WO2020037974A1 - 一种信号捕获方法及装置 - Google Patents

一种信号捕获方法及装置 Download PDF

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Publication number
WO2020037974A1
WO2020037974A1 PCT/CN2019/077451 CN2019077451W WO2020037974A1 WO 2020037974 A1 WO2020037974 A1 WO 2020037974A1 CN 2019077451 W CN2019077451 W CN 2019077451W WO 2020037974 A1 WO2020037974 A1 WO 2020037974A1
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Prior art keywords
group
positioning signals
signal
positioning
average
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PCT/CN2019/077451
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English (en)
French (fr)
Inventor
邓中亮
贾步云
莫君
边新梅
姜海君
范时伟
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北京邮电大学
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Priority to US16/647,171 priority Critical patent/US11303485B2/en
Publication of WO2020037974A1 publication Critical patent/WO2020037974A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
    • G01S1/04—Details
    • G01S1/045—Receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42—Determining position
    • G01S19/45—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
    • G01S19/46—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement the supplementary measurement being of a radio-wave signal type
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0014—Carrier regulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0058—Allocation criteria

Definitions

  • the present application relates to the technical field of signal acquisition, and in particular, to a signal acquisition method and device.
  • the TC-OFDM Time & Code Division-Orthogonal Frequency Division Multiplexing
  • the ground mobile broadcast network can superimpose the positioning signal on the mobile broadcast signal or mobile communication signal and broadcast through the base station. So as to provide users with high-precision indoor and outdoor positioning.
  • the positioning signal broadcast by the base station may have a large attenuation, which brings great difficulties for the positioning receiver to capture the signal.
  • a method for enhancing the ability to capture indoor weak signals is to lengthen the time of coherent integration or non-coherent integration, but for the use of PMF-FFT (Partial Matching Filter-Fast Fourier Transformation, partial matched filtering-fast Fourier transform)
  • PMF-FFT Partial Matching Filter-Fast Fourier Transformation, partial matched filtering-fast Fourier transform
  • the purpose of the embodiments of the present application is to provide a signal capturing method and device, so as to improve the success rate of capturing indoor positioning signals.
  • Specific technical solutions are as follows:
  • a signal acquisition method including:
  • the capture result is determined.
  • the dividing the positioning signals into at least two groups and performing frequency compensation on each group of positioning signals includes:
  • Frequency compensation is performed for each group of positioning signals, and the range of frequency compensation does not exceed one passband period.
  • the step of dividing each group of positioning signals subjected to frequency compensation into at least two signal blocks, and performing an average operation on the signal blocks in each group of signals to obtain each group of positioning signals after the block average processing includes:
  • each group of positioning signals after frequency compensation into at least two signal blocks, each signal block including the same number of sampling points;
  • an average operation is performed on sampling points at the same positions in each signal block to obtain each group of positioning signals after block average processing.
  • each group of positioning signals after the frequency compensation is:
  • Each group of positioning signals after the block average processing is:
  • n is the sequence number of the sampling point
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the n-th sampling point
  • c (nT s ) is the n-th sampling point Pseudo noise code
  • T s is the signal sampling period
  • Is the carrier phase Is the block average response of the i-th set of positioning signals
  • v B (nT s ) is the component of the noise of the n-th sampling point after block average processing.
  • the determining a capture result according to each group of positioning signals after block average processing includes:
  • the peak-to-average ratio of each group of positioning signals is determined according to the amplitude-frequency response of each group of positioning signals, and the peak-to-average ratio of each group of positioning signals is the ratio of the maximum amplitude value to the average value of the amplitude in the respective group of positioning signal amplitude-frequency responses
  • the average value of the amplitude is an average value of a preset number of amplitudes in the amplitude-frequency response of each group of positioning signals;
  • the code phase estimation value and the frequency estimation value of the positioning signal sent by the received base station are determined according to the group of positioning signals with the highest peak-to-average ratio among the at least two sets of positioning signals.
  • a signal capture device includes:
  • a signal receiving module configured to receive a positioning signal sent by a base station
  • a frequency compensation module configured to divide the positioning signals received by the signal receiving module into at least two groups, and perform frequency compensation on each group of positioning signals respectively;
  • a block average processing module configured to divide each group of positioning signals processed by the frequency compensation module into at least two signal blocks, and perform an average operation on the signal blocks in each group of signals to obtain each Group positioning signal
  • a determination module configured to determine a capture result according to each group of positioning signals processed by the block average processing module.
  • the frequency compensation module includes: a sampling unit, a grouping unit, and a frequency compensation unit;
  • the sampling unit is configured to perform analog-to-digital conversion on a positioning signal sent by the base station, and sample the positioning signal according to a preset sampling rate;
  • the grouping unit is configured to divide the positioning signals into at least two groups according to the sampling result determined by the sampling unit;
  • the frequency compensation unit is configured to perform frequency compensation on each group of positioning signals split by the grouping unit, and a frequency compensation range does not exceed one passband period.
  • the block average processing module is specifically configured to:
  • each group of positioning signals after frequency compensation into at least two signal blocks, each signal block including the same number of sampling points;
  • an average operation is performed on sampling points at the same positions in each signal block to obtain each group of positioning signals after block average processing.
  • each group of positioning signals after the frequency compensation may be:
  • n is the sequence number of the sampling points
  • r (i) (n) is the signal of the nth sampling point in the ith group of positioning signals
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the nth sampling point.
  • C (nT s ) is the pseudo noise code at the nth sampling point
  • Is the frequency of the i-th group of positioning signals after frequency compensation
  • T s is the signal sampling period
  • v (nT s ) is the noise at the nth sampling point;
  • Each group of positioning signals after the block average processing may be:
  • n is the sequence number of the sampling point
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the n-th sampling point
  • c (nT s ) is the n-th sampling point Pseudo noise code
  • T s is the signal sampling period
  • Is the carrier phase Is the block average response of the i-th set of positioning signals
  • v B (nT s ) is the component of the noise of the n-th sampling point after block average processing.
  • the determination module includes: an arithmetic unit, a peak-to-average ratio determination unit, a determination unit, a determination unit, and a parameter estimation unit;
  • the operation unit is configured to perform partial matching filtering-fast Fourier transform PMF-FFT operation on each group of positioning signals after block average processing, to obtain the amplitude-frequency response of each group of positioning signals;
  • the peak-to-average ratio determining unit is configured to determine a peak-to-average ratio of each group of positioning signals according to the amplitude-frequency response of each group of positioning signals calculated by the operation unit, and the peak-to-average ratio of each group of positioning signals is a respective group of positioning signals
  • the average amplitude value is an average value of a preset number of amplitude values in the amplitude frequency response of each group of positioning signals;
  • the determining unit is configured to determine a group of positioning signals with the highest peak-to-average ratio from the peak-to-average ratios of the at least two sets of positioning signals determined by the peak-to-average ratio determining unit;
  • the judging unit is configured to: if the peak-to-average ratio of a group of positioning signals with the largest peak-to-average ratio determined by the determining unit is greater than a preset threshold, the capture result is successful capture; If the peak-to-average ratio of a group of positioning signals with the highest peak-to-average ratio is not greater than a preset threshold, the capture result is a capture failure;
  • a parameter estimation unit configured to determine a code of a positioning signal sent by the received base station according to a group of positioning signals having a maximum peak-to-average ratio among at least two sets of positioning signals determined by the determining unit if the acquisition result is successful acquisition; Phase and frequency estimates.
  • an electronic device includes a processor, a communication interface, a memory, and a communication bus.
  • the processor, the communication interface, and the memory complete communication with each other through the communication bus.
  • the processor is configured to implement the steps of any one of the foregoing signal capture methods when executing a program stored in the memory.
  • an embodiment of the present application further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the steps of any of the foregoing signal capture methods. .
  • a signal acquisition method and device provided in the embodiments of the present application can divide the received positioning signals sent by the base station into at least two groups, and perform frequency compensation on each group of positioning signals; each group of positioning signals after frequency compensation It is divided into at least two signal blocks, and an average operation is performed on the signal blocks in each group of signals; the acquisition result is determined according to each group of positioning signals after the block average processing.
  • the embodiment of the present application can reduce the noise power of the received positioning signals, thereby improving the signal-to-noise ratio of the received positioning signals and improving the receiver's acquisition Sensitivity can improve the success rate of capturing weak signals.
  • the embodiments of the present application can obtain more accurate frequency estimation values during the acquisition phase.
  • FIG. 1 is a schematic structural diagram of a PMF-FFT signal acquisition device based on frequency compensation and block averaging according to an embodiment of the present application;
  • FIG. 2 is a flowchart of a signal acquisition method according to an embodiment of the present application.
  • FIG. 3 is a flowchart of a block average processing method according to an embodiment of the present application.
  • FIG. 4 is a flowchart of a method for frequency compensation in a signal acquisition method according to an embodiment of the present application
  • FIG. 5 is a schematic diagram of a block average response provided by an embodiment of the present application.
  • FIG. 6 is a schematic diagram of a PMF-FFT signal acquisition process according to an embodiment of the present application.
  • FIG. 7 is a PMF-FFT amplitude-frequency response curve of a group of positioning signals according to an embodiment of the present application.
  • FIG. 8 is a flowchart of a calculation method combining a fast Fourier transform and an inverse fast Fourier transform according to an embodiment of the present application
  • FIG. 9 is a schematic structural diagram of a signal acquisition device according to an embodiment of the present application.
  • FIG. 10 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
  • the signal acquisition method provided in the embodiment of the present application can be applied to a signal acquisition device shown in FIG. 1, and the device can be applied to an electronic device.
  • the device includes a frequency compensation module, a block average processing module, a PMF-FFT capture module, a peak comparison module, and a capture result determination module.
  • the signal capture device can perform analog-to-digital conversion on the positioning signal, and divide the positioning signal after the analog-to-digital conversion into multiple groups, and each frequency of the positioning signal is determined by the frequency compensation module.
  • the block average processing module performs block average processing on each group of positioning signals after frequency compensation
  • the PMF-FFT capture module performs capture operation on each group of positioning signals after block average processing, and then the peak comparison module according to the capture
  • the result of the operation determines the peak-to-average ratio of the set of positioning signals with the highest peak-to-average ratio
  • the capture result determination module determines the capture result according to the peak-to-average ratio of the set of positioning signals with the highest peak-to-average ratio.
  • the electronic device may be an electronic device such as a computer, a mobile phone, or a tablet computer with a positioning function.
  • FIG. 1 a flowchart of a signal acquisition method according to an embodiment of the present application, as shown in FIG. 2, includes the following steps:
  • Step 201 Receive a positioning signal sent by a base station.
  • step 202 the positioning signals are divided into at least two groups, and frequency compensation is performed for each group of positioning signals.
  • the positioning signal can be subjected to analog-to-digital conversion by the frequency compensation module and sampled at a preset sampling rate, and then divided into X groups, each of which contains the same number of sampling points, and then The X-group positioning signals are multiplied with the X-group local carriers of different frequencies generated by the local carrier generator to obtain the X-group positioning signals after frequency compensation.
  • the range of frequency compensation does not exceed one passband period, X ⁇ 2.
  • each group of positioning signals subjected to frequency compensation is divided into at least two signal blocks, and the signal blocks in each group of signals are averaged to obtain each group of positioning signals after block average processing.
  • the block average processing method is: dividing each group of positioning signals subjected to frequency compensation by the block average processing module into at least two signal blocks, each signal block including the same number of sampling points; for each group of positioning signals , Averaging the sampling points at the same positions in each signal block to obtain each group of positioning signals after the block average processing.
  • the length of the signal block is usually an integer multiple of the length of the PRN (Pseudo Random Code) in the positioning signal.
  • PRN Physical Random Code
  • FIG. 3 is a flowchart of a block average processing method according to an embodiment of the present application.
  • each group of positioning signals can be divided into M signal blocks, each signal block includes N sampling points; a sampling point n is selected in the first signal block of each group of signals, and then For other sampling points (n + iN) corresponding to the sampling point n position in other signal blocks, the sampling points n and (n + iN) are averaged to obtain each set of positioning signals after the block average processing.
  • i 0,1, ..., (M-1)
  • each group of positioning signals after block average processing is:
  • n is the sequence number of the sampling point
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the n-th sampling point
  • c (nT s ) is the n-th sampling point Pseudo noise code
  • T s is the signal sampling period
  • Is the carrier phase Is the carrier phase.
  • V B (nT s ) in formula (1) is the component of the noise of the n-th sampling point after block average processing.
  • the noise in the positioning signal is mainly Gaussian white noise
  • the Gauss of the positioning signal is processed after block average processing.
  • the power of white noise is:
  • S is the power of the positioning signal and N is the power of the Gaussian white noise.
  • N is the power of the Gaussian white noise.
  • Step 204 Determine a capture result according to each group of positioning signals after block average processing.
  • a PMF-FFT method a combination of a fast Fourier transform and an inverse fast Fourier transform, or a serial capture method may be used to determine the capture result, but the embodiment of the present application is not limited to this, and Other methods for capturing positioning signals may be used to determine the capture result according to each group of positioning signals after block average processing in the embodiments of the present application.
  • the positioning signal can be subjected to frequency compensation and block averaging processing, and then a preset signal acquisition method is used to acquire the positioning signal.
  • a preset signal acquisition method is used to acquire the positioning signal.
  • FIG. 4 is a flowchart of a method for frequency compensation in a signal acquisition method according to an embodiment of the present application, including the following steps:
  • Step 401 Perform analog-to-digital conversion on a positioning signal sent by a base station, and sample the positioning signal according to a preset sampling rate.
  • the block average signal length is generally selected to be an integer multiple of the PRN code length in the positioning signal, so the sampling rate can be an integer multiple of the PRN code rate in the positioning signal.
  • the period of the PRN code period is 2.5 ms, where the rate and the period are mutually inverse.
  • step 402 the positioning signals are divided into at least two groups according to the sampling results.
  • the positioning signals can be divided into X groups, and each group of positioning signals includes M * N sampling points; where M is a preset, M is the number of signal blocks during block average processing, and N is a fixed system Parameter, N is the number of sampling points in the signal block during block averaging, and "*" indicates a multiplication operation.
  • well code is a ranging code generated by Legendre sequence.
  • M and X are preset and determined by the following methods:
  • the passband main lobe width of the block average response is 2 / NMT s .
  • M is larger.
  • the number X of frequency compensation groups should be increased.
  • the attenuation threshold can be set to 3 dB.
  • the limiting conditions for the values of M and X are as in formula (6):
  • X may be 10 and M may be 10.
  • Step 403 Perform frequency compensation for each group of positioning signals, and the range of the frequency compensation does not exceed one passband period.
  • the block averaging process can be regarded as a dressing filter.
  • the passband period of the average response of the block is 1 / NT s .
  • the passband period is related to the sampling rate and the number of sampling points in the signal block, and has nothing to do with the average number of signal blocks in the block.
  • the passband main lobe width of the average response of the block is 2 / NMT s .
  • the frequency compensation method may be as follows: Referring to FIG. 1, positioning signals are divided into X groups, and each group of positioning signals is multiplied by a local carrier sent by a local carrier generator to obtain a frequency-compensated signal for each group of positioning signals. Each group of positioning signals after frequency compensation is formula (7):
  • n is the sequence number of the sampling points
  • r (i) (n) is the signal of the nth sampling point in the ith group of positioning signals
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the nth sampling point.
  • C (nT s ) is the pseudo noise code at the nth sampling point
  • Is the frequency of the i-th group of positioning signals after frequency compensation
  • T s is the signal sampling period
  • v (nT s ) is the noise at the n-th sampling point.
  • frequency compensation can be performed by grouping, so that after each group of positioning signals is processed through block averaging, at least one group of positioning signals can be guaranteed to fall within the passband of the block average response, and the group of positioning signals passes PMF. -After the FFT operation, the maximum peak-to-average ratio will be obtained. According to the maximum peak-to-average ratio, it is determined whether the positioning signal is successfully captured. In this way, since the noise power of the positioning signal processed by the block average processing module is reduced, the signal-to-noise ratio of the positioning signal is improved, and the success rate of capturing the positioning signal is improved.
  • the positioning signal after the positioning signal is subjected to block averaging and frequency compensation, the positioning signal may be captured in the following manner and the acquisition result may be determined:
  • a PMF-FFT method can be used to determine the capture result.
  • the specific steps are as follows:
  • the peak-to-average ratio of each group of positioning signals is determined according to the amplitude-frequency response of each group of positioning signals.
  • the peak-to-average ratio of the i-th group of positioning signals is the ratio of the maximum amplitude value to the average value of the amplitude in the i-th group's amplitude-frequency response:
  • f (i) is the peak-to-average ratio of the ith group of positioning signals
  • F is the number of sampling points participating in the FFT operation.
  • the average amplitude value is an average value of a preset number of amplitude values in the amplitude-frequency response of each group of positioning signals, where the preset number is F.
  • the capture result is successful. If the peak-to-average ratio of a group of positioning signals with the highest peak-to-average ratio is not greater than a preset threshold, the capture result is Capture failed.
  • FIG. 6 is a schematic diagram of a signal capture process performed by the PMF-FFT capture module, the peak comparison module, and the determination capture result module in FIG. 1.
  • each group of positioning signals after block averaging processing is first partially matched and filtered. Assuming that the length of each correlator is P and there are L correlators in total, each group of positioning signals is divided into L blocks, and each block of positioning signals includes P sampling points. Each correlator performs correlation accumulation on the P sampling points in each positioning signal, and the process of partial matching filtering is as shown in formula (9):
  • formula (9) can be reduced to:
  • the L filter processing sampling points obtained after partial matching filtering processing are supplemented by 0 to obtain F sampling points, and F sampling points are subjected to FFT operation, where F is an integer power of 2.
  • the amplitude-frequency response of each group of positioning signals obtained after the FFT operation is formula (11).
  • the PMF-FFT amplitude-frequency response curve of a group of positioning signals is shown in FIG. 7.
  • k is the serial number of the correlator
  • k 0, 1, ..., L-1
  • the filtered signal for the n-th sampling point of the i-th positioning signal The block-averaged response for the i-th positioning signal.
  • the frequency resolution of the i-th positioning signal is 1 / 2PFT s and the frequency search range is ⁇ 1 / 2PT s .
  • the local code is the same as the pseudo code of the positioning signal and the phase is the same, the amplitude-frequency response curve of the i-th positioning signal obtained by FFT will be in Produces the largest peak at.
  • the amplitude-frequency response of the FFT output calculate the group with the highest peak-to-average ratio of the X groups of signals;
  • the peak-to-average ratio of each group of positioning signals is the ratio of the maximum amplitude value to the average value of the amplitude in the amplitude-frequency response of the positioning signals of the respective groups;
  • the average amplitude value is an average value of a preset number of amplitude values in the amplitude-frequency response of each group of positioning signals, and the peak-to-average ratio of a group of positioning signals with the highest peak-to-average ratio is compared with a preset threshold.
  • the threshold value can be set to 1.5;
  • the capture result is that the capture was successful
  • the capture result is a capture failure.
  • the positioning signal is captured: the signal exists and the capture is successful, the signal exists but the capture fails, the signal does not exist but the capture is successful, the signal does not exist and the capture fails.
  • the probability that the signal exists and is successfully captured is the actual alarm rate
  • the probability that the signal is not present but is successfully captured is the false alarm rate.
  • the noise of the L sampling points obtained is a normal distribution with a mean value of 0 and a variance of ⁇ 2.
  • the noise will have a mean value of 0 and a variance. for Normal distribution.
  • the amplitude-frequency response curve of the FFT is a Rice distribution when the positioning signal is present, and the amplitude-frequency response curve of the FFT is a Rayleigh distribution when the positioning signal is not present.
  • the probability density function is f s (v)
  • the probability density function of the FFT amplitude-frequency response curve when the positioning signal is not present is f n (v)
  • the false alarm rate P fa satisfies formula (12):
  • F is the number of sampling points participating in the FFT operation
  • v is the amplitude of the positioning signal
  • v t is the threshold value.
  • the threshold value v t needs to satisfy that P fa is smaller than the false alarm rate threshold and P d is larger than the actual alarm rate threshold.
  • the false alarm rate threshold can be set to 0.1% or 1%, and the actual alarm rate threshold can be set to 95% or 90%.
  • Method 2 Use a combination of fast Fourier transform and inverse fast Fourier transform to capture the positioning signal. The specific steps are as follows:
  • FIG. 8 is a flowchart of an operation method combining a fast Fourier transform and an inverse fast Fourier transform according to an embodiment of the present application, including:
  • the local pseudo code sent by the generator is multiplied by a fast Fourier transform and a complex conjugate operation, and the inverse fast Fourier transform is performed on the multiplied positioning signal to obtain the code phase and Doppler frequency. According to the code phase and The Doppler frequency determines whether the positioning signal is successfully captured.
  • an estimated value of the received positioning signal code phase may also be calculated, including:
  • the local code is multiplied with each group of signals after the block average processing, and the product is subjected to an FFT operation to obtain the amplitude-frequency response of each group of signals after the block average processing.
  • the amplitude-frequency response curve of the group of positioning signals will have a peak value.
  • the corresponding local code phase is the code phase of the group of positioning signals. estimated value;
  • the code phase estimates of the M group of positioning signals will be approximately equal, so the code phase estimates of any group of positioning signals or the code phase estimates of the group of positioning signals with the highest peak-to-average ratio can be selected as the received signals.
  • a frequency estimation value of the positioning signal sent by the received base station may be calculated, that is, the Doppler frequency estimation value of the positioning signal sent by the received base station includes:
  • a preliminary frequency estimate of the Doppler frequency of the positioning signal can be obtained for:
  • k is the serial number of the correlator
  • P is the number of sampling points in the correlator
  • F is the number of sampling points participating in the FFT operation
  • T s is the sampling period of the positioning signal.
  • the set of positioning signals with the highest peak-to-average ratio must be within the passband of the average response of the block.
  • the frequency of the set of signals can be considered to be an integer multiple of 1 / NT s , so the positioning signal can be obtained.
  • the estimated Doppler frequency f d ′ is:
  • round means taking the integer with the smallest distance from the calculation result, Is the initial frequency estimation value, N is the number of sampling points in the signal block, T s is the sampling period of the positioning signal, and ⁇ f (i) is the frequency of the i-th positioning signal compensation.
  • the Doppler frequency estimation value in the traditional PMF-FFT acquisition method is calculated according to formula (14), and it can be known from formula (14) that the accuracy of the traditional Doppler frequency estimation is 1 / PFT s .
  • the accuracy of the Doppler frequency estimation value obtained in the embodiment of the present application is 1 / XNT s . Since 1 / PFT s > 1 / XNT s , the embodiment of the present application can obtain a more accurate Doppler frequency estimation value.
  • P is the number of sampling points in the correlator
  • L is the number of correlators
  • N is the number of sampling points in the signal block
  • X is the number of signal blocks in each group of positioning signals.
  • N PL
  • the Doppler frequency estimation value of the positioning signal obtained by applying the embodiment of the present application is more accurate and more accurate Doppler frequency estimation than the Doppler frequency estimation value of the positioning signal obtained by the conventional PMF-FFT acquisition method.
  • the receiver can enter the accurate tracking state more quickly; on the other hand, when the received positioning signal is a weak signal, a more accurate Doppler frequency estimation value can complete the signal pull. Into the quicker transition to the precise tracking stage; making it possible to obtain accurate ranging information faster.
  • FIG. 9 is a signal capture device provided by an embodiment of the present application.
  • the device includes:
  • a signal receiving module 901 configured to receive a positioning signal sent by a base station
  • a frequency compensation module 902 configured to divide the positioning signals received by the signal receiving module into at least two groups, and perform frequency compensation on each group of positioning signals respectively;
  • a block average processing module 903, configured to divide each group of positioning signals processed by the frequency compensation module into at least two signal blocks, and average the signal blocks in each group of signals to obtain each group after the block average processing Positioning signal
  • a determining module 904 is configured to determine a capture result according to each group of positioning signals processed by the block average processing module.
  • the frequency compensation module 902 may include: a sampling unit, a grouping unit, and a frequency compensation unit;
  • a sampling unit configured to perform analog-to-digital conversion on the positioning signal sent by the base station, and sample the positioning signal according to a preset sampling rate
  • a grouping unit configured to divide the positioning signals into at least two groups according to a sampling result determined by the sampling unit
  • the frequency compensation unit is configured to perform frequency compensation on each group of positioning signals split by the grouping unit, and the frequency compensation range does not exceed one passband period.
  • the block average processing module 903 may be specifically used for:
  • each group of positioning signals after frequency compensation into at least two signal blocks, each signal block including the same number of sampling points;
  • an average operation is performed on sampling points at the same positions in each signal block to obtain each group of positioning signals after block average processing.
  • each group of positioning signals after frequency compensation may be:
  • n is the sequence number of the sampling points
  • r (i) (n) is the signal of the nth sampling point in the ith group of positioning signals
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the nth sampling point.
  • C (nT s ) is the pseudo noise code at the nth sampling point
  • Is the frequency of the i-th group of positioning signals after frequency compensation
  • T s is the signal sampling period
  • v (nT s ) is the noise at the nth sampling point;
  • each group of positioning signals can be:
  • n is the sequence number of the sampling point
  • A is the signal amplitude
  • d (nT s ) is the navigation message of the n-th sampling point
  • c (nT s ) is the n-th sampling point Pseudo noise code
  • T s is the signal sampling period
  • Is the carrier phase Is the block average response of the i-th set of positioning signals
  • v B (nT s ) is the component of the noise of the n-th sampling point after block average processing.
  • the determination module 904 may include: an arithmetic unit, a peak-to-average ratio determination unit, a determination unit, a determination unit, and a parameter estimation unit;
  • An arithmetic unit configured to perform partial matching filtering-fast Fourier transform PMF-FFT operation on each group of positioning signals after block average processing, to obtain the amplitude-frequency response of each group of positioning signals;
  • the peak-to-average ratio determining unit is configured to determine the peak-to-average ratio of each group of positioning signals according to the amplitude-frequency response of each group of positioning signals calculated by the arithmetic unit, and the peak-to-average ratio of each group of positioning signals is the amplitude The ratio of the maximum value to the average value of the amplitude value; the average value of the amplitude value is the average value of a preset number of amplitude values in the amplitude-frequency response of each group of positioning signals;
  • a determining unit configured to determine a group of positioning signals with the highest peak-to-average ratio from the peak-to-average ratios of at least two sets of positioning signals determined by the peak-to-average ratio determining unit;
  • a judging unit configured to: if the peak-to-average ratio of a group of positioning signals with the highest peak-to-average ratio determined by the determining unit is greater than a preset threshold, the capture result is successful; The peak-to-average ratio is not greater than a preset threshold, the capture result is a capture failure;
  • a parameter estimation unit configured to determine, if the acquisition result is that the acquisition is successful, a code phase estimation value of the positioning signal and Frequency estimate.
  • a signal acquisition device can divide a received positioning signal sent by a base station into at least two groups, and perform frequency compensation on each group of positioning signals separately.
  • Each group of positioning signals after frequency compensation is divided into At least two signal blocks, perform an average operation on the signal blocks in each group of signals; determine the acquisition result according to each group of positioning signals after the block average processing.
  • the embodiment of the present application can reduce the noise power of the received positioning signals, thereby improving the signal-to-noise ratio of the received positioning signals and improving the receiver's acquisition Sensitivity can improve the success rate of capturing weak signals.
  • the embodiments of the present application can obtain more accurate frequency estimation values during the acquisition phase.
  • An embodiment of the present application further provides an electronic device, as shown in FIG. 10, including a processor 1001, a communication interface 1002, a memory 1003, and a communication bus 1004.
  • the processor 1001, the communication interface 1002, and the memory 1003 pass through the communication bus 1004. Complete communication with each other,
  • the processor 1001 is configured to implement steps executed by the electronic device in the foregoing method embodiment when executing a program stored in the memory 1003.
  • a signal acquisition electronic device provided in the embodiment of the present application can divide the received positioning signals sent by the base station into at least two groups, and perform frequency compensation on each group of positioning signals separately. For at least two signal blocks, an average operation is performed on the signal blocks in each group of signals; the acquisition result is determined according to each group of positioning signals after the block average processing. In this way, since the noise power of each group of positioning signals is reduced after the block average processing, the embodiment of the present application can reduce the noise power of the received positioning signals, thereby improving the signal-to-noise ratio of the received positioning signals and improving the receiver's acquisition Sensitivity can improve the success rate of capturing weak signals.
  • the embodiments of the present application can obtain more accurate frequency estimation values during the acquisition phase.
  • the communication bus mentioned in the above electronic device may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc.
  • PCI Peripheral Component Interconnect
  • EISA Extended Industry Standard Architecture
  • the communication bus can be divided into an address bus, a data bus, a control bus, and the like.
  • the figure only uses a thick line to represent, but it does not mean that there is only one bus or one type of bus.
  • the communication interface is used for communication between the aforementioned electronic device and other devices.
  • the memory may include random access memory (Random Access Memory, RAM), and may also include non-volatile memory (Non-Volatile Memory, NVM), such as at least one disk memory.
  • NVM non-Volatile Memory
  • the memory may also be at least one storage device located far from the foregoing processor.
  • the aforementioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc .; it may also be a digital signal processor (Digital Signal Processing, DSP), special integration Circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.
  • CPU central processing unit
  • NP network processor
  • DSP Digital Signal Processing
  • ASIC Application Specific Integrated Circuit
  • FPGA Field-Programmable Gate Array
  • a computer-readable storage medium stores a computer program, and the computer program implements any one of the foregoing signal capture methods when executed by a processor. A step of.
  • a computer program product containing instructions is also provided.
  • the computer program product When the computer program product is run on a computer, the computer causes the computer to execute any one of the signal capture methods in the foregoing embodiments.
  • the computer program product includes one or more computer instructions.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be from a website site, computer, server, or data center Transmission by wire (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) to another website site, computer, server, or data center.
  • the computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, and the like that includes one or more available medium integration.
  • the usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (Solid State Disk (SSD)), and the like.
  • a magnetic medium for example, a floppy disk, a hard disk, a magnetic tape
  • an optical medium for example, a DVD
  • a semiconductor medium for example, a solid state disk (Solid State Disk (SSD)

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Abstract

本申请实施例提供了一种信号捕获方法及装置，可以将接收到的由基站发出的定位信号分为至少两组，分别对每组定位信号进行频率补偿；将频率补偿后的每组定位信号分为至少两个信号块，对每组信号中信号块进行平均运算；根据块平均处理后的每组定位信号，确定捕获结果。这样，由于块平均处理后每组定位信号的噪声功率降低，所以应用本申请实施例能够减少接收的定位信号的噪声功率，从而提高了接收的定位信号的信噪比，所以能够提高信号的捕获成功率。

Description

一种信号捕获方法及装置
本申请要求于2018年08月20日提交中国专利局、申请号为201810949427.4发明名称为“一种信号捕获方法及装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及信号捕获技术领域，特别是涉及一种信号捕获方法及装置。
背景技术
如今，定位技术广泛应用于军事、交通或测绘等众多领域中。基于地面移动广播网络的TC-OFDM(Time&Code Division-Orthogonal Frequency Division Multiplexing，时分码分-正交频分复用)系统可将定位信号叠加在移动广播信号或移动通信信号上并通过基站进行广播，从而为用户提供高精度的室内外定位。但是，在遮挡物较多的室内环境中，基站广播的定位信号可能会出现较大的衰减，给定位接收机捕获信号带来很大困难。
现有技术对于增强室内弱信号的捕获能力的方法为：加长相干积分或非相干积分的时间，但是对于采用PMF-FFT(Partial Matching Filter-Fast Fourier Transformation，部分匹配滤波-快速傅里叶变换)运算的捕获方法而言，长时间的相干积分会导致FFT频率搜索范围下降，使得定位信号的捕获成功率较低。
发明内容
本申请实施例的目的在于提供一种信号捕获方法及装置，以实现提高室内定位信号的捕获成功率。具体技术方案如下：
第一方面，提供了一种信号捕获方法，所述方法包括：
接收基站发送的定位信号；
将所述定位信号分为至少两组，分别对每组定位信号进行频率补偿；
将经过频率补偿的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号；
根据经过块平均处理后的每组定位信号，确定捕获结果。
可选的，所述将所述定位信号分为至少两组，分别对每组定位信号进行频率补偿，包括：
对所述基站发送的定位信号进行模数转换，并根据预设采样速率对所述定位信号进行采样；
根据所述采样结果，将所述定位信号分为至少两组；
分别对每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
可选的，所述将经过频率补偿的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号，包括：
将经过频率补偿的每组定位信号分为至少两个信号块，每个信号块中包括相同数量的采样点；
对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
可选的，所述经过频率补偿后的每组定位信号为：
Figure PCTCN2019077451-appb-000001
其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000002
为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000003
为载波相位，v(nT s)为第n个采样点的噪声；
所述经过块平均处理后的每组定位信号为：
Figure PCTCN2019077451-appb-000004
其中，n为采样点的序号，
Figure PCTCN2019077451-appb-000005
为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000006
为第i组定位信号的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000007
为载波相位，
Figure PCTCN2019077451-appb-000008
为第i组定位信号的块平均响应，v B(nT s)为第n个采样点的噪声经过块平均处理后的分量。
可选的，所述根据经过块平均处理后的每组定位信号，确定捕获结果，包括：
分别对经过块平均处理之后的每组定位信号进行部分匹配滤波-快速傅里叶变换PMF-FFT运算，得到每组定位信号的幅频响应；
根据每组定位信号的幅频响应确定每组定位信号的峰均比，所述每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；所述幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值；
从所述至少两组定位信号的峰均比中确定峰均比最大的一组定位信号；
若峰均比最大的一组定位信号的峰均比大于预设阈值，则所述捕获结果为捕获成功；若峰均比最大的一组定位信号的峰均比不大于预设阈值，则所述捕获结果为捕获失败；
若捕获结果为捕获成功，则根据所述至少两组定位信号中峰均比最大的一组定位信号，确定所述接收到的基站发送的定位信号的码相位估计值和频率估计值。
第二方面，提供了一种信号捕获装置，所述装置包括：
信号接收模块，用于接收基站发送的定位信号；
频率补偿模块，用于将所述信号接收模块接收的所述定位信号分为至少两组，分别对每组定位信号进行频率补偿；
块平均处理模块，用于将经过所述频率补偿模块处理后的每组定位信号 分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号；
确定模块，用于根据经过所述块平均处理模块处理后的每组定位信号，确定捕获结果。
可选的，所述频率补偿模块，包括：采样单元、分组单元和频率补偿单元；
所述采样单元，用于对所述基站发送的定位信号进行模数转换，并根据预设采样速率对所述定位信号进行采样；
所述分组单元，用于根据所述采样单元确定的所述采样结果，将所述定位信号分为至少两组；
所述频率补偿单元，用于分别对所述分组单元拆分的每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
可选的，所述块平均处理模块，具体用于：
将经过频率补偿的每组定位信号分为至少两个信号块，每个信号块中包括相同数量的采样点；
对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
可选的，所述经过频率补偿后的每组定位信号可以为：
Figure PCTCN2019077451-appb-000009
其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000010
为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000011
为载波相位，v(nT s)为第n个采样点的噪声；
所述经过块平均处理后的每组定位信号可以为：
Figure PCTCN2019077451-appb-000012
其中，n为采样点的序号，
Figure PCTCN2019077451-appb-000013
为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000014
为第i组定位信号的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000015
为载波相位，
Figure PCTCN2019077451-appb-000016
为第i组定位信号的块平均响应，v B(nT s)为第n个采样点的噪声经过块平均处理后的分量。
可选的，所述确定模块，包括：运算单元、峰均比确定单元、确定单元、判断单元和参数估计单元；
所述运算单元，用于分别对经过块平均处理之后的每组定位信号进行部分匹配滤波-快速傅里叶变换PMF-FFT运算，得到每组定位信号的幅频响应；
所述峰均比确定单元，用于根据所述运算单元计算的每组定位信号的幅频响应确定每组定位信号的峰均比，所述每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；所述幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值；
所述确定单元，用于从所述峰均比确定单元确定的所述至少两组定位信号的峰均比中确定峰均比最大的一组定位信号；
所述判断单元，用于若所述确定单元确定的峰均比最大的一组定位信号的峰均比大于预设阈值，则所述捕获结果为捕获成功；用于若所述确定单元确定的峰均比最大的一组定位信号的峰均比不大于预设阈值，则所述捕获结果为捕获失败；
参数估计单元，用于若捕获结果为捕获成功，则根据所述确定单元确定的至少两组定位信号中峰均比最大的一组定位信号，确定所述接收到的基站发送的定位信号的码相位估计值和频率估计值。
第三方面，提供了一种电子设备，所述电子设备包括处理器、通信接口、存储器和通信总线，其中，处理器，通信接口，存储器通过通信总线完成相 互间的通信；
存储器，用于存放计算机程序；
处理器，用于执行存储器上所存放的程序时，实现上述任一信号捕获方法的步骤。
第四方面，本申请实施例还提供了一种计算机可读存储介质，所述计算机可读存储介质内存储有计算机程序，所述计算机程序被处理器执行时实现上述任一信号捕获方法的步骤。
第五方面，本申请实施例还提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行上述任一信号捕获方法。
本申请实施例提供的一种信号捕获方法及装置，可以将接收到的由基站发出的定位信号分为至少两组，分别对每组定位信号进行频率补偿；将频率补偿后的每组定位信号分为至少两个信号块，对每组信号中信号块进行平均运算；根据块平均处理后的每组定位信号，确定捕获结果。这样，由于块平均处理后每组定位信号的噪声功率降低，所以应用本申请实施例能够减少接收的定位信号的噪声功率，从而提高了接收的定位信号的信噪比，提高了接收机的捕获灵敏度，能够提高弱信号的捕获成功率。
由于频率补偿和块平均处理与捕获模块结合能够提高频率估计精度，所以应用本申请实施例能够在捕获阶段获得更加精确的频率估计值。
当然，实施本申请的任一产品或方法并不一定需要同时达到以上所述的所有优点。
附图说明
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本申请实施例提供的基于频率补偿和块平均的PMF-FFT信号捕获装置结构示意图；
图2为本申请实施例提供的一种信号捕获方法流程图；
图3为本申请实施例提供的块平均处理方法流程图；
图4为本申请实施例提供的一种信号捕获方法中频率补偿的方法流程图；
图5为本申请实施例提供的块平均响应的示意图；
图6为本申请实施例提供的PMF-FFT信号捕获过程的示意图；
图7为本申请实施例提供的一组定位信号的PMF-FFT幅频响应曲线图；
图8为本申请实施例提供的快速傅里叶变换和快速傅里叶逆变换结合的运算方法流程图；
图9为本申请实施例提供的一种信号捕获装置结构示意图；
图10为本申请实施例提供的一种电子设备的结构示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
本申请实施例提供的信号捕获方法可应用于如图1所示的信号捕获装置中，该装置可应用于电子设备。该装置包括频率补偿模块、块平均处理模块，PMF-FFT捕获模块、峰值比较模块和捕获结果确定模块。
其中，该信号捕获装置接收到射频形式的定位信号后，可对定位信号进行模数转换，并将模数转换后的定位信号分为多组，由频率补偿模块分别对每组定位信号进行频率补偿，之后再由块平均处理模块对频率补偿后的每组定位信号进行块平均处理，再由PMF-FFT捕获模块对块平均处理后的每组定位信号进行捕获运算，然后峰值比较模块根据捕获运算的结果确定峰均比最大的一组定位信号的峰均比，然后捕获结果确定模块根据峰均比最大的一组定位信号的峰均比，确定捕获结果。
本申请实施例中，电子设备可以是具有定位功能的计算机、手机或平板 电脑等电子设备。
结合图1，本申请实施例提供的一种信号捕获方法流程图，如图2所示，包括如下步骤：
步骤201，接收基站发送的定位信号。
步骤202，将定位信号分为至少两组，分别对每组定位信号进行频率补偿。
一种实现方式中，结合图1，可以由频率补偿模块将定位信号经过模数转换，并按照预设采样速率进行采样后，分为X组，每组信号中包含相同数量的采样点，然后将X组定位信号分别与本地载波发生器生成的X组不同频率的本地载波相乘，以得到X组经过频率补偿后的定位信号。其中，频率补偿的范围不超过一个通带周期，X≥2。
步骤203，将经过频率补偿的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号。
结合图1，块平均处理的方法为：将经过频率补偿的每组定位信号由块平均处理模块分为至少两个信号块，每个信号块中包括相同数量的采样点；对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
其中，信号块的长度通常为定位信号中PRN(Pseudo Random Noise Code，伪随机噪声码)长度的整数倍。此外，由于块平均处理是将每一组定位信号中，各个信号块中对应位置的采样点进行平均运算，这就要求每一信号块中包含相同数量的采样点。
参见图3，图3为本申请实施例提供的块平均处理方法流程图。一种实现方式中，可以将每组定位信号分别分为M个信号块，每个信号块中包含N个采样点；在每组信号的第一个信号块中选取一个采样点n，再选取其它信号块中与采样点n位置对应的其它采样点(n+iN)，对采样点n和(n+iN)进行平均运算，得到块平均处理后的每组定位信号。其中，i＝0,1,…,(M-1)，块平均处理后的每组定位信号为：
Figure PCTCN2019077451-appb-000017
其中，n为采样点的序号，
Figure PCTCN2019077451-appb-000018
为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000019
为第i组定位信号的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000020
为载波相位。
Figure PCTCN2019077451-appb-000021
为第i组定位信号的块平均响应，如公式(2)所示：
Figure PCTCN2019077451-appb-000022
公式(1)中的v B(nT s)为第n个采样点的噪声经过块平均处理后的分量，考虑到定位信号中的噪声主要为高斯白噪声，经过块平均处理后定位信号的高斯白噪声的功率为：
Figure PCTCN2019077451-appb-000023
从公式(3)可见，块平均处理后高斯白噪声的功率减小为块平均处理前的1/M，同时定位信号功率保持不变。信噪比的计算公式为：
10*log 10(S/N)       (4)
其中，S为定位信号的功率，N为高斯白噪声的功率，根据图3中的描述可知，由于每组定位信号功率不变，但每组定位信号的高斯白噪声功率减小为块平均处理前的1/M，所以相当于接收由基站发送的定位信号的信噪比提高了10log 10(M)，因此块平均处理能够提高捕获弱信号的能力。
步骤204，根据经过块平均处理后的每组定位信号，确定捕获结果。
可选的，本申请实施例中可采用PMF-FFT方式、快速傅里叶变换与快速傅里叶反变换结合的方式或串行捕获方式确定捕获结果，但本申请实施例不 限于此，也可采用其他捕获定位信号的方法来根据本申请实施例中经过块平均处理后的每组定位信号确定捕获结果。
可见，应用本申请实施例提供的一种信号捕获方法，可以通过对定位信号进行频率补偿及块平均处理，再利用预设的信号捕获方法捕获定位信号；这样，由于块平均处理后每组定位信号的噪声功率降低，所以应用本申请实施例能够减少接收的定位信号的噪声功率，从而提高了接收的定位信号的信噪比，提高了接收机的捕获灵敏度，能够提高弱信号的捕获成功率。
参见图4，图4为本申请实施例提供的一种信号捕获方法中频率补偿的方法流程图，包括如下步骤：
步骤401，对基站发送的定位信号进行模数转换，并根据预设采样速率对定位信号进行采样。
可选的，根据图2中的描述可知，块平均信号长度通常选择定位信号中PRN码长度的整数倍，所以采样速率可以为定位信号中PRN码速率的整数倍，在TC-OFDM系统中，PRN码周期时长为2.5ms，其中，速率和周期互为倒数。
步骤402，根据采样结果，将定位信号分为至少两组。
可选的，可以将定位信号分为X组，每组定位信号中包含M*N个采样点；其中，M是预设的，M为块平均处理时信号块的数量，N为系统的固定参数，N为块平均处理时信号块中采样点的数量，“*”表示相乘运算。
其中，由于信号块的长度为定位信号中PRN码周期长度的整数倍，信号块长度可以取定位信号的一个PRN码周期；TC-OFDM系统中使用的PRN码为码长为10230的测距码(weil码)，接收机对weil码的采样倍数为4.4倍，因此每个PRN码周期中含有45012个采样点，即每个信号块中含有45012个采样点。
其中，weil码是由勒让德序列生成的一种测距码。
需要说明的是，M和X是预设的，通过如下方法确定：
结合图5所示的块平均响应的示意图，块平均响应的通带主瓣宽度为2/NMT s，在信号块频率与快平均响应主瓣中心频率之差固定的情况下，M越大，定位信号衰减越快，为了避免定位信号的快速衰减，频率补偿的组数X应 该增大。先获得X组信号中定位信号的多普勒频率与块平均响应通带中心频率差最小的一组定位信号，根据该组定位信号确定由频率偏差引起的定位信号幅度最大衰减函数(5)：
Figure PCTCN2019077451-appb-000024
当信号组数X的取值远小于信号块数M时，会导致定位信号衰减严重，使得每组定位信号在块平均处理后，无法提高接收到由基站发出的定位信号的信噪比。所以，需要限定由于频率偏差引起的定位信号幅度衰减值不能超过衰减阈值，衰减阈值可以设置为3分贝，当衰减阈值为3分贝时，M和X的取值限制条件如公式(6)：
Figure PCTCN2019077451-appb-000025
满足公式(6)的(M，X)的取值组合都能够实现本申请实施例。
示例性的，X可以为10，M可以为10。
步骤403，分别对每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
下面分析需要进行频率补偿的原因：
如图5所示，块平均处理中落在阻带内的噪声分量将被抑制，所以块平均处理可以看作一个梳妆滤波器。从图5中可知，块平均响应的通带周期为1/NT s，可见，通带周期与采样速率及信号块内采样点数有关，与块平均的信号块数量无关。从图5中可知，块平均响应的通带主瓣宽度为2/NMT s，信号块数量越多，通带越窄且阻带越宽，同时阻带衰减也越高；可见，信号块数量决定了通带宽度和阻带衰减。定位信号若经过基带处理后直接进入块平均处理，由于定位信号的多普勒频率f d未知，则无法保证f d恰好落在块平均响应的通带以内，所以需要在块平均处理之前对定位信号进行频率补偿。
下面说明频率补偿的范围选择在一个通带周期内的原因：
将接收到的定位信号分为X组，每组定位信号进行频率补偿的频率为δf (i)，若频率补偿的范围为(0,1/NT s)，使得频率补偿后每组定位信号间的频率差值为1/XNT s，即δf (i)＝i/XNT s。由于X组定位信号频率共补偿了1/NT s，所以X组定位信号中必定有一组定位信号的频率落在块平均响应的通带以内，即可以保证有一组定位信号的f d恰好落在块平均响应的通带以内。
具体的，频率补偿的方法可以为：参见图1，将定位信号分为X组，每组定位信号分别与本地载波发生器发出的本地载波相乘，得到每组定位信号频率补偿后的信号。经过频率补偿后的每组定位信号为公式(7)：
Figure PCTCN2019077451-appb-000026
其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000027
为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000028
为载波相位，v(nT s)为第n个采样点的噪声。
可见，应用本申请实施例，能够通过分组进行频率补偿，使得每组定位信号在经过块平均处理后能够保证至少有一组定位信号落在块平均响应的通带以内，该组定位信号在经过PMF-FFT运算后会得到最大峰均比，根据最大峰均比判断定位信号是否捕获成功。这样，由于块平均处理模块处理后的定位信号的噪声功率降低，所以提高了定位信号的信噪比，提高了定位信号的捕获成功率。
在本申请实施例中，定位信号在经过块平均和频率补偿后，可以经过如下方式捕获定位信号并确定捕获结果：
方式一，可以利用PMF-FFT的方式确定捕获结果，具体步骤如下：
分别对经过块平均处理之后的每组定位信号进行PMF-FFT运算，得到每组定位信号的幅频响应；
根据每组定位信号的幅频响应确定每组定位信号的峰均比，第i组定位信 号的峰均比为第i组幅频响应中的幅值最大值与幅值均值的比值：
Figure PCTCN2019077451-appb-000029
其中，f (i)为第i组定位信号的峰均比，
Figure PCTCN2019077451-appb-000030
为第i组定位信号幅频响应的F个幅值中的最大值，
Figure PCTCN2019077451-appb-000031
为第i组定位信号幅频响应的第n采样点的幅值，F为参与FFT运算的采样点数量。
幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值；其中，预设数量为F。
若峰均比最大的一组定位信号的峰均比大于预设阈值，则捕获结果为捕获成功；若峰均比最大的一组定位信号的峰均比不大于预设阈值，则捕获结果为捕获失败。
图6为图1中的PMF-FFT捕获模块、峰值比较模块和确定捕获结果模块进行信号捕获的过程的示意图。如图6所示，先将块平均处理后的每组定位信号进行部分匹配滤波处理。假设每个相关器的长度为P，共有L个相关器，则每组定位信号被分为L块，每块定位信号中包含P个采样点。每个相关器对每块定位信号中的P个采样点进行相关累加，部分匹配滤波的过程如公式(9)：
Figure PCTCN2019077451-appb-000032
其中，
Figure PCTCN2019077451-appb-000033
为第i组定位信号的第n个采样点滤波处理后的信号，n为采样点序号，
Figure PCTCN2019077451-appb-000034
为频率补偿后的第i组定位信号的频率，k为相关器的序号，k＝0，1，…,L-1，
Figure PCTCN2019077451-appb-000035
为第i组定位信号中第n个采样点块平均处理后的信号，l(n)为本地伪码发生器发出的第n个本地码。
若不考虑比特反转和噪声的影响，当本地码与接收到的定位信号的PRN码相同且相位一致时，公式(9)可化为：
Figure PCTCN2019077451-appb-000036
再将部分匹配滤波处理后得到的L个滤波处理后的采样点进行补0操作，得到F个采样点，并对F个采样点进行FFT运算，其中，F为2的整数次幂。得到FFT运算后的每组定位信号的幅频响应为公式(11)。示例性地，其中一组定位信号的PMF-FFT幅频响应曲线如图7。
Figure PCTCN2019077451-appb-000037
其中，
Figure PCTCN2019077451-appb-000038
为第i组定位信号第k个采样点的幅频响应，k为相关器的序号，k＝0，1，…,L-1，
Figure PCTCN2019077451-appb-000039
为频率补偿后的第i组定位信号的频率，
Figure PCTCN2019077451-appb-000040
为第i组定位信号的第n个采样点滤波处理后的信号，
Figure PCTCN2019077451-appb-000041
为第i组定位信号的块平均响应。
根据FFT的计算结果可知，第i组定位信号的频率分辨率为1/2PFT s，频率搜索范围为±1/2PT s。当本地码与定位信号的伪码相同且相位一致时，通过FFT得到的第i组定位信号的幅频响应曲线会在
Figure PCTCN2019077451-appb-000042
处产生最大峰值。
根据FFT输出的幅频响应，计算X组信号峰均比最大的一组；每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值，将峰均比最大的一组定位信号的峰均比与预设门限值比较。
示例性的，门限值可以设置为1.5；
若峰均比最大的一组定位信号的峰均比大于1.5，则捕获结果为捕获成功；
若峰均比最大的一组定位信号的峰均比不大于1.5，则捕获结果为捕获失败。
在本申请实施例中，定位信号的捕获存在四种情况：信号存在且捕获成功，信号存在但捕获失败，信号不存在但捕获成功，信号不存在且捕获失败。其中，信号存在且捕获成功的概率为实警率，信号不存在但捕获成功的概率为虚警率，在设置门限值时需要权衡实警率和虚警率，设置合理的门限值。
在部分匹配滤波处理后，得到的L个采样点的的噪声均呈均值为0，方差为σ 2的正态分布，则这L个采样点经过FFT运算后，噪声会呈现均值为0，方差为
Figure PCTCN2019077451-appb-000043
的正态分布。根据概率论的知识，在定位信号存在时FFT的幅频响应曲线呈莱斯分布，在定位信号不存在时FFT的幅频响应曲线呈瑞利分布，假设在定位信号存在时FFT幅频响应曲线的概率密度函数为f s(v)，定位信号不存在时FFT幅频响应曲线的概率密度函数为f n(v)，则虚警率P fa满足公式(12)：
Figure PCTCN2019077451-appb-000044
实警率P d满足公式(13)：
Figure PCTCN2019077451-appb-000045
其中，F为参与FFT运算的采样点的数量，v为定位信号的幅值，v t为门限值。
门限值v t需要满足P fa小于虚警率阈值和P d大于实警率阈值。
例如，虚警率阈值可以设置为0.1％或1％，实警率阈值可以设置为95％或90％。
方式二，利用快速傅里叶变换和快速傅里叶逆变换结合的方式捕获定位信号，具体步骤如下：
参见图8，图8为本申请实施例提供的快速傅里叶变换和快速傅里叶逆变换结合的运算方法流程图，包括：
将载波振荡器发出的载波信号经过正弦处理和预先处理后分别与经过频率补偿及块平均处理后的定位信号进行快速傅里叶变换，将经过快速傅里叶变换后的定位信号与本地伪码发生器发出的本地伪码经过快速傅里叶变换和复数共轭运算后相乘，将相乘后的定位信号进行快速傅里叶逆变换，得到码 相位和多普勒频率，根据码相位和多普勒频率判断定位信号是否捕获成功。
进一步的，在判断接收的定位信号是否捕获成功后，还可以计算接收的定位信号码相位估计值，包括：
根据方式一中描述，本地码与块平均处理后的每组信号相乘，对乘积进行FFT运算，获得块平均处理后的每组信号的幅频响应；当一组定位信号的本地码与该组定位信号伪码粗对齐时，该组定位信号幅频响应曲线将出现峰值，在该组定位信号幅频响应的最大幅值处，此时对应的本地码相位即为该组定位信号码相位估计值；
一般情况下，M组定位信号的码相位估计值会近似相等，所以可以选择任意一组定位信号的码相位估计值或峰均比最大的一组定位信号的码相位估计值确定为接收到的基站发送的定位信号的码相位估计值；但当M组定位信号的码相位估计值不同时，取M组定位信号中峰均比最大的一组定位信号的码相位估计值确定为接收的定位信号的码相位估计值。
进一步的，在判断定位信号是否捕获成功之后，还可以计算接收到的基站发送的定位信号的频率估计值，即接收到的基站发送的定位信号的多普勒频率估计值，包括：
根据确定捕获结果的方式一得到的幅频响应以及峰均比最大的一组定位信号，可以得到定位信号的多普勒频率的初步频率估计值
Figure PCTCN2019077451-appb-000046
为：
Figure PCTCN2019077451-appb-000047
其中，k为相关器的序号，P为相关器中采样点的数量，F为参与FFT运算的采样点数量，T s为定位信号的采样周期。
根据步骤403中的描述可知，峰均比最大的一组定位信号必定在块平均响应的通带以内，则可以认为该组信号的频率是1/NT s的整数倍，因此能够得到定位信号的多普勒频率估计值f d′为：
Figure PCTCN2019077451-appb-000048
其中，round表示取与计算结果距离最小的整数，
Figure PCTCN2019077451-appb-000049
为初步频率估计值，N为信号块中采样点的数量，T s为定位信号的采样周期，δf (i)为第i组定位信号补偿的频率。
根据公式(15)可知，估计出的多普勒频率的精度取决于1/XNT s，由于δf (i)＝i/XNT s，所以频率补偿的步进越小，估计出的多普勒频率估计值越准确。
需要说明的是，传统的PMF-FFT捕获方法中的多普勒频率估计值是根据公式(14)计算的，由公式(14)可知，传统的多普勒频率估计精度为1/PFT s。而本申请实施例得到的多普勒频率估计值的精度为1/XNT s，由于1/PFT s>1/XNT s，所以本申请实施例能够得到更精确的多普勒频率估计值。
下面证明1/PFT s>1/XNT s：
由于P为相关器中的采样点数量，L为相关器数量，N为信号块中的采样点数量，X为每组定位信号中信号块数量。
根据确定捕获结果的方式一中的描述可知，N＝PL，L个采样点需要补零成为F个采样点，可以得到：L<F<2L，因此，PF<2PL＝2N；当X≥2时，即可满足PF<XN，由于定位信号至少被分为两组，可得X≥2，所以1/PFT s>1/XNT s成立。
可见，应用本申请实施例得到的定位信号的多普勒频率估计值相对于传统的PMF-FFT捕获方法得到的定位信号的多普勒频率估计值更为精确，更精确的多普勒频率估计值一方面能够使得接收机在定位信号捕获成功后，更快速的进入精确跟踪状态；另一方面当接收的定位信号为弱信号时，更精确的多普勒频率估计值能够完成对信号的牵入从而更快的转入精确跟踪阶段；使得能够更快的获得精确的测距信息。
参见图9，图9为本申请实施例提供的一种信号捕获装置，该装置包括：
信号接收模块901，用于接收基站发送的定位信号；
频率补偿模块902，用于将信号接收模块接收的定位信号分为至少两组，分别对每组定位信号进行频率补偿；
块平均处理模块903，用于将经过频率补偿模块处理后的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号；
确定模块904，用于根据经过块平均处理模块处理后的每组定位信号，确定捕获结果。
具体的，频率补偿模块902，可以包括：采样单元、分组单元和频率补偿单元；
采样单元，用于对基站发送的定位信号进行模数转换，并根据预设采样速率对定位信号进行采样；
分组单元，用于根据采样单元确定的采样结果，将定位信号分为至少两组；
频率补偿单元，用于分别对分组单元拆分的每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
具体的，块平均处理模块903，可以具体用于：
将经过频率补偿的每组定位信号分为至少两个信号块，每个信号块中包括相同数量的采样点；
对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
具体的，经过频率补偿后的每组定位信号可以为：
Figure PCTCN2019077451-appb-000050
其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000051
为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000052
为载波相位，v(nT s)为第n个采样点的噪声；
经过块平均处理后的每组定位信号可以为：
Figure PCTCN2019077451-appb-000053
其中，n为采样点的序号，
Figure PCTCN2019077451-appb-000054
为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
Figure PCTCN2019077451-appb-000055
为第i组定位信号的频率，T s为信号采样周期，
Figure PCTCN2019077451-appb-000056
为载波相位，
Figure PCTCN2019077451-appb-000057
为第i组定位信号的块平均响应，v B(nT s)为第n个采样点的噪声经过块平均处理后的分量。
具体的，确定模块904，可以包括：运算单元、峰均比确定单元、确定单元、判断单元和参数估计单元；
运算单元，用于分别对经过块平均处理之后的每组定位信号进行部分匹配滤波-快速傅里叶变换PMF-FFT运算，得到每组定位信号的幅频响应；
峰均比确定单元，用于根据运算单元计算的每组定位信号的幅频响应确定每组定位信号的峰均比，每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值；
确定单元，用于从峰均比确定单元确定的至少两组定位信号的峰均比中确定峰均比最大的一组定位信号；
判断单元，用于若确定单元确定的峰均比最大的一组定位信号的峰均比大于预设阈值，则捕获结果为捕获成功；若确定单元确定的峰均比最大的一组定位信号的峰均比不大于预设阈值，则捕获结果为捕获失败；
参数估计单元，用于若捕获结果为捕获成功，则根据确定单元确定的至少两组定位信号中峰均比最大的一组定位信号，确定接收到的基站发送的定位信号的码相位估计值和频率估计值。
本申请实施例提供的一种信号捕获装置，可以将接收到的由基站发出的 定位信号分为至少两组，分别对每组定位信号进行频率补偿；将频率补偿后的每组定位信号分为至少两个信号块，对每组信号中信号块进行平均运算；根据块平均处理后的每组定位信号，确定捕获结果。这样，由于块平均处理后每组定位信号的噪声功率降低，所以应用本申请实施例能够减少接收的定位信号的噪声功率，从而提高了接收的定位信号的信噪比，提高了接收机的捕获灵敏度，能够提高弱信号的捕获成功率。
由于频率补偿和块平均处理与捕获模块结合能够提高频率估计精度，所以应用本申请实施例能够在捕获阶段获得更加精确的频率估计值。
本申请实施例还提供了一种电子设备，如图10所示，包括处理器1001、通信接口1002、存储器1003和通信总线1004，其中，处理器1001，通信接口1002，存储器1003通过通信总线1004完成相互间的通信，
存储器1003，用于存放计算机程序；
处理器1001，用于执行存储器1003上所存放的程序时，实现上述方法实施例中由电子设备执行的步骤。
本申请实施例提供的一种信号捕获电子设备，可以将接收到的由基站发出的定位信号分为至少两组，分别对每组定位信号进行频率补偿；将频率补偿后的每组定位信号分为至少两个信号块，对每组信号中信号块进行平均运算；根据块平均处理后的每组定位信号，确定捕获结果。这样，由于块平均处理后每组定位信号的噪声功率降低，所以应用本申请实施例能够减少接收的定位信号的噪声功率，从而提高了接收的定位信号的信噪比，提高了接收机的捕获灵敏度，能够提高弱信号的捕获成功率。
由于频率补偿和块平均处理与捕获模块结合能够提高频率估计精度，所以应用本申请实施例能够在捕获阶段获得更加精确的频率估计值。
上述电子设备提到的通信总线可以是外设部件互连标准(Peripheral Component Interconnect，PCI)总线或扩展工业标准结构(Extended Industry Standard Architecture，EISA)总线等。该通信总线可以分为地址总线、数据总线、控制总线等。为便于表示，图中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
通信接口用于上述电子设备与其他设备之间的通信。
存储器可以包括随机存取存储器(Random Access Memory，RAM)，也可以包括非易失性存储器(Non-Volatile Memory，NVM)，例如至少一个磁盘存储器。可选的，存储器还可以是至少一个位于远离前述处理器的存储装置。
上述的处理器可以是通用处理器，包括中央处理器(Central Processing Unit，CPU)、网络处理器(Network Processor，NP)等；还可以是数字信号处理器(Digital Signal Processing，DSP)、专用集成电路(Application Specific Integrated Circuit，ASIC)、现场可编程门阵列(Field-Programmable Gate Array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。
在本申请提供的又一实施例中，还提供了一种计算机可读存储介质，该计算机可读存储介质内存储有计算机程序，所述计算机程序被处理器执行时实现上述任一信号捕获方法的步骤。
在本申请提供的又一实施例中，还提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行上述实施例中任一信号捕获方法。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如，软盘、硬盘、磁带)、光介质(例如，DVD)、或者半导体介质 (例如固态硬盘Solid State Disk(SSD))等。
需要说明的是，在本文中，诸如第一和第二等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。
本说明书中的各个实施例均采用相关的方式描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点说明的都是与其他实施例的不同之处。尤其，对于装置实施例而言，由于其基本相似于方法实施例，所以描述的比较简单，相关之处参见方法实施例的部分说明即可。
以上所述仅为本申请的较佳实施例而已，并非用于限定本申请的保护范围。凡在本申请的精神和原则之内所作的任何修改、等同替换、改进等，均包含在本申请的保护范围内。

Claims (13)

  1. 一种信号捕获方法，其特征在于，所述方法包括：
    接收基站发送的定位信号；
    将所述定位信号分为至少两组，分别对每组定位信号进行频率补偿；
    将经过频率补偿的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号；
    根据经过块平均处理后的每组定位信号，确定捕获结果。
  2. 根据权利要求1所述的方法，其特征在于，所述将所述定位信号分为至少两组，分别对每组定位信号进行频率补偿，包括：
    对所述基站发送的定位信号进行模数转换，并根据预设采样速率对所述定位信号进行采样；
    根据所述采样结果，将所述定位信号分为至少两组；
    分别对每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
  3. 根据权利要求2所述的方法，其特征在于，所述将经过频率补偿的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号，包括：
    将经过频率补偿的每组定位信号分为至少两个信号块，每个信号块中包括相同数量的采样点；
    对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
  4. 根据权利要求3所述的方法，其特征在于，
    所述经过频率补偿后的每组定位信号为：
    Figure PCTCN2019077451-appb-100001
    其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
    Figure PCTCN2019077451-appb-100002
    为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
    Figure PCTCN2019077451-appb-100003
    为载波相位，v(nT s)为第n个采样点的噪声；
    所述经过块平均处理后的每组定位信号为：
    Figure PCTCN2019077451-appb-100004
    其中，n为采样点的序号，
    Figure PCTCN2019077451-appb-100005
    为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
    Figure PCTCN2019077451-appb-100006
    为第i组定位信号的频率，T s为信号采样周期，
    Figure PCTCN2019077451-appb-100007
    为载波相位，
    Figure PCTCN2019077451-appb-100008
    为第i组定位信号的块平均响应，v B(nT s)为第n个采样点的噪声经过块平均处理后的分量。
  5. 根据权利要求1-4任一项所述的方法，其特征在于，所述根据经过块平均处理后的每组定位信号，确定捕获结果，包括：
    分别对经过块平均处理之后的每组定位信号进行部分匹配滤波-快速傅里叶变换PMF-FFT运算，得到每组定位信号的幅频响应；
    根据每组定位信号的幅频响应确定每组定位信号的峰均比，所述每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；所述幅值平均值为每组定位信号的幅频响应中预设数量的幅值的平均值；
    从所述至少两组定位信号的峰均比中确定峰均比最大的一组定位信号；
    若峰均比最大的一组定位信号的峰均比大于预设阈值，则所述捕获结果为捕获成功；若峰均比最大的一组定位信号的峰均比不大于预设阈值，则所述捕获结果为捕获失败；
    若捕获结果为捕获成功，则根据所述至少两组定位信号中峰均比最大的一组定位信号，确定所述接收到的基站发送的定位信号的码相位估计值和频率估计值。
  6. 一种信号捕获装置，其特征在于，所述装置包括：
    信号接收模块，用于接收基站发送的定位信号；
    频率补偿模块，用于将所述信号接收模块接收的所述定位信号分为至少两组，分别对每组定位信号进行频率补偿；
    块平均处理模块，用于将经过所述频率补偿模块处理后的每组定位信号分为至少两个信号块，分别对每组信号中的信号块进行平均运算，得到经过块平均处理后的每组定位信号；
    确定模块，用于根据经过所述块平均处理模块处理后的每组定位信号，确定捕获结果。
  7. 根据权利要求6所述的装置，其特征在于，所述频率补偿模块，包括：采样单元、分组单元和频率补偿单元；
    所述采样单元，用于对所述基站发送的定位信号进行模数转换，并根据预设采样速率对所述定位信号进行采样；
    所述分组单元，用于根据所述采样单元确定的所述采样结果，将所述定位信号分为至少两组；
    所述频率补偿单元，用于分别对所述分组单元拆分的每组定位信号进行频率补偿，频率补偿的范围不超过一个通带周期。
  8. 根据权利要求7所述的装置，其特征在于，所述块平均处理模块，具体用于：
    将经过频率补偿的每组定位信号分为至少两个信号块，每个信号块中包括相同数量的采样点；
    对于每组定位信号，分别对各信号块中各相同位置的采样点进行平均运算，得到经过块平均处理后的每组定位信号。
  9. 根据权利要求8所述的装置，其特征在于，
    所述经过频率补偿后的每组定位信号可以为：
    Figure PCTCN2019077451-appb-100009
    其中，n为采样点的序号，r (i)(n)为第i组定位信号中第n个采样点的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
    Figure PCTCN2019077451-appb-100010
    为第i组定位信号经过频率补偿后的频率，T s为信号采样周期，
    Figure PCTCN2019077451-appb-100011
    为载波相位，v(nT s)为第n个采样点的噪声；
    所述经过块平均处理后的每组定位信号可以为：
    Figure PCTCN2019077451-appb-100012
    其中，n为采样点的序号，
    Figure PCTCN2019077451-appb-100013
    为第i组定位信号中第n个采样点块平均处理后的信号，A为信号幅度，d(nT s)为第n个采样点的导航电文，c(nT s)为第n个采样点的伪噪声码，
    Figure PCTCN2019077451-appb-100014
    为第i组定位信号的频率，T s为信号采样周期，
    Figure PCTCN2019077451-appb-100015
    为载波相位，
    Figure PCTCN2019077451-appb-100016
    为第i组定位信号的块平均响应，v B(nT s)为第n个采样点的噪声经过块平均处理后的分量。
  10. 根据权利要求6-9任一项所述的装置，其特征在于，所述确定模块，包括：运算单元、峰均比确定单元、确定单元、判断单元和参数估计单元；
    所述运算单元，用于分别对经过块平均处理之后的每组定位信号进行部分匹配滤波-快速傅里叶变换PMF-FFT运算，得到每组定位信号的幅频响应；
    所述峰均比确定单元，用于根据所述运算单元计算的每组定位信号的幅频响应确定每组定位信号的峰均比，所述每组定位信号的峰均比为各自组定位信号幅频响应中的幅值最大值与幅值平均值的比值；所述幅值平均值为每 组定位信号的幅频响应中预设数量的幅值的平均值；
    所述确定单元，用于从所述峰均比确定单元确定的所述至少两组定位信号的峰均比中确定峰均比最大的一组定位信号；
    所述判断单元，用于若所述确定单元确定的峰均比最大的一组定位信号的峰均比大于预设阈值，则所述捕获结果为捕获成功；若所述确定单元确定的峰均比最大的一组定位信号的峰均比不大于预设阈值，则所述捕获结果为捕获失败；
    参数估计单元，用于若捕获结果为捕获成功，则根据所述确定单元确定的至少两组定位信号中峰均比最大的一组定位信号，确定所述接收到的基站发送的定位信号的码相位估计值和频率估计值。
  11. 一种电子设备，其特征在于，包括处理器、通信接口、存储器和通信总线，其中，处理器，通信接口，存储器通过通信总线完成相互间的通信；
    存储器，用于存放计算机程序；
    处理器，用于执行存储器上所存放的程序时，实现权利要求1-5任一所述的方法步骤。
  12. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质内存储有计算机程序，所述计算机程序被处理器执行时实现权利要求1-5任一所述的方法步骤。
  13. 一种计算机程序产品，其特征在于，当其在计算机上运行时，使得计算机执行权利要求1-5任一所述的方法步骤。
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