40 results about "Frequency domain equalization" patented technology

This application provides a signal receiving method, a transmitting method, a terminal, a system, and a storage medium, relating to, but not limited to, the field of optical communication technology. The receiving terminal removes a unique header from the time-domain signal data according to a first preset length. The time-domain signal data is obtained by transmitting the original signal data from the transmitting terminal through a transmission channel and is a linear convolution of the original signal data and the channel impulse response of the transmission channel. The original signal data includes a data group composed of a unique header of the first preset length and symbol data of the second preset length. Multiple intermediate time-domain data blocks are constructed from the time-domain signal data after removing the unique header, based on the length of the data group, so that each intermediate time-domain data block corresponds to a circular convolution of a data group and the channel impulse response. Frequency domain equalization is performed on the intermediate time-domain data blocks to obtain first equalized time-domain signal data. The embodiments of this application can improve the communication quality of the optical communication system while maintaining transmission capacity.

The invention discloses an OFDM (Orthogonal Frequency Division Multiplexing) communication channel estimation and signal detection method and system, and belongs to the technical field of channel estimation. The OFDM communication channel estimation and signal detection method comprises the following steps: receiving an LDACS downlink OFDM baseband signal; pilot frequency and data subcarriers are separated; arranging pilot frequency observation into a time sequence block according to a frequency index, and constructing a channel estimation subnet input tensor; performing convolution feature extraction and LSTM (Long Short Term Memory) time sequence modeling on the pilot frequency time sequence block in sequence, and outputting channel estimation of each subcarrier; performing frequency domain equalization on the data subcarriers; the signal detection subnet firstly extracts time sequence features through LSTM, then distributes weights through a self-attention mechanism, and finally outputs bit judgment through full connection; performing parameter optimization on the channel estimation subnet and the signal detection subnet by adopting a two-stage training strategy; the number K of subcarriers, the number P of pilots, the CP length and subcarrier mapping are set according to an LDACS frame structure and a protection interval, and an LDACS link layer interface is directly connected. By adopting the OFDM communication channel estimation and signal detection method and system provided by the invention, the problems of poor estimation precision and insufficient robustness of the existing method in a complex LDACS airspace channel environment can be solved.

This invention relates to the fields of high-speed serial communication and digital signal processing, and discloses a low-power approximate equalization circuit and method based on frequency domain error attribute mapping. The circuit includes: a Fast Fourier Transform (FFT) module for converting the time-domain signal to be equalized into a frequency-domain signal; a frequency-domain equalization processing module for equalizing the frequency-domain signal; an Inverse Fast Fourier Transform (IFT) module for converting the equalized frequency-domain signal into a time-domain output signal; and a mapping control module for constructing a three-dimensional error attribute mapping relationship with frequency domain sub-bands as the first dimension, approximate calculation accuracy level as the second dimension, and the error polarity of the approximate arithmetic unit as the third dimension. This invention simultaneously considers frequency domain position, approximate accuracy, and error polarity characteristics in frequency-domain equalization, and achieves system-level error balance without introducing additional compensation circuits, thereby achieving low-power, high-reliability frequency-domain equalization.

The application discloses a kind of underwater acoustic OFDM communication adaptive frequency domain equalization methods using Transform, it is related to underwater acoustic communication technical field, to solve the problems that existing underwater acoustic OFDM equalization method relies on cyclic prefix, is not sensitive to channel dynamic change, hard decision is prone to error propagation, the Transform framework containing only encoder is used in the present application, the soft decision of received symbol is completed by multi-head self-attention mechanism, and adaptive filtering is realized in combination with feedforward network;In the training phase, the loss function is calculated based on the network output and the true value, and the network parameters and the feedforward equalization filter coefficients are updated synchronously;In the inference phase, the network output is fed back to update the filter coefficients, and the real-time changes of the channel are adapted;The present application significantly reduces the probability of error propagation, and improves the communication reliability under complex underwater acoustic channel.

This invention discloses a system and method for acoustic wireless communication that eliminates frequency-selective fading and delay spread. Addressing the problems of frequency-selective fading and delay spread in acoustic wave transmission within the water-based drilling fluid channel inside the drill pipe, it employs orthogonal frequency division multiplexing (OFDM) technology. The transmitting end includes a coding and modulation module, an OFDM modulation module, a power amplification unit, an impedance matching network, and an underwater acoustic transducer. The receiving end includes a synchronization module, a cyclic prefix removal module, a Fourier transform module, a channel estimation module, a channel equalization module, and a decoding module. The synchronization module uses the Schmidl & Cox time-frequency joint synchronization algorithm, the channel estimation module uses the MMSE frequency domain estimation algorithm based on training sequences, and the channel equalization module uses the linear MMSE frequency domain equalization algorithm. Through the co-design of hardware and algorithms, this invention effectively eliminates frequency-selective fading and delay spread, achieving high-speed, low-error-rate acoustic wireless transmission. The data transmission rate can reach 250 kbit / s, and the bit error rate can be reduced to 10%. ‑3 .

The application provides a GMSK underwater acoustic communication method and system based on frequency domain equalization, and the method comprises the following steps: adding a cyclic prefix before a transmission signal sequence, adding a tail symbol after the transmission signal sequence, carrying out conversion and information-symbol mapping, modulating according to a GMSK signal modulation mode based on Laurent decomposition, obtaining a GMSK complex baseband signal, modulating the GMSK complex baseband signal to a carrier as a final transmission signal, and transmitting the final transmission signal to an underwater acoustic channel; receiving the transmission signal in the underwater acoustic channel, carrying out band-pass filtering, time-frequency two-dimensional synchronization, matched filtering, frequency domain equalization and iterative symbol detection on the received signal, obtaining a judged symbol, and completing the GMSK underwater acoustic communication based on the frequency domain equalization. The application has the advantages that the complexity of the symbol detection of the conventional frequency domain equalizer is reduced, and the communication performance is improved.

The invention provides an ultra-wideband electro-optical modulator integrating time domain and frequency domain equalization and a preparation method thereof. The ultra-wideband electro-optical modulator comprises a silicon substrate, a silicon dioxide buried oxide layer, a silicon nitride waveguide, a lead zirconate titanate thin film waveguide, a first coplanar traveling wave electrode and a silicon dioxide embedded layer, the lead zirconate titanate film waveguides form two parallel arms, the first sections of the two parallel arms are positively polarized, the second sections of the two parallel arms are reversely polarized, and the silicon nitride waveguide layer is arranged in the section, connected with the second section, of the first sections; the first coplanar traveling wave electrode is used for transmitting a microwave signal; performing forward phase modulation on the optical signal in the forward polarization section based on the microwave signal, and performing reverse phase modulation on the optical signal in the reverse polarization section; the silicon nitride waveguide introduces time domain delay between a microwave signal and an optical signal; the microwave loss difference of forward phase modulation and reverse phase modulation of the optical signal is improved based on the time domain delay, so that high-frequency modulation response attenuation is compensated, and combined equalization of the time domain and the frequency domain is realized.

The application provides a physical layer identity authentication method and device of a network time synchronization system, and belongs to the technical field of network security, and specifically comprises the following steps: encoding and modulating a sending end original time synchronization message, and inserting an identity authentication pilot sequence; performing pre-distortion of the message signal related to the sending end identity; performing step-by-step equalization of the message signal by each device based on a pre-measured and stored frequency domain channel matrix of a physical channel; a security demodulator extracts a current sub-block identity authentication pilot sequence, estimates, interpolates and stores the pre-distorted sequence, and then performs frequency domain equalization, demodulation and decoding on the current sub-block data sub-carrier by using the pre-distorted sequence to recover the original time synchronization message and a message security indication vector; identity authentication is judged based on the error code rate of the message security indication vector, and the original time synchronization message is sent to a receiving end or discarded according to the judgment. The scheme of the application effectively overcomes external and internal attackers, and realizes time source identity authentication.

The application provides a joint structured OFDM modulation and precoding design method of a large-scale MIMO system, and relates to the technical field of MIMO communication.In the application, a point-to-point large-scale MIMO structured OFDM (mMIMO-SOFDM) system is constructed by using a structured OFDM modulation method; and based on a joint spatial precoding and structured frequency domain equalization scheme, a closed-form solution of each subcarrier frequency domain equalizer, transmission precoding and reception precoding of the mMIMO-SOFDM system is solved.By proposing the structured OFDM scheme, the excessive cyclic prefix overhead caused by the double wideband effect of the large-scale MIMO system is reduced.In addition, the proposed joint spatial precoding and structured frequency domain equalization scheme further improves the spectral efficiency of the system and reduces the peak-to-average ratio.

The invention provides a power distribution transmission method and device under an OCDM frequency selection channel, and the method comprises the steps: converting a time domain signal into a frequency domain through a discrete Fourier transform matrix at a transmitting end, generating a power distribution matrix through combining channel state information and adopting a water injection algorithm, and carrying out the dynamic power precoding of a frequency domain subcarrier; generating a time domain OCDM signal through an inverse discrete Fourier transform matrix and an inverse discrete Fresnel transform matrix, adding a cyclic prefix, and transmitting the time domain OCDM signal; after a receiving end is subjected to prefix removal, a discrete Fourier transform matrix is converted into a frequency domain, a frequency domain equalizer is designed on the basis of a minimum mean square error criterion by utilizing channel diagonalization characteristics, signals are equalized in combination with transmitting power information, and finally time domain information is recovered through an inverse discrete Fourier transform matrix; therefore, the problem of traditional power distribution failure caused by OCDM channel energy dispersion is solved, and through receiving and transmitting joint optimization, diversity gain is fully mined, frequency selective channel fading is adaptively matched, the anti-interference and anti-multipath capabilities of the system are improved, and the spectrum efficiency and the transmission performance are maximized.

The invention discloses a deep learning assisted waveform index modulation single carrier communication method, and belongs to the technical field of wireless communication. According to the method, the frequency spectrum efficiency and the system performance are improved by fully utilizing the waveform freedom degree of the single-carrier system. Cooperative transmission of index information and symbol information is realized by jointly optimizing a constellation mapping set, a shaping filter bank and a Bi-LSTM detection network of a receiving end. Specifically, a sending end divides information bits into symbol bits and index bits, the index bits dynamically select a constellation mapping set and a shaping filter, and the symbol bits generate a time domain waveform through the selected constellation and filter. And after a receiving end adopts frequency domain equalization and matched filtering, joint detection of indexes and symbols is completed through a Bi-LSTM network. According to the method, bit mutual information can be achieved through end-to-end training optimization, the signal power and the spectrum template are constrained at the same time, a high-performance and low-complexity index modulation implementation method is provided for a single-carrier system, and the method is suitable for a future high-spectrum-efficiency communication scene.

The invention provides an OFDM (Orthogonal Frequency Division Multiplexing) waveform design method suitable for covered wire transmission, which comprises the steps of CRC (Cyclic Redundancy Check) check, Turbo coding / rate matching, serial-to-parallel conversion, constellation mapping, OFDM modulation and framing, and utilizes a mode of combining an OFDM transmission technology with high spectrum utilization rate with 16QAM (Quadrature Amplitude Modulation) and 4QAM modulation technologies with high information transmission rate. Compared with a traditional single-carrier frequency domain equalization technology and a PAM constellation mapping mode of covered line transmission, the frequency spectrum utilization rate and the data transmission rate are improved; meanwhile, compared with the traditional grid coding, the Turbo coding further improves the coding gain; the insertion of the CP-UW pilot signals can reduce the difficulty of subsequent receiving end signal processing and improve the channel estimation precision, so that distortion and attenuation signals introduced by covered wire long-distance transmission can be recovered more accurately, large-bandwidth and long-distance communication in a covered wire communication environment is realized, and audio and video transmission services can be supported.

A method of equalizing a plurality of single ended channels in a data communication network is disclosed. The method includes receiving real symmetrical input values over each of the plurality of single ended channels at an input of a frequency domain equalizer. Further, the method includes processing the received real symmetrical input values using a plurality of Fast Fourier Transform (FFT) implementations of the frequency domain equalizer. The method further includes processing the outputs of the plurality of FFT implementations using a matrix inversion implementation of the frequency domain equalizer. Furthermore, the method includes processing an output of the matrix inversion implementation using a plurality of Inverse FFT implementations, where each of the plurality of single ended channels is assigned to one of the plurality of Inverse FFT implementations.

The application provides an ultra-wideband electro-optical modulator integrating time domain and frequency domain equalization and a preparation method thereof. The ultra-wideband electro-optical modulator comprises a silicon substrate, a silicon dioxide buried oxygen layer, a silicon nitride waveguide, a lead zirconate titanate thin film waveguide, a first coplanar waveguide electrode and a silicon dioxide embedding layer. The lead zirconate titanate thin film waveguide forms two parallel arms. A first section of the two parallel arms is forwardly polarized, and a second section is reversely polarized. The silicon nitride waveguide layer is arranged in a section of the first section adjacent to the second section. The first coplanar waveguide electrode is used for transmitting a microwave signal. The microwave signal is used for forward phase modulation of an optical signal in the forwardly polarized section and reverse phase modulation of the optical signal in the reversely polarized section. The silicon nitride waveguide introduces a time domain delay between the microwave signal and the optical signal. Based on the time domain delay, a microwave loss difference of the forward phase modulation and the reverse phase modulation of the optical signal is improved, so as to compensate for high-frequency modulation response attenuation and realize joint equalization of the time domain and the frequency domain.

The application provides a joint time-frequency domain equalization method under PSK and QAM modulation, which comprises the following steps: receiving an initial signal, sampling, obtaining an initial head scattered pilot, processing the initial head scattered pilot, realizing time domain cross-correlation and autocorrelation, respectively performing fast Fourier transform on a first processed signal and a second processed signal to obtain a third processed signal and a fourth processed signal, taking the third processed signal as a numerator and the fourth processed signal as a denominator to obtain a channel estimation frequency response, estimating a signal-to-noise ratio of the second processed signal to obtain a signal-to-noise ratio curve, calculating a signal-to-noise ratio estimation value according to a peak value in the signal-to-noise ratio curve and data variance calculated according to other data, combining the channel estimation frequency response to obtain a frequency domain equalization coefficient, processing second data and a tail scattered pilot in the initial signal to obtain a fifth processed signal, and combining the frequency domain equalization coefficient to obtain a time domain signal.

This application provides a phase noise suppression method, apparatus, electronic device, and computer program product. The method first obtains a first phase estimate of the current unique word and a second phase estimate of the previous unique word for the received signal after single-carrier frequency domain equalization. The received signal includes alternating unique words and data blocks. Then, based on the first and second phase estimates, a phase estimate of each data symbol in the data block located between the previous and current unique words is calculated using linear interpolation. Next, a corresponding phase compensation complex number is generated based on the phase estimate of each data symbol. Finally, phase compensation is performed on the data block between the previous and current unique words based on the phase compensation complex number to suppress phase noise. This method can more accurately track and suppress time-varying phase noise, significantly improving the overall bit error rate performance of the system.

A method of equalizing a channel in a data communication network is disclosed. The method includes receiving digital input signals over a channel (H) at an input of a frequency domain equalizer and receiving digital input signals representing an inverse of the channel (H-1) at an input of the frequency domain equalizer. The method further includes processing the digital input signals using a plurality of Fast Fourier Transform (FFT) implementations of the frequency domain equalizer and processing digital input signals representing an inverse of the channel to find a value of a residue (R). The method further includes processing the outputs of the plurality of FFT implementations using a matrix inversion implementation to equalize the channel to H-1*R of the frequency domain equalizer. Furthermore, the method includes processing outputs of the matrix inversion implementation using a plurality of Inverse FFT implementations of the frequency domain equalizer.

The application discloses a kind of amplitude-phase grouping modulation-oriented received signal reconstruction methods, it is applicable to communication system receiving end, the amplitude-phase grouping modulation signal of distortion caused by power amplifier nonlinear amplification is reconstructed.The method is first to the frequency domain equalization of received signal, and eliminate the influence of power amplifier linear amplification;Then, the phase of received signal is adjusted, and demodulates additional phase;Subsequently, the amplitude of received signal is revised;Then, based on least square criterion, signal reconstruction optimization problem model is constructed, and least square optimization reconstruction is executed.Afterwards, additional phase demodulation, amplitude adjustment and least square optimization reconstruction are iteratively executed until the preset iteration number is reached, so as to obtain high-quality reconstructed signal.The application can effectively deal with nonlinear distortion at the receiving end of the communication system, realize high-quality signal reconstruction, thereby significantly improving the overall performance and power efficiency of the communication system.

The application discloses a signal processing method of power carrier communication based on OFDM modulation, relates to the technical field of power carrier communication, and comprises the following steps: S1, cyclic prefix and guard interval design and insertion; S2, improved synchronization algorithm for frequency offset processing; S3, noise suppression optimization of a front-end signal processing module; S4, parallel processing architecture design and task allocation; S5, channel estimation at a receiving end; S6, frequency domain equalization processing; S7, OFDM demodulation processing; and S8, symbol synchronization and data recovery. Through the steps S1 and S2, the effects of effectively resisting power line channel multipath delay, reducing inter-symbol interference and inter-carrier interference are achieved. Through the steps S3, S5 and S6, the effects of accurately identifying power line impulse noise and Gaussian noise characteristics and dynamically suppressing noise are achieved. Through the steps S4 and S8, the effects of improving signal processing efficiency by using a parallel processing architecture and avoiding processor overload are achieved, and meanwhile, the data error correction capability is enhanced by convolution coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.

The invention relates to a frequency domain equalization technology-based differential electrode Mach-Zehnder silicon-based electro-optical modulator, which comprises a substrate layer, a differential T-type electrode structure and a waveguide layer, and is characterized in that the waveguide layer comprises a first modulator region, a second modulator region and an equalizer region; the light path transmission direction and the circuit transmission direction in the first modulator area and the second modulator area are the same, and the light path transmission direction and the circuit transmission direction in the equalizer area are opposite; the first modulator region and the equalizer region are both located between the first signal electrode and the ground electrode, and the second modulator region is located between the ground electrode and the second signal electrode; and the first modulator region, the second modulation region and the equalizer region respectively comprise a first phase shift arm and a second phase shift arm which can form a serial PN junction structure. The bandwidth of the device can be further improved.

The application discloses a frequency domain equalization method based on a PD-DD-LMS architecture, a medium and equipment, relates to the field of digital signal processing of coherent optical communication systems, and mainly comprises the following steps: converting an input sequence into multiple data blocks by using an odd-even separation and serial-parallel conversion method, performing fast Fourier transform to obtain multiple frequency domain input block vectors, obtaining a frequency domain output block vector by using a multiple-input multiple-output frequency domain equalizer, performing inverse fast Fourier transform, discarding a preset number of elements in the front to obtain a time domain output block vector, and updating filter tap weights by using a phase-related decision-directed least mean square multiplication algorithm and a gradient descent algorithm according to the time domain output block vector. The frequency domain equalization method based on the PD-DD-LMS architecture, the medium and the equipment can reduce the computational complexity without reducing the anti-phase noise and anti-frequency offset performance.

The application discloses a single-carrier frequency domain equalization CV-QKD system and method, and the single-carrier frequency domain equalization CV-QKD system comprises an Alice laser, an IQ modulator, a quantum key generation module, an optical attenuator, an optical fiber channel, a Bob laser, an optical coupler, a balanced detector, a quantum key demodulation module, and an Alice post-processing module and a Bob post-processing module; at the Alice end, the Alice laser, the IQ modulator, the optical attenuator and the optical fiber channel are optically connected, the quantum key generation module is electrically connected with the IQ modulator, and the quantum key generation module is data-connected with the Alice post-processing module; at the Bob end, the Bob laser, the optical coupler and the balanced detector are optically connected with the optical fiber channel, the quantum key demodulation module is electrically connected with the balanced detector, and the quantum key demodulation module is data-connected with the Bob post-processing module. Through the application, the safety transmission performance of a high-speed CV-QKD system is remarkably improved, and the compensation cost of multi-effect noise is effectively reduced.

The application provides an equalizer for realizing multipath diversity in a spread spectrum SC-FDE system, which comprises the following steps: channel estimation is performed by using a UW word vector of each SC-FDE symbol; first noise reduction is performed on a channel impulse response estimated by using each SC-FDE symbol in a Doppler variation domain; the result after the noise reduction is converted to a time domain to perform second noise reduction; and Rake reception is performed on a data block of a sending end by using the time domain impulse response after the noise reduction, so as to perform coherent combination on multipath information in all received data blocks. The application realizes coherent combination of multipath in a spread spectrum single carrier frequency domain equalization SC-FDE system by improving a channel estimation method and combining the advantages of Rake reception, instead of passive combination, so that the SC-FDE system can obtain better performance when passing through a multipath fading channel in a low signal-to-noise ratio scene.

The invention provides an OFDM (Orthogonal Frequency Division Multiplexing) signal transmission and processing method based on affine transform domain pilot frequency, which belongs to the field of wireless communication, and comprises the following steps: generating an affine transform domain pilot frequency symbol and a data symbol by a transmitting end, splicing the affine transform domain pilot frequency symbol and the data symbol in a time domain and then transmitting through a high Doppler multipath channel; the receiving end processes the received signal to obtain a time domain received symbol, and predicts a predicted pilot symbol corresponding to a data symbol in the time domain received symbol by using a pilot symbol in the time domain received symbol; and estimating an affine transform domain channel matrix corresponding to the data symbol according to the predicted pilot symbol, converting the affine transform domain channel matrix to a frequency domain to obtain a frequency domain channel matrix, and performing frequency domain equalization on frequency domain data corresponding to the data symbol in the received signal by using the frequency domain channel matrix to obtain a final transmission result. According to the method, robustness and low complexity can be achieved, and the balance performance and Doppler interference resistance of the OFDM system are remarkably improved.

A channel estimation and equalization device and a channel estimation and equalization method, the channel estimation and equalization device comprising: a data parallel conversion module configured to perform data parallel conversion on a synchronized baseband digital signal to obtain M parallel data streams, M being an integer greater than 1, each of the data streams comprising a plurality of time domain OFDM symbol data; the orthogonal frequency division multiplexing demodulation module is configured to perform parallel demodulation on the M paths of data streams to obtain parallel M paths of frequency domain OFDM symbol data; the data flow control module is configured to separate reference symbol data for channel estimation and effective symbol data to be balanced from the M paths of frequency domain OFDM symbol data; the channel estimation module is configured to perform channel estimation based on the reference symbol data and generate and output channel estimation parameters; and the equalization module is configured to perform parallel frequency domain equalization on the effective symbol data based on the channel estimation parameters to obtain equalized data.

The application discloses a fine-grained adaptive OFDM modulation and demodulation system, which comprises a transmitting end and a receiving end, the transmitting end comprises a first serial-parallel conversion module, a fine-grained adaptive modulation module, a Hermite symmetry module, an IFFT module and a first parallel-serial conversion module, wherein the fine-grained adaptive modulation module can perform fine-grained adaptive modulation on data according to a channel estimation result fed back by the receiving end; and the receiving end comprises a second serial-parallel conversion module, an FFT module, a channel estimation module, a frequency domain equalization module, a fine-grained adaptive demodulation module and a second parallel-serial conversion module. The application can effectively solve the influence of low-pass frequency response of an actual system and realize maximization of system transmission rate.

The application provides a frequency domain equalization method, system, receiver and medium of a GNSS anti-interference filter, and particularly relates to the technical field of GNSS interference signal suppression, and the method comprises the following steps: inputting the collected intermediate frequency signal of the GNSS signal into the anti-interference filter to obtain a filtered intermediate frequency signal; based on the tracking result output by the receiver baseband and a preset spectrum amplitude, the intermediate frequency signal is predicted and filtered to obtain a reference spectrum of an interference frequency band; based on a normal intermediate frequency signal, a reference spectrum of a non-interference frequency band is obtained; the reference spectrum of the non-interference frequency band and the reference spectrum of the interference frequency band are fused to obtain a complete reference spectrum, and then the filtered intermediate frequency signal is equalized to obtain an equalized GNSS signal. The method can significantly improve the signal distortion caused by the traditional anti-interference filter, thereby effectively improving the anti-interference performance of the GNSS, and further improving the quality of the signal output by the receiver.

The application provides an intelligent image stabilization method and system for an unmanned intelligent rotary table. The method updates an interference library by acquiring electromagnetic interference data and generates wave-trap filter parameters by monitoring signal-to-noise ratio. Based on these parameters, the wave-trap is adjusted and nonlinear compensation and frequency domain equalization are triggered synchronously, while the key frame mutation signal of the image is identified to adjust the compensation strength, forming a closed loop suppression. In the closed loop, the inner loop extracts high-frequency jitter, and the outer loop fuses interference prediction to generate primary parameters, which are outputted as cross-domain suppression instructions after motion analysis. The instructions drive the anti-interference coding: the attitude coding scheme processes rotation suppression, the hierarchical error correction protocol processes electromagnetic suppression, and the link feedback is used for closed loop verification. The verification result feedback updates the interference library and the compensation strength, realizing the collaborative control of electromagnetic interference and mechanical jitter, and outputting stable images. The application builds a dynamic closed loop suppression mechanism to collaboratively suppress the electromagnetic interference and mechanical jitter of the rotary table, and realizes the image stabilization output of the unmanned intelligent rotary table.

The application relates to the technical field of industrial nondestructive testing, and discloses an industrial surface defect pure infrared light scanning detection system which comprises optical acquisition, frequency domain equalization, energy modulation, ratio construction, matrix decomposition and defect output modules. The system acquires first and second light source reflection signals and dark field noise signals in time sequence; a frequency domain equalization module constructs a space-variable equalization kernel, filters the second light source reflection signal from which the dark field noise is removed to realize frequency alignment; a ratio construction module calculates dark field thermal drift variance to generate a dynamic sparse penalty parameter, and combines the aligned signal to construct differential ratio data to generate a two-dimensional observation matrix; a matrix decomposition module decomposes the observation matrix by using a space weight matrix and the penalty parameter to output a sparse anomaly matrix; and a defect output module binarizes the anomaly matrix and maps and outputs physical coordinates. The application adaptively suppresses detector thermal drift noise, offsets material emissivity interference, eliminates space spread difference, and improves defect extraction precision under a complex background.

The invention discloses a signal processing method for power line carrier communication based on OFDM (Orthogonal Frequency Division Multiplexing) modulation, which relates to the technical field of power line carrier communication, and comprises the steps of S1, designing and inserting a cyclic prefix and a guard interval, S2, improving a synchronization algorithm to realize frequency offset processing, S3, performing noise suppression optimization on a front-end signal processing module, and S4, designing a parallel processing architecture and allocating tasks. S5, receiving end channel estimation, S6, frequency domain equalization processing, S7, OFDM demodulation processing, and S8, symbol synchronization and data recovery. According to the invention, through the steps S1 and S2, multipath time delay of a power line channel is effectively resisted, and inter-symbol interference and inter-carrier interference are reduced; through the steps S3, S5 and S6, the effects of accurately identifying the pulse noise and Gaussian noise characteristics of the power line and dynamically suppressing the noise are achieved; through the steps S4 and S8, the parallel processing architecture is utilized to improve the signal processing efficiency and avoid the overload effect of the processor, and meanwhile, the data error correction capability is enhanced through convolutional coding or Turbo coding, so that the real-time performance and reliability of high-speed data transmission are ensured.