Carrier communication interference resistant circuit regulation and control method and system

Abstract

The invention provides an anti-carrier communication interference circuit regulation and control method and system, and relates to the technical field of communication anti-interference, and the method comprises the following steps: S1, a signal passes through a filter, the filter filters out a carrier signal and residual waves, and an isolation transformer is used for isolating the electric connection between the carrier signal and a first useful signal; s2, frequency and phase information of the carrier signal is extracted through a demodulation module, and a second useful signal modulated on the carrier signal is restored; s3, a signal shaping circuit is used for shaping the demodulated second useful signal, noise and distortion in the second useful signal are eliminated, meanwhile, a spread spectrum channel is established, and the shaped second useful signal is amplified; and S4, outputting the first useful signal and the second useful signal to the equipment. The invention aims to optimize an anti-interference control strategy according to communication signal interference detection and prediction results, and error codes and interference are reduced to the greatest extent.

Description

Technical Field

[0001] The present invention relates to the technical field of communication anti-interference, and in particular to a method and system for controlling a circuit for anti-carrier communication interference. Background Art

[0002] Power carrier communication is a technology that uses power lines as a transmission medium to transmit analog or digital signals at high speed through carriers. The main advantage of this technology is that it does not require rewiring and can make full use of the existing power distribution network for communication. It has a wide coverage range and convenient access methods. However, since power lines are not designed for communication, their transmission characteristics are complex and changeable, and there are many interference sources, which seriously affect the communication quality. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention discloses a method and system for controlling a circuit that resists carrier communication interference, which can eliminate the interference of the carrier to data communication by means of isolation demodulation and the like. The technical solutions adopted are as follows: A method for controlling a circuit to prevent carrier communication interference, the method comprising: S1: The signal passes through a filter, which filters out the carrier signal and residual waves, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the first useful signal; S2: Through the demodulation module, the frequency and phase information of the carrier signal is extracted, and the second useful signal modulated on the carrier signal is restored; S3: using a signal shaping circuit to shape the demodulated useful signal No. 2, eliminate noise and distortion in the useful signal No. 2, and at the same time establish a spread spectrum channel to amplify the shaped useful signal No. 2; S4: Output the No. 1 useful signal and the No. 2 useful signal to the device.

[0004] Preferably, the S1 includes: S11: The signal enters through the signal input terminal of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; S12: After filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; S13: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal No. 1 can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

[0005] Preferably, S2 includes: S21: extracting the frequency and phase information of the carrier signal through the feedback circuit, and comparing the carrier signal with the frequency and phase generated by the oscillator, adjusting the frequency and phase of the oscillator, and synchronizing with the carrier signal; S22: Detect the frequency change of the carrier signal through the frequency detector, and then restore the second useful signal based on the carrier signal.

[0006] Preferably, S3 includes: S31: performing information modulation on the second useful signal to form a digital baseband signal; S32: Expand the baseband signal through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and modulate the expanded baseband signal to the radio frequency band, and transmit it to the receiving end through the wireless channel.

[0007] Preferably, the S4 includes: S41: a receiving device at the receiving end receives a radio frequency signal transmitted through a wireless channel, and reduces the frequency of the radio frequency signal to a baseband frequency through a frequency conversion device; S42: the despreading device despreads the radio frequency signal using the despreading code corresponding to the spreading code during the spreading process, and restores the signal into the second useful signal; S43: The first useful signal and the second useful signal are transmitted to the device through the wireless channel.

[0008] A circuit control system for resisting carrier communication interference, the system comprising: Filtering device: The signal passes through a filter, which filters out the carrier signal and the residual wave, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the No. 1 useful signal; Demodulation module: Through the demodulation module, the frequency and phase information of the carrier signal are extracted, and the second useful signal modulated on the carrier signal is restored; Spread spectrum device: Use the signal shaping circuit to shape the demodulated useful signal No. 2, eliminate the noise and distortion in the useful signal No. 2, and establish a spread spectrum channel to amplify the shaped useful signal No. 2; Signal transmission device: outputs useful signal No. 1 and useful signal No. 2 to the device.

[0009] Preferably, the filtering device comprises: Filter input: The signal enters through the signal input of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; Filter output end: after filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; Isolation transformer: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

[0010] Preferably, the demodulation module comprises: Carrier signal synchronization device: extracts the frequency and phase information of the carrier signal through the feedback circuit, compares the carrier signal with the frequency and phase generated by the oscillator, adjusts the frequency and phase of the oscillator, and synchronizes with the carrier signal; Frequency demodulation device: The frequency change of the carrier signal is detected by the frequency demodulator, and then the second useful signal is restored based on the carrier signal.

[0011] Preferably, the spectrum spreading device comprises: Pre-modulation device: modulates the second useful signal to form a digital baseband signal; Extended RF device: The baseband signal is expanded through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and the expanded baseband signal is modulated to the RF frequency band and transmitted to the receiving end through the wireless channel.

[0012] Preferably, the signal transmission device comprises: Frequency conversion device: The receiving device at the receiving end receives the radio frequency signal transmitted through the wireless channel and reduces the frequency of the radio frequency signal to the baseband frequency through the frequency conversion device; Despreading device: The despreading device uses the despreading code corresponding to the spreading code during the spreading to despread the radio frequency signal and restore it to the second useful signal; Wireless transmission device: The No. 1 useful signal and the No. 2 useful signal are transmitted to the device through a wireless channel.

[0013] Beneficial effects of the invention: The invention discloses a method and system for controlling a circuit against carrier interference in communication, which can separate a carrier signal from a useful signal through an isolation transformer, and further extract the useful signal from the carrier signal again through demodulation, and optimize the anti-interference control strategy according to the communication signal interference detection and prediction results, thereby minimizing bit errors and interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The invention provides a circuit control system for resisting carrier communication interference. Figure 2 The present invention provides a method for controlling a circuit that resists carrier communication interference. DETAILED DESCRIPTION

[0015] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0016] One embodiment of the present invention provides a method for controlling a circuit to prevent carrier communication interference, the method comprising: S1: The signal passes through a filter, which filters out the carrier signal and residual waves, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the first useful signal; S2: Through the demodulation module, the frequency and phase information of the carrier signal is extracted, and the second useful signal modulated on the carrier signal is restored; S3: using a signal shaping circuit to shape the demodulated useful signal No. 2, eliminate noise and distortion in the useful signal No. 2, and at the same time establish a spread spectrum channel to amplify the shaped useful signal No. 2; S4: Output the No. 1 useful signal and the No. 2 useful signal to the device.

[0017] The working principle and effect of the above technical solution are as follows: the signal first passes through a filter, the main function of which is to filter out the residual wave and other unnecessary frequency components in the carrier signal. The filter selectively transmits the spectrum part of interest through its specific frequency response characteristics, while suppressing or removing noise and interference signals to improve the quality of the signal. Subsequently, an isolation transformer is used to isolate the electrical connection between the carrier signal and the No. 1 useful signal. The isolation transformer not only avoids the direct interference of the carrier signal to the No. 1 useful signal through its electrical isolation characteristics, but also plays a role in lightning protection, filtering and circuit safety protection. At the same time, the isolation transformer uses the high-frequency loss characteristics of its iron core to effectively suppress the high-frequency clutter from entering the control loop, further enhancing the anti-interference ability of the circuit. After signal preprocessing, a demodulation module is established. The main task of this module is to extract the frequency and phase information of the carrier signal, and restore the No. 2 useful signal modulated on the carrier signal accordingly. The demodulation process usually involves a series of mathematical transformations and signal processing operations on the received signal to restore the original useful signal. : The demodulated No. 2 useful signal may contain noise and distortion, so it needs to be further processed by a signal shaping circuit. The function of the signal shaping circuit is to clean and shape the signal to eliminate noise and distortion, making the signal clearer and more stable. At the same time, a spread spectrum channel is established to amplify the shaped useful signal No. 2. Spread spectrum technology disperses the signal energy into a wider frequency band by expanding the spectrum width of the signal, thereby improving the signal's anti-interference ability and transmission reliability. In the spread spectrum channel, the signal is amplified to enhance its transmission distance and receiving sensitivity. Finally, the useful signal No. 1 and the useful signal No. 2 that have been preprocessed, demodulated, shaped and amplified are merged and output to the device. The residual wave and other interference signals in the carrier signal are filtered out by the filter, effectively reducing the impact of noise and clutter on the communication quality. The electrical connection between the carrier signal and the useful signal is isolated by using an isolation transformer to further prevent the carrier signal from interfering with the useful signal and improve the stability and reliability of the communication system. The demodulation module can accurately extract the frequency and phase information of the carrier signal, thereby restoring the useful signal modulated on the carrier signal and ensuring the integrity and accuracy of the signal. The establishment of the spread spectrum channel disperses the signal energy into a wider frequency band, improving the signal's anti-interference ability and transmission reliability. Even in an environment with strong interference, the signal can be transmitted stably. The signal amplification process enhances the transmission distance and receiving sensitivity of the signal, so that the signal can be accurately received at a longer distance, improving the coverage and application flexibility of the communication system.

[0018] In one embodiment of the present invention, the S1 includes: S11: The signal enters through the signal input terminal of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; S12: After filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; S13: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal No. 1 can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

[0019] The working principle and effect of the above technical solution are as follows: a specific LC filter circuit is used inside the filter to identify and screen the frequency components in the signal. The filter identifies the frequency components of the carrier signal and the afterwave, and uses its frequency response characteristics to selectively attenuate or suppress these unwanted frequency components. At the same time, the filter retains and allows the first useful signal to pass, and the frequency components of the first useful signal match the passband of the filter. After filtering, the carrier signal and the afterwave are effectively weakened or suppressed, while the first useful signal is relatively completely output from the signal output end of the filter. Subsequently, the signal output end of the filter is connected to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the two. The electrical isolation layer can block the influence of the carrier signal and the afterwave on the subsequent circuit through the electrical connection, while allowing the first useful signal to pass by electromagnetic induction. The above method has strong anti-interference ability, and the filtering process retains the integrity of the useful signal and reduces the distortion and attenuation of the signal during transmission. The enhancement of anti-interference ability and the improvement of signal quality help to improve the performance of the entire communication system, including transmission speed, stability and reliability.

[0020] In one embodiment of the present invention, S2 includes: S21: extracting the frequency and phase information of the carrier signal through the feedback circuit, and comparing the carrier signal with the frequency and phase generated by the oscillator, adjusting the frequency and phase of the oscillator, and synchronizing with the carrier signal; S22: Detect the frequency change of the carrier signal through the frequency detector, and then restore the second useful signal based on the carrier signal.

[0021] After obtaining the second useful signal, the evaluation device evaluates the modulation effect of the demodulated signal and makes adjustments according to the evaluation result. The evaluation steps are as follows: A: Obtain key parameters required for evaluating the demodulated signal, including signal-to-noise ratio, bit error rate, modulation index, and carrier frequency; B: Obtain the evaluation level through key parameters, wherein the evaluation level is obtained through the following formula:

[0022] Among them, MQI represents the frequency modulation quality index, SNR represents the signal-to-noise ratio. After normalization, the value range of SNR is [0,1]. BER represents the bit error rate, that is, the proportion of error bits in the transmission process. After normalization, the value range of BER is [0,1]. It indicates the actual frequency offset compared to the carrier frequency before demodulation during the demodulation process. mf indicates the modulation index, which reflects the strength of the modulation signal. The modulation index ranges from (0,1). represents the carrier frequency, α, β and γ represent the weight factors of the signal-to-noise ratio, bit error rate and demodulation index respectively, α=0.3, β=0.4, γ=0.3, and after obtaining the signal power and noise power of the second useful signal, the signal-to-noise ratio is obtained, where the signal-to-noise ratio can be obtained by the following formula:

[0023] represents the signal power of the second useful signal, represents the noise power; C: Get the evaluation criteria through the evaluation level. When MQI≈1, it indicates that the quality of the modulated signal is very good, with a high signal-to-noise ratio, low bit error rate, and small frequency deviation error; When 0.5<MQI<1, it indicates that the quality of the modulation signal is good; When 0.2<MQI<0.5, it means that the quality of the modulated signal is moderate, there may be significant degradation, and attention should be paid and some maintenance or adjustment may be required; When MQI is less than 0.2, it indicates that the quality of the modulated signal is very poor and there is severe degradation, including extremely low signal-to-noise ratio, extremely high bit error rate, or extremely large frequency offset error, and immediate measures need to be taken to repair or optimize it.

[0024] The working principle and effect of the above technical solution are as follows: the frequency and phase information of the carrier signal are extracted in real time through the feedback circuit. The extracted carrier signal frequency and phase are compared with the signal generated by the local oscillator. According to the comparison result, the frequency and phase of the oscillator are dynamically adjusted to keep it synchronized with the carrier signal. The frequency discriminator is used to detect the frequency change of the carrier signal. By analyzing these frequency changes, the discriminator can restore the second useful signal modulated on the carrier signal. After being processed by the discriminator, the second useful signal is successfully restored, and the modulation effect of the demodulated signal is divided into different evaluation levels according to the value of MQI. Through the synchronous processing of the carrier signal, the precise synchronization of the carrier signal and the local oscillator during the demodulation process is ensured, thereby reducing the demodulation failure or signal distortion caused by synchronization error and enhancing the stability of communication. The use of the discriminator can accurately detect the frequency change of the carrier signal and effectively restore the useful signal modulated on the carrier signal. This process reduces the loss and distortion of the signal during the demodulation process and improves the quality of signal demodulation. By evaluating the key parameters of the demodulated signal, such as the signal-to-noise ratio, bit error rate, modulation index, and carrier frequency, the signal transmission performance and modulation effect can be fully reflected. This comprehensive evaluation method provides a scientific basis for subsequent maintenance, adjustment, or optimization. Through real-time signal demodulation and evaluation, problems in the communication system can be discovered and solved in a timely manner, thereby improving the reliability and maintenance efficiency of the system. In addition, regular evaluation can also help predict potential system failures and take preventive measures in advance.

[0025] In one embodiment of the present invention, S3 includes: S31: performing information modulation on the second useful signal to form a digital baseband signal; S32: Expand the baseband signal through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and modulate the expanded baseband signal to the radio frequency band, and transmit it to the receiving end through the wireless channel.

[0026] The working principle and effect of the above technical solution are as follows: the second useful signal is modulated so as to be effectively transmitted in the channel. The baseband signal is modulated with the spread spectrum code to generate a spread spectrum signal. In this process, each code element of the baseband signal is expanded into a longer sequence by the spread spectrum code, thereby realizing the widening of the spectrum. The expanded baseband signal needs to be further modulated to the radio frequency band so as to be transmitted through the wireless channel. The modulated radio frequency signal is transmitted to the wireless channel through the antenna and reaches the receiving end after space propagation. Information modulation can convert the original useful signal into a digital baseband signal suitable for transmission in the digital communication system, thereby improving the transmission efficiency and accuracy of the signal. Spread spectrum communication spreads the signal energy to a wider frequency band by expanding the spectrum width of the signal, thereby reducing the signal power density within the unit bandwidth, making it difficult for the interference signal to effectively affect the communication signal. This characteristic makes spread spectrum communication have a strong anti-interference ability in a complex electromagnetic environment. In wireless communication, multipath effect is an important cause of signal attenuation and distortion. Spread spectrum communication can use the frequency diversity characteristics of the signal to resist multipath interference by expanding the signal's spectrum width, thereby improving the signal's transmission quality and reliability.

[0027] In one embodiment of the present invention, the S4 includes: S41: a receiving device at the receiving end receives a radio frequency signal transmitted through a wireless channel, and reduces the frequency of the radio frequency signal to a baseband frequency through a frequency conversion device; S42: the despreading device despreads the radio frequency signal using the despreading code corresponding to the spreading code during the spreading process, and restores the signal into the second useful signal; S43: The first useful signal and the second useful signal are transmitted to the device through the wireless channel.

[0028] The working principle and effect of the above technical solution are as follows: the receiving device at the receiving end first captures and receives the radio frequency signal transmitted through the wireless channel. The received radio frequency signal is then sent to the frequency conversion device. The main function of the frequency conversion device is to reduce the frequency of the radio frequency signal to the baseband frequency. This process is usually achieved through down-conversion technology, that is, the radio frequency signal is mixed with a signal generated by a local oscillator to obtain an intermediate frequency signal. Then, the intermediate frequency signal is further filtered and amplified and finally converted into a baseband signal. After the frequency conversion device reduces the radio frequency signal to the baseband frequency, the despreading device starts to work. The despreading device uses the same spread spectrum code as the transmitting end to perform despreading on the baseband signal. The despreading process is essentially the inverse process of spread spectrum. The original baseband signal is restored through the correlation operation of the spread spectrum code and the received signal. After despreading, the spread spectrum modulation part in the signal is removed, and the original useful signal No. 2 is restored. At this time, the recovered signal has removed the spectrum expansion effect brought by the spread spectrum, and its spectrum width is restored to the level before the spread spectrum. Spread spectrum communication technology achieves spread spectrum gain by expanding the spectrum width of the signal, so that the signal can resist interference from the outside world during transmission. This anti-interference ability is particularly important in complex electromagnetic environments, ensuring the reliability and stability of communication. Spread spectrum signals disperse energy over a wider frequency band, reducing the signal power density within a unit bandwidth, making it difficult for interference signals to effectively affect useful signals. The spectrum width of spread spectrum communication can be flexibly adjusted as needed to adapt to different communication environments and needs. This flexibility enables spread spectrum communication to make full use of spectrum resources and improve spectrum utilization.

[0029] One embodiment of the present invention provides a circuit control system for resisting carrier communication interference, the system comprising: Filtering device: The signal passes through a filter, which filters out the carrier signal and the residual wave, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the No. 1 useful signal; Demodulation module: Through the demodulation module, the frequency and phase information of the carrier signal are extracted, and the second useful signal modulated on the carrier signal is restored; Spread spectrum device: Use the signal shaping circuit to shape the demodulated useful signal No. 2, eliminate the noise and distortion in the useful signal No. 2, and establish a spread spectrum channel to amplify the shaped useful signal No. 2; Signal transmission device: outputs useful signal No. 1 and useful signal No. 2 to the device.

[0030] The working principle and effect of the above technical solution are as follows: the signal first passes through a filter, the main function of which is to filter out the residual wave and other unnecessary frequency components in the carrier signal. The filter selectively transmits the spectrum part of interest through its specific frequency response characteristics, while suppressing or removing noise and interference signals to improve the quality of the signal. Subsequently, an isolation transformer is used to isolate the electrical connection between the carrier signal and the No. 1 useful signal. The isolation transformer not only avoids the direct interference of the carrier signal to the No. 1 useful signal through its electrical isolation characteristics, but also plays a role in lightning protection, filtering and circuit safety protection. At the same time, the isolation transformer uses the high-frequency loss characteristics of its iron core to effectively suppress the high-frequency clutter from entering the control loop, further enhancing the anti-interference ability of the circuit. After signal preprocessing, a demodulation module is established. The main task of this module is to extract the frequency and phase information of the carrier signal, and restore the No. 2 useful signal modulated on the carrier signal accordingly. The demodulation process usually involves a series of mathematical transformations and signal processing operations on the received signal to restore the original useful signal. : The demodulated No. 2 useful signal may contain noise and distortion, so it needs to be further processed by a signal shaping circuit. The function of the signal shaping circuit is to clean and shape the signal to eliminate noise and distortion, making the signal clearer and more stable. At the same time, a spread spectrum channel is established to amplify the shaped useful signal No. 2. Spread spectrum technology disperses the signal energy into a wider frequency band by expanding the spectrum width of the signal, thereby improving the signal's anti-interference ability and transmission reliability. In the spread spectrum channel, the signal is amplified to enhance its transmission distance and receiving sensitivity. Finally, the useful signal No. 1 and the useful signal No. 2 that have been preprocessed, demodulated, shaped and amplified are merged and output to the device. The residual wave and other interference signals in the carrier signal are filtered out by the filter, effectively reducing the impact of noise and clutter on the communication quality. The electrical connection between the carrier signal and the useful signal is isolated by using an isolation transformer to further prevent the carrier signal from interfering with the useful signal and improve the stability and reliability of the communication system. The demodulation module can accurately extract the frequency and phase information of the carrier signal, thereby restoring the useful signal modulated on the carrier signal and ensuring the integrity and accuracy of the signal. The establishment of the spread spectrum channel disperses the signal energy into a wider frequency band, improving the signal's anti-interference ability and transmission reliability. Even in an environment with strong interference, the signal can be transmitted stably. The signal amplification process enhances the transmission distance and receiving sensitivity of the signal, so that the signal can be accurately received at a longer distance, improving the coverage and application flexibility of the communication system.

[0031] In one embodiment of the present invention, the filtering device comprises: Filter input: The signal enters through the signal input of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; Filter output end: after filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; Isolation transformer: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

[0032] The working principle and effect of the above technical solution are as follows: a specific LC filter circuit is used inside the filter to identify and screen the frequency components in the signal. The filter identifies the frequency components of the carrier signal and the afterwave, and uses its frequency response characteristics to selectively attenuate or suppress these unwanted frequency components. At the same time, the filter retains and allows the first useful signal to pass, and the frequency components of the first useful signal match the passband of the filter. After filtering, the carrier signal and the afterwave are effectively weakened or suppressed, while the first useful signal is relatively completely output from the signal output end of the filter. Subsequently, the signal output end of the filter is connected to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the two. The electrical isolation layer can block the influence of the carrier signal and the afterwave on the subsequent circuit through the electrical connection, while allowing the first useful signal to pass by electromagnetic induction. The above method has strong anti-interference ability, and the filtering process retains the integrity of the useful signal and reduces the distortion and attenuation of the signal during transmission. The enhancement of anti-interference ability and the improvement of signal quality help to improve the performance of the entire communication system, including transmission speed, stability and reliability.

[0033] In one embodiment of the present invention, the demodulation module includes: Carrier signal synchronization device: extracts the frequency and phase information of the carrier signal through the feedback circuit, compares the carrier signal with the frequency and phase generated by the oscillator, adjusts the frequency and phase of the oscillator, and synchronizes with the carrier signal; Frequency demodulation device: The frequency change of the carrier signal is detected by the frequency demodulator, and then the second useful signal is restored based on the carrier signal.

[0034] The working principle and effect of the above technical solution are as follows: the frequency and phase information of the carrier signal are extracted in real time through the feedback circuit. The extracted carrier signal frequency and phase are compared with the signal generated by the local oscillator. According to the comparison result, the frequency and phase of the oscillator are dynamically adjusted to keep it synchronized with the carrier signal. The frequency discriminator is used to detect the frequency change of the carrier signal. By analyzing these frequency changes, the discriminator can restore the second useful signal modulated on the carrier signal. After being processed by the discriminator, the second useful signal is successfully restored, and the modulation effect of the demodulated signal is divided into different evaluation levels according to the value of MQI. Through the synchronous processing of the carrier signal, the precise synchronization of the carrier signal and the local oscillator during the demodulation process is ensured, thereby reducing the demodulation failure or signal distortion caused by synchronization error and enhancing the stability of communication. The use of the discriminator can accurately detect the frequency change of the carrier signal and effectively restore the useful signal modulated on the carrier signal. This process reduces the loss and distortion of the signal during the demodulation process and improves the quality of signal demodulation. By evaluating the key parameters of the demodulated signal, such as the signal-to-noise ratio, bit error rate, modulation index, and carrier frequency, the signal transmission performance and modulation effect can be fully reflected. This comprehensive evaluation method provides a scientific basis for subsequent maintenance, adjustment, or optimization. Through real-time signal demodulation and evaluation, problems in the communication system can be discovered and solved in a timely manner, thereby improving the reliability and maintenance efficiency of the system. In addition, regular evaluation can also help predict potential system failures and take preventive measures in advance.

[0035] In one embodiment of the present invention, the spectrum spreading device comprises: Pre-modulation device: modulates the second useful signal to form a digital baseband signal; Extended RF device: The baseband signal is expanded through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and the expanded baseband signal is modulated to the RF frequency band and transmitted to the receiving end through the wireless channel.

[0036] The working principle and effect of the above technical solution are as follows: the second useful signal is modulated so as to be effectively transmitted in the channel. The baseband signal is modulated with the spread spectrum code to generate a spread spectrum signal. In this process, each code element of the baseband signal is expanded into a longer sequence by the spread spectrum code, thereby realizing the widening of the spectrum. The expanded baseband signal needs to be further modulated to the radio frequency band so as to be transmitted through the wireless channel. The modulated radio frequency signal is transmitted to the wireless channel through the antenna and reaches the receiving end after space propagation. Information modulation can convert the original useful signal into a digital baseband signal suitable for transmission in the digital communication system, thereby improving the transmission efficiency and accuracy of the signal. Spread spectrum communication spreads the signal energy to a wider frequency band by expanding the spectrum width of the signal, thereby reducing the signal power density within the unit bandwidth, making it difficult for the interference signal to effectively affect the communication signal. This characteristic makes spread spectrum communication have a strong anti-interference ability in a complex electromagnetic environment. In wireless communication, multipath effect is an important cause of signal attenuation and distortion. Spread spectrum communication can use the frequency diversity characteristics of the signal to resist multipath interference by expanding the signal's spectrum width, thereby improving the signal's transmission quality and reliability.

[0037] In one embodiment of the present invention, the signal transmission device comprises: Frequency conversion device: The receiving device at the receiving end receives the radio frequency signal transmitted through the wireless channel and reduces the frequency of the radio frequency signal to the baseband frequency through the frequency conversion device; Despreading device: The despreading device uses the despreading code corresponding to the spreading code during the spreading to despread the radio frequency signal and restore it to the second useful signal; Wireless transmission device: The No. 1 useful signal and the No. 2 useful signal are transmitted to the device through a wireless channel.

[0038] The working principle and effect of the above technical solution are as follows: the receiving device at the receiving end first captures and receives the radio frequency signal transmitted through the wireless channel. The received radio frequency signal is then sent to the frequency conversion device. The main function of the frequency conversion device is to reduce the frequency of the radio frequency signal to the baseband frequency. This process is usually achieved through down-conversion technology, that is, the radio frequency signal is mixed with a signal generated by a local oscillator to obtain an intermediate frequency signal. Then, the intermediate frequency signal is further filtered and amplified and finally converted into a baseband signal. After the frequency conversion device reduces the radio frequency signal to the baseband frequency, the despreading device starts to work. The despreading device uses the same spread spectrum code as the transmitting end to perform despreading on the baseband signal. The despreading process is essentially the inverse process of spread spectrum. The original baseband signal is restored through the correlation operation of the spread spectrum code and the received signal. After despreading, the spread spectrum modulation part in the signal is removed, and the original useful signal No. 2 is restored. At this time, the recovered signal has removed the spectrum expansion effect brought by the spread spectrum, and its spectrum width is restored to the level before the spread spectrum. Spread spectrum communication technology achieves spread spectrum gain by expanding the spectrum width of the signal, so that the signal can resist interference from the outside world during transmission. This anti-interference ability is particularly important in complex electromagnetic environments, ensuring the reliability and stability of communication. Spread spectrum signals disperse energy over a wider frequency band, reducing the signal power density within a unit bandwidth, making it difficult for interference signals to effectively affect useful signals. The spectrum width of spread spectrum communication can be flexibly adjusted as needed to adapt to different communication environments and needs. This flexibility enables spread spectrum communication to make full use of spectrum resources and improve spectrum utilization.

[0039] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for controlling a circuit to prevent carrier interference, characterized in that: The method comprises: S1: The signal passes through a filter, which filters out the carrier signal and residual waves, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the first useful signal; S2: The frequency and phase information of the carrier signal are extracted through the demodulation module, and the second useful signal modulated on the carrier signal is restored. After the second useful signal is obtained, the evaluation device evaluates the modulation effect of the demodulated signal and makes adjustments according to the evaluation result. The evaluation steps are as follows: A: Obtain key parameters required for evaluating the demodulated signal, including signal-to-noise ratio, bit error rate, modulation index, and carrier frequency; B: Obtain the evaluation level through key parameters, wherein the evaluation level is obtained through the following formula: , Among them, MQI represents the frequency modulation quality index, SNR represents the signal-to-noise ratio. After normalization, the value range of SNR is [0,1]. BER represents the bit error rate, that is, the proportion of error bits in the transmission process. After normalization, the value range of BER is [0,1]. It indicates the actual frequency offset compared to the carrier frequency before demodulation during the demodulation process. mf indicates the modulation index, which reflects the strength of the modulation signal. The modulation index ranges from (0,1). represents the carrier frequency, α, β and γ represent the weight factors of the signal-to-noise ratio, bit error rate and demodulation index respectively, α=0.3, β=0.4, γ=0.3, and after obtaining the signal power and noise power of the second useful signal, the signal-to-noise ratio is obtained, where the signal-to-noise ratio can be obtained by the following formula: ,, represents the signal power of the second useful signal, represents the noise power; C: Get the evaluation criteria through the evaluation level. When MQI≈1, it indicates that the quality of the modulated signal is very good, with a high signal-to-noise ratio, low bit error rate, and small frequency deviation error; When 0.5<MQI<1, it indicates that the quality of the modulation signal is good; When 0.2<MQI<0.5, it means that the quality of the modulation signal is moderate, there may be obvious degradation, and attention should be paid and some maintenance or adjustment may be required; When MQI is less than 0.2, it indicates that the quality of the modulated signal is very poor and there is severe degradation, including extremely low signal-to-noise ratio, extremely high bit error rate, or extremely large frequency offset error, and immediate measures need to be taken to repair or optimize; S3: using a signal shaping circuit to shape the demodulated useful signal No. 2, eliminate noise and distortion in the useful signal No. 2, and at the same time establish a spread spectrum channel to amplify the shaped useful signal No. 2; S4: Output the No. 1 useful signal and the No. 2 useful signal to the device.

2. According to claim 1, a method for controlling a circuit against carrier communication interference, characterized in that: The S1 includes: S11: The signal enters through the signal input terminal of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; S12: After filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; S13: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal No. 1 can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

3. The method for controlling a circuit against carrier communication interference according to claim 1, characterized in that: The S2 includes: S21: extracting the frequency and phase information of the carrier signal through the feedback circuit, and comparing the carrier signal with the frequency and phase generated by the oscillator, adjusting the frequency and phase of the oscillator, and synchronizing with the carrier signal; S22: Detect the frequency change of the carrier signal through the frequency discriminator, and then restore the second useful signal based on the carrier signal.

4. The method for controlling a circuit against carrier communication interference according to claim 1, characterized in that: The S3 includes: S31: performing information modulation on the second useful signal to form a digital baseband signal; S32: Expand the baseband signal through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and modulate the expanded baseband signal to the radio frequency band, and transmit it to the receiving end through the wireless channel.

5. The method for controlling a circuit against carrier communication interference according to claim 1, characterized in that: The S4 includes: S41: a receiving device at the receiving end receives a radio frequency signal transmitted through a wireless channel, and reduces the frequency of the radio frequency signal to a baseband frequency through a frequency conversion device; S42: the despreading device despreads the radio frequency signal using the despreading code corresponding to the spreading code during the spreading process, and restores the signal into the second useful signal; S43: The first useful signal and the second useful signal are transmitted to the device through the wireless channel.

6. A circuit control system for resisting carrier communication interference, characterized in that: The system comprises: Filtering device: The signal passes through a filter, which filters out the carrier signal and the residual wave, and uses an isolation transformer to isolate the electrical connection between the carrier signal and the No. 1 useful signal; Demodulation module: Through the demodulation module, the frequency and phase information of the carrier signal are extracted, and the second useful signal modulated on the carrier signal is restored; Spread spectrum device: Use the signal shaping circuit to shape the demodulated useful signal No. 2, eliminate the noise and distortion in the useful signal No. 2, and establish a spread spectrum channel to amplify the shaped useful signal No. 2; Signal transmission device: outputs useful signal No. 1 and useful signal No. 2 to the device.

7. The circuit control system for resisting carrier communication interference according to claim 6, characterized in that: The filtering device comprises: Filter input: The signal enters through the signal input of the filter, and the internal circuit of the filter analyzes the signal to identify the frequency components of the carrier signal and the residual wave; Filter output end: after filtering, the carrier and the residual wave are weakened, while the first useful signal is complete, and the first useful signal is output through the signal output end of the filter; Isolation transformer: Connect the signal output end of the filter to the signal input end of the isolation transformer. The isolation transformer uses the principle of electromagnetic induction to establish an electrical isolation layer between the signal output end of the filter and the signal input end of the isolation transformer. The useful signal can pass through the electrical isolation layer while the carrier and the residual wave are isolated. Then the useful signal is output through the signal output end of the isolation transformer.

8. The circuit control system for resisting carrier communication interference according to claim 6, characterized in that: The demodulation module comprises: Carrier signal synchronization device: extracts the frequency and phase information of the carrier signal through the feedback circuit, compares the carrier signal with the frequency and phase generated by the oscillator, adjusts the frequency and phase of the oscillator, and synchronizes with the carrier signal; Frequency demodulation device: The frequency change of the carrier signal is detected by the frequency demodulator, and then the second useful signal is restored based on the carrier signal.

9. The circuit control system for resisting carrier communication interference according to claim 6, characterized in that: The spectrum spreading device comprises: Pre-modulation device: modulates the second useful signal to form a digital baseband signal; Extended RF device: The baseband signal is expanded through the spread spectrum code so that the spectrum of the baseband signal is widened to a range far larger than the original signal bandwidth, and the expanded baseband signal is modulated to the RF frequency band and transmitted to the receiving end through the wireless channel.

10. The circuit control system for resisting carrier communication interference according to claim 6, characterized in that: The signal transmission device comprises: Frequency conversion device: The receiving device at the receiving end receives the radio frequency signal transmitted through the wireless channel and reduces the frequency of the radio frequency signal to the baseband frequency through the frequency conversion device; Despreading device: The despreading device uses the despreading code corresponding to the spreading code during the spreading to despread the radio frequency signal and restore it to the second useful signal; Wireless transmission device: The No. 1 useful signal and the No. 2 useful signal are transmitted to the device through a wireless channel.

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