Method for realizing safe flight through mutual communication between hovercars

Abstract

The invention relates to the technical field of wireless communication and intelligent algorithms, in particular to a method for realizing safe flight through mutual communication between hovercars, which comprises the following steps that: a data acquisition and encoding module acquires data of the hovercars in real time, encodes the data, processes encoded digital signals and converts the digital signals into radio frequency signals; a radio-frequency signal is transmitted to a space through an antenna, the signal transmitting and processing module receives and processes the radio-frequency signal, the signal receiving and demodulation module converts and processes the radio-frequency signal, sets a judgment threshold value, judges a signal amplitude value acquired in the data acquisition and coding module, and transmits the signal to the data acquisition and coding module. According to the invention, real-time sharing of information such as position and speed among hovercars is realized, tracks of surrounding vehicles can be accurately pre-judged, path conflicts and collision risks are effectively avoided, and through technologies such as error correction coding, low-noise amplification and multiple filtering, the anti-interference capability of the system and the accuracy of data transmission are remarkably enhanced, and the stability of communication in a complex environment is ensured.

Description

Technical Field

[0001] This invention relates to the fields of wireless communication and intelligent algorithm technology, and more specifically, to a method for flying cars to communicate with each other to achieve safe flight. Background Technology

[0002] With the development of industrial technology and the guidance of national policies, low-altitude economy and flying cars are gradually entering people's lives. As a means of transportation, navigation function is indispensable, and as a low-altitude aircraft, safety is of course the primary requirement.

[0003] For flying cars, navigation is a fundamental requirement as a means of transportation. However, due to their operation in low-altitude environments with numerous dynamic flying targets, flight safety is paramount. Currently, traditional aircraft navigation and obstacle avoidance largely rely on ground control systems or single onboard sensors (such as radar or cameras), which suffer from data acquisition lag and insufficient prediction of surrounding dynamic targets. When multiple flying cars operate in the same low-altitude area, it is difficult to obtain the precise position and displacement changes of other flying cars in real time, easily leading to flight path conflicts due to information asymmetry. Maintaining a safe distance between flying cars cannot be guaranteed, seriously threatening low-altitude flight safety. Therefore, this invention proposes a method to achieve real-time communication between flying cars to address the safety hazards existing in the prior art. Summary of the Invention The purpose of this invention is to provide a method for safe flight through communication between flying cars, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides a method for safe flight through communication between flying cars. The data acquisition and encoding module acquires vehicle data in real time, encodes the data, processes the encoded digital signal and converts it into a radio frequency (RF) signal, and transmits the RF signal into space through an antenna. The signal transmission and processing module receives the RF signal and processes it. The signal reception and demodulation module converts the RF signal, processes it, sets a decision threshold, and makes a decision on the amplitude value of the signal acquired by the data acquisition and encoding module.

[0005] Preferably, the data acquisition and encoding module includes a data acquisition unit and a data encoding unit. The data acquisition unit acquires the vehicle's position and displacement information in real time through a global positioning system and encodes the data. The data encoding unit filters the digital signal through a Gaussian low-pass filter and then changes the carrier frequency of the filtered digital signal through wireless communication and intelligent algorithm "0" and wireless communication and intelligent algorithm "1".

[0006] Preferably, in the data acquisition unit, if the number of check bits raised to the power of 2 is greater than or equal to the number of original data bits plus the number of check bits plus 1, then the original data bits and check bits are arranged according to a specific rule. Each check bit is responsible for verifying a portion of the data bits. After calculating the value of the check bit, the check bit is inserted into a specified position and combined with the original data bits to form the encoded data. If the result of subsequent calculation is different from the check bit, it can be determined that there is an error in the acquired data, and then the erroneous data can be corrected.

[0007] Preferably, in the data encoding unit, the frequency response of the filter changes with the frequency of the input signal. When the frequency of the input signal gradually increases, the frequency response of the filter decays exponentially.

[0008] Preferably, the data encoding unit also pre-sets two different carrier frequencies, corresponding to the "0" and "1" states of the digital signal respectively. The information of the digital signal is loaded onto the frequency change of the carrier to form a frequency shift keying modulation signal, i.e., a radio frequency signal.

[0009] Preferably, the signal transmission processing module includes a pre-filtering and modulation unit, a radio frequency signal transmission unit, and a down-conversion and intermediate frequency signal generation unit. The pre-filtering and modulation unit receives the radio frequency signal and amplifies the weak radio frequency signal through a low-noise amplifier. The radio frequency signal transmission unit suppresses interference signals outside the frequency band through a bandpass filter. The down-conversion and intermediate frequency signal generation unit converts the filtered radio frequency signal at a higher frequency into an intermediate frequency signal with a relatively lower and fixed frequency.

[0010] Preferably, in the pre-filtering and modulation unit, the ratio of input signal power to input noise power is divided by the ratio of output signal power to output noise power. In the radio frequency signal transmitting unit, if the filter is at a certain frequency... When the gain at a given frequency is 1, it means that a signal at that frequency can pass through the filter without attenuation. If the filter has a gain of 1 at a given frequency... When the gain at a certain point is equal to 0, it means that the signal at that frequency is completely suppressed by the filter and cannot pass through. In the downconversion and intermediate frequency signal generation unit, the frequency of the intermediate frequency signal is equal to the absolute value of the difference between the frequency of the radio frequency signal input to the mixer and the frequency of the local oscillator signal generated by the local oscillator.

[0011] Preferably, the signal receiving and demodulation module includes a low-noise amplification and filtering unit, a down-conversion and intermediate frequency processing unit, and a sampling decision and data recovery unit. The low-noise amplification and filtering unit uses a frequency discriminator to convert the frequency change of the intermediate frequency signal into a voltage change. The down-conversion and intermediate frequency processing unit and the sampling decision and data recovery unit again use a low-pass filter to filter out high-frequency noise and noise introduced during the frequency discrimination process. Then, the filtered signal is sampled, and the signal amplitude is determined at the optimal sampling time of each symbol period.

[0012] Preferably, in the low-noise amplification and filtering unit, the output voltage of the frequency discriminator is equal to the sensitivity of the frequency discriminator multiplied by the frequency offset of the input signal. At this time, the output of the frequency discriminator is proportional to the frequency offset of the input signal. In the down-conversion and intermediate frequency processing unit, when the absolute value of the input signal frequency is less than or equal to the cutoff frequency of the low-pass filter, the gain of the filter on that frequency signal is 1; when the absolute value of the input signal frequency is greater than the cutoff frequency of the low-pass filter, the gain of the filter on that frequency signal is 0. In order to recover the original signal from the sampled signal without distortion, the sampling frequency must be greater than or equal to twice the highest frequency component of the original signal.

[0013] Preferably, in the sampling decision and data recovery unit, the signal amplitude value at a certain moment is compared with a decision threshold. If the signal amplitude value is greater than the decision threshold, the digital signal corresponding to that sampling moment is determined to be "1"; if the signal amplitude value is less than or equal to the decision threshold, it is determined to be "0". For binary Gaussian frequency shift keying signals, the decision threshold is equal to the sum of the average signal amplitude corresponding to "0" and the average signal amplitude corresponding to "1" after frequency discrimination and low-pass filtering, divided by 2.

[0014] Compared with existing technologies, the beneficial effects of this invention are as follows: it enables real-time sharing of information such as position and speed among flying cars, accurately predicts the trajectories of surrounding vehicles, effectively avoids path conflicts and collision risks, significantly enhances the system's anti-interference capability and data transmission accuracy through error correction coding, low-noise amplification, and multiple filtering technologies, ensures stable communication in complex environments, adopts GFSK modulation and Gaussian filtering to make the signal spectrum more compact, and precisely controls the operating frequency band through bandpass filtering to effectively reduce interference to other channels, down-conversion technology simplifies the signal processing flow, and frequency discrimination, filtering, and adaptive decision-making steps ensure that the original data can still be recovered efficiently and accurately even when the signal is attenuated or interfered with. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall module of the present invention; Figure 2 This is a schematic diagram of the data acquisition and encoding module of the present invention; Figure 3This is a schematic diagram of the signal transmission and processing module of the present invention; Figure 4 This is a schematic diagram of the signal receiving and demodulation module of the present invention; Figure 5 This is a schematic diagram of the sampling decision and data recovery unit of the present invention.

[0016] Reference numerals: 100, Data acquisition and encoding module; 110, Data acquisition unit; 120, Data encoding unit; 200, Signal transmission and processing module; 210, Pre-filtering and modulation unit; 220, Radio frequency signal transmission unit; 230, Down-conversion and intermediate frequency signal generation unit; 300, Signal reception and demodulation module; 310, Low noise amplification and filtering unit; 320, Down-conversion and intermediate frequency processing unit; 330, Sampling decision and data recovery unit. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0019] Because flying cars cannot obtain real-time information on the location and displacement of similar vehicles in the vicinity when flying at low altitudes, and cannot accurately predict the movement trajectory of surrounding vehicles, flight safety cannot be guaranteed. The data acquisition unit (110) collects the vehicle's position and displacement information (such as latitude, longitude, speed, direction, etc.) in real time through the Global Positioning System (GPS), and encodes the data. The specific working principle is as follows: First, based on the number of original data bits... Determine the required number of check bits If the original data bits Number of check bits satisfy ,in Number of original data bits Number of check bits Then, the original data bits and check bits are arranged according to a specific rule, with each check bit responsible for checking a portion of the data bits; Then, according to the verification equation (using four data bits) and 3 check bits (For example) , , After calculating the value of the check bit, the check bit is inserted into the specified position and combined with the original data bits to form the encoded data. If the calculation result is inconsistent with the check bit, it is determined that there is an error in the collected data, and then the error is corrected. Because flying cars cannot obtain real-time information on the location and displacement of similar vehicles in the vicinity when flying at low altitudes, and cannot accurately predict the movement trajectory of surrounding vehicles, flight safety cannot be guaranteed. The data acquisition unit (110) collects the vehicle's position and displacement information (such as latitude, longitude, speed, direction, etc.) in real time through the Global Positioning System (GPS), and encodes the data. The specific working principle is as follows: First, based on the number of original data bits... Determine the required number of check bits If the original data bits Number of check bits satisfy ,in Number of original data bits Number of check bits Then, the original data bits and check bits are arranged according to a specific rule, with each check bit responsible for checking a portion of the data bits; Then, according to the verification equation (using four data bits) and 3 check bits (For example) , , After calculating the value of the check bit, the check bit is inserted into the specified position and combined with the original data bits to form the encoded data. If the calculation result is inconsistent with the check bit, it is determined that there is an error in the collected data, and then the error is corrected. Since the encoded data is a digital signal, it cannot be effectively transmitted directly over a wireless channel. It needs to be modulated onto a high-frequency carrier signal to facilitate subsequent transmission of the collected data to other flying cars. Therefore, the data encoding unit (120) filters the digital signal through a Gaussian low-pass filter, and then changes the carrier frequency of the filtered digital signal through wireless communication and intelligent algorithm "0" and wireless communication and intelligent algorithm "1". The specific working principle is as follows: First, pre-filtering is performed using a Gaussian low-pass filter. The calculation formula is as follows: ,in, This is the frequency response of a Gaussian low-pass filter. The frequency of the input signal, This is the 3dB bandwidth of the Gaussian low-pass filter, where the input signal frequency... The increase in frequency response of the filter It exhibits exponential decay, meaning the gain for high-frequency signals gradually decreases, thus achieving the function of low-pass filtering. It can effectively smooth out the rising and falling edges of digital signals, which helps to make the carrier frequency change more stable in subsequent frequency shift keying modulation, reduce the generation of high-frequency harmonics, further reduce interference to other channels, and also help the receiver to demodulate the signal more accurately. Then, two different carrier frequencies are preset, corresponding to the "0" and "1" states of the digital signal, respectively. For example, when the digital signal is "0", the carrier frequency is set to... When the digital signal is "1", the carrier frequency is set to ,and ≠ As the sequence of "0"s and "1"s in the digital signal changes, the carrier frequency changes. and Switching between frequencies, when the input digital signal is "0", the modulator output frequency is... The carrier signal, when the input digital signal is "1", the modulator output frequency is The carrier signal is then loaded with digital signal information onto the frequency change of the carrier, forming a frequency shift keying modulation signal for transmission in the wireless channel. Finally, the modulated radio frequency signal is transmitted into space through an antenna (an antenna is a device that converts radio frequency signals into spatial electromagnetic waves and radiates them to the surroundings), so that other flying cars can receive the signal. During wireless propagation, the signal is affected by various factors, resulting in attenuation and interference. The received radio frequency signal strength is usually much weaker than that transmitted and may be mixed with noise and other interference signals, affecting the accuracy of signal reception by other flying cars. Therefore, the pre-filtering and modulation unit (210) receives the radio frequency signal and amplifies the weak radio frequency signal through a low-noise amplifier (LNA) (which can minimize the noise introduced by itself). The specific working principle is as follows: when the radio frequency signal in space is received by the antenna, the signal strength is very weak and may also be mixed with various noises (such as thermal noise, cosmic noise, etc.). The weak input radio frequency signal is amplified to a suitable amplitude, and the noise figure (NF) is a key indicator for measuring the performance of the low-noise amplifier. Its calculation formula is: ,in, This indicates the input signal power, that is, the signal power input from the antenna to the LNA. This represents the input noise power, which is the sum of the noise carried by the input signal and the noise introduced by front-end components such as antennas. This represents the output signal power, which is the power of the input signal after amplification by the LNA. It represents the output noise power, including the input noise after amplification by the LNA, as well as the noise power generated by the LNA itself. It can effectively amplify the radio frequency signal while ensuring that the noise does not increase excessively during the amplification process. Because there are various electromagnetic signals in space, including signals from other communication systems (such as mobile phone communication, broadcasting, etc.) and electromagnetic noise in the environment, these out-of-band signals can interfere with communication between flying cars. Therefore, the radio frequency signal transmitting unit (220) suppresses interference signals outside the frequency band through a bandpass filter (BPF). Specifically, its working principle is as follows: when the radio frequency signal passes through the bandpass filter, in order to ensure the radio frequency signal communication frequency band... Signals within this frequency band pass through smoothly, while signals outside this frequency band are suppressed, as calculated using the formula: ,in, Indicates the filter at frequency The gain (or transmission coefficient) at that point, when This indicates that a signal at that frequency can pass through the filter without attenuation. When this occurs, it means that the signal at that frequency is completely suppressed by the filter and cannot pass through; this is the frequency of the input signal. It refers to the frequency range of the target communication band. The lower cutoff frequency is the lowest frequency that the bandpass filter allows to pass through. The upper cutoff frequency is the highest frequency that the bandpass filter allows to pass through; it can effectively process signals and electromagnetic noise in the environment, improving the accuracy of signals received by other flying cars. The downconversion and intermediate frequency signal generation unit (230) converts the filtered, higher-frequency radio frequency signal into a relatively lower and fixed intermediate frequency signal for subsequent signal processing. Specifically, when the filtered radio frequency signal is input to the mixer, the mixer nonlinearly mixes the radio frequency signal with the local oscillator signal. Based on the frequency conversion characteristics of the nonlinear device, the mixer output includes the intermediate frequency signal. Its frequency value is the absolute value of the difference between the radio frequency signal frequency and the local oscillator signal frequency, i.e. ,in, The input RF signal frequency is the frequency of the RF signal to the mixer, which is the frequency of the RF signal that needs to be down-converted after filtering. The local oscillator frequency is the frequency of the local oscillator signal generated by the local oscillator. Its frequency value can be set according to the design requirements of the communication system to obtain a suitable intermediate frequency signal frequency. , This is the intermediate frequency signal frequency obtained after down-conversion. This frequency is relatively low and fixed, which facilitates subsequent signal processing. Since the intermediate frequency signal obtained by the downconversion and intermediate frequency signal generation unit (230) may still be relatively weak, it needs to be further amplified by the intermediate frequency amplifier (IFA) to meet the requirements of subsequent demodulation and other processing for signal amplitude. Therefore, the (240) passes through the intermediate frequency bandpass filter again to further suppress interference and noise in the intermediate frequency range and ensure the purity of the signal. In order to effectively transmit the digital information such as the position and displacement of the flying car in the wireless channel, the digital signal is loaded onto the high-frequency carrier through modulation technology, and some parameters of the carrier (such as frequency, phase, amplitude, etc.) are changed to meet the requirements of wireless transmission. At this time, the signal received by other flying cars is a signal after a series of processes such as modulation, transmission, and wireless propagation. Only after demodulation to recover the original information can it be correctly analyzed and processed. Without demodulation, it is impossible to extract useful digital information from the high-frequency carrier signal, and the flying car communication system will not be able to realize the perception of the movement status of surrounding vehicles and its own safe flight control. Therefore, the low-noise amplification and filtering unit (310) uses a frequency discriminator to convert the frequency change of the intermediate frequency signal into a voltage change. At this time, the output of the frequency discriminator is proportional to the frequency offset of the input signal. ,in, It refers to the sensitivity of the frequency discriminator. It is the frequency offset of the input signal. At this time, the intermediate frequency signal frequency can be discriminated, and the information of frequency change is converted into a signal of voltage change over time. This signal contains the original digital information. Since the function of a low-pass filter (LPF) is to allow low-frequency signals to pass through while attenuating high-frequency signals, from the perspective of the signal spectrum, the useful information of the original digital signal is mainly concentrated in the low-frequency band, while noise and clutter often contain more high-frequency components. The low-pass filter, through its frequency response characteristics, filters out high-frequency noise and clutter, thereby making the signal cleaner and providing a high-quality input signal for subsequent sampling and decision-making. Therefore, the downconversion and intermediate frequency processing unit (320) again uses a low-pass filter (LPF) to filter out high-frequency noise and noise introduced during the frequency discrimination process. Then, it samples the filtered signal and determines the signal amplitude at the optimal sampling time of each symbol period (usually the time when the symbol energy is most concentrated). The calculation formula is as follows: ,in, The frequency response function of a low-pass filter describes the gain of the filter for signals of different frequencies. The function, It refers to the frequency values ​​of each frequency component contained in the input signal. It is the cutoff frequency of the low-pass filter, which is the highest frequency limit that the low-pass filter allows to pass through, and is determined by the filter's design parameters; Then, according to the Nyquist sampling theorem, in order to recover the original signal from the sampled signal without distortion, the sampling frequency... ,in, It is the highest frequency component of the original signal. In GFSK signal processing, Related to factors such as the symbol rate of the signal, satisfying this theorem can guarantee that the sampled signal contains all the information of the original signal; During the demodulation of binary Gaussian Frequency Shift Keying (GFSK) signals, after frequency discrimination and low-pass filtering, the signals representing "0" and "1" will exhibit different amplitude characteristics. Therefore, in order to accurately recover the original binary digital signal from the processed signal, the sampling decision and data recovery unit (330) sets a decision threshold and samples the processed signal. It compares the signal amplitude value at a certain moment with the decision threshold (in the range of 0 and 1). If the signal amplitude value > the decision threshold, the digital signal corresponding to that sampling moment is determined to be "1"; if the signal amplitude value ≤ the decision threshold, it is determined to be "0". For binary Gaussian frequency shift keying signals, the formula for calculating the decision threshold is: ,in, This is the decision threshold, used to distinguish the signal amplitude corresponding to "0" and "1". The mean amplitude of the signal corresponding to "0" after frequency discrimination and low-pass filtering. The mean amplitude of the signal corresponding to "1" after frequency discrimination and low-pass filtering, and > It can convert the amplitude of analog signals into a sequence of digital "0" and "1", thereby recovering the original digital information, making it easier for other flying cars to receive the signals, thus effectively improving safety.

[0020] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for enabling safe flight by communicating between air cars, characterized by: The data acquisition and coding module (100) collects real-time data of the vehicle and encodes the data, converts the encoded digital signal after processing into a radio frequency signal, and transmits the radio frequency signal into space through an antenna, the signal transmission processing module (200) receives the radio frequency signal and processes the radio frequency signal, the signal receiving and demodulation module (300) converts the radio frequency signal and processes the radio frequency signal, and sets a decision threshold to judge the signal amplitude value collected by the data acquisition and coding module (100).

2. The method for realizing safe flight through mutual communication between air cars according to claim 1, characterized in that: The data acquisition and coding module (100) includes a data acquisition unit (110) and a data coding unit (120), the data acquisition unit (110) collects real-time vehicle position and displacement information (such as latitude and longitude, speed, direction, etc.) through a global positioning system (GPS) and encodes the data, and the data coding unit (120) filters the digital signal through a Gaussian low-pass filter, then changes the frequency of the carrier through wireless communication and intelligent algorithm "0" and wireless communication and intelligent algorithm "1".

3. The method for realizing safe flight through mutual communication between air cars according to claim 2, characterized in that: In the data acquisition unit (110), if the number of check bits is greater than or equal to the number of original data bits plus the number of check bits plus 1, the original data bits and the check bits are arranged according to a specific rule, each check bit is responsible for checking a part of the data bits, the value of the check bit is calculated, and the check bit is inserted into the specified position and combined with the original data bit to form the encoded data. If the result of the subsequent calculation is different from the check bit, it can be judged that the collected data has an error, and the error data is corrected.

4. The method for realizing safe flight through mutual communication between air cars according to claim 3, characterized in that: In the data coding unit (120), the frequency response of the filter changes with the change of the input signal frequency, and when the frequency of the input signal gradually increases, the frequency response of the filter decays exponentially.

5. The method for realizing safe flight through mutual communication between air cars according to claim 4, characterized in that: In the data coding unit (120), two different carrier frequencies are preset, corresponding to the "0" and "1" states of the digital signal respectively, and the information of the digital signal is loaded on the frequency change of the carrier to form a frequency shift keying modulation signal, i.e. a radio frequency signal.

6. The method for realizing safe flight through mutual communication between air vehicles according to claim 5, characterized in that: The signal transmission processing module (200) includes a pre-filtering and modulation unit (210), a radio frequency signal transmission unit (220), and a down-conversion and intermediate frequency signal generation unit (230), the pre-filtering and modulation unit (210) receives the radio frequency signal and amplifies the weak radio frequency signal through a low noise amplifier (LNA) (which can reduce the noise introduced by itself as much as possible), the radio frequency signal transmission unit (220) suppresses the interference signals outside the frequency band through a band-pass filter (BPF), and the down-conversion and intermediate frequency signal generation unit (230) converts the filtered radio frequency signal at a relatively high frequency into an intermediate frequency signal with a relatively low and fixed frequency.

7. The method of claim 6, wherein the method further comprises: In the pre-filtering and modulation unit (210), the ratio of input signal power to input noise power is divided by the ratio of output signal power to output noise power. In the radio frequency signal transmitting unit (220), if the gain of the filter at frequency is equal to 1, it means that the signal at the frequency can pass through the filter without attenuation. If the gain of the filter at frequency is equal to 0, it means that the signal at the frequency is completely suppressed by the filter and cannot pass through. In the down-conversion and intermediate frequency signal generating unit (230), the frequency of the intermediate frequency signal is equal to the absolute value of the difference between the frequency of the radio frequency signal input to the mixer and the frequency of the local signal generated by the local oscillator.

8. The method of claim 7, wherein the method further comprises: transmitting a signal from the first aerial vehicle to the second aerial vehicle, the signal indicating that the first aerial vehicle is in the vicinity of the second aerial vehicle. The signal receiving and demodulating module (300) comprises a low-noise amplification and filtering unit (310), a frequency down-conversion and intermediate frequency processing unit (320) and a sampling decision and data recovery unit (330), the low-noise amplification and filtering unit (310) converts the frequency variation of the intermediate frequency signal into voltage variation by using a frequency discriminator, the frequency down-conversion and intermediate frequency processing unit (320) and the sampling decision and data recovery unit (330) filter out the high-frequency noise and the introduced noise in the frequency discrimination process by using a low-pass filter (LPF) again, and then sample the filtered signal and make a decision on the signal amplitude at the best sampling time (usually the time when the symbol energy is most concentrated) of each symbol period.

9. The method of claim 8, wherein the method further comprises: In the low-noise amplification and filtering unit (310), the output voltage of the frequency discriminator is equal to the sensitivity of the frequency discriminator multiplied by the frequency offset of the input signal, at this time the output of the frequency discriminator is proportional to the frequency offset of the input signal, in the frequency down-conversion and intermediate frequency processing unit (320), when the absolute value of the input signal frequency is less than or equal to the cutoff frequency of the low-pass filter, the gain of the filter to the frequency signal is 1; when the absolute value of the input signal frequency is greater than the cutoff frequency of the low-pass filter, the gain of the filter to the frequency signal is 0, and in order to recover the original signal without distortion from the sampled signal, the sampling frequency is greater than or equal to 2 times the highest frequency component of the original signal.

10. The method of claim 9, wherein the method further comprises: In the sampling decision and data recovery unit (330), the signal amplitude value at a certain time is compared with the decision threshold (the interval is 0 and 1), if the signal amplitude value > the decision threshold, it is determined that the digital signal corresponding to the sampling time is "1"; if the signal amplitude value ≤ the decision threshold, it is determined to be "0", for the binary Gaussian frequency shift keying signal, the decision threshold is equal to the sum of the signal amplitude mean corresponding to "0" and the signal amplitude mean corresponding to "1" after frequency discrimination and low-pass filtering divided by 2.

Images