Satellite internet rapid high-precision navigation positioning method

Abstract

The invention provides a satellite internet rapid high-precision navigation positioning method, a transmitting end modulates a navigation message and broadcasts the navigation message through a satellite internet frequency band, the advantage of satellite internet multi-carrier modulation is utilized, an I branch of QPSK is adopted for rapid parallel broadcasting, and the satellite internet multi-carrier modulation speed is improved. Basic navigation positioning parameters obtained for the first time are improved from the second level to the millisecond level of single-wave-position residence; a receiving end demodulates a received signal to obtain a navigation message, QPSK modulation is adopted, phase division is carried out on a Q branch supporting high-precision measurement and an I branch of the modulated message, and the Q branch is used for high-precision frequency offset estimation and time delay estimation; and the branch I carries out rapid navigation message broadcasting, so that high-precision frequency and time delay measurement is realized, and rapid message broadcasting is also realized.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation, and in particular to a satellite Internet fast and high-precision navigation and positioning method. Background Art

[0002] With the rise of the construction of satellite Internet systems, navigation and positioning based on satellite Internet constellations has gradually become a research hotspot in the field of satellite navigation.

[0003] The beam range broadcast by the satellite Internet constellation is relatively narrow, and generally multi-wavelength polling is used to achieve wide-area coverage. Assuming there are 1,000 wavelengths and each wavelength has a dwell time of 5ms, the polling cycle is as long as 5s. In addition, the impact of the satellite Internet constellation navigation message frame structure on the positioning time is mainly reflected in the acquisition time of important positioning information such as CED+GST (ephemeris star clock parameters and system time). If the basic parameters CED+GST required for satellite Internet navigation positioning cannot be broadcast to users in a single wavelength, but need to be sent in multiple frames, it will take a long time for users to receive all CED+GST information. Assuming that 10 frames of navigation messages need to be broadcast, the total time for the first collection of CED+GST information is 50s.

[0004] At the same time, satellite Internet navigation positioning signals are generally burst signals. Users need to receive multiple frames to complete the first positioning, which requires high channel conditions. If a frame of telegram is not received, it will affect the current positioning and it will take another 50 seconds to position. The traditional GNSS telegram frame structure normalizes the data rate to 50bps, and the shortest acquisition time is about 18s. If the acquisition time of the basic parameters CED+GST of satellite Internet navigation positioning can be reduced to the single-wave position dwell time (for example, 5ms), it will have important engineering application value and system innovation value.

[0005] In addition to the rapid broadcast of navigation messages, satellite Internet navigation signals must also support high-precision Doppler and delay measurements to achieve satellite-to-ground pseudo-range calculations. This requires that satellite Internet navigation signals must also be compatible with high-precision measurement system design. Summary of the invention

[0006] In view of the problem in the prior art that the satellite Internet beam polling cycle is long, resulting in a long time to receive all navigation messages and the demand for high-precision measurement, the present invention proposes a satellite Internet fast and high-precision navigation and positioning method, thereby achieving rapid positioning with millimeter-level message acquisition time and meter-level high-precision measurement.

[0007] The technical solution of the present invention is:

[0008] A satellite Internet fast and high-precision navigation and positioning method comprises the following steps:

[0009] Step 1: Modulate the navigation message and broadcast it through the satellite Internet frequency band; including the following processes:

[0010] Step 1.1: Perform CRC check, channel coding and interleaving operations on the navigation message to form a navigation message frame sequence ;

[0011] Step 1.2: The navigation message frame sequence after encoding and interleaving in step 1.1 A pseudo-random code is used for spread spectrum modulation to generate an I-branch baseband signal; the I-branch baseband signal obtained after spread spectrum modulation and the Q-branch pilot signal are then QPSK modulated to generate a navigation baseband complex sequence, wherein the Q-branch pilot signal does not modulate the telegram information;

[0012] Step 1.3: Perform subcarrier mapping on the navigation baseband complex sequence obtained in step 1.2, use IFFT operation, and fuse the navigation signal and communication signal to obtain the CP-OFDM baseband time domain waveform , then the obtained CP-OFDM baseband time domain waveform is up-converted and modulated, and broadcasted via the satellite Internet frequency band;

[0013] Step 2: Demodulate the received signal to obtain the navigation message; specifically, the following process is included:

[0014] Step 2.1: Down-convert the received signal, and generate a Q branch reference signal complex sequence locally, and use IFFT operation on the Q branch reference signal complex sequence to generate a reference signal CP-OFDM time domain waveform;

[0015] Step 2.2: performing time domain correlation on the reference signal CP-OFDM time domain waveform and the received signal after down-conversion to obtain a frequency offset estimation value and an integer delay estimation value; performing frequency domain correlation on the reference signal CP-OFDM time domain waveform and the received signal after down-conversion to obtain a fractional delay estimation value; obtaining a total delay estimation value according to the integer delay estimation value and the fractional delay estimation value;

[0016] Step 2.3: Correlate the received signal after stripping the frequency offset with the I branch pseudo code signal in the received signal after down-conversion according to the frequency offset estimation value and the total delay estimation value, estimate the message symbol according to the correlation value, deinterleave and decode the message symbol estimation, and obtain a demodulated navigation message;

[0017] Step 3: Complete high-precision navigation positioning based on the navigation message demodulated in step 2 and the total delay estimate.

[0018] Furthermore, the specific process of step 1.1 is:

[0019] (101): CRC check: Assume the navigation message is ,in Represents the discrete sequence number, and the CRC generating polynomial is , then the navigation message sequence after CRC check is: ;

[0020] (102): Channel coding: The navigation message sequence after CRC check is Perform convolution or LDPC channel coding, and assume that the convolution or LDPC channel coding generation matrix is , then the encoded navigation message sequence for: ;

[0021] (103): Interleaving coding: Interleave the navigation message after channel coding, and set the interleaving matrix as , then the interleaved navigation message frame sequence is for: .

[0022] Furthermore, the specific process of step 1.2 is as follows:

[0023] (201): Using pseudo-random code to align the navigation message frame sequence Perform spread spectrum modulation: Assume the pseudo-random code sequence of branch I is , then the I branch baseband signal obtained after spread spectrum modulation is for: ;

[0024] (202): QPSK modulation: QPSK modulation is performed on the I branch baseband signal and the Q branch pilot signal obtained after spread spectrum modulation. Let the Q branch pilot signal be , then the navigation baseband complex sequence obtained after QPSK modulation is for: , where Superscript Indicates the launch system, subscript Indicates the navigation baseband, Represents an imaginary unit.

[0025] Furthermore, the specific process of step 1.3 is as follows:

[0026] (301): Perform subcarrier mapping on the navigation baseband complex sequence obtained after QPSK modulation: Assume that the number of available subcarriers for navigation is , the satellite Internet beam dwell time is , the total number of OFDM symbols in the dwell time is , then the number of navigation messages mapped to each subcarrier is: ,in is the spreading ratio;

[0027] (302): Perform IFFT operation on the QPSK modulation sequence after subcarrier mapping to generate OFDM symbols, and insert cyclic redundancy CP into the OFDM symbols to generate CP-OFDM navigation baseband waveform ,in is the number of inverse Fourier transform points, is the OFDM symbol period, Indicates the moment;

[0028] (303): According to the satellite Internet configuration, the navigation signal can be unified with the communication signal to generate a CP-OFDM baseband time domain waveform to achieve signal level fusion; the fused CP-OFDM baseband time domain waveform is as follows:

[0029]

[0030] in is the communication baseband complex sequence, occupying subcarriers, navigation baseband complex sequence Occupancy subcarriers;

[0031] (304): Perform up-conversion modulation on the obtained CP-OFDM baseband time domain waveform to obtain an up-conversion modulation signal:

[0032]

[0033] in is the carrier frequency.

[0034] Furthermore, the specific process of step 2.1 is:

[0035] (401): Establish a receiving signal model: Assume that after the transmitted signal passes through the Gaussian white noise propagation channel, the frequency deviation is , the delay is , then the received signal after down-conversion is: ,in is the amplitude, is Gaussian white noise;

[0036] (402): Generate a reference signal: Generate a Q branch reference signal complex sequence according to the Q branch pilot signal: , perform IFFT operation on the Q branch reference signal complex sequence to generate a reference signal CP-OFDM time domain waveform: .

[0037] Furthermore, the specific process of step 2.2 is as follows:

[0038] (501): Frequency offset estimation and integer time delay estimation: The reference signal CP-OFDM time domain waveform is correlated with the received signal in the time domain, and the Doppler and integer time delay ranges are traversed to perform two-dimensional frequency offset and integer time delay estimation. The estimation method is as follows:

[0039] R r ( Δ f , τ ) = ifft [ fft ( S base r ( t ) ) fft ∗ ( S ref r ( t ) ) ]

[0040]

[0041] In the formula is the Fourier transform, is the Fourier transform The conjugate of is the inverse Fourier transform, is the frequency offset estimate, is the integer delay estimate, represents the relevant value, Indicates the maximum value of the correlation value amplitude;

[0042] (502): Fractional delay estimation: The reference signal CP-OFDM time domain waveform is subjected to frequency domain correlation algorithm with the received signal to obtain the fractional delay estimation:

[0043] Defining intermediate variables :

[0044]

[0045] represents the Q branch reference signal complex sequence The conjugate of . Then the fractional delay estimate is for: , where is the complex phase angle calculation function, is an intermediate variable conjugation of;

[0046] Adding the integer delay and the fractional delay gives the total delay estimate: .

[0047] Furthermore, the specific process of step 2.3 is as follows:

[0048] (601): Message demodulation: The received signal is frequency and time-delay adjusted and FFT operation is performed to obtain the received sequence , the received sequence is correlated with the pseudo-random code sequence of the I branch, and the correlation value It is expressed as: R d ata ( k ) = ifft [ fft ( Y ( k ) ) fft ∗ (C I ( k ) ) ] , according to the correlation value, the message symbol is estimated, then the message symbol estimation value for: ,in sign [ • ] is the symbolic operation function;

[0049] (602): Deinterleaving and decoding verification: Deinterleave and decode the message symbol estimate to obtain the original modulated navigation message estimate. ,in , , They are CRC generator polynomials. , channel coding generation matrix , interleaving matrix The inverse matrix of .

[0050] Furthermore, in step 3, the navigation positioning solution is completed by using the satellite Internet ephemeris and clock parameters and system time in the demodulated navigation message, combined with the total delay estimate.

[0051] In addition, the present invention also provides an electronic device and a readable storage medium:

[0052] An electronic device comprises a processor and a memory, wherein the memory is used to store one or more programs;

[0053] When the one or more programs are executed by the processor, the above method is implemented.

[0054] A readable storage medium stores a computer program, and when the computer program is executed by a processor, the above method is implemented.

[0055] Beneficial effects:

[0056] The present invention has the following advantages:

[0057] (1) The beam range of satellite Internet constellations is relatively narrow and is generally a burst signal. If the basic positioning parameters required for the first positioning cannot be broadcast in a single wave position, the first positioning time will be too long, which is not conducive to the rapid positioning of the user terminal. The present invention takes advantage of the satellite Internet multi-carrier modulation to broadcast the message parameters required for navigation positioning quickly and in parallel using the I branch of QPSK, thereby improving the first acquisition of basic navigation positioning parameters from seconds to milliseconds of a single wave position. For example, through multi-carrier modulation, a 900-bit navigation message can be broadcast in about 240 subcarriers. The broadcasting time is the residence time of a wave position. If it is 5ms, then the acquisition time of the entire basic navigation positioning parameters is in milliseconds.

[0058] (2) In addition to fast message broadcasting, the satellite Internet constellation positioning signal also needs to support high-precision measurement, that is, support high-precision Doppler estimation and time delay estimation. To this end, the present invention adopts QPSK modulation to separate the Q branch supporting high-precision measurement from the I branch of the modulated message, where the Q branch is used for high-precision frequency offset estimation and time delay estimation; the I branch performs fast navigation message broadcasting, thereby achieving both high-precision frequency and delay measurement and fast message broadcasting.

[0059] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0061] Figure 1 It is a system principle block diagram of the present invention;

[0062] Figure 2 is a frequency estimation curve of an embodiment;

[0063] Figure 3 is a delay estimation curve of an embodiment;

[0064] Figure 4 It is a demodulation performance curve of the embodiment. DETAILED DESCRIPTION

[0065] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0066] Figure 1 The principle block diagram of the satellite Internet fast and high-precision navigation and positioning method proposed in this embodiment is described in detail, and the principle block diagram includes a modulation part and a demodulation part. Specifically, the following steps are included:

[0067] Step 1: Modulate the navigation message and broadcast it through the satellite Internet frequency band; specifically, the following processes are involved:

[0068] Step 1.1: Perform CRC check, channel coding and interleaving operations on the navigation message to form a navigation message frame sequence; the specific process is as follows:

[0069] (101): CRC check: Assume the navigation message is ,in Represents the discrete sequence number, and the CRC generating polynomial is , then the navigation message sequence after CRC check is: ;

[0070] (102): Channel coding: The navigation message sequence after CRC check is Perform convolution or LDPC channel coding, and assume that the convolution or LDPC channel coding generation matrix is , then the encoded navigation message sequence for: ;

[0071] (103): Interleaving coding: Interleave the navigation message after channel coding, and set the interleaving matrix as , then the interleaved navigation message frame sequence is for: .

[0072] Step 1.2: The navigation message frame sequence after encoding and interleaving in step 1.1 Use pseudo-random code for spread spectrum modulation to generate an I-branch baseband signal; then perform QPSK modulation on the I-branch baseband signal obtained after spread spectrum modulation and the Q-branch pilot signal to generate a navigation baseband complex sequence, where the Q-branch pilot signal does not modulate the message information, supporting high-precision Doppler measurement and delay measurement; the specific process is:

[0073] (201): Using pseudo-random code to align the navigation message frame sequence Perform spread spectrum modulation: Assume the pseudo-random code sequence of branch I is , then the I branch baseband signal obtained after spread spectrum modulation is for: ;

[0074] (202): QPSK modulation: QPSK modulation is performed on the I branch baseband signal and the Q branch pilot signal obtained after spread spectrum modulation. Let the Q branch pilot signal be , then the navigation baseband complex sequence obtained after QPSK modulation is for: , where Superscript Indicates the launch system, subscript Indicates the navigation baseband, Represents an imaginary unit.

[0075] Step 1.3: Perform subcarrier mapping on the navigation baseband complex sequence obtained in step 1.2, use IFFT operation, and fuse the navigation signal and communication signal to obtain the CP-OFDM baseband time domain waveform , and then up-convert and modulate the obtained CP-OFDM baseband time domain waveform and broadcast it through the satellite Internet frequency band; the specific process is:

[0076] (301): Perform subcarrier mapping on the navigation baseband complex sequence obtained after QPSK modulation: Assume that the number of available subcarriers for navigation is , the satellite Internet beam dwell time is , the total number of OFDM symbols in the dwell time is , then the number of navigation messages mapped to each subcarrier is: , is the spread spectrum ratio, and the number of navigation messages broadcast within a single wave position dwell time is: .

[0077] (302): Perform IFFT operation on the QPSK modulation sequence after subcarrier mapping to generate OFDM symbols, and insert cyclic redundancy CP into the OFDM symbols to generate CP-OFDM navigation baseband waveform ,in is the number of inverse Fourier transform points, is the OFDM symbol period, Indicates time.

[0078] (303): According to the satellite Internet configuration, the navigation signal can be unified with the communication signal to generate a CP-OFDM baseband time domain waveform to achieve signal level fusion. The fused CP-OFDM baseband time domain waveform is as follows:

[0079]

[0080] in is the communication baseband complex sequence, occupying subcarriers, navigation baseband complex sequence Occupancy subcarriers.

[0081] (304): Perform up-conversion modulation on the obtained CP-OFDM baseband time domain waveform to obtain an up-conversion modulation signal:

[0082]

[0083] in is the carrier frequency.

[0084] Step 2: Demodulate the received signal to obtain the navigation message; specifically, the following process is included:

[0085] Step 2.1: Down-convert the received signal, and generate a Q branch reference signal complex sequence locally, and use IFFT operation on the Q branch reference signal complex sequence to generate a reference signal CP-OFDM time domain waveform; the specific process is:

[0086] (401): Establish a receiving signal model: Assume that after the transmitted signal passes through the Gaussian white noise propagation channel, the frequency deviation is , the delay is , then the received signal after down-conversion is: ,in is the amplitude, is Gaussian white noise.

[0087] (402): Generate a reference signal: Generate a Q branch reference signal complex sequence according to the Q branch pilot signal: , perform IFFT operation on the Q branch reference signal complex sequence to generate a reference signal CP-OFDM time domain waveform: .

[0088] Step 2.2: performing time domain correlation on the reference signal CP-OFDM time domain waveform and the received signal to obtain a frequency offset estimation value and an integer delay estimation value; performing frequency domain correlation on the reference signal CP-OFDM time domain waveform and the received signal to obtain a fractional delay estimation value; the specific process is:

[0089] (501): Frequency offset estimation and integer time delay estimation: The reference signal CP-OFDM time domain waveform is correlated with the received signal in the time domain, and the Doppler and integer time delay ranges are traversed to perform two-dimensional frequency offset and integer time delay estimation. The estimation method is as follows:

[0090] R r ( Δ f , τ ) = ifft [ fft ( S base r ( t ) ) fft ∗ ( S ref r ( t ) ) ]

[0091]

[0092] In the formula is the Fourier transform, is the Fourier transform The conjugate of is the inverse Fourier transform, is the frequency offset estimate, is the integer delay estimate, represents the relevant value, Indicates the maximum value of the correlation value amplitude. Frequency offset estimation accuracy and signal-to-noise ratio Curve Figure 2 ,It can be seen from the figure that when the signal-to-noise ratio is 0dB, the frequency offset estimation accuracy is better than 0.5Hz.

[0093] (502): Fractional delay estimation: The reference signal CP-OFDM time domain waveform is subjected to frequency domain correlation algorithm with the received signal to obtain the fractional delay estimation:

[0094] Defining intermediate variables :

[0095]

[0096] represents the Q branch reference signal complex sequence The conjugate of . Then the fractional delay estimate is for: , where is the complex phase angle calculation function, is an intermediate variable The conjugation of.

[0097] The total delay estimate obtained by adding the integer delay and the fractional delay is: .

[0098] Delay estimation accuracy and signal-to-noise ratio Curve Figure 3 ,It can be seen from the figure that when the signal-to-noise ratio is 0dB, the delay estimation accuracy is better than 1ns.

[0099] Step 2.3: According to the frequency offset estimation value and the delay estimation value, the received signal is stripped of the frequency offset and correlated with the I branch pseudo code signal in the received signal, the message symbol is estimated according to the correlation value, and the message symbol estimation is deinterleaved and decoded to obtain a demodulated navigation message; the specific process is as follows:

[0100] (601): Message demodulation: The received signal is frequency and time-delay adjusted and FFT operation is performed to obtain the received sequence , the received sequence is correlated with the pseudo-random code sequence of the I branch, and the correlation value It is expressed as: R d ata ( k ) = ifft [ fft ( Y ( k ) ) fft ∗ (C I ( k ) ) ] , according to the correlation value, the message symbol is estimated, then the message symbol estimation value for: ,in sign [ • ] is the symbolic operation function.

[0101] Symbol Error Rate and Signal-to-Noise Ratio Curve Figure 4 ,It can be seen from the figure that when the signal-to-noise ratio is 3.15dB, the symbol error rate is better than 2.60E-7.

[0102] (602): Deinterleaving and decoding verification: Deinterleave and decode the message symbol estimate to obtain the original modulated navigation message estimate. ,in , , They are CRC generator polynomials. , channel coding generation matrix , interleaving matrix The inverse matrix of .

[0103] Step 3: Complete high-precision navigation positioning according to the navigation message demodulated in step 2 and the total delay estimate. Specifically, the satellite Internet ephemeris and clock parameters and system time in the demodulated navigation message are combined with the total delay estimate and the known technology in the field can be used to complete fast and high-precision navigation positioning solution.

[0104] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A satellite Internet fast and high-precision navigation and positioning method, characterized by: The following steps are involved: Step 1: Modulate the navigation message and broadcast it through the satellite Internet frequency band; including the following processes: Step 1.1: Perform CRC check, channel coding and interleaving operations on the navigation message to form a navigation message frame sequence ; Step 1.2: The navigation message frame sequence after encoding and interleaving in step 1.1 Use pseudo-random code for spread spectrum modulation to generate the I branch baseband signal ; Then the I branch baseband signal obtained after spread spectrum modulation With the Q branch pilot signal Perform QPSK modulation to generate a navigation baseband complex sequence , where the Q branch pilot signal does not modulate the message information; Step 1.3: Perform subcarrier mapping on the navigation baseband complex sequence obtained in step 1.2, use IFFT operation, and fuse the navigation signal and communication signal to obtain the CP-OFDM baseband time domain waveform , then the obtained CP-OFDM baseband time domain waveform is up-converted and modulated, and broadcasted via the satellite Internet frequency band; Step 2: Demodulate the received signal to obtain the navigation message; specifically, the following process is included: Step 2.1: Down-convert the received signal to obtain a down-converted received signal , and generate the Q branch reference signal complex sequence locally The Q branch reference signal complex sequence is processed by IFFT operation to generate a reference signal CP-OFDM time domain waveform ; Step 2.2: Convert the reference signal CP-OFDM time domain waveform The received signal after down conversion Perform time domain correlation to obtain frequency offset estimate and integer delay estimates ; The reference signal CP-OFDM time domain waveform The received signal after down conversion Perform frequency domain correlation to obtain fractional delay estimates ; Based on the integer delay estimate and fractional delay estimates Get the total delay estimate ; Step 2.3: Correlate the received signal after stripping the frequency offset with the I branch pseudo code signal in the received signal after down-conversion according to the frequency offset estimation value and the total delay estimation value, estimate the message symbol according to the correlation value, deinterleave and decode the message symbol estimation, and obtain a demodulated navigation message; Step 3: Complete high-precision navigation positioning based on the navigation message demodulated in step 2 and the total delay estimate.

2. According to claim 1, a satellite Internet fast and high-precision navigation and positioning method is characterized by: The specific process of step 1.1 is: S101: CRC check: Assume the navigation message is ,in Represents the discrete sequence number, and the CRC generating polynomial is , then the navigation message sequence after CRC check is: ; S102: Channel coding: The navigation message sequence after CRC check is converted into Perform convolution or LDPC channel coding, and assume that the convolution or LDPC channel coding generation matrix is , then the encoded navigation message sequence for: ; S103: Interleaving coding: Interleave the navigation message after channel coding and frame it. Suppose the interleaving matrix is , then the interleaved navigation message frame sequence is for: .

3. The satellite Internet fast and high-precision navigation and positioning method according to claim 1, characterized in that: The specific process of step 1.2 is: S201: Use pseudo-random code to sequence the navigation message frame Perform spread spectrum modulation: Assume the pseudo-random code sequence of branch I is , then the I branch baseband signal obtained after spread spectrum modulation is for: ; S202: QPSK modulation: QPSK modulation is performed on the I branch baseband signal and the Q branch pilot signal obtained after spread spectrum modulation. Assume that the Q branch pilot signal is , then the navigation baseband complex sequence obtained after QPSK modulation is for: , where Superscript Indicates the launch system, subscript Indicates the navigation baseband, Represents an imaginary unit.

4. The satellite Internet fast and high-precision navigation and positioning method according to claim 1, characterized in that: The specific process of step 1.3 is: S301: Perform subcarrier mapping on the navigation baseband complex sequence obtained after QPSK modulation: Assume that the number of available subcarriers for navigation is , the satellite Internet beam dwell time is , the total number of OFDM symbols in the dwell time is , then the number of navigation messages mapped to each subcarrier is: ,in is the spreading ratio; S302: Perform IFFT operation on the QPSK modulation sequence after subcarrier mapping to generate OFDM symbols, and insert cyclic redundancy CP into the OFDM symbols to generate CP-OFDM navigation baseband waveform ,in is the number of inverse Fourier transform points, is the OFDM symbol period, Indicates the moment; S303: According to the satellite Internet configuration, the navigation signal and the communication signal can be uniformly generated into a CP-OFDM baseband time domain waveform to achieve signal level fusion; the fused CP-OFDM baseband time domain waveform is as follows: in is the communication baseband complex sequence, occupying subcarriers, navigation baseband complex sequence Occupancy subcarriers; S304: Perform up-conversion modulation on the obtained CP-OFDM baseband time domain waveform to obtain an up-conversion modulation signal: in is the carrier frequency.

5. According to claim 1, a satellite Internet fast and high-precision navigation and positioning method is characterized by: The specific process of step 2.1 is: S401: Establish a receiving signal model: Assume that the frequency deviation of the transmitted signal after passing through the propagation channel is , the delay is , then the received signal after down-conversion is: ,in is the amplitude, for noise; S402: Generate a reference signal: Generate a Q branch reference signal complex sequence according to the Q branch pilot signal: , represents an imaginary unit; performing IFFT operation on the Q branch reference signal complex sequence to generate a reference signal CP-OFDM time domain waveform: , is the number of inverse Fourier transform points, is the OFDM symbol period, Indicates time.

6. According to claim 1, a satellite Internet fast and high-precision navigation and positioning method is characterized by: The specific process of step 2.2 is: S501: Frequency offset estimation and integer delay estimation: The reference signal CP-OFDM time domain waveform The received signal after down conversion Perform time domain correlation and two-dimensional estimation of frequency offset and integer delay. The estimation method is as follows: In the formula is the Fourier transform, is the Fourier transform The conjugate of is the inverse Fourier transform, is the frequency offset estimate, is the integer delay estimate, represents the relevant value, Indicates the maximum value of the correlation value amplitude; is the frequency deviation of the transmitted signal after passing through the propagation channel, is the time delay of the transmitted signal after passing through the propagation channel; S502: Fractional delay estimation: A frequency domain correlation algorithm is performed on the reference signal CP-OFDM time domain waveform and the received signal after down-conversion to obtain a fractional delay estimation: Defining intermediate variables : represents the Q branch reference signal complex sequence The conjugate of for: In the formula is the complex phase angle calculation function, is an intermediate variable The conjugate of is the number of inverse Fourier transform points, is the OFDM symbol period, Indicates the moment; Adding the integer delay and the fractional delay gives the total delay estimate: .

7. According to claim 1, a satellite Internet fast and high-precision navigation and positioning method is characterized by: The specific process of step 2.3 is: S601: Message demodulation: frequency and delay adjustment of the received signal and FFT operation are performed to obtain the received sequence , the received sequence is compared with the pseudo-random code sequence of the I branch Perform correlation, correlation value It is expressed as: , according to the correlation value, the message symbol is estimated to obtain the message symbol estimation value for: ,in is the symbolic operation function; S602: Deinterleaving and decoding verification: Deinterleave and decode the message symbol estimation value to obtain the original modulated navigation message estimation value. ,in , , They are CRC generator polynomials. , channel coding generation matrix , interleaving matrix The inverse matrix of .

8. According to claim 1, a satellite Internet fast and high-precision navigation and positioning method is characterized by: In step 3, the navigation positioning solution is completed by using the satellite Internet ephemeris and clock parameters and system time in the demodulated navigation message, combined with the total delay estimate.

9. An electronic device, comprising a processor and a memory, wherein the memory is used to store one or more programs; characterized in that: When the one or more programs are executed by the processor, the method described in any one of claims 1 to 8 is implemented.

10. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method described in any one of claims 1 to 8 is implemented.

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