the data bits of the data signal are demodulated in real time using the pilot signal as a phase reference. Here, real-time means processing the incoming data at the same rate as the data rate in the receiver. For example, the GNSS L5 signal data symbol rate is 100 Hz (i.e., 10 ms per data symbol). Real-time processing means the receiver needs to process each data symbol within 10 ms, without needing to store multiple symbols for later processing. However, the method of this disclosure can be applied to both real-time and non-real-time processing. Non-real-time means the receiver stores several symbols and then processes them in batches. For example, the GPS L5 signal data period = 10 ms per symbol. The receiver stores 20 symbols (both data and pilot) in memory, which is 200 ms of data and pilot symbols. Then, the receiver processes the symbols at the end of this 200 ms period. The outputs of these multipliers 306, 310 are passed to the coherent summing module 308 and the incoherent clearing module 312, respectively, which produce a complex correlation output P. p,i and P d,i Modules 308 and 312 perform the integration and dump process, where consecutive samples over 20 ms are summed before output. These outputs are used to support both tracking and data demodulation. For real-time demodulation, the pilot output P... p,i In module 350, a complex conjugate operation is performed to generate... Then, in multiplier 352, it is combined with the data output P. d,i Multiply. The real part of the resulting product is used in module 354 to estimate the navigation data bits to be transmitted via the sign function. .

[0038] In parallel, data output P d,i Also multiplied by phasor in multiplier 356 To remove residual phase (i.e., remove constant phase offset by a phase rotator), and then again with the estimated bit in multiplier 358. Multiplying produces the corrected data component, that is, removing the demodulated data bits from the data signal, step 406. It should be understood that this removal is to eliminate the data signal... Data modulation in the middle, thereby realizing the pilot signal and data signals The pilot signal and the corrected data signal are coherently combined. In step 408, the pilot signal and the corrected data signal are added in adder 360 and averaged in divider 362 to produce a combined signal P. i That is, the pilot signal and the data signal are coherently combined to generate the combined signal P. i It is used for one or more tracking loops.

[0039] Intervention decision logic module 364 monitors signal conditions, such as the measured carrier-to-noise ratio (C / N0), and can determine in real time whether to select a pilot, data, or combined signal path as input. Module 364 uses the measured average C / N0 and real-time signal power (based on the coherence sum of the pilot and data signals) to generate a real-time intervention decision to control whether real-time data signal demodulation and pilot / data signal combination should be performed based on the following conditions:

[0040] (1) Average C / N0 > threshold 1; and

[0041] (2) + Threshold 2

[0042] It should be understood that thresholds 1 and 2 can be manually selected via simulation or analysis to achieve a better expected bit error rate than the target (e.g., target = 25%). This intervention logic improves reliability under varying signal quality conditions. If the conditions fail, the pilot output P... p,i It is passed to the tracking loop.

[0043] Output P i The signal is also routed to a carrier phase discriminator 316, which generates a phase error signal filtered by a phase loop filter 318. The system also includes a frequency discriminator 320 and an associated frequency loop filter 322, enabling robust frequency tracking. The filtered output drives a carrier digitally controlled oscillator (NCO) 324, which generates an updated carrier phase estimate to clear the incoming signal. Simultaneously, the code tracking path includes a code phase discriminator 328 and a code phase loop filter 330, whose output updates the code NCO 332 to maintain alignment with the spreading code. Together, the carrier tracking loop and the code tracking loop ensure accurate synchronization and allow the GNSS receiver to maintain lock on the signal while decoding the transmitted navigation data.

[0044] It should be understood that demodulation and coherent combination are performed over multiple integration periods, and the coherent combination gain is dynamically adjusted based on a real-time estimate of the bit error rate determined from the measured average C / N0 and real-time signal power as described above. It should be understood that "multiple integration periods" refers to multiple coherent integration periods. For example, the method of this disclosure can be applied to coherent integration periods of 20 ms, 40 ms, or 60 ms, etc. For example, GPS L5 has a data symbol period of 10 ms, so for a coherent integration period of 20 ms, the method demodulates two data symbols (20 ms) and coherently combines them (after data clearing) with a 20 ms pilot symbol. To achieve higher sensitivity, the coherent integration period can be chosen to be equal to 40 ms, and then four data symbols (40 ms) are demodulated and coherently combined with a 40 ms pilot symbol, and so on.

[0045] Figure 5 This is the architecture of a GNSS receiver according to another embodiment of the present disclosure.

[0046] refer to Figure 5 The diagram illustrates a signal processing architecture 500 configured to process an incoming sampled signal y[n] for combined pilot channel and data channel tracking.

[0047] Figure 6 This is a flowchart illustrating a method 600 for coherently combining pilot signals and data signals in an architecture 500 to improve tracking.

[0048] In step 602, an incoming signal y[n] comprising pilot and data signals from the same GNSS source is received. The incoming signal y[n] is mixed in a first multiplier 502 with an estimated carrier phase signal generated by a carrier numerically controlled oscillator (NCO) 524, the output of which is provided to both the pilot channel branch and the data channel branch.

[0049] In step 604, the data bits in the data signal are demodulated in real time using the pilot signal as a phase reference, as will be described below.

[0050] In the pilot channel branch, the mixed signal is combined with the locally generated pilot code in the second multiplier 506. The signals are multiplied and then coherently summed in coherent summing module 508 to produce pilot correlation value P. p , i Pilot correlation value P p , i The decision-making logic module 564 and the complex conjugate module 550 are provided to generate The output of the complex conjugate module 550 is multiplied in multiplier 552 with a phase-rotated data correlation signal from the data channel branch.

[0051] In the data channel branch, the mixed signal from multiplier 502 is combined with the locally generated data code in the third multiplier 510. The signals are multiplied and then coherently summed in the coherent summing module 512 to produce a data correlation value P. d , i Data correlation value P d , i Multiply by a phase rotation term in multiplier 556 The output of the multiplier 552 is then provided to both the multiplier 552 and the intervention decision logic module 564. The output of the multiplier 552 is processed by the sign detection module 554 to generate the detected data bits. .

[0052] In step 606, the detected data bits are then multiplied in multiplier 558. Pilot correlation value P p , i Multiply them to generate a despread pilot signal, that is, modulate the pilot signal with the demodulated data bits.

[0053] In step 608, the despread pilot signal is correlated with the data value P in adder 560. d , i The sum is combined, and then divided by 2 in divider 562 to generate the pilot output P for tracking. i That is, the pilot signal and the data signal are coherently combined to generate a combined signal P for one or more tracking loops. i .

[0054] Pilot output P i The carrier phase discriminator 516, such as the Costas loop discriminator, further processes the signal to generate a carrier phase error signal, which is filtered by the phase loop filter 518 and applied to the carrier NCO 524. The frequency discriminator 520 generates a frequency error signal, which is filtered by the frequency loop filter 522 and also applied to the carrier NCO 524. Furthermore, the code phase discriminator 528 receives the mixed signal from the multiplier 502 and generates a code phase error signal, which is filtered by the code phase loop filter 530 and applied to the code NCO 532 to produce an estimated code phase provided to the second multiplier 506 and the third multiplier 510. In this way, the architecture 500 facilitates simultaneous pilot and data channel processing, real-time intervention decision-making, and accurate estimation of carrier and code phase for robust signal tracking.

[0055] It should be understood that the intervention decision logic module 564 monitors signal conditions, such as the measured carrier-to-noise ratio (C / N0), and can determine in real time whether to select a pilot, data, or combined signal path as input. Module 564 uses the measured average C / N0 and real-time signal power (based on the coherence sum of the pilot and data signals) to generate a real-time intervention decision to control whether real-time modulation of the pilot signal and the pilot / data signal combination should be performed based on the following conditions:

[0056] (1) Average C / N0 > threshold 1; and

[0057] (2) + Threshold 2

[0058] It should be understood that thresholds 1 and 2 can be manually selected via simulation or analysis to achieve a better expected bit error rate than the target (e.g., target = 25%). This intervention logic improves reliability under varying signal quality conditions.

[0059] The algorithm of this disclosure will now be described in more detail. The algorithm is illustrated here using an L5 signal (such as a GALE5a signal) with a data bit period of 20 ms, without loss of generality. The algorithm can also be applied to other L5 signals (GPS L5, BDS B2a, GALE5b) and L1 signals (GPS L1C, GALE1, BDS B1C) that include pilot and data components, with slight variations due to different data bit periods.

[0060] The GNSS signal y[n], which includes data and pilot components, can be modeled at the baseband of the receiver, as shown in equation (1).

[0061]

[0062] Equation (1) is the sum of three terms: the data component and the pilot component, and the additive white Gaussian noise (AWGN) component. It is the received power of the pilot signal, and This is the ratio between the data power level and the pilot power level, derived from the signal specifications in the ICD. For example, for all L5 signals and GAL E1 signals, And for BDS B1C signals, . These are navigation data (or symbol) bits, while and The PRN codes representing the data component and pilot component respectively, including the influence of the secondary code. It is a time index and It is the sampling interval. and These are the delay, Doppler frequency, and carrier phase. Data components and pilot components can be transmitted in different phases, as specified by constants in the ICD. To model noise. It has zero mean, and has independent and identically distributed (i.e., i.i.d.) real and imaginary parts, both of which have variance. .

[0063] Then, It is associated with the carrier and local copies of the data code and pilot code. During tracking, the outputs of the data correlator and pilot correlator are (ignoring the effects of residual frequency errors).

[0064]

[0065] In equations (2) and (3), It is the time index of PDI. It is the residual delay error, and This is the delay assumption in the receiver. It is the residual carrier phase error, and This is the carrier phase assumption in the receiver. It is a data symbol and is assumed to be constant over the coherent integration time (PDI). It is the signal amplitude, and It is a known constant that includes the possible amplitude and phase difference between the data component and the pilot component.

[0066] and These are the data autocorrelation function and the pilot autocorrelation function, respectively. and The actual purpose is the same.

[0067]

[0068] Different noise components and It is a zero-mean Gaussian random variable iid. and The real and imaginary parts have variance ,in This refers to the number of samples used in the relevant process.

[0069] For each PDI cycle, before the input is fed into the tracking loop, The phase can be obtained by using For reference ( yes To remove (the complex conjugate):

[0070]

[0071] Then the data bits can be processed as shown in equation (6). Demodulate.

[0072]

[0073] This is a differential data demodulation method. The differential demodulation BER can be estimated using equation (7):

[0074]

[0075] In equation (7), It is the data bit period, here s.

[0076] For each PDI, the demodulation operation occurs before the signal is input to the tracking loop. Demodulated data bits It can be used to clear or eliminate data signals. The data bits in the middle, thus allowing the pilot signal and data signals Coherent combination. This allows the combined signal to be input into the tracking loop in real time.

[0077] Equation (8) shows the general formula for the output of the coherent combination of the pilot signal and the data signal.

[0078]

[0079] In equation (8), and These are the weights of the pilot and data components during coherent combining, respectively. For all L5 signals in this study, ,therefore .

[0080]

[0081] As shown in equation (9), for each bit, when the data demodulation is correct ( hour, Having more than or A 3dB SNR gain. However, when the data demodulation is incorrect ( hour, It will contain only noise.

[0082] Real-time demodulation is used only for on-time taps to demodulate data bits, but the pilot signal + data signal combination should be operated for on-time, advance, and lag taps (or all taps currently entering the tracking loop). According to this disclosure, even when the BER is high, the coherent combination gain of the tracking loop is quite considerable, and it converges rapidly to the theoretical limit of 3dB as the BER decreases.

[0083] Based on the above, Table 1 shows some of the benefits of this algorithm.

[0084] Table 1 - Summary of the benefits of the proposed algorithm relative to the baseline

[0085]

[0086] Additional benefits of the algorithm may include: (1) ease of implementation; (2) no changes to any tracking loop design; and (3) implementation in SW.

[0087] When data bits are demodulated within a tracking loop (such as a Costas loop), it is likely impractical to feed back the demodulated data bits to clear or eliminate them. This is because the data signal (with Nav bits) has already been input and used to drive the loop. Clearing could be performed and the loop rerun with a coherently combined signal. However, this would be complex and likely not a real-time operation.

[0088] Compared to Costas-based data demodulation, the algorithm in this disclosure has other advantages: (1) it is robust to frequency or phase drift and jitter because they are eliminated in the data signal when a pilot signal is used as a reference; and (2) it can operate at a much lower C / N0 level than the Costas loop, so it can be used for frequency tracking loops and delay-locked loops at low C / N0 (the C / N0 region that is important for L5 applications in smartphones).

[0089] The above disclosure focuses on tracking, but it can also be applied to obtain performance improvements, for example, if demodulation bits are used to clear or eliminate data symbols and then coherently combined with pilot symbols.

[0090] Figure 7 This is a block diagram of an electronic device in a network environment 700 according to an embodiment.

[0091] refer to Figure 7In network environment 700, electronic device 701 can communicate with electronic device 702 via a first network 798 (e.g., a short-range wireless communication network), or with electronic device 704 or server 708 via a second network 799 (e.g., a long-range wireless communication network). Electronic device 701 can communicate with electronic device 704 via server 708. Electronic device 701 may include processor 720, memory 730, input device 750, sound output device 755, display device 760, audio module 770, sensor module 776, interface 777, haptic module 779, camera module 780, power management module 788, battery 789, communication module 790, subscriber identification module (SIM) card 796, or antenna module 797. In some embodiments, at least one component (e.g., display device 760 or camera module 780) may be omitted from electronic device 701, or one or more other components may be added to electronic device 701. Some components may be implemented as a single integrated circuit (IC). For example, a sensor module 776 (e.g., a fingerprint sensor, an iris sensor, an illuminance sensor, etc.) may be embedded in a display device 760 (e.g., a display).

[0092] Processor 720 can execute software (e.g., program 740) to control at least one other component (e.g., hardware or software component) of electronic device 701 coupled to processor 720, and can perform various data processing or calculations. For example, in some embodiments, processor 720 is designed for... Figure 3 The receiver architecture shown implements Figure 4 The data processing is illustrated. For example, in another embodiment, processor 720 is designed for... Figure 5 The receiver architecture shown implements Figure 6 The data processing is shown in the figure.

[0093] As at least part of data processing or computation, processor 720 can load commands or data received from another component (e.g., sensor module 776 or communication module 790) into volatile memory 732, process the commands or data stored in volatile memory 732, and store the resulting data in non-volatile memory 734. Processor 720 may include a main processor 721 (e.g., a central processing unit (CPU) or application processor (AP)) and an auxiliary processor 723 (e.g., a graphics processing unit (GPU), image signal processor (ISP), sensor hub processor, or communication processor (CP)) that may operate independently of or in conjunction with the main processor 721. Additionally or alternatively, auxiliary processor 723 may be adapted to consume less power than the main processor 721 or to perform specific functions. Auxiliary processor 723 may be implemented separately from or as part of the main processor 721.

[0094] When the main processor 721 is inactive (e.g., in sleep mode), instead of the main processor 721, the auxiliary processor 723 can control at least some of the functions or states associated with at least one component of the electronic device 701 (e.g., display device 760, sensor module 776, or communication module 790). Alternatively, when the main processor 721 is active (e.g., running an application), the auxiliary processor 723 can work with the main processor 721 to control at least some of the functions or states associated with at least one component of the electronic device 701 (e.g., display device 760, sensor module 776, or communication module 790). The auxiliary processor 723 (e.g., an image signal processor or a communication processor) can be implemented as part of another component (e.g., camera module 780 or communication module 790) functionally associated with the auxiliary processor 723.

[0095] Memory 730 may store various data used by at least one component of electronic device 701 (e.g., processor 720 or sensor module 776). The various data may include, for example, software (e.g., program 740) and input or output data for commands associated with it. Memory 730 may include volatile memory 732 or non-volatile memory 734. Non-volatile memory 734 may include internal memory 736 and / or external memory 738.

[0096] The program 740 can be stored as software in the memory 730 and may include, for example, an operating system (OS) 742, middleware 744, or application 746.

[0097] Input device 750 can receive commands or data from outside electronic device 701 (e.g., a user) that will be used by another component of electronic device 701 (e.g., processor 720). Input device 750 may include, for example, a microphone, mouse, or keyboard.

[0098] The sound output device 755 can output sound signals to the outside of the electronic device 701. The sound output device 755 may include, for example, a speaker or a receiver. The speaker can be used for general purposes, such as playing multimedia or recording, and the receiver can be used to receive incoming calls. The receiver can be implemented separately from the speaker or as part of the speaker.

[0099] Display device 760 can visually provide information to the outside of electronic device 701 (e.g., to a user). Display device 760 may include, for example, a display, a holographic device, or a projector, and control circuitry for controlling a corresponding one of the display, holographic device, and projector. Display device 760 may include touch circuitry adapted to detect touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of the force caused by touch.

[0100] The audio module 770 can convert sound into electrical signals and vice versa. The audio module 770 can acquire sound via the input device 750, or output sound via the sound output device 755 or headphones of the external electronic device 702 that are directly (e.g., wired) or wirelessly connected to the electronic device 701.

[0101] Sensor module 776 can detect the operating state of electronic device 701 (e.g., power or temperature) or the environmental state outside electronic device 701 (e.g., user state), and then generate an electrical signal or data value corresponding to the detected state. Sensor module 776 may include, for example, a gesture sensor, gyroscope sensor, atmospheric pressure sensor, magnetic sensor, accelerometer, grip sensor, proximity sensor, color sensor, infrared (IR) sensor, biometric sensor, temperature sensor, humidity sensor, or illuminance sensor.

[0102] Interface 777 may support one or more specified protocols for enabling electronic device 701 to be directly (e.g., wired) or wirelessly coupled to external electronic device 702. Interface 777 may include, for example, a High Definition Multimedia Interface (HDMI), a Universal Serial Bus (USB) interface, a Secure Digital Card (SD) interface, or an audio interface.

[0103] Connection 778 may include a connector, through which electronic device 701 can be physically connected to external electronic device 702. Connection 778 may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0104] The haptic module 779 can convert electrical signals into mechanical stimuli (e.g., vibration or motion) or electrical stimuli that can be recognized by a user through touch or kinesthesia. The haptic module 779 may include, for example, a motor, a piezoelectric element, or an electrical stimulator.

[0105] Camera module 780 can acquire still or moving images. Camera module 780 may include one or more lenses, an image sensor, an image signal processor, or a flash. Power management module 788 can manage the power supply to electronic device 701. Power management module 788 may be implemented as at least a part of, for example, a power management integrated circuit (PMIC).

[0106] Battery 789 can power at least one component of electronic device 701. Battery 789 may include, for example, a non-rechargeable primary battery, a rechargeable rechargeable battery, or a fuel cell.

[0107] Communication module 790 can support the establishment of a direct (e.g., wired) or wireless communication channel between electronic device 701 and external electronic devices (e.g., electronic device 702, electronic device 704, or server 708), and perform communication via the established communication channel. Communication module 790 may include one or more communication processors that can operate independently of processor 720 (e.g., AP), and support direct (e.g., wired) or wireless communication. Communication module 790 may include wireless communication module 792 (e.g., cellular communication module, short-range wireless communication module, or Global Navigation Satellite System (GNSS) communication module) or wired communication module 794 (e.g., local area network (LAN) communication module or power line communication (PLC) module). A corresponding one of these communication modules can communicate via a first network 798 (e.g., a short-range communication network, such as Bluetooth). TM The communication module 792 communicates with external electronic devices via a wireless communication module 793 (e.g., a Wi-Fi Direct or Infrared Data Association (IrDA) standard) or a second network 799 (e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., a LAN or a wide area network (WAN))). These various types of communication modules can be implemented as a single component (e.g., a single IC) or as multiple components separate from each other (e.g., multiple ICs). The wireless communication module 792 can use subscriber information (e.g., International Mobile Subscriber Identity (IMSI)) stored in the subscriber identification module 796 to identify and authenticate electronic devices 701 within the communication network (e.g., a first network 798 or a second network 799).

[0108] In some embodiments, Figure 3 and Figure 5 The receiver architecture shown can be housed in the communication module 790. In some embodiments, the communication module 790 may include at least one processor to control... Figure 3 and Figure 5 The receiver architecture and implementation of... Figure 4 and Figure 6 The method is shown and described. In other embodiments, the processor 720 controls... Figure 3 and Figure 5 The architecture. In another embodiment, Figure 3 and Figure 5The receiver architecture shown can be housed within processor 720. Antenna module 797 can transmit or receive signals or power from or from the outside of electronic device 701 (e.g., external electronic device). Antenna module 797 may include one or more antennas, and at least one antenna suitable for a communication scheme used in a communication network (such as a first network 798 or a second network 799) can be selected from the one or more antennas, for example, via communication module 790 (e.g., wireless communication module 792). Signals or power can then be transmitted or received between communication module 790 and external electronic device via the selected at least one antenna.

[0109] Commands or data can be sent or received between electronic device 701 and external electronic device 704 via server 708 coupled to the second network 799. Each of electronic devices 702 and 704 can be a device of the same or different type as electronic device 701. All or some operations to be performed at electronic device 701 can be performed at one or more of the external electronic devices 702, 704, or 708. For example, if electronic device 701 is required to automatically perform a function or service, or to perform a function or service in response to a request from a user or another device, electronic device 701 can perform that function or service in its own name, or request one or more external electronic devices to perform at least a portion of the function or service in addition to performing that function or service. Upon receiving the request, one or more external electronic devices can perform at least a portion of the requested function or service, or perform additional functions or services related to the request, and transmit the result of the performance to electronic device 701. Electronic device 701 can provide the result as at least a part of its response to the request, with or without further processing. For this purpose, cloud computing, distributed computing, or client-server computing technologies can be used, for example.

[0110] Figure 8 A system including a UE 805 and a gNB 810 communicating with each other is shown. The UE may include a radio 815 and processing circuitry (or means for processing) 820, which can perform various methods disclosed herein, for example, Figure 1 The method shown. For example, the processing circuit 820 can receive transmissions from the network node (gNB) 810 via radio 815, and the processing circuit 820 can send signals to the gNB 810 via radio 815.

[0111] Embodiments of the subject matter and operations described in this specification can be implemented in digital electronic circuits, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or combinations thereof. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs (i.e., one or more modules of computer program instructions) encoded on a computer storage medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus. Alternatively or additionally, the program instructions can be encoded on artificially generated propagating signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information for transmission to a suitable receiver device for execution by the data processing apparatus. The computer storage medium can be or is included in a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination thereof. Furthermore, although the computer storage medium is not a propagating signal, it can be a source or destination of computer program instructions encoded in artificially generated propagating signals. The computer storage medium can also be or be included in one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices). Furthermore, the operations described in this specification can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

[0112] While this specification may contain numerous specific implementation details, these details should not be construed as limiting the scope of any claimed subject matter, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of individual embodiments in this specification may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, although features may be described above as functioning in certain combinations and even initially claimed in this way, in some cases one or more features from the claimed combination may be removed from the combination, and the claimed combination may be for sub-combinations or variations thereof.

[0113] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or to perform all the shown operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of the various system components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0114] Therefore, specific embodiments of the subject matter have been described herein. Other embodiments are within the scope of the following claims. In some cases, the actions set forth in the claims can be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing may be advantageous.

[0115] As those skilled in the art will recognize, the innovative concepts described herein can be modified and varied across a wide range of applications. Therefore, the scope of the claimed subject matter should not be limited to any of the specific exemplary teachings discussed above, but is defined by the appended claims.

Claims

1. A method for coherently combining pilot signals and data signals in a GNSS receiver of a Global Navigation Satellite System, the method comprising: Receive pilot and data signals from the same GNSS signal source; The pilot signal is used as a phase reference to demodulate the data bits in the data signal; Eliminate the demodulated data bits from the data signal; as well as The pilot signal and the data signal are coherently combined to generate a combined signal.

2. The method of claim 1 further includes, after the integral clearing operation, using a phase rotator to remove the constant phase offset between the pilot signal and the data signal.

3. The method according to claim 1 further includes performing secondary code cancellation on both the pilot signal and the data signal after the integral clearing operation.

4. The method of claim 1, further comprising generating an intervention decision for enabling or disabling data demodulation and pilot / data signal combination, wherein, The intervention decision is based on: The average carrier-to-noise ratio (C / N0) exceeds the first threshold; as well as The sum of the pilot signal power and the data signal power exceeds the second threshold.

5. The method according to claim 1, wherein, Demodulating the data bits involves using differential demodulation between the pilot signal and the data signal.

6. The method according to claim 1, wherein, The combined signal is used as the input to the frequency tracking loop, phase tracking loop, and code tracking loop of the GNSS receiver.

7. The method according to claim 1, wherein, The demodulation and coherent combination are performed within at least one integration period, wherein the gain of the coherent combination is dynamically adjusted based on a real-time estimate of the bit error rate.

8. The method according to claim 1, wherein, The demodulation and coherence combination is applied during acquisition to improve the sensitivity of the GNSS receiver by at least 1.5 dB relative to the pilot signal baseline alone.

9. The method according to claim 1, wherein, The demodulation of the data bits in the data signal using the pilot signal as the phase reference is performed in real time.

10. A Global Navigation Satellite System (GNSS) receiver, comprising: At least one processing unit; and Memory, storing instructions that, when executed by the at least one processing unit, cause the GNSS receiver to: Receive pilot signals and data signals from the same GNSS signal source. The pilot signal is used as a phase reference to demodulate the data bits in the data signal. Remove the demodulated data bits from the data signal, and The pilot signal and the data signal are coherently combined to generate a combined signal.

11. The GNSS receiver according to claim 10, wherein, The at least one processing unit is further configured to use a phase rotator to remove the constant phase offset between the pilot signal and the data signal after the integral clearing operation.

12. The GNSS receiver according to claim 10, wherein, The at least one processing unit is further configured to perform secondary code cancellation on both the pilot signal and the data signal after the integral clearing operation.

13. The GNSS receiver according to claim 10, wherein, The at least one processing unit is further configured to generate an intervention decision for enabling or disabling data demodulation and pilot / data signal combination, wherein the intervention decision is based on: The average carrier-to-noise ratio (C / N0) exceeds the first threshold; and The sum of the pilot signal power and the data signal power exceeds the second threshold.

14. The GNSS receiver according to claim 10, wherein, The at least one processing unit is configured to demodulate the data bits using differential demodulation between the pilot signal and the data signal.

15. The GNSS receiver according to claim 10, wherein, The combined signal is provided as input to the frequency tracking loop, phase tracking loop, and code tracking loop of the GNSS receiver.

16. The GNSS receiver according to claim 10, wherein, The at least one processing unit is configured to dynamically adjust the coherent combination gain based on a real-time estimate of the bit error rate.

17. The GNSS receiver according to claim 10, wherein, The at least one processing unit is configured to perform the demodulation and coherence combination during the signal acquisition phase to improve the sensitivity of the GNSS receiver by at least 1.5 dB relative to the pilot signal baseline alone.

18. The GNSS receiver according to claim 10, wherein, The GNSS receiver is implemented in software, so that the demodulation and coherent combination are performed without modifying the existing tracking loop architecture.

19. The GNSS receiver according to claim 10, wherein, The at least one processing unit is configured to use the pilot signal as the phase reference in real time to perform the demodulation of the data bits in the data signal.

20. A method for coherently combining pilot signals and data signals in a GNSS receiver of a Global Navigation Satellite System, the method comprising: Receive pilot and data signals from the same GNSS signal source; The pilot signal is used as a phase reference to demodulate the data bits in the data signal; The demodulated data bits are used to modulate the pilot signal; as well as The pilot signal and the data signal are coherently combined to generate a combined signal.

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