Satellite navigation signal tracking device and forming method, tracking method

Abstract

The application provides a double-loop satellite navigation signal tracking device and a forming method thereof, and a satellite navigation signal tracking method. The double-loop satellite navigation signal tracking device comprises a sub-carrier loop and a code loop. The forming method comprises the following steps: determining the sub-carrier loop by parameters of a satellite navigation signal to be tracked, a weight parameter of a sub-carrier loop discriminator, a number of sub-carrier loop correlators and distance parameters among a plurality of sub-carrier loop correlators; and determining the code loop by parameters of the satellite navigation signal to be tracked, a weight parameter of a code loop discriminator, a number of code loop correlators and distance parameters among a plurality of code loop correlators. The double-loop satellite navigation signal tracking device formed according to the forming method can effectively suppress the influence of multipath errors including sub-carrier multipath errors and code multipath errors, and improve the tracking precision of the satellite navigation signal.

Description

TECHNICAL FIELD

[0001] The present application relates to a global navigation satellite system (GNSS), in particular to a double-loop satellite navigation signal tracking device, a method for forming a double-loop satellite navigation signal tracking device, and a satellite navigation signal tracking method. BACKGROUND

[0002] The positioning, velocity measurement, and time service accuracy of a user in a GNSS depends on the measurement accuracy of the receiver to the delay of a navigation signal. In a practical environment, various factors can affect the measurement accuracy of the delay, and the multipath error caused by the multipath effect is the most special one among the factors. The multipath error is related to the specific environment around the user, and is difficult to eliminate by means of difference and multi-frequency. The multipath error has become a bottleneck factor for further improving the ranging accuracy of a satellite navigation system.

[0003] In addition, in terms of the design of a navigation signal, the navigation signal currently generally adopts a binary offset carrier (BOC) modulation mode. Compared with a navigation signal of a traditional binary phase shift key (BPSK) modulation mode, the BOC signal can provide better spectral separation than the existing signal in limited frequency band resources, reduce inter-system interference, and also provide better potential for anti-multipath error.

[0004] However, while the BOC signal provides these more advantageous performances, it also brings challenges to the processing technology of a navigation receiver. The correlation function of the BOC signal has a multi-peak characteristic, which leads to a multi-peak ambiguity problem in signal tracking, limits the ranging accuracy in the practical application of the BOC signal, and also limits the anti-multipath performance of the BOC signal. Further, with the increase of the modulation order in the BOC signal, the difficulty caused by the above problems also increases.

[0005] Therefore, there is an urgent need for a satellite navigation signal tracking method and device that can better resist the multipath effect and improve the satellite ranging accuracy. SUMMARY

[0006] Embodiments of the present application provide a double-loop satellite navigation signal tracking device and a method for forming the same, and a satellite navigation signal tracking method, which can at least partially solve the above problems or other problems in the related art.

[0007] On the one hand, the present application provides a method for forming a dual-loop satellite navigation signal tracking device, wherein the dual-loop satellite navigation signal tracking device includes a subcarrier loop and a code loop, and the method includes: determining the subcarrier loop through the parameters of the satellite navigation signal to be tracked, the weight parameters of the subcarrier loop phase detector, the number of subcarrier loop correlators, and the distance parameters between the multiple subcarrier loop correlators; and determining the code loop through the parameters of the satellite navigation signal to be tracked, the weight parameters of the code loop phase detector, the number of code loop correlators, and the distance parameters between the multiple code loop correlators.

[0008] In one embodiment of the present application, the number N of the subcarrier loop correlators is s is any positive even number greater than or equal to 4.

[0009] In one embodiment of the present application, the number N of the code loop correlators is c is any positive even number greater than or equal to 4.

[0010] In one embodiment of the present application, the number of the subcarrier loop correlators is the same as the number of the code loop correlators.

[0011] In one embodiment of the present application, the number of the subcarrier loop correlators is different from the number of the code loop correlators.

[0012] In one embodiment of the present application, the parameters of the satellite navigation signal to be tracked include the order of the binary offset carrier signal, the signal unilateral bandwidth and the multipath relative amplitude.

[0013] In one embodiment of the present application, a heuristic algorithm is called to optimize at least one of a weight parameter of the subcarrier loop phase detector, a weight parameter of the code loop phase detector, a distance parameter between a plurality of the subcarrier loop correlators, and a distance parameter between a plurality of the code loop correlators to determine the subcarrier loop and the code loop.

[0014] In one embodiment of the present application, the heuristic algorithm includes at least one or a combination of a swarm intelligence optimization algorithm, an ant colony algorithm, a genetic algorithm, and a differential evolution algorithm.

[0015] In one embodiment of the present application, the method further includes: determining the subcarrier loop and the code loop by using the parameters of the satellite navigation signal to be tracked, the number of the subcarrier loop correlators, the number of the code loop correlators and the optimization algorithm parameters, and calling a heuristic algorithm to optimize the weight parameters of the subcarrier loop phase detector, the weight parameters of the code loop phase detector, the distance parameters between the multiple subcarrier loop correlators and at least one of the distance parameters between the multiple code loop correlators.

[0016] In one embodiment of the present application, the subcarrier loop correlator distance parameter, the code loop correlator distance parameter, the subcarrier loop phase detector weight parameter, and the code loop phase detector weight parameter are adjusted to minimize the average multipath error envelope area or minimize the roll-off multipath error, thereby suppressing the multipath error of the satellite navigation signal to be tracked.

[0017] In one embodiment of the present application, the method further includes: establishing a two-dimensional multipath optimization tracking device model including the subcarrier loop and the code loop.

[0018] In one embodiment of the present application, the two-dimensional multipath optimization tracking device model includes:

[0019]

[0020]

[0021]

[0022] Where V(·) is the multipath error; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the relative amplitude of the multipath; N c is the number of the code loop correlators; and N s is the number of the subcarrier loop correlators.

[0023] In one embodiment of the present application, establishing the two-dimensional multipath optimization tracking device model includes: establishing a two-dimensional dual-loop phase detector model, wherein the two-dimensional dual-loop phase detector model includes a subcarrier loop phase detector model and a code loop phase detector model; determining the multipath error based on the two-dimensional dual-loop phase detector model, wherein the multipath error includes a subcarrier multipath error and a code multipath error; and establishing the two-dimensional multipath optimization tracking device model based on the two-dimensional dual-loop phase detector model and the multipath error.

[0024] In one embodiment of the present application, the two-dimensional dual-loop phase detector model includes:

[0025]

[0026]

[0027] Where R is the two-dimensional autocorrelation function of the binary offset carrier signal; τ c is the code delay; τ sis the subcarrier delay; τ m is the multipath relative delay; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the relative amplitude of the multipath; N c is the number of the code loop correlators; and N s is the number of the subcarrier loop correlators.

[0028] In one embodiment of the present application, the phase detector outputs of the code loop and the subcarrier tracking loop are determined according to the two-dimensional dual-loop phase detector model; and the phase detector output is iteratively calculated using an F function to determine the multipath error, wherein the F function is used to find the zero-crossing point of the curve of the phase detector output that is closest to the origin.

[0029] On the other hand, the present application provides a dual-loop satellite navigation signal tracking device, the device comprising: an acquisition module configured to acquire a non-delayed local subcarrier, a non-delayed local code, a plurality of delayed local subcarriers, and a plurality of delayed local codes for a baseband satellite signal; a subcarrier loop comprising a subcarrier loop phase detector and a plurality of subcarrier loop correlators, the subcarrier loop being configured to perform correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local subcarrier to obtain a first correlation value, and weightedly combine the plurality of first correlation values ​​to obtain a subcarrier multipath error. difference; and a code loop, comprising a code loop phase detector and multiple code loop correlators, the code loop being configured to perform correlation processing on the baseband satellite signal, the undelayed local subcarrier, and the delayed local code to obtain a second correlation value, and weightedly combine multiple second correlation values ​​to obtain a code multipath error, wherein at least one of a distance parameter between the subcarrier loop correlators, a distance parameter between the code loop correlators, a weight parameter of the subcarrier loop phase detector, and a weight parameter of the code loop phase detector is used to suppress the subcarrier multipath error and the code multipath error.

[0030] In one embodiment of the present application, the number N of the subcarrier loop correlators is s is any positive even number greater than or equal to 4.

[0031] In one embodiment of the present application, the number N of the code loop correlators is c is any positive even number greater than or equal to 4.

[0032] In an embodiment of the application, the number of the delayed local subcarriers is the same as the number of the subcarrier loop correlators; and the number of the delayed local codes is the same as the number of the code loop correlators.

[0033] In an embodiment of the application, the plurality of the delayed local subcarriers comprises a plurality of different phase-advanced or phase-lagged local subcarriers, wherein the distance parameters between the subcarrier loop correlators are phase distances between the delayed local subcarriers; and the plurality of the delayed local codes comprises a plurality of different phase-advanced or phase-lagged local codes, wherein the distance parameters between the code loop correlators are phase distances between the delayed local codes.

[0034] In an embodiment of the application, the subcarrier loop phase detector is configured to apply a weight parameter of the corresponding subcarrier loop phase detector to each of the first correlation values, and to combine the first correlation values after applying the weight parameter of the corresponding subcarrier loop phase detector to obtain the subcarrier multipath error; and the code loop phase detector is configured to apply a weight parameter of the corresponding code loop phase detector to each of the second correlation values, and to combine the second correlation values after applying the weight parameter of the corresponding code loop phase detector to obtain the code multipath error.

[0035] In an embodiment of the application, at least one of the distance parameters between the subcarrier loop correlators, the distance parameters between the code loop correlators, the weight parameters of the subcarrier loop phase detectors, and the weight parameters of the code loop phase detectors is used to minimize an average multipath error envelope area or to minimize a roll-off of the multipath error to suppress the multipath error.

[0036] In an embodiment of the application, the apparatus is further configured to invoke a heuristic algorithm to optimize at least one of the distance parameters between the subcarrier loop correlators, the distance parameters between the code loop correlators, the weight parameters of the subcarrier loop phase detectors, and the weight parameters of the code loop phase detectors.

[0037] In an embodiment of the application, the subcarrier loop is further configured to multiply the baseband satellite signal and the non-delayed local subcarrier to obtain a first intermediate signal, wherein the subcarrier loop correlator is configured to multiply and integrate the first intermediate signal and the delayed local subcarrier to obtain the first correlation value; and the code loop is further configured to multiply the baseband satellite signal and the non-delayed local code to obtain a second intermediate signal, wherein the code loop correlator is configured to multiply and integrate the second intermediate signal and the delayed local code to obtain the second correlation value.

[0038] In an embodiment of the application, the device further comprises a capturing module configured to capture a satellite binary offset carrier signal to obtain a satellite number, a carrier frequency and a code phase of the signal.

[0039] In an embodiment of the application, the obtaining module is further configured to strip a carrier of the signal according to the carrier frequency of the signal to obtain the baseband satellite signal; and generate the no-delay local code and the plurality of delayed local codes using a code digital control oscillator according to the satellite number and the code phase of the signal, and generate the no-delay local subcarrier and the plurality of delayed local subcarriers using a subcarrier digital control oscillator.

[0040] In an embodiment of the application,

[0041] the ith delayed local code

[0042] the ith delayed local subcarrier

[0043] wherein, is an optimized value of a range parameter of the ith code loop correlator; is an optimized value of a range parameter of the ith subcarrier loop correlator; N c is a number of the code loop correlators; and N s is a number of the subcarrier loop correlators.

[0044] In an embodiment of the application,

[0045]

[0046]

[0047] wherein, is the ith first correlation value; is the ith second correlation value; T is an integration time; and g(t) is the baseband satellite signal. is an optimized value of a range parameter of the ith code loop correlator; is an optimized value of a range parameter of the ith subcarrier loop correlator; N c is a number of the code loop correlators; and N s is a number of the subcarrier loop correlators.

[0048] In an embodiment of the application,

[0049]

[0050]

[0051] wherein, is the ith first correlation value; is the ith second correlation value;E s is the subcarrier multipath error;E c is the code multipath error; is an optimized value of a weight parameter of the ith code loop phase detector; and is an optimized value of a weight parameter of the ith subcarrier loop phase detector.

[0052] In an embodiment of the present application, the subcarrier loop further comprises a subcarrier loop filter configured to process the subcarrier multipath error to obtain a subcarrier loop correction value; and the code loop further comprises a code loop filter configured to process the code multipath error to obtain a code loop correction value.

[0053] In an embodiment of the present application, the apparatus further comprises a correction module configured to adjust the subcarrier digital control oscillator according to the subcarrier loop correction value to correct a subcarrier delay estimation value, and adjust the code digital control oscillator according to the code loop correction value to correct a code delay estimation value.

[0054] In another aspect of the present application, a satellite navigation signal tracking method is provided, which comprises: performing carrier separation on a captured satellite navigation signal to obtain a baseband satellite signal; generating a non-delayed local subcarrier, a non-delayed local code, a plurality of delayed local subcarriers and a plurality of delayed local codes for the baseband satellite signal; performing correlation processing on the baseband satellite signal, the non-delayed local code and the delayed local subcarriers to obtain first correlation values, and performing correlation processing on the baseband satellite signal, the non-delayed local subcarrier and the delayed local codes to obtain second correlation values; and weighting and combining a plurality of the first correlation values to obtain a subcarrier multipath error, and weighting and combining a plurality of the second correlation values to obtain a code multipath error, wherein at least one of a phase distance between the delayed local subcarriers, a phase distance between the delayed local codes, a weighting value of the first correlation values and a weighting value of the second correlation values is adjusted to suppress a multipath error of the captured satellite navigation signal, wherein the multipath error comprises the subcarrier multipath error and the code multipath error.

[0055] In an embodiment of the present application, the plurality of delayed local subcarriers comprises a plurality of different phase-advanced or phase-lagged local subcarriers; and the plurality of delayed local codes comprises a plurality of different phase-advanced or phase-lagged local codes.

[0056] In an embodiment of the present application, the number of the delayed local subcarriers is any positive even number greater than or equal to 4; and the number of the delayed local codes is any positive even number greater than or equal to 4.

[0057] In an embodiment of the present application, the weighting and combining the plurality of the first correlation values to obtain a subcarrier multipath error and weighting and combining the plurality of the second correlation values to obtain a code multipath error comprises: applying a weighting value of a corresponding first correlation value to each of the first correlation values, and combining the plurality of the first correlation values after applying the weighting value of the corresponding first correlation value to each of the first correlation values to obtain the subcarrier multipath error; and applying a weighting value of a corresponding second correlation value to each of the second correlation values, and combining the plurality of the second correlation values after applying the weighting value of the corresponding second correlation value to each of the second correlation values to obtain the code multipath error.

[0058] In an embodiment of the present application, the adjusting at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighting value of the first correlation value and the weighting value of the second correlation value comprises: calling a heuristic algorithm to optimize at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighting value of the first correlation value and the weighting value of the second correlation value.

[0059] In an embodiment of the present application, the heuristic algorithm comprises at least one or a combination of a swarm intelligence optimization algorithm, an ant colony algorithm, a genetic algorithm and a differential evolution algorithm.

[0060] In an embodiment of the present application, the adjusting at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighting value of the first correlation value and the weighting value of the second correlation value to suppress the multipath error of the acquired satellite navigation signal, wherein the multipath error comprises the subcarrier multipath error and the code multipath error comprises: adjusting at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighting value of the first correlation value and the weighting value of the second correlation value to minimize an average multipath error envelope area or to minimize a roll-off multipath error, thereby achieving the suppression of the multipath error of the satellite navigation signal to be tracked.

[0061] In an embodiment of the present application, the correlating the baseband satellite signal, the non-delayed local code and the delayed local subcarriers to obtain a first correlation value comprises: multiplying the baseband satellite signal and the non-delayed local code to obtain a first intermediate signal; and multiplying and integrating the first intermediate signal and the delayed local subcarriers to obtain the first correlation value.

[0062] In one embodiment of the present application, correlating the baseband satellite signal, the undelayed local subcarrier, and the delayed local code to obtain a second correlation value includes: multiplying the baseband satellite signal and the undelayed local subcarrier to obtain a second standby signal; and multiplying and integrating the second standby signal and the delayed local code to obtain the second correlation value.

[0063] In one embodiment of the present application, performing carrier separation on a captured satellite navigation signal to obtain a baseband satellite signal includes: capturing a binary offset carrier signal to obtain a satellite number, carrier frequency, and code phase of the binary offset carrier signal; and stripping the carrier of the binary offset carrier signal according to the carrier frequency of the binary offset carrier signal to obtain the baseband satellite signal.

[0064] In one embodiment of the present application,

[0065] The i-th delayed local code

[0066] The i-th delayed local subcarrier

[0067] in, Optimize the distance parameter value of the i-th code loop correlator; N is the parameter optimization value of the loop correlator distance of the i-th subcarrier; c is the number of the code loop correlators; and N s is the number of the subcarrier loop correlators.

[0068] In one embodiment of the present application,

[0069]

[0070]

[0071] in, is the i-th first correlation value; is the i-th second correlation value; T is the integration time; g(t) is the baseband satellite signal; Optimize the distance parameter value of the i-th code loop correlator; is the optimized value of the distance parameter of the i-th subcarrier loop correlator; N c is the number of the code loop correlators; and N s is the number of the subcarrier loop correlators.

[0072] In one embodiment of the present application,

[0073]

[0074]

[0075] in, is the i-th first correlation value; is the i-th second correlation value; E s is the subcarrier multipath error; E c is the code multipath error; is the optimized value of the weight parameter of the i-th code loop phase detector; and is the optimized value of the weight parameter of the loop phase detector of the i-th subcarrier.

[0076] In one embodiment of the present application, after obtaining the subcarrier multipath error and the code multipath error, the method further includes: processing the subcarrier multipath error to obtain a subcarrier loop correction value, and correcting the subcarrier delay estimate based on the subcarrier loop correction value; and processing the code multipath error to obtain a code loop correction value, and correcting the code delay estimate based on the code loop correction value.

[0077] The dual-loop satellite navigation signal tracking device and its formation method, as well as the satellite navigation signal tracking method provided in accordance with at least one embodiment of the present application can effectively suppress the multipath effects including subcarrier multipath error and code multipath error, and improve the accuracy of satellite navigation signal tracking.

[0078] Furthermore, in at least one embodiment of the present application, by providing a dual-loop satellite navigation signal tracking device with at least four subcarrier loop correlators and code loop correlators (which can be understood as a multi-correlator dual-loop satellite navigation signal tracking device), the satellite ranging accuracy of the dual-loop satellite navigation signal tracking device and its tracking method can be improved. Furthermore, by separately obtaining multipath error components associated with the subcarrier loop and code loop in the dual-loop satellite navigation signal tracking device and correcting the subcarrier loop and code loop using these multipath error components, the multipath error of the multi-correlator dual-loop satellite navigation signal tracking device can be effectively reduced.

[0079] In addition, in at least one embodiment of the present application, by optimizing structural parameters related to the average multipath error envelope area or minimizing the roll-off multipath error, the provided dual-loop satellite navigation signal tracking device and satellite navigation signal tracking method can have better anti-multipath performance.

[0080] Furthermore, the relationship between the structures of the above-mentioned multi-correlator dual-loop satellite navigation signal tracking device is usually very complex, and therefore multiple iterations are required when calculating the multipath error. According to the dual-loop satellite navigation signal tracking device and its formation method, and the satellite navigation signal tracking method provided in at least one embodiment of the present application, by adopting an optimization method based on a heuristic algorithm of swarm intelligence, optimized values ​​of structural parameters related to the multipath error can be obtained, thereby solving the technical problem in existing related technical solutions that it is difficult to use accurate mathematical expressions to solve and express the multipath error corresponding to the above-mentioned structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings, in which:

[0082] Figure 1 1 is a schematic diagram of steps of a method for forming a dual-loop satellite navigation signal tracking device according to an embodiment of the present application;

[0083] Figure 2 Schematic diagram of the structure and working mode of a dual-loop satellite navigation signal tracking device according to one embodiment of the present application;

[0084] Figure 3 is a structural diagram of a dual-loop satellite navigation signal tracking device according to an embodiment of the present application; and

[0085] Figure 4 1 is a schematic diagram of the steps of a satellite navigation signal tracking method according to one embodiment of the present application. DETAILED DESCRIPTION

[0086] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0087] It should be noted that in this specification, the terms first, second, third, etc. are used only to distinguish one feature from another feature area, and do not represent any limitation on the features, and in particular do not represent any order of precedence. Therefore, without departing from the teachings of this application, the first correlation value discussed in this application can also be referred to as the second correlation value, and vice versa.

[0088] In the accompanying drawings, the thickness, size, and shape of components have been slightly adjusted for ease of illustration. The accompanying drawings are for illustration only and are not drawn strictly to scale. As used herein, the terms "substantially," "approximately," and similar terms are used to indicate approximations, not degrees, and are intended to account for the inherent variations in measurements or calculations that would be recognized by one of ordinary skill in the art.

[0089] It should also be understood that expressions such as "comprises," "including," "having," "includes," and / or "comprising" are open rather than closed expressions in this specification, indicating the presence of the stated features, elements, and / or components, but do not exclude the presence of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application." And, the term "exemplary" is intended to refer to an example or illustration.

[0090] Unless otherwise defined, all words used herein (including engineering terms and scientific and technological terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that, unless otherwise specified in this application, words defined in commonly used dictionaries should be interpreted as having the same meaning as they do in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense.

[0091] It should be noted that, unless otherwise specified or inconsistent with the context, the embodiments and features of the embodiments in this application may be combined with each other. Furthermore, unless expressly limited or inconsistent with the context, the specific steps included in the methods described in this application are not necessarily limited to the order in which they are described, but may be performed in any order or in parallel. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0092] In addition, in the present application, when “connected” or “coupled” is used, it may indicate direct contact or indirect contact between corresponding components, unless otherwise clearly defined or inferred from the context.

[0093] Figure 1 FIG. 1 is a schematic diagram of steps of a method 1000 for forming a dual-loop satellite navigation signal tracking device according to an embodiment of the present application. Figure 1 As shown, the present application provides a method 1000 for forming a dual-loop satellite navigation signal tracking device, which may include:

[0094] S11, determining a subcarrier loop according to parameters of a satellite navigation signal to be tracked, weight parameters of a subcarrier loop phase detector, the number of subcarrier loop correlators, and distance parameters between multiple subcarrier loop correlators.

[0095] S12, determining a code loop according to parameters of the satellite navigation signal to be tracked, weight parameters of a code loop phase detector, the number of code loop correlators, and distance parameters between multiple code loop correlators.

[0096] The following will be combined Figures 1 to 3 The specific steps of the above-mentioned forming method 1000 are described in detail.

[0097] With the widespread use of BOC signals in GNSS, ambiguity and multipath errors have become two major factors affecting ranging accuracy. To mitigate the impact of ambiguity on ranging accuracy, dual-loop tracking technologies such as the Double Estimator Technique (DET) and the Double Phase Estimator (DPE) have been proposed. However, in addition to ambiguity, ranging performance is also affected by multipath signals.

[0098] When a GNSS receiver operates in a multipath environment, in addition to receiving the electromagnetic wave signal propagating linearly from the GNSS satellite, it also receives at least one multipath signal resulting from the electromagnetic wave's reflection from the surrounding environment. Compared to the direct signal, the multipath signal travels a longer distance, resulting in a relative delay. Furthermore, after multiple refractions and reflections, the multipath signal's signal strength partially fades, reducing the relative amplitude of the multipath signal. This can cause errors in the GNSS receiver's signal measurement and make tracking difficult. This phenomenon is known as the multipath effect, and the resulting measurement error is called multipath error.

[0099] In other words, the currently used dual-loop tracking structure typically includes a code tracking loop and a subcarrier tracking loop. These loops can independently estimate the code propagation delay and the subcarrier propagation delay, respectively, thereby obtaining unambiguous propagation delays. However, while this conventional dual-loop tracking structure can handle ambiguous threats, it does not improve its multipath mitigation performance. Therefore, a dual-loop tracking technology solution with improved multipath mitigation performance is needed.

[0100] Figure 2 2000 and a schematic diagram of the working mode of a dual-loop satellite navigation signal tracking device according to an embodiment of the present application. Figure 3 2 is a schematic structural diagram of a dual-loop satellite navigation signal tracking device 2000 according to an embodiment of the present application.

[0101] like Figures 1 to 3 As shown, the present application forms a dual-loop satellite navigation signal tracking device 2000 through the above steps S11 and S12, which can effectively suppress the multipath effects including subcarrier multipath error and code multipath error, and improve the tracking accuracy of satellite navigation signals. The above steps S11 and S12 can be performed in parallel or in steps. The present application does not limit the order in which steps S11 and S12 are performed.

[0102] Specifically, in one embodiment of the present application, a dual-loop satellite navigation signal tracking device can be formed by modeling. Designing the corresponding dual-loop tracking structure by modeling can effectively improve design efficiency and is also beneficial for controlling design costs. However, it can be understood by those skilled in the art that the dual-loop tracking structure can be formed by modeling or by other methods, and the structural characteristics, implementation principles and technical effects of the dual-loop tracking structure ultimately obtained are similar. Therefore, the present application does not limit the specific formation method. Without departing from the teachings of the present application, other methods can be used to form the dual-loop tracking structure to obtain the various results and advantages described in the specification.

[0103] The following will use the modeling method as an example to describe in detail the specific process of forming a dual-loop tracking structure.

[0104] In one embodiment of the present application, establishing a two-dimensional multipath optimization tracking device model including a subcarrier loop and a code loop includes establishing a two-dimensional dual-loop phase detector model, wherein the two-dimensional dual-loop phase detector model includes a subcarrier loop phase detector model and a code loop phase detector model; determining a multipath error based on the two-dimensional dual-loop phase detector model, wherein the multipath error includes a subcarrier multipath error and a code multipath error; and establishing a two-dimensional multipath optimization tracking device model based on the two-dimensional dual-loop phase detector model and the multipath error.

[0105] Specifically, the two-dimensional dual-loop phase detector model can be obtained based on the code loop phase detector output model and the subcarrier loop phase detector output model. The code loop phase detector output model can be obtained by S c (τ c ,τ s |w c ,d c ) indicates that the subcarrier loop phase detector output model can be expressed as S s (τ c ,τ s |w s ,d s ). The specific formula can be expressed as follows:

[0106]

[0107]

[0108] Where R is the two-dimensional autocorrelation function of the binary offset carrier signal; τ c is the code delay; τ s is the subcarrier delay; τ m is the multipath relative delay; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the relative amplitude of the multipath; N c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0109] In at least one embodiment of the present application, in order to improve the satellite ranging accuracy of the dual-loop satellite navigation signal tracking device and the tracking method thereof, no less than four subcarrier loop correlators and code loop correlators may be provided in the dual-loop satellite navigation signal tracking device.

[0110] Therefore, as an option, the number of subcarrier loop correlators N S It can be any positive even number greater than or equal to 4. In addition, the number of code loop correlators N C It may also be any positive even number greater than or equal to 4. The dual-loop satellite navigation signal tracking device having multiple subcarrier loop correlators and code loop correlators may also be referred to as a multi-correlator dual-loop satellite navigation signal tracking device.

[0111] In addition, the present application can effectively reduce the multipath error of the above-mentioned multi-correlator dual-loop satellite navigation signal tracking device by separately obtaining the multipath error components related to the subcarrier loop and code loop in the dual-loop satellite navigation signal tracking device, and correcting the subcarrier loop and code loop respectively through the above-mentioned multipath error components. The specific steps are detailed below.

[0112] Furthermore, as an option, the number of subcarrier loop correlators may be the same as the number of code loop correlators; as another option, the number of subcarrier loop correlators may be different from the number of code loop correlators. Those skilled in the art will appreciate that the number of subcarrier loop correlators and code loop correlators may be selected based on actual application scenarios or actual needs to achieve the various results and advantages described in the specification.

[0113] To ensure that the tracking of the code loop and subcarrier loop is unbiased, the basic relationship between the model parameters is as follows:

[0114]

[0115]

[0116] When the dual-loop structure achieves stable tracking, the phase detector outputs of both the code loop and the subcarrier loop are 0. The code phase and subcarrier phase at this point are the estimated code delay and subcarrier delay. The code delay estimated by the code loop is unbiased, while the subcarrier autocorrelation function is a periodic function with multiple peaks. Therefore, the subcarrier delay estimated by the subcarrier loop is biased. Furthermore, the subcarrier delay is more accurate than the code delay. By combining code delay and subcarrier delay, a highly accurate and unambiguous propagation delay can be obtained.

[0117] Because the multipath signal is obtained by attenuating and delaying the direct signal, and its code phase and subcarrier phase are strictly aligned, the code relative delay and subcarrier relative delay of the multipath signal are strictly equal. When considering the impact of the multipath signal on the code phase and subcarrier phase, due to the coupling effect of the code and subcarrier, the code phase multipath error and subcarrier phase multipath error will cause the subcarrier autocorrelation function and code autocorrelation function to lose their symmetry respectively. To this end, the two-dimensional autocorrelation function R(τ c ,τ s ), multipath relative delay τ m , multipath relative phase φ, multipath relative amplitude α and iteration number N, the two-dimensional multipath error is calculated based on the iterative method through the two-dimensional dual-loop phase detector model.

[0118] Therefore, the two-dimensional dual-loop phase detector model can be expressed as follows:

[0119]

[0120]

[0121] Where R is the two-dimensional autocorrelation function of the binary offset carrier signal; τ c is the code delay; τ s is the subcarrier delay; τ m is the multipath relative delay; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the relative amplitude of the multipath; N c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0122] The above formula is the formula for the two-dimensional dual-loop phase detector model when a single multipath signal is present, based on the formula for the code loop phase detector output model and the formula for the subcarrier loop phase detector output model. When multipath signals are present, the zero crossing points of the code loop phase detector and the subcarrier loop phase detector will shift, resulting in deviations in the code delay and subcarrier delay estimates. The shifted phase estimate here is the multipath error caused by the multipath signal and can be expressed as:

[0123]

[0124] in, are code delay multipath error and subcarrier delay multipath error respectively; τ c is the code delay; τ s is the subcarrier delay; τ m is the multipath relative delay; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the multipath relative amplitude; φ is the multipath relative phase.

[0125] Specifically, determining the multipath error according to the two-dimensional dual-loop phase detector model, wherein the multipath error includes the subcarrier multipath error and the code multipath error, may include: determining the phase detector outputs of the code loop and the subcarrier tracking loop according to the two-dimensional dual-loop phase detector model; and iteratively calculating the phase detector output through the F function to determine the multipath error, wherein the F function is used to find the zero-crossing point of the curve of the phase detector output closest to the origin.

[0126] In one embodiment of the present application, multipath error can be calculated according to the following steps: input calculation parameters, which include the two-dimensional autocorrelation function of the BOC signal, the multipath relative delay, the multipath relative phase, the multipath relative amplitude and the number of iterations; initialize the code multipath error and the subcarrier multipath error to obtain the initial value of the code multipath error and the initial value of the subcarrier multipath error; call the two-dimensional dual-loop phase detector model to calculate the phase detector output of the code and subcarrier tracking loop according to the calculation parameters; call the F function; iteratively calculate the code multipath error and the subcarrier multipath error according to the F function, the phase detector output of the code and subcarrier tracking loop, the initial value of the code multipath error, the initial value of the subcarrier multipath error and the number of iterations, thereby obtaining the multipath error, and thus obtaining a two-dimensional multipath optimization tracking device model.

[0127] In addition, during the calculation of the multipath error, when the multipath relative phase is 0° / 180°, the multipath error can reach a maximum. The multipath error curve at this time can be called a multipath error envelope.

[0128] Therefore, in one embodiment of the present application, the subcarrier loop correlator distance parameter, code loop correlator distance parameter, subcarrier loop phase detector weight parameter, and code loop phase detector weight parameter can be adjusted to minimize the average multipath error envelope area or minimize the roll-off multipath error, thereby suppressing the multipath error of the satellite navigation signal to be tracked. In other words, by optimizing the structural parameters related to the average multipath error envelope area or minimizing the roll-off multipath error, the provided dual-loop satellite navigation signal tracking device and satellite navigation signal tracking method have better anti-multipath performance.

[0129] Specifically, the multipath error envelope can be expressed as:

[0130] M ± (τ m |w c ,w s ,d c ,d s ,α).

[0131] The average multipath error envelope area is an important indicator for measuring multipath performance. In order to achieve better multipath suppression performance, the multipath error needs to be as small as possible.

[0132] Therefore, the two-dimensional multipath optimization tracking device model can be expressed as follows:

[0133]

[0134]

[0135]

[0136] Where V(·) is the multipath error; w c is the weight parameter of the code loop phase detector; w s is the weight parameter of the subcarrier loop phase detector; d c is the distance of the code loop correlator; d s is the distance of the subcarrier loop correlator; α is the relative amplitude of the multipath; N c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0137] From the above two-dimensional multipath optimization tracking device model, it can be determined that, in the case of multipath relative amplitude determination, the average multipath error envelope area is determined by the weight parameters of the code loop phase detector, the weight parameters of the subcarrier loop phase detector, the distances of the code loop correlators, and the distances of the subcarrier loop correlators. Therefore, by optimizing the structure parameters related to the average multipath error envelope area or minimizing the roll-off multipath error, the provided double-loop satellite navigation signal tracking device and satellite navigation signal tracking method have better anti-multipath performance.

[0138] In addition, the above-mentioned double-loop satellite navigation signal tracking device has multiple correlators, so that the relationship between its internal structures is generally very complex, and since multiple iterations are required when calculating the multipath error, it is difficult to solve and express the multipath error corresponding to the structure with an accurate mathematical expression.

[0139] In other words, according to the forming method of the double-loop satellite navigation signal tracking device provided by an embodiment of the present application, by optimizing the structure parameters related to the average multipath error envelope area or minimizing the roll-off multipath error, the provided double-loop satellite navigation signal tracking device and satellite navigation signal tracking method have better anti-multipath performance. Further, the subcarrier loop of the double-loop satellite navigation signal tracking device is determined according to the optimized weight parameters of the subcarrier loop phase detector, the distance parameters between the multiple subcarrier loop correlators, and the parameters of the satellite navigation signal to be tracked and the number of subcarrier loop correlators. The code loop of the double-loop satellite navigation signal tracking device is determined according to the optimized weight parameters of the code loop phase detector, the distance parameters between the multiple code loop correlators, and the parameters of the satellite navigation signal to be tracked and the number of code loop correlators.

[0140] In an embodiment of the present application, the optimization method based on the heuristic algorithm of swarm intelligence can also be used to obtain the optimized value of the structure parameter related to the multipath error, and solve the above technical problems of the existing related technical solutions.

[0141] Specifically, the heuristic algorithm can be called to optimize at least one of the weight parameters of the subcarrier loop phase detector, the weight parameters of the code loop phase detector, the distance parameters between the multiple subcarrier loop correlators, and the distance parameters between the multiple code loop correlators, to determine the subcarrier loop and the code loop.

[0142] As an option, the heuristic algorithm can include at least one or a combination of swarm intelligence optimization algorithm, ant colony algorithm, genetic algorithm, and differential evolution algorithm.

[0143] In addition, the subcarrier loop and the code loop can be determined by using the parameters of the satellite navigation signal to be tracked, the number of subcarrier loop correlators, the number of code loop correlators and the optimization algorithm parameters, and calling a heuristic algorithm to optimize at least one of the weight parameters of the subcarrier loop phase detector, the weight parameters of the code loop phase detector, the distance parameters between multiple subcarrier loop correlators and the distance parameters between multiple code loop correlators.

[0144] Furthermore, taking the differential evolution algorithm as an example of a heuristic algorithm, its optimization algorithm parameters may include population size, generation number, number of iterations, gene mutation probability, gene hybridization probability, etc. Furthermore, parameters of the satellite navigation signal to be tracked may include the order of the binary offset carrier signal, the signal unilateral bandwidth, and the relative multipath amplitude.

[0145] In one embodiment of the present application, the sine modulated BOC baseband signal can be recorded as BOC S (kn,n), where k represents the ratio of the subcarrier frequency to the pseudo-code rate; n represents the ratio of the pseudo-code rate to the GNSS reference clock f0 = 1.023MHz. The specific modulation method can be expressed as:

[0146]

[0147] Where t is the signal modulation time; c(t) is the pseudo-random code sequence signal; s(t) is the sinusoidal periodic pulse signal, also known as the subcarrier modulation signal; c n is a pseudo-random sequence with a value of ±1; p(t-nT C ) is the unit pulse signal; n is the ratio of the pseudo code rate to the GNSS reference clock f0; T c is the length of a chip; f s is the frequency of the subcarrier modulation signal; and sgn(x) is the sign function, when x≥0, sgn(x) takes the value of 1, when x<0, sgn(x) takes the value of 0.

[0148] According to the above formula, the two-dimensional autocorrelation function can be further obtained. Under the condition of infinite front-end filter bandwidth, the autocorrelation function of the binary offset carrier signal is calculated as:

[0149]

[0150] Among them, τ c is the code delay; τ s is the subcarrier delay; T c is the length of a chip; t is the signal modulation time; c(t) is the pseudo-random code sequence signal; s(t) is the sinusoidal periodic pulse signal; c(t-τ c ) is the pseudo-random code sequence signal obtained by subtracting the code delay from the signal modulation time; s(t-τs ) is the subcarrier modulation signal obtained by subtracting the subcarrier delay from the signal modulation time.

[0151] Based on the two-dimensional autocorrelation function under infinite front-end filter bandwidth, the two-dimensional autocorrelation function image of the BOC signal under infinite bandwidth can be obtained. In the specific implementation, the two-dimensional autocorrelation function image is distorted due to the coupling effect of the BOC signal. Although the coupling effect between the BOC signal code and subcarrier affects the estimation of code phase and subcarrier phase, the dual-loop tracking structure has good robustness and can ensure tracking stability.

[0152] Under the condition of limited front-end filtering broadband, the two-dimensional autocorrelation function of the BOC signal is calculated as:

[0153]

[0154] Among them, τ c is the code delay; τ s is the subcarrier delay; T c is the length of a chip; β r is the signal unilateral bandwidth; is the frequency domain characteristic function of the baseband signal when the code delay and subcarrier delay are equal; is the frequency domain characteristic function of the baseband signal when the subcarrier delay correlator subtracts the code delay; f is the frequency of the BOC signal; e is a natural constant; and j is an imaginary unit.

[0155] In specific implementations, the front-end filter bandwidth is always limited. Based on the two-dimensional autocorrelation function under limited front-end filter bandwidth conditions, a two-dimensional autocorrelation function image of the BOC signal under limited bandwidth can be further derived. Due to the coupling effect of the BOC signal, the two-dimensional autocorrelation function image under limited front-end filter bandwidth conditions is distorted, just like the image under infinite front-end filter bandwidth conditions. Due to the robustness of the two-dimensional tracking loop, the stability of the dual-loop tracking structure is guaranteed.

[0156] Under limited front-end filtering bandwidth, the frequency domain characteristic function of the baseband signal can be expressed as:

[0157]

[0158] Where t0 is the time parameter; f is the frequency of the BOC signal; T s is the subcarrier signal period; T c is the code signal period; e is a natural constant; and j is an imaginary unit.

[0159] When obtaining the optimized values ​​of the model parameters of the two-dimensional multipath optimization tracking device for multipath suppression, a heuristic algorithm can be used to optimize the parameters of the two-dimensional multipath optimization tracking device model. The heuristic algorithm can be understood as a swarm intelligence optimization algorithm, and specifically may include, for example, an ant colony algorithm, a genetic algorithm, and a differential evolution algorithm. This application is not limited to this. Those skilled in the art should understand that, without departing from the teachings of this application, different heuristic algorithms can be used according to actual circumstances to obtain the various results and advantages described in this specification.

[0160] The following optimization operations are performed using the differential evolution algorithm as an example. The differential evolution algorithm is a swarm intelligence optimization algorithm, a highly efficient global optimization algorithm based on a swarm-based heuristic. The differential evolution algorithm uses population reproduction to find the most surviving offspring. The offspring's fitness corresponds to the optimal objective function value, and the offspring's genes correspond to the optimal parameters. The differential evolution algorithm serializes genes, resolving the Hamming cliff problem introduced by discrete gene encoding in genetic algorithms. Furthermore, the introduction of the "difference" operation enhances the differential genetic algorithm's global search capabilities, making it less susceptible to local optima.

[0161] In a specific implementation process, when calculating the optimized values ​​of the model parameters of the two-dimensional multipath optimization tracking device, it is necessary to determine the input parameters, which include BOC signal parameters, the number of correlators, and optimization algorithm parameters.

[0162] BOC signal parameters may include the order k of the BOC signal, the signal unilateral bandwidth β r and the multipath relative amplitude α. The number of correlators may include the number N of code loop correlators in the dual-loop tracking structure. c and the number of subcarrier loop correlators N s .

[0163] Table 1 shows the input parameters for calculating the model parameters of the two-dimensional multipath optimization tracking device according to one embodiment of the present application. As an alternative, the optimization algorithm parameters can be the parameters of the differential evolution algorithm, and thus can be directly determined by the following Table 1:

[0164]

[0165]

[0166] Table 1

[0167] According to the known input parameters, the two-dimensional autocorrelation function of the BOC signal is calculated, and the weight parameter w of the code loop phase detector in the two-dimensional dual-loop phase detector model structure parameters is initialized. c , weight parameter w of the subcarrier loop phase detector s , the distance d between the code loop correlators cThe distance d of the sub-carrier loop correlator s .

[0168] By the above known quantities, the differential evolution algorithm is called to iteratively calculate G times, and when the target values of the above parameters converge (i.e. remain unchanged), the iteration is stopped, and the optimized values of the weight parameters of the code loop phase detector, the optimized values of the weight parameters of the sub-carrier loop phase detector, the optimized value of the distance of the code loop correlator, and the optimized value of the distance of the sub-carrier loop correlator are obtained.

[0169] Specifically, as one option, in an embodiment of the present application, in one overall iteration, the differential evolution algorithm can be used to first optimize the code correlator weight parameters and the sub-carrier correlator weight parameters to obtain the local code correlator weight parameter optimized value and the local sub-carrier correlator weight parameter optimized value, and the distance parameters of the code loop correlator and the distance parameters of the sub-carrier loop correlator remain unchanged in the above optimization process. Then, the differential evolution algorithm is used to continue to optimize the distance parameters of the code loop correlator and the distance parameters of the sub-carrier loop correlator, and the weight parameters of the code loop phase detector and the weight parameters of the sub-carrier loop phase detector used in this optimization process can be the local optimized values obtained in the last optimization process (which can be understood as the local code correlator weight parameter optimized value and the local sub-carrier correlator weight parameter optimized value). After several overall iterations of the above algorithm, the optimized value of the distance parameter of the code loop correlator, the optimized value of the distance parameter of the sub-carrier loop correlator, the optimized value of the weight parameter of the code loop phase detector, and the optimized value of the weight parameter of the sub-carrier loop phase detector can be finally obtained.

[0170] Further, the sub-carrier loop of the double-loop satellite navigation signal tracking device is determined according to the optimized weight parameters of the sub-carrier loop phase detector, the distance parameters between the plurality of sub-carrier loop correlators, and the parameters of the satellite navigation signal to be tracked and the number of sub-carrier loop correlators. The code loop of the double-loop satellite navigation signal tracking device is determined according to the optimized weight parameters of the code loop phase detector, the distance parameters between the plurality of code loop correlators, and the parameters of the satellite navigation signal to be tracked and the number of code loop correlators.

[0171] In other words, from the above two-dimensional multipath optimization tracking device model, it can be determined that, in the case of determining the relative amplitude of the multipath, the average multipath error envelope area is determined by the weight parameters of the code loop phase detector, the weight parameters of the sub-carrier loop phase detector, the distance of the code loop correlator, and the distance of the sub-carrier loop correlator. Therefore, by optimizing the structure parameters related to the average multipath error envelope area or minimizing the roll-off multipath error, the double-loop satellite navigation signal tracking device and the satellite navigation signal tracking method provided have better anti-multipath performance.

[0172] In addition, since the dual-loop satellite navigation signal tracking device has multiple correlators, the relationship between its internal structures is usually very complex. Furthermore, since multiple iterations are required to calculate the multipath error, it is difficult to use an accurate mathematical expression to solve and express the multipath error corresponding to the structure.

[0173] Therefore, according to the method for forming a dual-loop satellite navigation signal tracking device provided in one embodiment of the present application, the subcarrier loop of the dual-loop satellite navigation signal tracking device can be determined based on the optimized weight parameters of the subcarrier loop phase detector, the distance parameters between the multiple subcarrier loop correlators, the parameters of the satellite navigation signal to be tracked, and the number of subcarrier loop correlators. The code loop of the dual-loop satellite navigation signal tracking device can also be determined based on the optimized weight parameters of the code loop phase detector, the distance parameters between the multiple code loop correlators, the parameters of the satellite navigation signal to be tracked, and the number of code loop correlators. This effectively reduces the multipath error of the multi-correlator dual-loop satellite navigation signal tracking device.

[0174] Reference again Figure 2 and Figure 3 On the other hand, the present application further provides a dual-loop satellite navigation signal tracking device 2000. The dual-loop satellite navigation signal tracking device 2000 can be formed by the method provided in any of the above embodiments.

[0175] Specifically, the dual-loop satellite navigation signal tracking device 2000 may include an acquisition module 2400, a subcarrier loop 2100, and a code loop 2200. Acquisition module 2400 may be configured to acquire a baseband satellite signal and a non-delayed local subcarrier, a non-delayed local code, multiple delayed local subcarriers, and multiple delayed local codes for the baseband satellite signal. Subcarrier loop 2100 includes a subcarrier loop phase detector 2120 and multiple subcarrier loop correlators 2110. Subcarrier loop 2100 is configured to perform correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local subcarrier to obtain a first correlation value, and to weightedly combine the multiple first correlation values ​​to obtain a subcarrier multipath error. Code loop 2200 includes a code loop phase detector 2220 and multiple code loop correlators 2210. Code loop 2200 is configured to correlate the baseband satellite signal, the undelayed local subcarrier, and the delayed local code to obtain a second correlation value, and to weightedly combine the multiple second correlation values ​​to obtain a code multipath error. At least one of the distance parameters between the multiple subcarrier loop correlators 2110, the distance parameters between the multiple code loop correlators 2210, the weight parameters of the subcarrier loop phase detector 2120, and the weight parameters of the code loop phase detector 2220 is used to suppress subcarrier multipath error and code multipath error.

[0176] The double-loop satellite navigation signal tracking device according to at least one embodiment of the present application can effectively suppress the multipath effects including the subcarrier multipath error and the code multipath error, and improve the accuracy of satellite navigation signal tracking.

[0177] Specifically, the BOC signal can be obtained by directly multiplying the direct spread spectrum sequence (DSSS) signal and the square wave subcarrier signal, and thus the two-dimensional tracking technology needs two loops (e.g., the subcarrier loop 2100 and the code loop 2200) to track the code and the subcarrier respectively, so as to estimate the code delay and the subcarrier delay.

[0178] In an embodiment of the present application, the double-loop satellite navigation signal tracking device 2000 can further include an acquisition module 2300. The acquisition module 2300 is configured to acquire a satellite binary offset carrier (BOC) signal to obtain the satellite number, the carrier frequency and the code phase of the signal. Specifically, the acquisition module 2300 is configured to strip the carrier of the acquired satellite signal according to the carrier frequency of the acquired satellite signal to obtain a baseband satellite signal g(t), and to generate a local prompt code and a plurality of local late codes using a code digital control oscillator according to the satellite number and the code phase of the acquired satellite signal, and to generate a local prompt subcarrier and a plurality of local late subcarriers using a subcarrier digital control oscillator.

[0179] In at least one embodiment of the present application, the plurality of local late subcarriers can include a plurality of different phase-advanced or phase-lagged local subcarriers. The plurality of local late codes can include a plurality of different phase-advanced or phase-lagged local codes.

[0180] Further, in at least one embodiment of the present application,

[0181] The i-th local late code can be expressed as

[0182] The i-th local late subcarrier can be expressed as

[0183] wherein, is the distance parameter optimization value of the i-th code loop correlator; is the distance parameter optimization value of the i-th subcarrier loop correlator; N c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0184] As Figure 2As shown, after the baseband satellite signal g(t) enters the subcarrier loop 2100 and the code loop 2200, a subcarrier loop correlator 2110 performs correlation processing with the undelayed local code and the delayed local subcarrier in the subcarrier loop 2100 to obtain a first correlation value. A subcarrier loop phase detector 2120 then weights and combines multiple first correlation values ​​to obtain a subcarrier multipath error. In the code loop 2200, a code loop correlator 2210 performs correlation processing with the undelayed local subcarrier and the delayed local code to obtain a second correlation value. A code loop phase detector 2220 then weights and combines multiple second correlation values ​​to obtain a code multipath error.

[0185] In at least one embodiment of the present application, in order to improve the satellite ranging accuracy of the dual-loop satellite navigation signal tracking device and the tracking method thereof, no fewer than four subcarrier loop correlators 2110 and code loop correlators 2210 may be provided in the dual-loop satellite navigation signal tracking device.

[0186] Therefore, as an option, the number of subcarrier loop correlators N S It can be any positive even number greater than or equal to 4. In addition, the number of code loop correlators N C It may also be any positive even number greater than or equal to 4. The dual-loop satellite navigation signal tracking device having multiple subcarrier loop correlators and code loop correlators may also be referred to as a multi-correlator dual-loop satellite navigation signal tracking device.

[0187] Optionally, the number of delayed local subcarriers is the same as the number of subcarrier loop correlators; the number of delayed local codes is the same as the number of code loop correlators.

[0188] In addition, the present application can effectively reduce the multipath error of the above-mentioned multi-correlator dual-loop satellite navigation signal tracking device by separately obtaining the multipath error components related to the subcarrier loop and code loop in the dual-loop satellite navigation signal tracking device, and correcting the subcarrier loop and code loop respectively through the above-mentioned multipath error components.

[0189] Furthermore, as an option, the number of subcarrier loop correlators may be the same as the number of code loop correlators; as another option, the number of subcarrier loop correlators may be different from the number of code loop correlators. Those skilled in the art will appreciate that the number of subcarrier loop correlators and code loop correlators may be selected based on actual application scenarios or actual needs to achieve the various results and advantages described in the specification.

[0190] like Figure 2As shown, after the baseband satellite signal g(t) enters the subcarrier loop 2100 and the code loop 2200, in the subcarrier loop 2100, the baseband satellite signal g(t) is first multiplied by a non-delayed local code to obtain a first to-be-used signal, and then the first to-be-used signal is multiplied by a plurality of delayed local subcarriers and integrated to obtain a first correlation value, which is used to obtain a subcarrier multipath error. In the code loop 2200, the baseband satellite signal g(t) is first multiplied by a non-delayed local subcarrier to strip off the subcarrier to obtain a second to-be-used signal, and then the second to-be-used signal is multiplied by a plurality of delayed local codes and integrated to obtain a second correlation value, which is used to obtain a code multipath error.

[0191] The plurality of delayed local subcarriers have an advanced or delayed phase compared with the non-delayed local subcarrier. The phase distance between the delayed local subcarrier and the non-delayed local subcarrier is defined as a distance parameter between the subcarrier loop correlators. Similarly, the plurality of delayed local codes have an advanced or delayed phase compared with the non-delayed local code. The phase distance between the delayed local code and the non-delayed local code is defined as a distance parameter between the code loop correlators.

[0192] In other words, the distance parameter between the subcarrier loop correlators is the phase distance between the delayed local subcarriers. The distance parameter between the code loop correlators is the phase distance between the delayed local codes.

[0193] Further, in at least one embodiment of the present application, the first correlation value and the second correlation value can be represented as:

[0194]

[0195]

[0196] wherein, is the ith first correlation value; is the ith second correlation value; T is an integration time; and g(t) is a baseband satellite signal. is an optimized value of the distance parameter of the ith code loop correlator; is an optimized value of the distance parameter of the ith subcarrier loop correlator; N c is a number of code loop correlators; and N s is a number of subcarrier loop correlators.

[0197] Furthermore, during a specific implementation, the phase detectors of the dual-loop satellite navigation signal tracking device 2000 (e.g., the subcarrier loop phase detector 2120 and the code loop phase detector 2220) can be divided into incoherent phase detectors and coherent phase detectors. When carrier tracking is relatively stable, a coherent phase detector has better thermal noise performance than an incoherent phase detector, and the coherent phase detector has lower structural complexity and a smaller computational burden. Therefore, to fully utilize the coherent phase detector's better thermal noise performance and lower computational complexity, the dual-loop satellite navigation signal tracking device 2000 can adopt a coherent phase detector mode. During a specific implementation, the receiver can first use an incoherent phase detector and then switch to a coherent phase detector when the entire tracking loop is stable.

[0198] In one embodiment of the present application, the subcarrier loop phase detector 2120 is configured to apply a corresponding subcarrier loop phase detector weight parameter to each first correlation value, and to merge multiple first correlation values ​​after applying the corresponding subcarrier loop phase detector weight parameter to obtain a subcarrier multipath error; the code loop phase detector 2220 is configured to apply a corresponding code loop phase detector weight parameter to each second correlation value, and to merge multiple second correlation values ​​after applying the corresponding code loop phase detector weight parameter to obtain a code multipath error.

[0199] Furthermore, in at least one embodiment of the present application, the subcarrier multipath error and the code multipath error can be respectively expressed as:

[0200]

[0201]

[0202] in, is the i-th first correlation value; is the i-th second correlation value; E s is the subcarrier multipath error; E c is the code multipath error; is the optimized value of the weight parameter of the i-th code loop phase detector; and is the optimized value of the weight parameter of the loop phase detector of the i-th subcarrier.

[0203] In one embodiment of the present application, the dual-loop satellite navigation signal tracking device 2000 may further include a subcarrier loop filter and a code loop filter. The subcarrier loop filter is located in the subcarrier loop and is configured to process subcarrier multipath errors to obtain subcarrier loop correction values. The code loop filter is located in the code loop and is configured to process code multipath errors to obtain code loop correction values.

[0204] Specifically, if Figure 3As shown, as an option, the dual-loop satellite navigation signal tracking device 2000 may also include a correction module 2500, which is configured to adjust the subcarrier digital controlled oscillator according to the subcarrier loop correction value to correct the subcarrier delay estimate; and adjust the code digital controlled oscillator according to the code loop correction value to correct the code delay estimate.

[0205] Therefore, the dual-loop satellite navigation signal tracking device provided according to at least one embodiment of the present application can provide no less than four subcarrier loop correlators and code loop correlators respectively (which can be understood as a multi-correlator dual-loop satellite navigation signal tracking device), thereby improving the satellite ranging accuracy of the dual-loop satellite navigation signal tracking device and its tracking method.

[0206] Furthermore, by separately obtaining the multipath error components related to the subcarrier loop and the code loop in the dual-loop satellite navigation signal tracking device, and correcting the subcarrier loop and the code loop respectively by using the multipath error components, the multipath error of the multi-correlator dual-loop satellite navigation signal tracking device can be effectively reduced.

[0207] Furthermore, in one embodiment of the present application, by optimizing the structural parameters of the dual-loop satellite navigation signal tracking device 2000 related to the average multipath error envelope area or minimizing the roll-off multipath error, the provided dual-loop satellite navigation signal tracking device and satellite navigation signal tracking method can have better anti-multipath performance.

[0208] Specifically, the structural parameters may include at least one of a distance parameter between subcarrier loop correlators, a distance parameter between code loop correlators, a weight parameter of a subcarrier loop phase detector, and a weight parameter of a code loop phase detector. In other words, at least one of the distance parameter between subcarrier loop correlators, the distance parameter between code loop correlators, the weight parameter of a subcarrier loop phase detector, and the weight parameter of a code loop phase detector is used to minimize the average multipath error envelope area or minimize the roll-off multipath error, thereby suppressing the subcarrier multipath error and code multipath error.

[0209] In addition, because the above-mentioned dual-loop satellite navigation signal tracking device 2000 has multiple correlators (for example, the subcarrier loop correlator 2110 and the code loop correlator 2210), the relationship between its internal structures is usually very complex, and since multiple iterations are required when calculating the multipath error, it is difficult to solve and express the multipath error corresponding to the above-mentioned structure using an accurate mathematical expression.

[0210] Therefore, in one embodiment of the present application, an optimization method based on a heuristic algorithm of swarm intelligence may be used to obtain optimized values ​​of structural parameters related to multipath errors, thereby solving the above-mentioned technical problems of the existing related technical solutions.

[0211] In particular, the heuristic algorithm can be invoked to optimize at least one of the weight parameters of the sub-carrier loop phase detectors, the weight parameters of the code loop phase detectors, the distance parameters among the plurality of sub-carrier loop correlators, and the distance parameters among the plurality of code loop correlators to determine the sub-carrier loop and the code loop.

[0212] As an option, the heuristic algorithm can include at least one or a combination of swarm intelligence optimization algorithm, ant colony algorithm, genetic algorithm, and differential evolution algorithm.

[0213] Further, the sub-carrier loop and the code loop can be determined by parameters of a satellite navigation signal to be tracked, a number of sub-carrier loop correlators, a number of code loop correlators, and optimization algorithm parameters, and invoking the heuristic algorithm to optimize at least one of the weight parameters of the sub-carrier loop phase detectors, the weight parameters of the code loop phase detectors, the distance parameters among the plurality of sub-carrier loop correlators, and the distance parameters among the plurality of code loop correlators.

[0214] Further, the optimization algorithm parameters can include a population number, a generation number, an iteration number, a gene mutation probability, and a gene crossover probability. In addition, the parameters of the satellite navigation signal to be tracked can include an order of a binary offset carrier signal of the satellite navigation signal to be tracked, a signal single sideband width, and a multipath relative amplitude.

[0215] Figure 4 is a schematic diagram of steps of a satellite navigation signal tracking method 3000 according to an embodiment of the present application. As shown in Figure 4 The satellite navigation signal tracking method 3000 can employ the double-loop satellite navigation signal tracking device 2000 provided by any of the above embodiments.

[0216] The satellite navigation signal tracking method 3000 can include:

[0217] S31, performing carrier separation on the captured satellite navigation signal to obtain a baseband satellite signal.

[0218] S32, generating a non-delayed local sub-carrier, a non-delayed local code, a plurality of delayed local sub-carriers, and a plurality of delayed local codes for the baseband satellite signal.

[0219] S33, performing correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local sub-carrier to obtain a first correlation value, and performing correlation processing on the baseband satellite signal, the non-delayed local sub-carrier, and the delayed local code to obtain a second correlation value.

[0220] S34, weightedly combining multiple first correlation values ​​to obtain a subcarrier multipath error, and weightedly combining multiple second correlation values ​​to obtain a code multipath error, wherein at least one of the phase distance between delayed local subcarriers, the phase distance between delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value is adjusted to suppress the multipath error of the captured satellite navigation signal, wherein the multipath error includes a subcarrier multipath error and a code multipath error.

[0221] Since the contents and structures involved in the above description of the formation method 1000 of the dual-loop satellite navigation signal tracking device and the dual-loop satellite navigation signal tracking device 2000 can be fully or partially applied to the quantum imaging system described here, the related or similar contents will not be repeated.

[0222] Specifically, in one embodiment of the present application, the multiple delayed local subcarriers include multiple different phase-advanced or phase-delayed local subcarriers, and the multiple delayed local codes include multiple different phase-advanced or phase-delayed local codes.

[0223] Furthermore, in order to improve the satellite ranging accuracy of the satellite navigation signal tracking method, no fewer than four subcarrier loop correlators and code loop correlators may be provided in the dual-loop satellite navigation signal tracking device.

[0224] Therefore, as an option, the number of subcarrier loop correlators N S It can be any positive even number greater than or equal to 4. In addition, the number of code loop correlators N C It can also be any positive even number greater than or equal to 4.

[0225] Optionally, the number of delayed local subcarriers is the same as the number of subcarrier loop correlators; the number of delayed local codes is the same as the number of code loop correlators.

[0226] Furthermore, the relationship between the structures of the above-mentioned multi-correlator dual-loop satellite navigation signal tracking device is usually very complex, and therefore multiple iterations are required when calculating the multipath error. The satellite navigation signal tracking method provided in accordance with at least one embodiment of the present application can effectively reduce the multipath error by separately obtaining the multipath error components related to the subcarrier loop and the code loop in the dual-loop satellite navigation signal tracking device, and correcting the subcarrier loop and the code loop respectively using the above-mentioned multipath error components.

[0227] In addition, in one embodiment of the present application, step S31 of performing carrier separation on the captured satellite navigation signal to obtain a baseband satellite signal may include: capturing a satellite binary offset carrier signal to obtain the satellite number, carrier frequency, and code phase of the binary offset carrier signal; and stripping the carrier of the above signal according to the carrier frequency of the binary offset carrier signal to obtain the baseband satellite signal.

[0228] Optionally, step S32 of generating a non-delayed local subcarrier, a non-delayed local code, a plurality of delayed local subcarriers, and a plurality of delayed local codes for a baseband satellite signal can be expressed as follows:

[0229] The i-th delayed local code

[0230] The i-th delayed local subcarrier

[0231] in, Optimize the distance parameter value of the i-th code loop correlator; N is the parameter optimization value of the loop correlator distance of the i-th subcarrier; c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0232] In addition, in one embodiment of the present application, step S33 may include performing correlation processing on the baseband satellite signal, the undelayed local code, and the delayed local subcarrier to obtain a first correlation value, which may include: multiplying the baseband satellite signal and the undelayed local code to obtain a first standby signal; and multiplying the first standby signal and the delayed local subcarrier and integrating the result to obtain the first correlation value.

[0233] Accordingly, step S33 may include performing correlation processing on the baseband satellite signal, the undelayed local subcarrier, and the delayed local code to obtain a second correlation value, which may include: multiplying the baseband satellite signal and the undelayed local subcarrier to obtain a second standby signal; and multiplying and integrating the second standby signal and the delayed local code to obtain a second correlation value.

[0234] Optionally, in one embodiment of the present application, the first correlation value and the second correlation value may be expressed as:

[0235]

[0236]

[0237] in, is the i-th first correlation value; is the i-th second correlation value; T is the integration time; g(t) is the baseband satellite signal; Optimize the distance parameter value of the i-th code loop correlator; is the optimized value of the distance parameter of the i-th subcarrier loop correlator; N c is the number of code loop correlators; and N s is the number of subcarrier loop correlators.

[0238] In addition, in one embodiment of the present application, the weighted combination of multiple first correlation values ​​to obtain subcarrier multipath error and the weighted combination of multiple second correlation values ​​to obtain code multipath error in step S34 may include: applying a corresponding first correlation value weighting value to each first correlation value, and combining multiple first correlation values ​​after applying the corresponding first correlation value weighting value to obtain the subcarrier multipath error; applying a corresponding second correlation value weighting value to each second correlation value, and combining multiple second correlation values ​​after applying the corresponding second correlation value weighting value to obtain the code multipath error.

[0239] Specifically, a heuristic algorithm can be invoked to optimize at least one of the phase distance between delayed local subcarriers, the phase distance between delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value to suppress subcarrier multipath error and code multipath error in captured satellite navigation signals. By employing an optimization method based on a swarm intelligence heuristic algorithm, optimized values ​​for structural parameters related to multipath error can be obtained, thereby resolving the technical issue in existing related art solutions where it is difficult to accurately express the multipath error corresponding to the aforementioned structure using mathematical expressions.

[0240] As an option, the heuristic algorithm may include at least one or a combination of a swarm intelligence optimization algorithm, an ant colony algorithm, a genetic algorithm, and a differential evolution algorithm, which is not limited in this application.

[0241] Furthermore, by adjusting at least one of the phase distance between delayed local subcarriers, the phase distance between delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value, the average multipath error envelope area or the roll-off multipath error can be minimized, thereby suppressing the multipath error of the satellite navigation signal to be tracked. In other words, by optimizing structural parameters related to the average multipath error envelope area or the roll-off multipath error minimization, the satellite navigation signal tracking method can achieve better anti-multipath performance.

[0242] Optionally, in one embodiment of the present application, the subcarrier multipath error and the code multipath error may be expressed as:

[0243]

[0244]

[0245] in, is the i-th first correlation value; is the i-th second correlation value; E s is the subcarrier multipath error; E c is the code multipath error; is the optimized value of the weight parameter of the i-th code loop phase detector; and An optimized value of a weight parameter of the i-th subcarrier loop phase discriminator.

[0246] In addition, the satellite navigation signal tracking method 3000 further comprises: processing the subcarrier multipath error to obtain a subcarrier loop correction value, and correcting the subcarrier delay estimation value according to the subcarrier loop correction value; and processing the code multipath error to obtain a code loop correction value, and correcting the code delay estimation value according to the code loop correction value.

[0247] Therefore, the satellite navigation signal tracking method according to the above-mentioned at least one embodiment of the present application can effectively suppress the multipath influence including the subcarrier multipath error and the code multipath error, and improve the precision of satellite navigation signal tracking.

[0248] The above description is merely preferred implementation of the present application and the explanation of the technical principles applied. It should be understood by those skilled in the art that the protection scope of the present application is not limited to the technical solutions formed by the specific combinations of the technical features described above, and should also cover other technical solutions formed by any combinations of the technical features described above or their equivalent features without departing from the technical concept. For example, the technical solutions formed by the mutual replacement of the above-mentioned features and the technical features disclosed in the present application (but not limited to) having similar functions.

Claims

1. A method for forming a dual-loop satellite navigation signal tracking device, wherein the dual-loop satellite navigation signal tracking device includes a subcarrier loop and a code loop, characterized in that: The method comprises: The subcarrier loop is determined based on parameters of a satellite navigation signal to be tracked, weight parameters of a subcarrier loop phase detector, the number of subcarrier loop correlators, and distance parameters between a plurality of the subcarrier loop correlators, including: correlating a baseband satellite signal, a non-delayed local code, and a delayed local subcarrier to obtain a first correlation value; and weightedly combining a plurality of the first correlation values ​​to obtain a subcarrier multipath error; and The code loop is determined by using parameters of the satellite navigation signal to be tracked, weight parameters of a code loop phase detector, the number of code loop correlators, and distance parameters between multiple code loop correlators, including: correlating a baseband satellite signal, an undelayed local subcarrier, and a delayed local code to obtain a second correlation value; and weightedly combining multiple second correlation values ​​to obtain a code multipath error. The method further includes adjusting at least one of a phase distance between the delayed local subcarriers, a phase distance between the delayed local codes, a weighted value of the first correlation value, and a weighted value of the second correlation value to suppress a multipath error of a captured satellite navigation signal, wherein the multipath error includes a subcarrier multipath error and a code multipath error.

2. The method according to claim 1, characterized in that The number of subcarrier loop correlators is any positive even number greater than or equal to 4.

3. The method according to claim 1, characterized in that The number of code loop correlators is any positive even number greater than or equal to 4.

4. The method according to claim 1, wherein The number of the subcarrier loop correlators is the same as the number of the code loop correlators.

5. The method according to claim 1, wherein The number of the subcarrier loop correlators is different from the number of the code loop correlators.

6. The method according to claim 1, characterized in that The parameters of the satellite navigation signal to be tracked include the order of the binary offset carrier signal, the signal unilateral bandwidth and the multipath relative amplitude.

7. The method according to any one of claims 1 to 6, characterized in that A heuristic algorithm is called to optimize at least one of a weight parameter of the subcarrier loop phase detector, a weight parameter of the code loop phase detector, a distance parameter between a plurality of the subcarrier loop correlators, and a distance parameter between a plurality of the code loop correlators to determine the subcarrier loop and the code loop.

8. The method according to claim 7, characterized in that The heuristic algorithm includes at least one or a combination of a swarm intelligence optimization algorithm, an ant colony algorithm, a genetic algorithm, and a differential evolution algorithm.

9. The method according to claim 7, characterized in that The method further comprises: The subcarrier loop and the code loop are determined by using the parameters of the satellite navigation signal to be tracked, the number of the subcarrier loop correlators, the number of the code loop correlators, and optimization algorithm parameters, and calling a heuristic algorithm to optimize at least one of the weight parameters of the subcarrier loop phase detector, the weight parameter of the code loop phase detector, the distance parameters between multiple subcarrier loop correlators, and the distance parameters between multiple code loop correlators.

10. The method according to any one of claims 1 to 6, characterized in that Adjusting the subcarrier loop correlator distance parameter, the code loop correlator distance parameter, the subcarrier loop phase detector weight parameter, and the code loop phase detector weight parameter to minimize the average multipath error envelope area or minimize the roll-off multipath error, thereby suppressing the multipath error of the satellite navigation signal to be tracked.

11. The method according to claim 10, characterized in that The method further comprises: A two-dimensional multipath optimization tracking device model including the subcarrier loop and the code loop is established.

12. The method according to claim 11, characterized in that The two-dimensional multipath optimization tracking device model includes: in, is the multipath error; is the weight parameter of the code loop phase detector; is the weight parameter of the subcarrier loop phase detector; is the distance of the code loop correlator; is the distance of the subcarrier loop correlator; is the relative amplitude of multipath; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

13. The method according to claim 11, characterized in that Establishing the two-dimensional multipath optimization tracking device model includes: Establishing a two-dimensional dual-loop phase detector model, wherein the two-dimensional dual-loop phase detector model includes a subcarrier loop phase detector model and a code loop phase detector model; Determining a multipath error according to the two-dimensional dual-loop phase detector model, wherein the multipath error includes a subcarrier multipath error and a code multipath error; and Based on the two-dimensional dual-loop phase detector model and the multipath error, the two-dimensional multipath optimization tracking device model is established.

14. The method according to claim 13, wherein: The two-dimensional dual-loop phase detector model includes: in, is the two-dimensional autocorrelation function of the binary offset carrier signal; is the code delay; is the subcarrier delay; is the multipath relative delay; is the weight parameter of the code loop phase detector; is the weight parameter of the subcarrier loop phase detector; is the distance of the code loop correlator; is the distance of the subcarrier loop correlator; is the relative amplitude of multipath; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

15. The method according to claim 13, wherein The method further comprises: Determining phase detector outputs of the code loop and the subcarrier tracking loop according to the two-dimensional dual-loop phase detector model; and pass F The function iteratively calculates the phase detector output to determine the multipath error. Among them, the F The function is used to find the zero-crossing point of the curve output by the phase detector that is closest to the origin.

16. A dual-loop satellite navigation signal tracking device, characterized in that: include: an acquisition module configured to acquire a non-delayed local subcarrier, a non-delayed local code, a plurality of delayed local subcarriers, and a plurality of delayed local codes for a baseband satellite signal; a subcarrier loop, comprising a subcarrier loop phase detector and a plurality of subcarrier loop correlators, wherein the subcarrier loop is configured to perform correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local subcarrier to obtain a first correlation value, and to weightedly combine a plurality of the first correlation values ​​to obtain a subcarrier multipath error; as well as a code loop comprising a code loop phase detector and a plurality of code loop correlators, wherein the code loop is configured to perform correlation processing on the baseband satellite signal, the undelayed local subcarrier, and the delayed local code to obtain a second correlation value, and to weightedly combine a plurality of the second correlation values ​​to obtain a code multipath error. At least one of the distance parameter between the subcarrier loop correlators, the distance parameter between the code loop correlators, the weight parameter of the subcarrier loop phase detector, and the weight parameter of the code loop phase detector is used to suppress the subcarrier multipath error and the code multipath error.

17. The device according to claim 16, characterized in that The number of subcarrier loop correlators is any positive even number greater than or equal to 4.

18. The device according to claim 16, characterized in that The number of code loop correlators is any positive even number greater than or equal to 4.

19. The device according to claim 16, wherein The number of the delayed local subcarriers is the same as the number of the subcarrier loop correlators; and The number of the delayed local codes is the same as the number of the code loop correlators.

20. The device according to claim 16, wherein The plurality of delayed local subcarriers include a plurality of different phase-advanced or phase-delayed local subcarriers, wherein the distance parameter between the subcarrier loop correlators is the phase distance between the delayed local subcarriers; and The multiple delayed local codes include multiple different phase-advanced or phase-delayed local codes, wherein the distance parameter between the code loop correlators is the phase distance between the delayed local codes.

21. The device according to claim 16, wherein The subcarrier loop phase detector is configured to apply a corresponding weight parameter of the subcarrier loop phase detector to each first correlation value, and combine a plurality of first correlation values ​​after applying the corresponding weight parameter of the subcarrier loop phase detector to obtain the subcarrier multipath error; as well as The code loop phase detector is configured to apply a corresponding weight parameter of the code loop phase detector to each second correlation value, and to combine multiple second correlation values ​​to which the corresponding weight parameters of the code loop phase detector are applied, so as to obtain the code multipath error.

22. The device according to any one of claims 16 to 21, characterized in that At least one of the distance parameter between the subcarrier loop correlators, the distance parameter between the code loop correlators, the weight parameter of the subcarrier loop phase detector, and the weight parameter of the code loop phase detector is used to minimize the average multipath error envelope area or minimize the roll-off of the multipath error to suppress the multipath error.

23. The device according to any one of claims 16 to 21, characterized in that The apparatus is further configured to call a heuristic algorithm to optimize at least one of the distance parameter between the subcarrier loop correlators, the distance parameter between the code loop correlators, the weight parameter of the subcarrier loop phase detector, and the weight parameter of the code loop phase detector.

24. The device according to any one of claims 16 to 21, characterized in that The subcarrier loop is further configured to multiply the baseband satellite signal and the undelayed local code to obtain a first inactive signal, wherein the subcarrier loop correlator is configured to multiply and integrate the first inactive signal and the delayed local subcarrier to obtain the first correlation value; and The code loop is further configured to multiply the baseband satellite signal and the undelayed local subcarrier to obtain a second inactive signal, wherein the code loop correlator is configured to multiply and integrate the second inactive signal and the delayed local code to obtain a second correlation value.

25. The device according to any one of claims 16 to 21, characterized in that The apparatus further includes an acquisition module configured to acquire a binary offset carrier signal to obtain a satellite number, a carrier frequency, and a code phase of the signal.

26. The device according to claim 25, wherein The acquisition module is further configured to strip the carrier of the signal according to the carrier frequency of the signal to obtain the baseband satellite signal; and According to the satellite number and code phase of the signal, a code digitally controlled oscillator is used to generate the zero-delay local code and the multiple delayed local codes, and a subcarrier digitally controlled oscillator is used to generate the zero-delay local subcarrier and the multiple delayed local subcarriers.

27. The device according to claim 26, wherein No. i Delayed local code No. i Delayed local subcarrier in, For the i Optimized value of distance parameter of each code loop correlator; For the i Optimized parameter value of the subcarrier loop correlator distance; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

28. The device according to any one of claims 16 to 21, characterized in that in, For the i First correlation values; For the i Second correlation value; T is the integration time; is the baseband satellite signal; For the i Optimized value of distance parameter of each code loop correlator; For the i Optimized value of distance parameter of each subcarrier loop correlator; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

29. The device according to claim 28, characterized in that in, For the said i First correlation values; For the said i Second correlation value; is the subcarrier multipath error; is the code multipath error; For the i Optimized values ​​of weight parameters of the code loop phase detector; and For the i The optimized values ​​of the weight parameters of the subcarrier loop phase detector.

30. The device according to any one of claims 16 to 21, characterized in that The subcarrier loop further includes a subcarrier loop filter configured to process the subcarrier multipath error to obtain a subcarrier loop correction value; and The code loop further includes a code loop filter configured to process the code multipath error to obtain a code loop correction value.

31. The device according to any one of claims 16 to 21, characterized in that The apparatus further includes a correction module, wherein the correction module is configured to: Adjusting the subcarrier digital controlled oscillator according to the subcarrier loop correction value to correct the subcarrier delay estimate; and According to the code loop correction value, the code digital controlled oscillator is adjusted to correct the code delay estimation value.

32. A satellite navigation signal tracking method, characterized in that: include: Carrier separation is performed on the captured satellite navigation signal to obtain the baseband satellite signal; generating an undelayed local subcarrier, an undelayed local code, a plurality of delayed local subcarriers, and a plurality of delayed local codes for the baseband satellite signal; performing correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local subcarrier to obtain a first correlation value, and performing correlation processing on the baseband satellite signal, the non-delayed local subcarrier, and the delayed local code to obtain a second correlation value; as well as weightedly combining a plurality of the first correlation values ​​to obtain a subcarrier multipath error, and weightedly combining a plurality of the second correlation values ​​to obtain a code multipath error, At least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value is adjusted to suppress a multipath error of the captured satellite navigation signal, wherein the multipath error includes the subcarrier multipath error and the code multipath error.

33. The method according to claim 32, wherein The plurality of delayed local subcarriers include a plurality of different phase-advanced or phase-delayed local subcarriers; and The multiple delayed local codes include multiple different phase-advanced or phase-delayed local codes.

34. The method according to claim 32, wherein The number of delayed local subcarriers is any positive even number greater than or equal to 4; and The number of the delayed local codes is any positive even number greater than or equal to 4.

35. The method according to claim 32, wherein The weighted combination of the plurality of first correlation values ​​to obtain a subcarrier multipath error, and the weighted combination of the plurality of second correlation values ​​to obtain a code multipath error include: applying a corresponding weighted value of the first correlation value to each first correlation value, and combining a plurality of first correlation values ​​to which the corresponding weighted values ​​of the first correlation values ​​are applied, to obtain the subcarrier multipath error; and A corresponding weighted value of the second correlation value is applied to each second correlation value, and a plurality of second correlation values ​​to which the corresponding weighted values ​​of the second correlation value are applied are combined to obtain the code multipath error.

36. The method according to claim 32, wherein Adjusting at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value includes: A heuristic algorithm is invoked to optimize at least one of the phase distance between the delayed local subcarriers, the phase distance between the delayed local codes, the weighted value of the first correlation value, and the weighted value of the second correlation value.

37. The method according to claim 36, wherein The heuristic algorithm includes at least one or a combination of a swarm intelligence optimization algorithm, an ant colony algorithm, a genetic algorithm, and a differential evolution algorithm.

38. The method according to claim 32, wherein adjusting at least one of a phase distance between the delayed local subcarriers, a phase distance between the delayed local codes, a weighted value of the first correlation value, and a weighted value of the second correlation value to suppress a multipath error of the acquired satellite navigation signal, wherein the multipath error includes the subcarrier multipath error and the code multipath error, comprising: At least one of a phase distance between the delayed local subcarriers, a phase distance between the delayed local codes, a weighted value of the first correlation value, and a weighted value of the second correlation value is adjusted to minimize an average multipath error envelope area or minimize a roll-off multipath error, thereby suppressing the multipath error.

39. The method according to claim 32, wherein Performing correlation processing on the baseband satellite signal, the non-delayed local code, and the delayed local subcarrier to obtain a first correlation value includes: multiplying the baseband satellite signal and the delay-free local code to obtain a first standby signal; and The first inactive signal and the delayed local subcarrier are multiplied and integrated to obtain the first correlation value.

40. The method according to claim 32, wherein Performing correlation processing on the baseband satellite signal, the non-delayed local subcarrier, and the delayed local code to obtain a second correlation value includes: multiplying the baseband satellite signal and the undelayed local subcarrier to obtain a second standby signal; and The second inactive signal and the delayed local code are multiplied and integrated to obtain the second correlation value.

41. The method according to claim 32, wherein Carrier separation of captured satellite navigation signals to obtain baseband satellite signals includes: Capturing a binary offset carrier signal to obtain a satellite number, a carrier frequency, and a code phase of the binary offset carrier signal; and The carrier of the binary offset carrier signal is stripped according to the carrier frequency of the binary offset carrier signal to obtain the baseband satellite signal.

42. The method according to claim 32, wherein No. i Delayed local code No. i Delayed local subcarrier in, For the i Optimized value of distance parameter of each code loop correlator; For the i Optimized parameter value of the subcarrier loop correlator distance; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

43. The method according to claim 32, wherein in, For the i First correlation values; For the i Second correlation value; T is the integration time; is the baseband satellite signal; For the i Optimized value of distance parameter of each code loop correlator; For the i Optimized value of distance parameter of each subcarrier loop correlator; is the number of the code loop correlators; and is the number of the subcarrier loop correlators.

44. The method according to claim 43, wherein in, For the said i First correlation values; For the said i Second correlation value; is the subcarrier multipath error; is the code multipath error; For the i Optimized values ​​of weight parameters of the code loop phase detector; and For the i The optimized values ​​of the weight parameters of the subcarrier loop phase detector.

45. The method according to claim 32, wherein After acquiring the subcarrier multipath error and the code multipath error, the method further includes: processing the subcarrier multipath error to obtain a subcarrier loop correction value, and correcting the subcarrier delay estimate value based on the subcarrier loop correction value; and The code multipath error is processed to obtain a code loop correction value, and a code delay estimate is corrected according to the code loop correction value.

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