35 results about "Residual frequency offset" patented technology

The invention relates to the technical field of satellite internet, in particular to a low-orbit satellite communication system positioning method and a terminal. Comprising the following steps: a user terminal receives satellite broadcast to obtain ephemeris information at the current moment and position information of a wave position center point, and carries out initial time delay estimation and initial frequency offset estimation; then the user terminal carries out time-frequency pre-compensation processing on the PRACH signal according to the initial time delay and frequency offset estimation and sends the PRACH signal to a satellite; and after the satellite captures the PRACH signal, positioning the user terminal corresponding to the PRACH signal according to the residual time delay and the residual frequency offset carried in the PRACH signal and the position of the wave position center point. Therefore, under the condition of not depending on GNSS information, the satellite side can position the GNSS-free terminal.

The invention discloses an HRF signal synchronization method, device and system of a dual-mode carrier communication system, and belongs to the technical field of power line carrier communication. The method comprises the following steps: dividing a frequency offset range into a plurality of frequency offset hypothesis intervals based on an allowable maximum residual frequency offset range; performing frequency offset pre-compensation on the received signal according to each frequency offset hypothesis interval to obtain multiple paths of frequency offset compensation signals, and performing cross-correlation processing on the multiple paths of frequency offset compensation signals and a local reference sequence to obtain multiple paths of cross-correlation value sequences; in any cross-correlation value sequence, performing self-correlation processing on cross-correlation values of adjacent symbol intervals to obtain a corresponding self-correlation sequence; correlation peak values corresponding to the frequency offset hypotheses are extracted from the multiple paths of self-correlation sequences respectively, the maximum correlation peak value is determined from the correlation peak values, and if the maximum correlation peak value is larger than a synchronization judgment threshold value, the corresponding position is determined to be the synchronization position. According to the invention, high-precision wireless signal synchronization is realized, and high-quality signal transmission is ensured.

The invention relates to a Doppler frequency offset compensation method based on double-link cooperation and a satellite communication system. The Doppler frequency offset compensation method comprises the following steps that a UHF transmitter of a mobile platform terminal sends GPS information data of the mobile platform terminal to a UHF receiver of a satellite end; the UHF receiver of the satellite end receives GPS information data of the mobile platform terminal and transmits the GPS information data to the Ka receiver of the satellite end; a Ka receiver at the satellite end calculates UHF Doppler frequency offset by using the GPS information data of the mobile platform terminal and the position and speed of the satellite, and calculates Ka Doppler frequency offset based on the UHF Doppler frequency offset; injecting the Ka Doppler frequency offset into a local oscillator synthesizer of a Ka receiver at a satellite end to carry out Ka Doppler frequency offset pre-compensation; and compensating the pre-compensated residual frequency offset by using the phase-locked loop. According to the Doppler frequency offset compensation method, the time delay bottleneck of Ka link frequency offset compensation is highlighted, and the requirement that the end-to-end time delay of low-orbit satellite real-time services is smaller than or equal to 50 ms is met.

The invention relates to the technical field of wireless communication, and discloses a novel channel estimation method based on residual frequency offset elimination, which comprises the following steps of: despreading descrambled pilot frequency data to obtain a channel estimation value after noise smoothing, and transmitting the channel estimation value to an FIR (Finite Impulse Response) filter to generate a noise suppression channel estimation signal; phase-frequency response of the noise suppression channel estimation signal is obtained through calculation, conjugate multiplication and smoothing are conducted on the phase-frequency response of the noise suppression channel estimation signal and the phase-frequency response of the FIR filter, a residual frequency offset estimation signal for suppressing the noise influence is obtained and compensated to the noise suppression channel estimation signal output by the FIR filter, and a noise suppression channel estimation value for eliminating the residual frequency offset influence is obtained. And balancing with the service de-spreading signal compensated by the residual frequency offset estimation signal to obtain a final output signal. According to the method, the phase-frequency response characteristics of the filter are deeply analyzed, the FIR filter is used for improving the signal-to-noise ratio, meanwhile, the residual frequency offset is estimated through the phase-frequency characteristics of the FIR filter, finally, the phase error is compensated for, an accurate channel estimation value is obtained, and the signal detection precision is improved.

The application relates to a UWB preamble signal receiving processing method, which comprises the following steps: receiving a discrete digital signal obtained through sampling conversion after front-end processing; in a coarse acquisition stage, a locally reproduced preamble sequence is used to perform convolution processing on the discrete digital signal, coherent accumulation and fast Fourier transform are performed on the signal after convolution processing to obtain a first processing signal, a preamble is detected according to the strongest peak value response of the first processing signal, and frequency offset coarse estimation and CMR coarse estimation are performed when the preamble is detected; in an accurate receiving stage, the signal after convolution processing is subjected to frequency offset coarse compensation processing by using the frequency offset coarse estimation to obtain a compensation signal, interpolation processing is performed by taking the compensation signal as input, coherent accumulation and fast Fourier transform are performed on the signal after interpolation processing to obtain a second processing signal, residual frequency offset estimation and CMR accurate estimation are performed on the second processing signal. The application can improve the reliability of preamble detection and acquisition.

The invention discloses a frequency offset estimation method of a Bluetooth signal based on a reconstructed GFSK (Gaussian Frequency Shift Keying) differential phase. A Bluetooth receiver solves an actual differential phase on each sampling point of each Bluetooth symbol of a synchronization word or an access address in a Bluetooth receive signal and reconstructs a reference differential phase of each Bluetooth symbol of a synchronization word or an access address in a Bluetooth receive signal based on and calculates an initial of a Bluetooth receive signal and performing initial frequency offset compensation on the initial frequency offset estimation value. And the Bluetooth receiving end tracks the residual frequency offset of the Bluetooth receiving signal after the initial frequency offset compensation. According to the method, the frequency offset estimation precision can be effectively improved, the operand is greatly simplified, and the implementation complexity is reduced.

Systems, methods, apparatuses, and computer program products for physical layer specification support for the reduction of reference signal resource overhead for time-and frequency tracking reference signal. For example, some example embodiments may include a method comprising receiving, by a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal; and determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

The invention provides a low-orbit satellite Doppler frequency offset compensation method, device and equipment and a medium, and the method comprises the steps: dividing a coverage area into a plurality of continuous frequency offset subareas based on the real-time orbit parameters of a low-orbit satellite and the geographical range information of the coverage area; for each frequency offset partition, according to the partition characteristic parameters of the frequency offset partition, adjusting the beam forming parameters of the low-orbit satellite so as to perform Doppler frequency offset compensation on the frequency offset partition; selecting a part of terminals from each frequency offset partition, and obtaining residual frequency offset information fed back by the part of terminals; and dynamically adjusting the beam forming parameters of the corresponding frequency offset partitions according to the residual frequency offset information fed back by part of the terminals. According to the embodiment of the invention, the influence of terminal movement and track disturbance on compensation precision can be effectively suppressed, deep coupling of beam regulation and frequency offset characteristics is realized, the frequency offset fluctuation in the beam is stabilized in a traceable range of a terminal phase-locked loop, and continuous and reliable communication of the terminal in a high-speed movement process is ensured.

The present specification relates to the technical field of satellite internet, and particularly relates to a low-orbit satellite communication system positioning method and a terminal. The method comprises the following steps: a user terminal receives satellite broadcast to obtain ephemeris information at a current time and position information of a wave position center point, and performs initial time delay estimation and initial frequency offset estimation; then the user terminal performs time-frequency pre-compensation processing on a PRACH signal according to the initial time delay and frequency offset estimation, and sends the PRACH signal to a satellite; after the satellite captures the PRACH signal, the user terminal corresponding to the PRACH signal is positioned according to residual time delay and residual frequency offset carried in the PRACH signal and the position of the wave position center point. Thus, the positioning of the satellite side for the GNSS terminal is realized without relying on GNSS information.

This application relates to the field of intelligent conditioning technology for grating filter sensing signals, and discloses a grating filter sensing signal conditioning method based on machine learning. The invention acquires observation response characterization data and conditional constraint state quantities, first performs spectral axis registration processing based on a preset reference frequency window to eliminate the influence of measurement coordinate offset, then performs residual frequency offset decoupling processing on the preset target frequency band to extract residual frequency offset characterization quantities, and constructs a residual dynamic state sequence by combining historical control states, further utilizes a preset time-series inference model to output voltage compensation quantity and conditioning reliability results, and finally determines the final control voltage through reliable gating conditioning and local spectrum scanning verification, thereby effectively distinguishing pseudo offset from the preset target frequency band true offset, and reducing the interference of original observation signal fluctuations, environmental changes and uneven internal electric field distribution on the control results.

The invention discloses a short baseline synthetic aperture passive positioning method and system based on Chirp-Z spectrum estimation, and mainly solves the problem of large positioning error and frequency estimation error caused by residual frequency deviation in the prior art. According to the implementation scheme, the method comprises the steps that a geometric scene comprising a reconnaissance plane, two short baseline antennas and an unknown radiation source is built; obtaining signals of the radiation source received by the two short baseline antennas on the reconnaissance plane according to the geometric scene; performing down-conversion and correlation method processing on the received signal to obtain a single-frequency signal sequence; a Chirp-Z spectrum estimation algorithm is adopted for the single-frequency signal sequence to obtain a frequency estimation value, and the coordinates of the radiation source are calculated according to the frequency estimation value. According to the invention, frequency measurement is carried out by using a Chirp-Z spectrum estimation method, and Z transformation is converted into an FFT processable form through convolution operation, so that the operation complexity and spectrum estimation errors are reduced, phase ambiguity and signal coherence dependence are avoided, the reliability of the model is improved, and the method is suitable for large-scale popularization and application. The method can be used for an unknown signal source which has a short baseline and does not have a periodic discontinuous short signal sequence.

The invention relates to the technical field of satellite communication, in particular to a satellite communication frequency offset estimation and synchronization method, a storage medium and a satellite communication terminal.The satellite communication frequency offset estimation and synchronization method comprises the steps that a satellite wireless signal containing a frequency correction channel burst and a broadcast control channel burst is received; detecting frequency correction channel burst to obtain coarse carrier frequency offset; positioning baseband data corresponding to a broadcast control channel burst in the satellite wireless signal; pre-compensating baseband data corresponding to the broadcast control channel burst by using coarse carrier frequency offset, and calculating residual frequency offset of a residual frequency offset signal; obtaining a total carrier frequency offset according to the coarse carrier frequency offset and the residual frequency offset; and performing complete compensation, demodulation and channel decoding on the baseband data corresponding to the broadcast control channel burst by using the total carrier frequency offset to obtain decoded data. According to the method, the coarse estimation of the FCCH and the fine estimation and verification mechanism of the BCCH are combined, and the synchronization reliability can still be ensured under the complex channel condition.

The application discloses a residual frequency offset estimation method based on multi-channel in-track interference, and belongs to the field of radio reconnaissance. The method comprises the following steps: arranging multiple detection antennas in front of and behind the flight direction; the detection antennas passively receive signals emitted by a radiation source target; and the received signals are processed. Since the multiple antennas pass through the same slant range course in sequence, interference processing is performed after compensating for the phase caused by time delay. In an ideal case, the interference phase between channels is 0. In the case that there is a residual frequency offset, the interference phase between channels is the phase generated by the joint action of time delay and the residual frequency offset. The residual frequency offset can be estimated according to the corresponding relationship between the residual frequency offset and the interference phase. The application can realize accurate estimation of the residual frequency offset in the case of non-cooperative reception, and eliminate the influence of the residual frequency offset on subsequent signal processing.

Systems, methods, apparatuses, and computer program products for physical layer specification support for the reduction of reference signal resource overhead for time-and frequency tracking reference signal. For example, some example embodiments may include a method comprising receiving, by a user equipment, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal; and determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

The invention discloses a short baseline synthetic aperture passive positioning method and system based on MUSIC spectrum estimation, and mainly solves the problem of large positioning error and frequency estimation error caused by residual frequency deviation in the prior art. According to the implementation scheme, the method comprises the steps that a geometric scene comprising a reconnaissance plane, two short baseline antennas and an unknown radiation source is built; obtaining signals of the radiation source received by the two short baseline antennas on the reconnaissance plane according to the geometric scene; performing down-conversion and correlation method processing on the received signal to obtain a single-frequency signal, and performing noise adding and sampling processing on the single-frequency signal to obtain discrete data; performing MUSIC spectrum estimation on the discrete data to obtain a frequency estimation value; and calculating the coordinates of the radiation source according to the frequency estimation value. Through the MUSIC spectrum estimation algorithm, the original positioning problem is converted into the frequency estimation problem of the signal to be measured, the spectrum estimation error can be reduced, the reliability of the model is improved, the high-precision, high-real-time and high-robustness frequency estimation of the single-frequency short signal is realized, and the method can be used for a discontinuous short signal sequence unknown signal source with a short baseline and without periodicity.

This invention discloses a method and system for suppressing distributed co-channel interference in a region-coexisting environment. The method includes: a desired signal node generating a desired signal and transmitting it through an antenna; distributed interference nodes generating interference signals and transmitting them through antennas; authorized receiving nodes receiving and processing the signals to obtain the down-converted received signal; converting the received distributed interference signal into real and imaginary parts, expanding it with respect to time error and residual frequency offset to obtain the interference signal expression after expansion with time error and residual frequency offset; merging the time-invariant coefficients before the real and imaginary parts of the interference signal into one term to obtain the reconstruction coefficient expression of the distributed interference; estimating the coefficients of the distributed interference suppression system model; reconstructing the interference signal; performing distributed interference suppression; and obtaining the desired signal. This invention achieves the reconstruction and suppression of distributed interference signals under constraints of time error, frequency offset, and IQ imbalance.

The invention discloses a self-adaptive dual-threshold quick capture method and device in satellite communication and a medium. The method comprises the following steps: performing down-conversion mixing and residual frequency offset removal on IQ data and a local sweep frequency control carrier to obtain first data; performing AGC amplification processing on the first data to obtain second data with a predetermined amplitude; performing timing deviation removal on the second data to obtain third data; performing correlation accumulation on the third data to obtain fourth data; according to the fourth data, capturing and tracking are carried out based on a self-adaptive double-threshold mode, the position of a frame header is identified, and captured data are obtained; the self-adaptive double-threshold value is a double-threshold value capturing mode of capturing a high threshold value and tracking a low threshold value. The method has the advantages of high-probability capture and low-probability missed alarm.

This disclosure provides a fine timing method, apparatus, electronic device, storage medium, and chip, including determining the residual frequency offset of a first target frequency and a second target frequency in a detection sequence; wherein the first target frequency and the second target frequency are determined when the detection sequence is converted into a spectrum; determining the adjustment amount of the DC component at the first target frequency and the second target frequency based on the residual frequency offset; determining the phase of the first target frequency and the second target frequency based on the adjustment amount; and determining the fine timing adjustment amount based on the phase of the first target frequency and the second target frequency. Compared with related technologies, this disclosure, by determining the residual frequency offset, determining the adjustment amount of the first target frequency and the second target frequency based on the residual frequency offset, and determining the phase based on the adjustment amount, makes the fine timing adjustment amount obtained based on the phase more accurate, and makes the TOA estimate more accurate.

The invention discloses a modulation identification method based on phase entropy blind frequency offset compensation, and the method comprises the steps: carrying out the polar coordinate transformation of a complex baseband signal, and achieving the blind estimation and compensation of carrier frequency offset; extracting features such as high-order cumulant, skewness, peak ratio and power spectrum from the compensated signal, inputting the extracted feature vectors into a full-connection neural network for modulation classification, and outputting identification confidence; then, combining the phase entropy and the confidence coefficient to construct a dynamic uncertainty score, and calculating a sample selection probability for quantifying the residual frequency offset and confidence coefficient condition of the sample; and finally, incremental training is carried out on the selected sample by using weighted cross entropy loss, and online adaptive updating of a dynamic environment is realized, so that the accuracy and robustness of modulation identification are remarkably improved in a non-cooperative communication scene without pilot frequency and protocol information.

The embodiment of the invention provides a frequency offset compensation method, and the method comprises the steps: carrying out the time-domain frequency offset estimation and compensation of a PPDU (Physical Protocol Data Unit), and determining a first frequency offset compensation value of the time domain of the PPDU; and converting the frequency domain residual frequency offset compensation value of the signaling field of the PPDU into a second frequency offset compensation value of the time domain, and updating the first frequency offset compensation value according to the second frequency offset compensation value. According to the embodiment of the invention, the problem that the accuracy of the generated PPDU frequency offset compensation value is low in the related technology is solved, and the effect of generating the accurate frequency offset compensation value through the feedback mechanism of the frequency domain residual frequency offset is achieved.

The method for fine timing provided by the present disclosure comprises the following steps: acquiring residual frequency offset of a detection sequence determined according to a target signal point and a marker signal point in the detection sequence, wherein the target signal is a sampling point in the detection sequence except the marker signal; correcting the residual frequency offset according to the target signal and the marker signal to obtain a corrected detection sequence; determining phase values of a first target frequency point and a second target frequency point in the corrected detection sequence, wherein the first target frequency point and the second target frequency point are determined when the detection sequence is converted into a frequency spectrum; and determining a fine timing adjustment amount according to the phase values of the first target frequency point and the second target frequency point. By determining the residual frequency offset and correcting the residual frequency offset in the detection sequence, the phase values are calculated according to the corrected detection sequence, so that the fine timing adjustment amount based on the phase values is more accurate, and the accuracy of the estimated value of TOA is improved.

The application discloses a low-orbit satellite communication system time-frequency estimation method based on differential pilots, utilizes the good autocorrelation characteristics and the lower cross-correlation characteristics of a ZC sequence, designs a time-domain differential pilot sequence to solve the problems of large frequency offset estimation and timing synchronization in low-orbit satellite communication, and has the advantages of large frequency offset estimation range, no interference between frequency offset estimation and timing estimation, fast initial frequency offset estimation and timing estimation, and subsequent residual frequency offset estimation by using an M-PART algorithm, so as to meet the requirements of a low-orbit satellite mobile communication system on the frequency offset estimation range and precision. The differential design pilot sequence and the time-frequency estimation method based on the pilot sequence have the advantages that the estimation precision of the frequency offset is improved by 2-4 dB compared with the traditional M-PART method, the frequency offset estimation range is much better than that of the traditional method, the design requirements of the low-orbit satellite system are met, and the method has high practical value.

A user equipment (UE) communicating with a base station (BS) and an operation method of the UE are provided. The operation method of a UE communicating with a base station (BS) includes calculating a frequency offset difference between a serving cell and an interfering cell based on a first frequency offset of the serving cell and a second frequency offset of the interfering cell, the frequency offset difference including a subcarrier offset and a residual frequency offset, the subcarrier offset being an integer multiple of a subcarrier spacing (SCS); and removing an interference signal from a received signal received by the UE by compensating the frequency offset difference based on the residual frequency offset.

The application provides a residual frequency offset and phase offset joint estimation method and device based on linear fitting, which comprises the following steps: obtaining symbol data after symbol synchronization based on a preset target modulation mode, obtaining a signal model based on the symbol data, obtaining a continuous phase sequence of the signal model, performing linear fitting based on the continuous phase sequence, calculating a residual frequency offset estimation value, compensating the signal model based on the residual frequency offset estimation value to obtain a target signal model after residual frequency offset compensation, performing operation on the target signal model and solving to obtain a phase value of each symbol sample, taking an average value of the phase value of each symbol sample to obtain a final initial phase offset estimation value, and performing phase compensation on the target signal model based on the initial phase offset estimation value to obtain target symbol data after final carrier synchronization.

The application discloses a frequency offset calculation method and a terminal in a high-frequency high-speed frequency hopping system. The frequency offset calculation method comprises the following steps: performing first correction on a received signal according to an initial frequency offset at a receiving end; rotating synchronization header data of the received signal, so that the phase of the rotated synchronization header data and the phase of service data are located in the same quadrant; combining the rotated synchronization header data and the service data; performing first equalization calculation on the combined data to obtain an average frequency offset of the combined data; performing second correction on the received data after the first correction based on the average frequency offset of the combined data to obtain corrected data; and performing second equalization calculation on the corrected data to obtain an accurate received signal. Through the calculation of the average frequency offset, the twice correction and equalization calculation are performed on the received data, the residual frequency offset range is reduced, and the accuracy of the received signal is improved.

The invention discloses a communication device and method with a frequency offset tracking mechanism. The method comprises the following steps: a phase compensation circuit receives a current symbol section of a data part of a packet and performs phase compensation according to a frequency offset to generate a phase compensation symbol section; the symbol processing circuit descrambles and balances the phase compensation symbol section according to the scrambling information, and further calculates and generates a phase difference and a data time difference between the symbol section and a previous symbol section according to a balancing result, and then the residual frequency offset estimation circuit performs specific value calculation to generate an instantaneous frequency offset estimation value. The frequency offset smoothing calculation circuit calculates the data time difference according to a function in positive correlation with the data time difference to generate a correction coefficient, multiplies the instantaneous frequency offset estimation value and the smoothing coefficient to generate a smoothing frequency offset estimation value, and then superposes the smoothing frequency offset estimation value with a previous frequency offset estimation value to generate a current frequency offset estimation value to update the frequency offset quantity.

The invention relates to the technical field of communication, and provides a phase tracking method and device, electronic equipment, a storage medium and a computer product, and the method comprises the steps: extracting a receiving synchronization head segment symbol block, a coding modulation mode indication segment symbol block and a data symbol block from a receiving quadrature phase shift keying signal after frequency offset compensation; determining a first phase deviation estimation value of the synchronization head segment based on the received synchronization head segment symbol block; maximum likelihood estimation is carried out based on a coding modulation mode indication section symbol block, and a second phase deviation estimation value of an indication section middle point is obtained; performing unwrapping processing on the second phase deviation estimation value to obtain a third phase deviation estimation value of the indication section; determining a residual frequency offset estimation value based on the first phase offset estimation value and the third phase offset estimation value; and performing phase compensation on the data symbol block based on the second phase deviation estimation value and the residual frequency deviation estimation value in combination with phase estimation based on hard decision feedback. According to the invention, the phase track of the data symbol can be accurately estimated.

The invention relates to a cascade carrier frequency offset estimation method and device and a storage medium. The method comprises the following steps: generating an initial local carrier signal, and performing coherent demodulation processing on a received quadrature amplitude modulation signal to obtain an initial receiving demodulation signal; performing discrete Fourier transform carrier coarse acquisition with adaptive precision adjustment, regenerating a coarse acquisition local carrier signal, performing coherent demodulation processing and clock synchronization on the quadrature amplitude modulation signal again, and outputting a first demodulation symbol; compensating the first demodulation symbol through a direct judgment phase-locked loop to obtain a second demodulation symbol, finding and outputting an ideal constellation symbol through a direct judgment method, and determining a second phase offset; tracking the phase error through phase integration and loop filtering according to the second phase offset, and determining a phase error tracking result; and determining the residual frequency offset of the first demodulation symbol according to the phase error tracking result. The method is high in anti-noise capability and high in execution efficiency.

The invention discloses a frequency offset synchronization control method and system, network equipment and a storage medium. The method comprises the following steps: receiving an uplink signal from a terminal; performing residual frequency offset detection on the uplink signal to obtain a detection result; residual frequency offset compensation control information is generated based on the detection result, and the residual frequency offset compensation control information is used for feeding back real uplink residual frequency offset to the terminal; and sending the detection result to the terminal through the residual frequency offset compensation control information so as to guide the terminal to pre-compensate a subsequently transmitted uplink signal according to the detection result provided in the residual frequency offset compensation control information. According to the invention, the technical problem of low residual frequency offset compensation accuracy caused by factors such as ephemeris information accuracy, equipment processing time delay and hardware crystal oscillator oscillation precision in the prior art is solved.

The invention relates to the technical field of communication, and discloses a joint frequency offset estimation method, device and equipment based on pilot frequency and data, and the method comprises the steps: determining a frequency offset search range based on a preset frequency offset estimation resolution, and enabling the frequency offset search range to cover a residual frequency offset range; based on each candidate frequency offset in the frequency offset search range, performing frequency offset compensation on the received signal to obtain a compensation pilot symbol and a compensation data symbol; performing channel estimation on the compensation pilot symbol to obtain an estimated channel; balancing the compensation data symbol based on the estimation channel to obtain a balanced symbol; and calculating a symbol error of the equalization symbol, and determining a target frequency offset based on the symbol error corresponding to each candidate frequency offset. According to the method, the pilot symbols and the data symbols are combined for frequency offset estimation, dependence on long data is eliminated, the frequency offset estimation error of the terminal on the residual frequency offset can be met, and the communication quality under narrowband satellite communication is effectively guaranteed.