CN115755123A - Satellite signal carrier-to-noise ratio estimation method and device - Google Patents
Satellite signal carrier-to-noise ratio estimation method and device Download PDFInfo
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Abstract
The embodiment of the invention provides a method and a device for estimating a carrier-to-noise ratio of a satellite signal, wherein the method comprises the following steps: processing the satellite signal to obtain a digital intermediate frequency signal; according to the satellite number, pseudo code capturing is carried out on the corresponding digital intermediate frequency signal to obtain capturing detection statistics; if the capture detection statistic is larger than a preset threshold, acquiring digital intermediate frequency signals of a preset number of segments and a preset data length; for each segment of digital intermediate frequency signals, acquiring a capture correlation value through pseudo code capture, calculating a segment correlation ratio according to the capture correlation value, and acquiring an average correlation ratio; calculating the absolute value of an autocorrelation function of the satellite signal pseudo code sequence, calculating a theoretical correlation ratio based on the maximum value and the secondary maximum value, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of second-largest correlation values; and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters. The embodiment of the invention realizes the rapid and high-precision estimation of the carrier-to-noise ratio based on a small amount of data.
Description
Technical Field
The embodiment of the invention relates to the technical field of signal processing and analysis, in particular to a satellite signal carrier-to-noise ratio estimation method and device.
Background
The Global Navigation Satellite System (GNSS) represented by GPS, GLONASS, galileo and Beidou can provide all-weather positioning, navigation and time service for users. The GNSS occupies irreplaceable positions in traditional application scenes such as military, electric power, navigation, surveying and mapping and the like, plays a potential role in numerous emerging intelligent application scenes such as unmanned driving, mobile communication, internet of things and the like, promotes information fusion and integration, and creates a brand new 'GNSS +' era.
Among the indexes of satellite signal, carrier-to-noise ratio C/N 0 Is a common measure of signal quality and is a standard measurement scale used to indicate the relationship between signal and noise. C/N 0 Regardless of the signal reception bandwidth, it is an important parameter for describing the signal reception quality. C/N 0 The quality of the representative signal is high, and the accuracy of the corresponding signal pseudo-range and carrier phase observed quantity is high, so that the subsequent navigation positioning accuracy is improved. In addition to measuring satellite signal quality, C/N 0 It can also be used for spoof interference detection once a C/N is found 0 Too large, beyond the normal signal range, indicates that the current signal is often a spoofing interferer. However, the various types of applications based on carrier-to-noise ratios described above tend to rely on their estimation accuracy. In order to obtain an accurate carrier-to-noise ratio estimation result, researchers have proposed methods such as a wide-narrow band power ratio method, a correlator comparison method, a variance summation method, a moment estimation method, and the like. But limited by the dependence of these methods on the signal tracking process and the influence of self-estimation performance, these methods generally need to process signals for several seconds or even tens of seconds to obtain higher carrier-to-noise ratio estimation accuracy. This greatly affects the speed of carrier-to-noise ratio estimation, and further seriously affects various subsequent applications based on carrier-to-noise ratios.
Disclosure of Invention
Aiming at the defects in the prior art, the embodiment of the invention provides a satellite signal carrier-to-noise ratio estimation method and a satellite signal carrier-to-noise ratio estimation device.
The embodiment of the invention provides a satellite signal carrier-to-noise ratio estimation method, which comprises the following steps: processing the received satellite signal to obtain a digital intermediate frequency signal; according to the satellite number, pseudo code capturing is carried out on the corresponding digital intermediate frequency signal, and capturing detection statistics are obtained; responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio; calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a second maximum value according to the absolute value of the autocorrelation function, and acquiring the number of second maximum correlation values relative to the second maximum value; calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values; and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
According to an embodiment of the present invention, after obtaining the acquisition detection statistic, the method further includes: and in response to the acquisition detection statistic being less than or equal to the preset threshold, performing pseudo code acquisition on the digital intermediate frequency signal of the next satellite number to acquire acquisition detection statistic.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the calculation of the global maximum correlation value and the co-frequency maximum correlation value according to the acquisition correlation value comprises the following steps: acquiring the maximum value of the capture correlation value as the global maximum correlation value; acquiring a carrier frequency and a code phase corresponding to the global maximum correlation value; and acquiring the largest one of other acquisition correlation values which have the same carrier frequency as the global maximum correlation value and are at least two chips away from the global maximum correlation value as the same-frequency maximum correlation value.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the step of calculating the segmental correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value comprises the following steps: and obtaining the segment correlation ratio by calculating the ratio of the global maximum correlation value and the same-frequency maximum correlation value.
According to the method for estimating the carrier-to-noise ratio of the satellite signal, provided by the embodiment of the invention, the calculation of the theoretical correlation ratio based on the maximum value and the secondary maximum value comprises the following steps: and calculating the ratio of the second largest value to the maximum value to obtain the theoretical correlation ratio.
According to the satellite signal carrier-to-noise ratio estimation method provided by the embodiment of the invention, the relation between the average correlation ratio, the theoretical correlation ratio, the number of the secondary maximum correlation values and the equivalent parameter is expressed as follows:
wherein the content of the first and second substances,
representing the average correlation ratio, p representing the theoretical correlation ratio, N y Represents the number of the second largest correlation values, sigma represents the equivalent parameter, and f (x; n, delta) represents
F (x; n, delta) represents
Is determined by the probability distribution function of (a),
representing a chi-squared distribution with n degrees of freedom and δ non-central parameter.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the carrier-to-noise ratio estimation value is expressed as follows:
(C/N 0 ) m ＝-10log(2Tσ)
wherein, (C/N) 0 ) m And T represents the estimated carrier-to-noise ratio value of the satellite signal with the satellite number m, and the preset data length.
The embodiment of the invention also provides a satellite signal carrier-to-noise ratio estimation device, which comprises: a front-end processing module to: processing the received satellite signal to obtain a digital intermediate frequency signal; a capture detection statistics acquisition module to: according to the satellite number, carrying out pseudo code acquisition on the corresponding digital intermediate frequency signal to obtain acquisition detection statistics; a segmentation processing module to: responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; an average correlation ratio obtaining module, configured to: for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio; the theoretical correlation ratio and the second largest correlation value number obtaining module is used for: calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; an equivalence parameter calculation module for: calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values; a carrier-to-noise ratio estimation module to: and calculating a carrier-to-noise ratio estimated value according to the equivalent parameters.
An embodiment of the present invention further provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps of any of the above satellite signal carrier-to-noise ratio estimation methods when executing the program.
Embodiments of the present invention further provide a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the method for estimating a carrier-to-noise ratio of a satellite signal as described in any one of the above.
An embodiment of the present invention further provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the method for estimating a carrier-to-noise ratio of a satellite signal according to any of the above methods are implemented.
The method and the device for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention process the received satellite signal to obtain a digital intermediate frequency signal, acquiring capturing detection statistic, responding to the capturing detection statistic being larger than a preset threshold, acquiring signals of preset number of segments and preset data length from the digital intermediate frequency signals corresponding to the satellite numbers, for each segment of digital intermediate frequency signal, acquiring corresponding acquisition correlation value through pseudo code acquisition, calculating global maximum correlation value and same-frequency maximum correlation value according to the acquisition correlation value, calculating segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset number of segments to obtain average correlation ratio, calculating the autocorrelation function of the satellite signal pseudo code sequence according to the satellite number, calculating the theoretical correlation ratio based on the maximum value and the second maximum value according to the absolute value of the autocorrelation function, and acquiring the number of the second maximum correlation values relative to the second maximum value, calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of second-largest correlation values, calculating a carrier-to-noise ratio estimation value according to the equivalent parameters, realizing that the carrier-to-noise ratio of the received signal can be quickly estimated through the correlation value ratio obtained by pseudo code acquisition, and compared with the traditional carrier-to-noise ratio estimation method based on the tracking process, the required data volume is shorter, can quickly realize the carrier-to-noise ratio estimation of the received signal, can realize high-precision estimation, has the advantages of less required data quantity, high carrier-to-noise ratio estimation precision, high estimation speed and the like, the method has wide application prospect in the fields of satellite navigation signal quality monitoring, deception jamming detection and the like based on the carrier-to-noise ratio.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic flowchart of a method for estimating a carrier-to-noise ratio of a satellite signal according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an apparatus for estimating a carrier-to-noise ratio of a satellite signal according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Aiming at the situation that the traditional carrier-to-noise ratio estimation method needs longer data to cause that the carrier-to-noise ratio estimation speed is slower and the traditional carrier-to-noise ratio estimation method is difficult to be applied to short data, the invention provides a method for quickly estimating the carrier-to-noise ratio by using the shorter data, which can realize the quick estimation of the carrier-to-noise ratio, can also be applied to the carrier-to-noise ratio estimation situation that the longer data is difficult to obtain, namely only the shorter data can be obtained, simultaneously achieves the aim of the quick estimation of the carrier-to-noise ratio and simultaneously realizes the high-precision carrier-to-noise ratio estimation.
Fig. 1 is a schematic flowchart of a method for estimating a carrier-to-noise ratio of a satellite signal according to an embodiment of the present invention. As shown in fig. 1, the method includes:
step S1, processing the received satellite signals to obtain digital intermediate frequency signals.
According to the type of the global navigation satellite system to be processed, a satellite signal receiver receives a satellite signal of a corresponding type, and if the carrier-to-noise ratio of the GPS signal is estimated, the GPS signal of the GPS satellite navigation system is received; and if the carrier-to-noise ratio of the Beidou signal is estimated, receiving the Beidou signal of the Beidou satellite navigation system.
And processing the received satellite signals to obtain digital intermediate frequency signals. Various types of global navigation satellite systems include multiple satellites. And processing the received satellite signals of a plurality of satellites with corresponding types according to the type of the processed global navigation satellite system to obtain digital intermediate frequency signals. The digital intermediate frequency signals comprise signals obtained by processing satellite signals of a plurality of satellites, and the digital intermediate frequency signals of different satellites can be distinguished through satellite numbers.
The digital intermediate frequency signal can be obtained by performing front-end processing such as amplification, frequency conversion, sampling and the like on the received satellite signal according to a conventional method.
And S2, performing pseudo code acquisition on the corresponding digital intermediate frequency signal according to the satellite number to acquire acquisition detection statistics.
And according to the difference of the satellite numbers, performing pseudo code acquisition on the digital intermediate frequency signals obtained from the satellite signals of the corresponding satellites to obtain acquisition detection statistics. The pseudo code acquisition can be performed in sequence according to the satellite number, acquisition detection statistics can be obtained, and subsequent processing can be performed. For example, the pseudo code acquisition is performed on the digital intermediate frequency signal obtained from the satellite signal with the satellite number m at present, so as to obtain the acquisition detection statistic.
And S3, responding to the situation that the capture detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers.
If the acquisition detection statistic is larger than the preset threshold, the satellite signal acquisition of the m-number satellite is successful, and the carrier-to-noise ratio is rapidly estimated. Firstly, signals with preset number of segments and preset data length are taken from digital intermediate frequency signals corresponding to m-number satellites. Here, the number of preset segments is N, and the length of the preset data is T seconds, that is, data with the length of T seconds of each segment of N segments is taken from the digital intermediate frequency signal, and the data segments may be continuous or discontinuous.
S4, acquiring corresponding acquisition correlation values of each section of the digital intermediate frequency signals through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation values, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset number of sections to obtain an average correlation ratio.
For example, for the nth segment (N =1,2,3, \8230;, N) signal, pseudo code capturing is performed according to a conventional method to obtain a corresponding capturing correlation value, a global maximum correlation value and a same-frequency maximum correlation value are calculated according to the capturing correlation value, a segment correlation ratio is calculated according to the global maximum correlation value and the same-frequency maximum correlation value, and segment correlation ratios corresponding to a preset number of segments of digital intermediate frequency signals are averaged to obtain an average correlation ratio.
And S5, calculating an autocorrelation function of the satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on the maximum value and the second maximum value according to the absolute value of the autocorrelation function, and acquiring the number of second maximum correlation values relative to the second maximum value.
The satellite signal pseudo code sequences of different satellites are different and can be published by each satellite navigation system. For example, for the currently processed m-numbered satellite, an autocorrelation function of a satellite signal pseudo code sequence of the satellite is calculated, an absolute value is taken, the maximum value and the second largest value in absolute values of the autocorrelation function are obtained, a theoretical correlation ratio is calculated according to the maximum value and the second largest value in absolute values of the autocorrelation function, and the number of the second largest correlation values relative to the second largest value is obtained. The second largest correlation value number with respect to the second largest value refers to the number of values next to the second largest value among the absolute values of the autocorrelation function.
And S6, calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values.
And calculating the equivalent parameters according to the relationship among the established average correlation ratio, theoretical correlation ratio, the number of the second largest correlation values and the equivalent parameters and the obtained average correlation ratio, theoretical correlation ratio and the number of the second largest correlation values.
And S7, calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
And calculating the carrier-to-noise ratio estimation value according to the calculated equivalent parameter according to the established relation between the equivalent parameter and the carrier-to-noise ratio estimation value.
The method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention comprises the steps of processing a received satellite signal to obtain a digital intermediate frequency signal, acquiring a capturing detection statistic by carrying out pseudo code capturing on the corresponding digital intermediate frequency signal according to a satellite number, acquiring signals with preset segments and preset data length from the digital intermediate frequency signal corresponding to the satellite number in response to the capturing detection statistic being greater than a preset threshold, acquiring a corresponding capturing correlation value for each segment of the digital intermediate frequency signal through pseudo code capturing, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the capturing correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, averaging the segment correlation values corresponding to the digital intermediate frequency signal with the preset segments to obtain an average correlation ratio, calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on the maximum value and the second maximum correlation value according to the absolute value of the autocorrelation function, acquiring a second maximum correlation value relative to the second maximum correlation value, calculating a second-to-noise ratio based on the received signal interference ratio, and realizing rapid estimation based on the received signal interference ratio, and the advantages of the received signal noise ratio, the received signal.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, after the acquisition detection statistic is obtained, the method further comprises the following steps: and in response to the acquisition detection statistic being less than or equal to the preset threshold, performing pseudo code acquisition on the digital intermediate frequency signal of the next satellite number to acquire acquisition detection statistic.
And if the acquisition detection statistic is less than or equal to the preset threshold, which indicates that the currently processed satellite signal of the m satellite is not successfully acquired, continuously performing pseudo code acquisition on the next satellite number, for example, performing pseudo code acquisition on the satellite signal of the m +1 satellite to obtain the acquisition detection statistic. If the acquisition detection statistic of the satellite signal of the m +1 satellite is larger than the preset threshold, the satellite signal of the m +1 satellite is successfully acquired, and the subsequent processing steps for carrier-to-noise ratio estimation are continued. If the acquisition detection statistic of the satellite signal of the m +1 satellite is smaller than or equal to the preset threshold, the satellite signal of the m +1 satellite is not successfully acquired, and the satellite signal of the m +2 satellite is further subjected to pseudo code acquisition to obtain the acquisition detection statistic. And repeating the steps until the carrier-to-noise ratio estimation of the satellite signals of all the satellites of the corresponding satellite navigation system is realized.
In the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the carrier-to-noise ratio of the satellite signals of all satellites can be estimated by performing the step of acquiring the acquisition detection statistic by performing the pseudo code acquisition on the digital intermediate frequency signal of the next satellite number in response to the acquisition detection statistic being less than or equal to the preset threshold.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the calculation of the global maximum correlation value and the same-frequency maximum correlation value according to the acquisition correlation value comprises the following steps: acquiring the maximum value of the capture correlation value as the global maximum correlation value; acquiring a carrier frequency and a code phase corresponding to the global maximum correlation value; and acquiring the largest one of other acquisition correlation values which have the same carrier frequency as the global maximum correlation value and are at least two chips away from the global maximum correlation value as the same-frequency maximum correlation value.
And acquiring a corresponding acquisition correlation value for each section of the digital intermediate frequency signal through pseudo code acquisition. For example, toPerforming pseudo code capture on the obtained nth segment (N =1,2,3, \ 8230;, N) signal according to a conventional method to obtain a corresponding capture correlation value V n (f, τ), where f denotes a carrier frequency and τ denotes a code phase, and then corresponding parameters are calculated according to equations (1) to (3)
And
wherein the content of the first and second substances,
representative acquisition correlation value V n The maximum value in (f, τ), referred to as the global maximum correlation value; (f) dn ,τ qn ) Wherein two parameters respectively represent
The corresponding carrier frequency and code phase;
representing the same carrier frequency f as the maximum correlation value dn The largest of the other correlation values that are at least two chips apart is called the intra-frequency maximum correlation value.
According to the satellite signal carrier-to-noise ratio estimation method provided by the embodiment of the invention, the carrier frequency and the code phase corresponding to the global maximum correlation value are obtained by obtaining the maximum value of the acquisition correlation value as the global maximum correlation value, the maximum value of other acquisition correlation values which have the same carrier frequency with the global maximum correlation value and are at least two chips away from the global maximum correlation value is obtained as the same-frequency maximum correlation value, and the global maximum correlation value and the method for obtaining the same-frequency maximum correlation value capable of realizing high-precision carrier-to-noise ratio quick estimation are provided.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the step of calculating the segmental correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value comprises the following steps: and obtaining the segment correlation ratio by calculating the ratio of the global maximum correlation value and the same-frequency maximum correlation value.
Using the calculated global maximum correlation value
And maximum correlation value of same frequency
Calculating corresponding segment correlation ratio values
Averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio. Average correlation ratio
The method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention obtains the sectional correlation ratio by calculating the ratio of the global maximum correlation value and the same-frequency maximum correlation value, and provides a method for solving the sectional correlation ratio, which can realize the rapid estimation of the high-precision carrier-to-noise ratio.
According to the method for estimating the carrier-to-noise ratio of the satellite signal, which is provided by the embodiment of the invention, the theoretical correlation ratio is calculated based on the maximum value and the secondary maximum value, and the method comprises the following steps: and calculating the ratio of the second largest value to the maximum value to obtain the theoretical correlation ratio.
Maximum table in absolute values of autocorrelation functionIs shown as C m The second largest value in the absolute value of the autocorrelation function is denoted as C s And calculating the ratio of the second largest value and the maximum value in the absolute value of the autocorrelation function to obtain the theoretical correlation ratio. Theoretical correlation ratio
And counting the absolute value of the autocorrelation function to obtain a correlation value C s The number N of next largest correlation values y 。
The method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention obtains the theoretical correlation ratio by calculating the ratio of the second largest value to the largest value, and provides a method for solving the theoretical correlation ratio, which can realize the rapid estimation of the high-precision carrier-to-noise ratio.
According to the satellite signal carrier-to-noise ratio estimation method provided by the embodiment of the invention, the relation between the average correlation ratio, the theoretical correlation ratio, the number of the secondary maximum correlation values and the equivalent parameter is expressed as follows:
wherein the content of the first and second substances,
representing the average correlation ratio, p representing the theoretical correlation ratio, N y Represents the number of the second largest correlation values, sigma represents the equivalent parameter, and f (x; n, delta) represents
F (x; n, delta) represents
Is determined by the probability distribution function of (a),
representing a chi-square distribution with a degree of freedom n and a non-central parameter δ.
According toCalculating the average correlation ratio
Theoretical correlation ratio p and number of next largest correlation values N y The corresponding equivalent parameter σ is calculated using equation (4).
In addition, the calculation of the equivalent parameter σ can be simplified by:
carrying out approximate processing on the formula (4) according to the carrier-to-noise ratio estimation error allowed by a user; calculating average correlation ratio in advance according to the result of the approximation processing
Corresponding relation with equivalent parameter sigma, when using, the corresponding relation is used again according to average correlation ratio
And quickly obtaining the corresponding equivalent parameter sigma.
The embodiment of the invention provides a satellite signal carrier-to-noise ratio estimation method, and provides an equivalent parameter solving method capable of realizing high-precision carrier-to-noise ratio quick estimation.
According to the method for estimating the carrier-to-noise ratio of the satellite signal provided by the embodiment of the invention, the carrier-to-noise ratio estimation value is expressed as follows:
(C/N 0 ) m ＝-10log(2Tσ) (5)
wherein, (C/N) 0 ) m And the estimated carrier-to-noise ratio value of the satellite signal with the satellite number m is represented, and T represents the preset data length.
According to the obtained equivalent parameter sigma, calculating a corresponding carrier-to-noise ratio estimated value (C/N) by the formula (5) 0 ) m ＝-10log(2Tσ)。
The embodiment of the invention provides a method for estimating the carrier-to-noise ratio of a satellite signal, which can realize high-precision rapid estimation of the carrier-to-noise ratio and can obtain the estimated value of the carrier-to-noise ratio according to equivalent parameters.
In order to check the effect of the invention, the embodiment of the invention utilizes the GPS C/A code signal to carry out test verification. Satellite signal down-convertedRear intermediate frequency of f i =4.13MHz, satellite signal sampling rate f s =16.36MHz. The acquired signals include signals with satellite numbers (GPS PRN numbers) of 3, 15, 16, 18, 21, and 22.
As shown in table 1, the estimated carrier-to-noise ratio values and the corresponding estimated average error of the carrier-to-noise ratio are obtained when the data segment length is 0.001 second and the number of segments N is 20, 30, 40, and 50, respectively. As can be seen from table 1, the estimated carrier-to-noise ratio of the present invention is very close to the true signal carrier-to-noise ratio. Under the condition that the data segment length is 0.001 second and the segment number N is 20, 30, 40 and 50 respectively, the average errors of the estimated carrier-to-noise ratio compared with the actual signal carrier-to-noise ratio are 0.47dB, 0.46dB and 0.36dB respectively. This shows that the invention has very high carrier-to-noise ratio estimation accuracy under a short data length (such as NT < =0.05 s).
TABLE 1 estimated carrier-to-noise ratio of satellite signals/(dBHz)
To further illustrate the flow of the method for estimating the carrier-to-noise ratio of a satellite signal provided by the embodiment of the present invention, the implementation steps of the method are described below by taking a GPS C/a code signal as an example. The method is not limited to a specific system (suitable for various global navigation satellite systems), signals (such as intermediate frequency digital signals of various frequencies) and specific parameters (such as various sampling rates), and can be flexibly selected by a user according to needs. The specific implementation steps are as follows:
s1: firstly, processing received satellite signals by amplification, frequency conversion, sampling and the like according to a conventional method to obtain digital intermediate frequency signals;
s2: for the digital intermediate frequency signal, the C/a code signal acquisition is performed for the GPS satellite with number (PRN number) 1 in the conventional manner. If the obtained acquisition detection statistic is larger than a preset threshold, the acquisition of the GPS satellite signal with the number of 1 is successful, and then the carrier-to-noise ratio is quickly estimated according to the subsequent steps. Otherwise, if the acquired acquisition detection statistic does not exceed the preset threshold, the acquisition is failed, and other GPS satellite signals are continuously acquired at the moment;
s3: selecting 20 segments of data from the digital intermediate frequency signal obtained in the S1 by taking T =0.001 seconds as one segment;
s4: carrying out pseudo code capture on the first section of data in S1 according to a conventional method to obtain a capture correlation value V 1 (f,τ)；
S5: from V 1 Selecting a global maximum correlation value from (f, tau)
And obtaining the carrier frequency f corresponding to the correlation value d1 Sum code phase τ q1 ；
S6: from V 1 Of (f, τ) the carrier frequency f d1 And the code phase and tau q1 Selecting the maximum correlation value of the same frequency from all correlation values which differ by at least two chips
S7: according to the global maximum correlation value
And maximum correlation value of same frequency
Calculating to obtain the segment correlation ratio corresponding to the segment data
S8: calculating the corresponding segment correlation ratio of the remaining 19 segments of the S3 according to the steps S4 to S7
Wherein n =2,3, \ 8230;, 20;
s9: calculating the average correlation ratio:
s10: according to the satellite signal pseudo code sequence published by the GPS, the number of the satellite signal pseudo code sequence is calculated to be 1And (3) performing a pseudo code sequence autocorrelation function of the GPS satellite, taking an absolute value, and obtaining a maximum correlation value of 1023 and a second-largest correlation value of 65 according to the size of data in the absolute value. The theoretical correlation ratio is obtained by calculation
The number of the second largest correlation values with the correlation value of 65 in the autocorrelation function is counted to be N y ＝120；
S11: average correlation ratio obtained according to S9
And the theoretical correlation ratio p and the number N of second largest correlation values obtained in S10 y Calculating by using the formula (4) to obtain a corresponding equivalent parameter sigma;
s12: and calculating a corresponding carrier-to-noise ratio estimation value according to the equation (5) according to the equivalent parameter sigma obtained in the S11.
S13: and repeating the steps S2 to S12 to estimate the carrier-to-noise ratio of other satellite signals.
The embodiment of the invention provides a method for estimating a carrier-to-noise ratio of a satellite signal, and aims to design a method for rapidly estimating the carrier-to-noise ratio of the satellite signal, utilize shorter data to rapidly estimate the carrier-to-noise ratio of the signal, and solve the problem that the carrier-to-noise ratio estimation speed is slower due to longer required data so as to seriously influence subsequent application in the current method for estimating the carrier-to-noise ratio. Meanwhile, the method can also be applied to other carrier-to-noise ratio estimation scenes in which longer data are difficult to obtain.
It should be noted that, on the premise that logics or structures do not conflict with each other, a plurality of preferred embodiments provided in this embodiment may be freely combined, and the present invention is not limited to this.
The following describes the satellite signal carrier-to-noise ratio estimation apparatus provided in the embodiment of the present invention, and the satellite signal carrier-to-noise ratio estimation apparatus described below and the satellite signal carrier-to-noise ratio estimation method described above may be referred to correspondingly.
Fig. 2 is a schematic structural diagram of an apparatus for estimating a carrier-to-noise ratio of a satellite signal according to an embodiment of the present invention. As shown in fig. 2, the apparatus includes: the front-end processing module 10 is configured to: processing the received satellite signal to obtain a digital intermediate frequency signal; the capture detection statistics acquisition module 20 is configured to: according to the satellite number, carrying out pseudo code acquisition on the corresponding digital intermediate frequency signal to obtain acquisition detection statistics; the segmentation processing module 30 is configured to: responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; the average correlation ratio obtaining module 40 is configured to: for each segment of the digital intermediate frequency signals, acquiring corresponding acquisition correlation values through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation values, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the preset segments of the digital intermediate frequency signals to obtain an average correlation ratio; the theoretical correlation ratio and second largest correlation value number obtaining module 50 is configured to: calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; the equivalent parameter calculation module 60 is configured to: calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values; the carrier-to-noise ratio estimation module 70 is configured to: and calculating a carrier-to-noise ratio estimated value according to the equivalent parameters.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention processes the received satellite signal to obtain a digital intermediate frequency signal, performs pseudo code capture on the corresponding digital intermediate frequency signal according to the satellite number to obtain capture detection statistic, obtains signals with preset segments and preset data length from the digital intermediate frequency signal corresponding to the satellite number in response to the capture detection statistic being greater than a preset threshold, obtains a corresponding capture correlation value through pseudo code capture for each segment of digital intermediate frequency signal, calculates a global maximum correlation value and a same-frequency maximum correlation value according to the capture correlation value, calculates a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, averages the segment correlation values corresponding to the digital intermediate frequency signal with the preset segments to obtain an average correlation ratio, calculates an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculates an equivalent correlation value based on the maximum value and the second maximum correlation value according to the absolute value of the autocorrelation function, obtains a second maximum correlation value relative to the second maximum correlation value, calculates a second maximum correlation value based on a theoretical correlation value and calculates a second maximum correlation value, calculates a second estimated signal carrier-to-noise ratio based on the received signal carrier ratio, and the like, and can realize the fast estimation of the received signal interference ratio based on the advantages of the received signal.
According to the satellite signal carrier-to-noise ratio estimation apparatus provided in the embodiment of the present invention, after obtaining the acquisition detection statistic, the acquisition detection statistic obtaining module 20 is further configured to: and in response to the acquisition detection statistic being less than or equal to the preset threshold, performing pseudo code acquisition on the digital intermediate frequency signal of the next satellite number to acquire acquisition detection statistic.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention can realize the carrier-to-noise ratio estimation of the satellite signals of all satellites by performing the steps of acquiring the acquisition detection statistic by performing the pseudo code acquisition on the digital intermediate frequency signal of the next satellite number in response to the acquisition detection statistic being less than or equal to the preset threshold.
According to the satellite signal carrier-to-noise ratio estimation apparatus provided in the embodiment of the present invention, when the average correlation ratio obtaining module 40 is configured to calculate the global maximum correlation value and the intra-frequency maximum correlation value according to the acquisition correlation value, it is specifically configured to: acquiring the maximum value of the capture correlation value as the global maximum correlation value; acquiring a carrier frequency and a code phase corresponding to the global maximum correlation value; and acquiring the largest one of other acquisition correlation values which have the same carrier frequency as the global maximum correlation value and are at least two chips away from the global maximum correlation value as the same-frequency maximum correlation value.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention obtains the carrier frequency and the code phase corresponding to the global maximum correlation value by obtaining the maximum value of the acquisition correlation value as the global maximum correlation value, obtains the maximum one of other acquisition correlation values which has the same carrier frequency as the global maximum correlation value and is at least two chips away from the global maximum correlation value as the same-frequency maximum correlation value, and provides a method for obtaining the global maximum correlation value and the same-frequency maximum correlation value, which can realize high-precision carrier-to-noise ratio quick estimation.
According to the satellite signal carrier-to-noise ratio estimation apparatus provided in the embodiment of the present invention, when the average correlation ratio obtaining module 40 is configured to calculate the segment correlation ratio according to the global maximum correlation value and the intra-frequency maximum correlation value, specifically configured to: and obtaining the segment correlation ratio by calculating the ratio of the global maximum correlation value and the same-frequency maximum correlation value.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention obtains the segment correlation ratio by calculating the ratio of the global maximum correlation value and the same-frequency maximum correlation value, and provides a method for solving the segment correlation ratio, which can realize high-precision carrier-to-noise ratio quick estimation.
According to the satellite signal carrier-to-noise ratio estimation apparatus provided in the embodiment of the present invention, the theoretical correlation ratio and the number of second largest correlation values obtaining module 50 is specifically configured to: and calculating the ratio of the second largest value to the maximum value to obtain the theoretical correlation ratio.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention obtains the theoretical correlation ratio by calculating the ratio of the second largest value to the largest value, and provides a method for solving the theoretical correlation ratio, which can realize high-precision carrier-to-noise ratio quick estimation.
According to the satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the present invention, the relation between the average correlation ratio, the theoretical correlation ratio, the number of the secondary maximum correlation values and the equivalent parameter is expressed as follows:
wherein the content of the first and second substances,
representing the average correlation ratio, p representing the theoretical correlation ratio, N y Represents the number of the second largest correlation values, sigma represents the equivalent parameter, and f (x; n, delta) represents
F (x; n, delta) represents
Is determined by the probability distribution function of (a),
representing a chi-squared distribution with n degrees of freedom and δ non-central parameter.
The satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention provides an equivalent parameter solving method capable of realizing high-precision carrier-to-noise ratio quick estimation.
According to the satellite signal carrier-to-noise ratio estimation device provided by the embodiment of the invention, the carrier-to-noise ratio estimation value is expressed as follows:
(C/N 0 ) m ＝-10log(2Tσ) (5)
wherein, (C/N) 0 ) m And the estimated carrier-to-noise ratio value of the satellite signal with the satellite number m is represented, and T represents the preset data length.
The embodiment of the invention provides a satellite signal carrier-to-noise ratio estimation device, and provides a method for obtaining a carrier-to-noise ratio estimation value according to equivalent parameters, which can realize high-precision carrier-to-noise ratio quick estimation.
Fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, and as shown in fig. 3, the electronic device may include: a processor (processor) 310, a communication Interface (communication Interface) 320, a memory (memory) 330 and a communication bus 340, wherein the processor 310, the communication Interface 320 and the memory 330 communicate with each other via the communication bus 340. The processor 310 may invoke logic instructions in the memory 330 to perform a method of satellite signal carrier-to-noise ratio estimation comprising: processing the received satellite signal to obtain a digital intermediate frequency signal; according to the satellite number, pseudo code capturing is carried out on the corresponding digital intermediate frequency signal, and capturing detection statistics are obtained; responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio; calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary maximum correlation values; and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
In addition, the logic instructions in the memory 330 may be implemented in the form of software functional units and stored in a computer readable storage medium when the software functional units are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk, and various media capable of storing program codes.
In another aspect, an embodiment of the present invention further provides a computer program product, where the computer program product includes a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, a computer can execute a satellite signal carrier-to-noise ratio estimation method provided by the above methods, where the method includes: processing the received satellite signal to obtain a digital intermediate frequency signal; according to the satellite number, pseudo code capturing is carried out on the corresponding digital intermediate frequency signal, and capturing detection statistics are obtained; responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of preset segments and preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio; calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values; and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
In yet another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program is implemented to, when executed by a processor, perform the satellite signal carrier-to-noise ratio estimation method provided by the foregoing methods, where the method includes: processing the received satellite signal to obtain a digital intermediate frequency signal; according to the satellite number, pseudo code capturing is carried out on the corresponding digital intermediate frequency signal, and capturing detection statistics are obtained; responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of preset segments and preset data length from the digital intermediate frequency signals corresponding to the satellite numbers; for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio; calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value; calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values; and calculating a carrier-to-noise ratio estimated value according to the equivalent parameters.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on the understanding, the above technical solutions substantially or otherwise contributing to the prior art may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the various embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (11)
1. A method for estimating a carrier-to-noise ratio of a satellite signal, comprising:
processing the received satellite signal to obtain a digital intermediate frequency signal;
according to the satellite number, carrying out pseudo code acquisition on the corresponding digital intermediate frequency signal to obtain acquisition detection statistics;
responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of preset segments and preset data length from the digital intermediate frequency signals corresponding to the satellite numbers;
for each segment of the digital intermediate frequency signals, acquiring corresponding acquisition correlation values through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation values, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the preset segments of the digital intermediate frequency signals to obtain an average correlation ratio;
calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value;
calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values;
and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
2. The method of satellite signal carrier-to-noise ratio estimation according to claim 1, wherein after said obtaining acquisition detection statistics, said method further comprises:
and in response to the acquisition detection statistic being less than or equal to the preset threshold, performing pseudo code acquisition on the digital intermediate frequency signal of the next satellite number to acquire acquisition detection statistic.
3. The method according to claim 1, wherein the calculating a global maximum correlation value and an intra-frequency maximum correlation value according to the acquisition correlation value comprises:
acquiring the maximum value of the capture correlation value as the global maximum correlation value;
acquiring a carrier frequency and a code phase corresponding to the global maximum correlation value;
and acquiring the largest one of other acquisition correlation values which have the same carrier frequency with the global maximum correlation value and are at least two chips away from the global maximum correlation value as the same-frequency maximum correlation value.
4. The method according to claim 1, wherein the calculating a segment correlation ratio according to the global maximum correlation value and the intra-frequency maximum correlation value comprises:
and calculating the ratio of the global maximum correlation value to the same-frequency maximum correlation value to obtain the segmental correlation ratio.
5. The method according to claim 1, wherein said calculating a theoretical correlation ratio based on the maximum value and the second maximum value comprises:
and calculating the ratio of the second largest value to the maximum value to obtain the theoretical correlation ratio.
6. The method according to claim 1, wherein the relation between the average correlation ratio, the theoretical correlation ratio, the number of the second largest correlation values and the equivalent parameter is represented as follows:
wherein the content of the first and second substances,
representing the average correlation ratio, p representing the theoretical correlation ratio, N y Represents the number of the second largest correlation values, sigma represents the equivalent parameter, and f (x; n, delta) represents
F (x; n, delta) represents
Is determined by the probability distribution function of (a),
representing a chi-squared distribution with n degrees of freedom and δ non-central parameter.
7. The method according to claim 1, wherein the carrier-to-noise ratio estimate is expressed as:
(C/N 0 ) m ＝-10log(2Tσ)
wherein, (C/N) 0 ) m Representing the carrier-to-noise ratio estimate of the satellite signal with satellite number m,and T represents the preset data length.
8. An apparatus for estimating a carrier-to-noise ratio of a satellite signal, comprising:
a front-end processing module to: processing the received satellite signal to obtain a digital intermediate frequency signal;
a capture detection statistics acquisition module to: according to the satellite number, carrying out pseudo code acquisition on the corresponding digital intermediate frequency signal to obtain acquisition detection statistics;
a segmentation processing module to: responding to the fact that the capturing detection statistic is larger than a preset threshold, and acquiring signals of a preset number of sections and a preset data length from the digital intermediate frequency signals corresponding to the satellite numbers;
an average correlation ratio obtaining module, configured to: for each segment of the digital intermediate frequency signals, acquiring a corresponding acquisition correlation value through pseudo code acquisition, calculating a global maximum correlation value and a same-frequency maximum correlation value according to the acquisition correlation value, calculating a segment correlation ratio according to the global maximum correlation value and the same-frequency maximum correlation value, and averaging the segment correlation ratios corresponding to the digital intermediate frequency signals of the preset segment number to obtain an average correlation ratio;
the theoretical correlation ratio and the second largest correlation value number obtaining module is used for: calculating an autocorrelation function of a satellite signal pseudo code sequence according to the satellite number, calculating a theoretical correlation ratio based on a maximum value and a secondary maximum value according to the absolute value of the autocorrelation function, and acquiring the number of secondary maximum correlation values relative to the secondary maximum value;
an equivalent parameter calculation module for: calculating equivalent parameters according to the average correlation ratio, the theoretical correlation ratio and the number of the secondary large correlation values;
a carrier-to-noise ratio estimation module to: and calculating a carrier-to-noise ratio estimation value according to the equivalent parameters.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the method for estimating a carrier to noise ratio of a satellite signal according to any of claims 1 to 7.
10. A non-transitory computer-readable storage medium, having stored thereon a computer program, which, when being executed by a processor, carries out the steps of the method for estimating a carrier-to-noise ratio of a satellite signal according to any one of claims 1 to 7.
11. A computer program product comprising a computer program, wherein the computer program when executed by a processor implements the steps of the method for satellite signal carrier to noise ratio estimation according to any of claims 1 to 7.
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