20 results about "Blind equalization" patented technology

The invention relates to the technical field of signal processing, in particular to an intelligent blind equalization method and device for large-scale carrier frequency deviation, and the method comprises the steps: carrying out the down-conversion of an original received signal of a preset modulation type, so as to sample an original complex sampling point sequence with large-scale carrier frequency deviation; performing local information exchange, parameter correction and splicing on the original complex sampling point sequence to obtain a compensated complex sampling point sequence; performing pre-extraction and channel amplification on the compensated complex sampling point sequence to obtain pre-extraction features containing implicit channel state information, and further extracting spatial information and time sequence dependence in the pre-extraction features to balance multipath fading of the original complex sampling point sequence and obtain balanced output; and demodulating the original bit information of the original complex sampling point sequence according to the balanced output. Therefore, the problem that a blind equalization method in the related technology cannot effectively adapt to a time-varying multipath channel and a scene with large-scale carrier frequency deviation is solved.

The invention discloses a parallel receiving method and system for high-speed 16 QAM (Quadrature Amplitude Modulation) data demodulation, and the method comprises the following steps: S1, carrying out the sampling of received intermediate-frequency 16 QAM data through a high-speed ADC (Analog to Digital Converter), and obtaining four paths of signals through the serial-to-parallel conversion function of the ADC; s2, converting the four paths of signals into 32 paths of parallel signals at a conversion rate of 1: 8 by using a serial-to-parallel converter special for the FPGA; and S3, carrying out digital orthogonal down-conversion on the 32 paths of parallel signals to obtain 16 paths of baseband signals of an I path and a Q path, and then sequentially carrying out matched filtering, timing synchronization, blind equalization, carrier synchronization, frame synchronization and 16QAM judgment decoding to complete parallel receiving. According to the invention, the requirement of high bit rate is met based on three key technologies of timing synchronization, blind equalization and carrier synchronization, and the receiving and demodulation recovery functions of high-speed data in a 16 QAM modulation mode can be effectively completed.

This invention belongs to the field of visible light communication technology and relates to a nonlinear blind equalization method for a VLC system based on a variational autoencoder. The method includes: inputting the received signal into a trained blind equalization network model to obtain an equalized signal; the training process of the blind equalization network model includes: preprocessing the transmitted and received signals of the VLC to obtain a preprocessed transmitted signal Tx and its counterpart to the received signal Rx; and inputting Rx into an equalizer network to obtain the latent variable signal Tx. * The prior probability distribution and the posterior probability distribution of a given received signal Rx are obtained; the prior probability distribution and the posterior probability distribution are input into the channel estimation network to obtain the likelihood probability distribution and the equalization signal; the loss function value is calculated based on the prior probability distribution, the posterior probability distribution and the likelihood probability distribution, and the parameters of the model are updated based on the loss function value until the stopping condition is reached; the present invention integrates multiple loss functions to avoid the local optimum problem caused by a single loss function.

The application provides a multimode blind equalization method based on a swallow line function and a variable fractional order gradient. The algorithm uses statistical characteristics of an equalizer output signal and a transmitting end signal to construct a multimode cost function based on a swallow line function, so that phase errors in a channel equalization process can be compensated without an additional carrier recovery loop. Subsequently, a variable fractional order gradient method is used to replace a traditional fixed order gradient updating mode to adaptively update equalizer weight vectors, so that optimal weight vectors are obtained. Compared with the prior art, the application can not only realize channel equalization and phase recovery, but also effectively reduce residual inter-symbol interference and bit error rate in a strong impulse noise environment, while the convergence speed is accelerated, and higher equalization efficiency and robustness are shown.

This disclosure describes embodiments of methods, systems, and non-transitory computer readable media that can quickly and accurately determine equalizer coefficients for an equalizer based on estimated point-spread-function values and estimated noise values derived from expected response signals of oligonucleotide clusters. For example, the disclosed systems can receive signal values for expected response signals from one or more clusters of oligonucleotides incorporating labeled nucleobases. Based on the signal values, the disclosed systems can determine estimated point-spread-function values for one or more such clusters of oligonucleotides and estimated noise values within a channel. From the estimated point-spread-function values and the estimated noise values, the disclosed systems can determine equalizer coefficients that compensate for the estimated point-spread-function values and the estimated noise values. The disclosed systems can further determine a base call for one or more such clusters of oligonucleotides by utilizing the equalizer coefficients.

The present invention discloses a joint blind equalization method, device, electronic device, medium and program product. By combining an improved MCMA algorithm based on simulated annealing and a DDLMS algorithm whose step size is adjusted by an inverse hyperbolic sine function, the problem that the existing blind equalization method is not effective in low signal-to-noise ratio environments is solved. Specifically, in the early stage of communication, the tap coefficients of the equalizer are adjusted using the improved MCMA algorithm to perform preliminary equalization processing to quickly achieve a stable equalization effect, and then switch to the DDLMS algorithm with a step size optimization mechanism, thereby further improving the steady-state error performance in subsequent stages. It can avoid the dependence of traditional adaptive equalization on training sequences, effectively reduce channel resource consumption, and improve the equalization effect in complex transmission environments through step size optimization, adapting to the equalization needs in low signal-to-noise ratio scenarios.

This invention relates to the field of telemetry technology, proposing a telemetry system and method suitable for close-range testing of high-speed rotating components. The telemetry system includes a rotating transmitter and a fixed receiver. The rotating transmitter includes a target rotating component, a signal acquisition and processing module, and a transmitting antenna. The signal acquisition and processing module acquires and processes test parameters of the target rotating component and radiates the processed test data outward through the transmitting antenna. The fixed receiver includes a receiving antenna, a signal optimization module, and a data processing module. The receiving antenna receives the test data, the signal optimization module performs adaptive diversity synthesis and blind equalization processing on the test data to obtain processed data, and the data processing module outputs corresponding telemetry data based on the processed data. This invention enables high bit rate and low bit error rate transmission, meeting the high-precision, high-speed rotation testing requirements of aerospace, industrial equipment, and other fields.

This invention discloses an adaptive blind demodulation method, system, terminal, and medium based on a satellite communication system. The method includes: performing parameter estimation, frequency offset compensation, and timing synchronization processing on the original baseband sampled data sequence to obtain a single symbol rate data symbol sequence; performing hierarchical phase-locked loop carrier coarse synchronization iterative processing on the single symbol rate data symbol sequence to obtain a target convergent constellation diagram symbol sequence; extracting high-order cumulant features based on the target convergent constellation diagram symbol sequence and performing modulation scheme identification and confidence judgment, iterating until a preset judgment condition is met to obtain a target modulation identification result; and performing adaptive carrier fine phase-locking and blind equalization joint processing on the target modulation scheme to obtain a demodulated symbol sequence. This invention solves the coupling problem between carrier synchronization and modulation identification by combining hierarchical carrier synchronization, high-order cumulant feature identification, and adaptive fine phase-locking blind equalization, thereby improving demodulation reliability.

The invention relates to the field of channel blind equalization, and provides an adaptive blind equalization method and device based on channel perception, and the method comprises the steps: obtaining a digital intermediate frequency signal; performing channel feature extraction on the digital intermediate frequency signal to obtain a channel feature parameter; mapping the channel characteristic parameters to obtain pre-equalization parameters and initial working mode suggestions; comprehensive decision processing is carried out according to the pre-equalization parameters, the initial working mode suggestion and error signals, a dynamic weighting factor is obtained, and the error signals comprise error signals output by the equalizer in real time; performing signal conditioning and distortion correction processing according to the dynamic weighting factor to obtain a baseband signal; according to the method, through the synergistic effect of the technical means, signal conditioning and distortion correction are finally carried out by utilizing the dynamic weight, the baseband signal is accurately recovered, and system parameters are continuously optimized through closed-loop adaptive adjustment.

Systems and methods for classifying a modulation scheme of a wireless signal are described. In some embodiments, a system receives a wireless signal modulated based on a modulation scheme having a constant modulus. The system can generate a resampled signal from the wireless signal based on features extracted from the wireless signal and perform blind equalization on the resampled signal based on a constant modulus criterion to generate an equalized signal. Then, the system can cause a modulation classifier to classify the received wireless signal to a modulation scheme from a plurality of predetermined modulation schemes based on the equalized signal. By preconditioning the wireless signal to reduce feature variability imparted by a propagation channel onto the wireless signal, the system can increase the classification accuracy of the modulation classifier.

The invention provides a signal modulation identification method and device, electronic equipment and a storage medium, and relates to the technical field of signal modulation identification, and the method comprises the steps: carrying out the blind equalization processing of a first synchronization signal obtained after blind matching and bit synchronization processing, and obtaining a second synchronization signal; converting the second synchronization signal into a corresponding constellation diagram, and performing feature extraction on the constellation diagram by adopting a first residual network to obtain a feature vector of the constellation diagram; and adopting a classification network to perform open set identification of modulation modes based on the feature vectors to obtain a target modulation mode, the target modulation mode comprising one of an unknown modulation mode and at least one known modulation mode. Therefore, the known modulation mode can be accurately identified, and the modulation mode of the to-be-identified signal can be accurately determined to be the unknown modulation mode when the to-be-identified signal is not modulated by adopting the known modulation mode, so that a complex and changeable electromagnetic environment and diversified modulation signals can be effectively coped with.

The present invention discloses a GMSK receiving method based on blind equalization, comprising the following steps: down-converting the received GMSK signal to baseband; low-pass filtering the GMSK baseband waveform; capturing and synchronizing the received signal based on the pseudo-random sequence in the frame header; equalizing the received GMSK signal using a CMA constant modulus algorithm; derotating the equalized signal; estimating the phase offset of the derotated signal and performing phase compensation; demodulating the soft information, extracting the real part, and making a decision. This method effectively solves the inter-symbol interference problem caused by multipath channels in the current GMSK system, achieving a low-complexity equalization and receiving method suitable for high-speed GMSK transmission.

The invention provides an anti-noise high-precision error vector amplitude measurement system and method for a satellite launching system. The system comprises a demodulator, an A / D conversion circuit, a data distributor, a decoding function module and an EVM processing module. And the demodulator carries out carrier synchronization, code synchronization and blind equalization processing on the digital signal, and outputs real I-path data Ireal and Q-path data Qreal. The data distributor copies the Ireal and the Qreal and divides the Ireal and the Qreal into two paths for output, one path is transmitted to the decoding function module, and the other path is transmitted to the EVM processing module. And the EVM processing module comprises a phase error calculation unit, an amplitude error calculation unit and an error vector amplitude calculation unit which are respectively used for carrying out parallel processing on the Ireal and the Qreal, calculating to obtain a phase error ErrPhase, an amplitude error ErrMag and an error vector amplitude value, and reporting an analysis and processing result through a CPCI (Compact Peripheral Component Interconnect) bus. According to the invention, high-precision and anti-noise measurement of the satellite emission signal quality is realized through shunt parallel processing and a multi-bit-width quantization and smoothing strategy.

The invention discloses an incremental Markov chain Monte Carlo (MCMC) underwater acoustic channel blind equalization method which is used for solving the problem that traditional MCMC blind equalization cannot be converged due to excessive unknown parameters in a long pulse response underwater acoustic channel. The method is divided into two stages: in the first stage, MCMC blind equalization is started with a smaller initial channel length, and the length is gradually increased until a normalized reconstruction error is lower than a threshold; and in the second stage, the result of the previous stage is inherited, the channel length is increased by the step length delta, and MCMC blind equalization is initialized and executed based on the result of the previous stage until the reconstruction error is not reduced any more. Through an incremental strategy and intermediate result multiplexing, the calculation complexity is significantly reduced, and the convergence and accuracy of long channel estimation are improved. The method is suitable for an underwater communication system, the blind equalization of the long pulse response underwater acoustic channel becomes possible through an incremental strategy, the high calculation complexity is avoided by reasonably utilizing the blind equalization intermediate result, and the method has high practical application value.

The invention discloses a dual-mode switching constant modulus blind equalization-minimum mean square frequency domain equalization method, which specifically comprises the following steps that: a transmitting end modulates N paths of input electric signals # imgabs0 # onto N paths of Gaussian beams respectively, and outputs N paths of Gaussian beams carrying data information; enabling the N paths of Gaussian beams carrying data information obtained in the step 1 to pass through different spiral phase plates to generate N OAM beams carrying different topological charges; n OAM light beams with different topological charges are multiplexed into one path of OAM multiplexed light beam by using an OAM state multiplexer, and the OAM multiplexed light beam reaches a receiving end after passing through an atmospheric turbulence channel; the method comprises the following steps: processing an OAM multiplexing light beam received by a receiving end through an OAM state demultiplexer and a deconverter to obtain each path of user receiving signal # imgabs1 #; and processing each path of user receiving signal # imgabs2 # by using a frequency domain equalizer so as to continuously update a filter tap vector # imgabs3 #. According to the invention, the problems of signal attenuation and inter-mode crosstalk of a traditional OAM multiplexing system in the prior art are solved.

This invention discloses a MAPSK blind equalization method and system suitable for complex channel environments with low signal-to-noise ratios (SNR). The system includes: a transverse filter with multiple taps that receives a MAPSK signal sequence after symbol synchronization processing; an error calculator that calculates the amplitude and / or phase error of the signal based on the output of the transverse filter; and a weight vector updater that updates the weights of the transverse filter taps based on the calculated error. The blind equalization method of this invention can converge quickly in low SNR and complex channel environments, significantly improving the communication quality and reliability of satellite communications.

The invention provides an information transmission method and system for a submersible, and the method comprises the following steps: a target receiving submersible broadcasts a detection signal, and enables a transmitting submersible to carry out the parametric modeling of a distorted signal. When data needs to be transmitted, the transmitting submersible generates a pre-coding signal based on the channel model, and the signal can realize space-time focusing at the position of the target receiver after being transmitted through the underwater environment. And if different data needs to be sent to a plurality of different targets at the same time, acoustic orbital angular momentum phase factors of different modes are loaded for each path of data so as to realize distinguishing. And the plurality of transmitting submersible vehicles cooperatively transmit respective pre-coded signals under the synchronization of the high-precision clock. And finally, the target receiving submersible sharpens the received focusing signal through adaptive blind equalization processing, eliminates residual interference and recovers original data. The underwater communication method has the effect of improving the underwater communication reliability of the submersible.

An embodiment of the present invention provides a channel equalization method, device, and storage medium, belonging to the field of communication technologies. The channel equalization method includes: receiving a signal sent by a sender; attempting to perform scrambling synchronization on the signal through a scrambling synchronization module, and determining whether a receiver can lock the scrambling according to a predetermined decision criterion; if the determination result is yes, performing time-domain equalization using a training sequence output by the scrambling synchronization module; if the determination result is no, first performing blind equalization on the signal to obtain a pre-equalized signal, and then performing scrambling synchronization on the pre-equalized signal to complete time-domain equalization. The method of the present invention is used in an environment with low signal-to-noise ratio and / or poor channels, and can avoid the situation where the receiver is deadlocked in the scrambling synchronization stage and fails to complete channel equalization.

The invention provides a variable step size constant modulus algorithm blind equalization method and system based on cyclic redundancy check. The method comprises the following steps: acquiring a receiving signal sent by a sending end after being coded and modulated by the cyclic redundancy check; initializing equalizer parameters; performing iterative processing: performing equalization filtering by using the current tap coefficient to obtain an output signal, and performing symbol judgment and cyclic redundancy check on the output to generate a check result; dynamically adjusting the iteration step length of the constant modulus algorithm according to the verification result; if the data is wrong, increasing the step length, and if the data is correct, adopting the default step length; updating a tap coefficient based on the adjusted step length and a constant modulus algorithm error function; and repeating iteration until all the signals are processed, and outputting a final equalization sequence. According to the method, the channel state is sensed in real time and the step length is dynamically adjusted through the verification result, the steady-state error is remarkably reduced while the convergence speed of the algorithm is increased, and the adaptability and the transmission reliability of a communication system under the time-varying channel are improved.

The application discloses a variable step-size dual-mode blind equalization method for QAM signals, a storage medium and equipment, and belongs to the technical field of blind receiving and demodulation of wireless communication systems. The application solves the problem that the traditional hard switching mechanism is easy to cause system transient oscillation and lock loss. The application adjusts the iteration step size by constructing an error exponential function with a transient error signal as an independent variable, automatically gives the system a larger step size in the initial stage of the algorithm to accelerate convergence, and adaptively attenuates when the error tends to zero to suppress steady-state fluctuations, effectively overcoming the inherent contradiction between convergence speed and steady-state accuracy of the traditional fixed step-size algorithm; a soft switching mechanism based on a continuous confidence factor is used to replace the traditional hard switching decision, the global convergence ability of the MMA algorithm and the extremely high steady-state accuracy of the DD algorithm are smoothly and non-oscillatingly fused through a nonlinear fusion factor, transient oscillation and error propagation effect caused by mode switching are significantly suppressed, and system lock loss is avoided. The application can be applied to blind equalization of wireless communication systems.