50 results about "Channel frequency response" patented technology

The invention relates to the technical field of circuit fault processing, and discloses an automatic identification and remote isolation method for a fault section of a low-voltage distribution line, and the method comprises the steps: building a reference fingerprint database based on channel state information through a central coordination node; monitoring real-time channel frequency response and executing threshold comparison to judge suspected fault points; triggering an active impedance control unit of the terminal agent node to execute controlled perturbation; a transmission line network model is used for calculating a theoretical transmission function variable quantity, fitting analysis is carried out on the theoretical transmission function variable quantity and a measured value, and a physical fault is judged and load interference is stripped through a normalized residual coefficient; calculating a residual drift distance between adjacent nodes based on the topological mapping table to execute differential positioning so as to lock a fault physical interval; and issuing a tripping message, and driving the circuit breaker to execute physical isolation at the power frequency zero crossing point. According to the scheme, on-line fault identification and isolation are realized through active impedance perturbation and distributed residual analysis, and the robustness of fault judgment in a complex load environment is improved.

The invention discloses a channel estimation method for a 5G-OFDM system based on deep learning, and the method comprises the steps: building an OFDM orthogonal frequency division multiplexing system, and forming a low-resolution channel matrix; establishing a deep learning neural network channel estimation model; the low-resolution channel matrix is input into a deep learning neural network channel estimation model to be processed, the deep learning neural network channel estimation model adopts an interpolation-free end-to-end learning framework, and feature extraction is directly conducted on channel response data which are not interpolated; and outputting a complete channel frequency response matrix through the deep learning neural network channel estimation model to realize channel estimation. Under a 3GPP TDL-A multipath channel, the model provided by the invention has excellent performance in a signal-to-noise ratio range of 1-30dB: compared with an existing deep learning model, the estimation precision has the advantage that the parameter quantity is reduced by 93% under similar precision; the reasoning time is only 12.44 ms, the speed is increased by 25.7% compared with that of an SRCNN, the model calculation amount is only 38.24 MMac, and the method is easy to deploy in a mobile terminal with limited resources.

In one aspect, a method includes receiving, in a first wireless device, a data transmission including at least one orthogonal frequency division multiplexing (OFDM) packet from a second wireless device; processing the at least one OFDM packet to recover data and providing the data to a host processor of the first wireless device; encoding, in the first wireless device, at least one decoded symbol of the at least one OFDM packet using forward error correction coding; processing the encoded at least one decoded symbol to recover at least one corresponding transmission symbol of the at least one OFDM packet; and determining a distance estimate between the first wireless device and the second wireless device based at least in part on the corresponding transmitted symbols.

A channel feedback method, apparatus and system. The method comprises: acquiring multipath component information of a communication channel between a first device and a second device; on the basis of a self-supervised neural network, performing processing on the multipath component information and second channel information, so as to obtain intermediate information; and sending the intermediate information, wherein the second channel information is determined on the basis of first channel information and multipath delay information, the second channel information comprises a variable channel impulse response (CIR), the first channel information comprises a channel frequency response (CFR), which is obtained by means of a measurement, and the intermediate information and the multipath component information are used for determining a reconstructed CIR. By means of the solution, channel feedback is performed in combination with multipath component information and a self-supervised neural network, thereby reducing measurement overheads and feedback overheads.

This application provides a behavior recognition method, apparatus, electronic device, and storage medium based on exponential fitting, comprising: determining the corresponding power delay spectrum for the channel frequency response of a Wi-Fi signal at each observation time; fitting an exponential probability density function based on the power distribution of each sampling point in the power delay spectrum; performing a Fourier transform on the probability density function to obtain a frequency domain correlation function; determining filter coefficients based on the frequency domain correlation function and a preset frequency domain signal-to-noise ratio; filtering the channel frequency response based on the filter coefficients to obtain a denoised channel frequency response; and performing behavior recognition of passive targets based on the denoised channel frequency response at multiple observation times. This application's solution effectively denoises the channel frequency response of a Wi-Fi signal using exponential fitting, thereby enabling accurate behavior recognition based on the denoised channel frequency response.

The present disclosure provides a channel optimization method and device, system, electronic equipment and program product. The method comprises: obtaining a channel frequency response value of a target channel based on current state information of a feedforward equalizer of a receiving end of the target channel in a serial system, the channel frequency response value being used to represent transmission quality of different frequency band signals in the target channel; generating an adjustment instruction of a target parameter based on the channel frequency response value, the target parameter being a parameter in a channel before the feedforward equalizer in the target channel; and adjusting the target parameter based on the adjustment instruction of the target parameter, so that the target channel transmits serial signals with the adjusted target parameter. The embodiments of the present disclosure can reduce the time and cost of channel optimization, and help to reduce the bit error rate of the channel and improve the stability of the channel.

A system and method for determining the distance between two wireless network devices is disclosed. The present system utilizes an algorithm that leverages additional information contained in the pseudo-spectrum generated the MUSIC algorithm. Specifically, since the MUSIC algorithm operates using the square of the channel frequency response, additional peaks are created in the pseudo-spectrum, which can be used to verify the correctness of the distance measurement. The algorithm verifies that the first peak is correct by identifying a second peak and looking for an additional peak located within a search region that is determined based on the first two peaks.

The invention discloses a photon terahertz OFDM (Orthogonal Frequency Division Multiplexing) system phase noise self-adaptive compensation method based on a double-branch Transform, and belongs to the field of terahertz communication. The method specifically comprises the following steps: a transmitting end performs constellation mapping on a bit stream to generate a complex symbol, performs OFDM coding, maps the complex symbol to a frequency domain subcarrier, adjusts the signal amplitude and outputs a transmitting signal to a receiving end; a receiving end performs channel estimation on the terahertz OFDM signal to obtain a channel frequency response; on the basis, OFDM decoding is carried out on the received signal, and a signal after preliminary phase correction is obtained; then, the signals are input into a phase noise neural network decoder, features of phase noise are extracted and input into a double-branch processing network for parallel processing, phase noise compensated signals output by a Transform phase estimation branch and enhanced signals output by a CNN signal enhancement branch are obtained, and self-adaptive fusion processing is carried out based on confidence score; and finally, demapping to obtain a final result. According to the invention, the influence of phase noise on the system performance is relieved, and the bit error rate performance is improved.

An example apparatus includes: channel frequency response (CFR) circuitry configured to: receive communication signals; and determine magnitudes of the communication signals; and quality metric circuitry coupled to the CFR circuitry and configured to: determine a quality metric using the magnitudes of the communication signals; select one of a first distance estimation model or a second distance estimation model using the quality metric; and estimate a distance using characteristics of the communication signals and the selected distance estimation model.

This invention discloses a method for cascading electricity meter reading, belonging to the field of smart meter reading technology. Specifically, it includes: acquiring the channel frequency response sequence and message response timing of each preset frequency point, constructing a dynamic transmission map for each frequency point; analyzing the signal correlation between nodes in the map, restoring the physical layer connectivity state at each frequency point, and extracting data forwarding reachability relationships; acquiring the power supply ripple sequence and crystal oscillator frequency deviation value of each node to form a node operating state feature set and establishing a joint parameter correlation matrix; training and generating a frequency-node joint optimization strategy mapping model; updating the joint parameter correlation matrix, inputting the model to output the optimal operating frequency point and corresponding relay node sequence, and executing the frequency point configuration and node allocation of the cascaded meter reading path. This invention, through dynamic sensing of the standing wave state at each frequency point and real-time frequency switching, achieves active adaptation to the time-varying filter effect of the power line channel, improving the communication effectiveness of the cascaded meter reading path under complex load environments.

This invention discloses an adaptive phase noise compensation method for a photonic terahertz OFDM system based on a dual-branch Transformer, belonging to the field of terahertz communication. Specifically, the transmitter performs constellation mapping on the bitstream, generates complex symbols, performs OFDM encoding, maps them onto frequency domain subcarriers, and adjusts the signal amplitude to output the transmitted signal to the receiver. The receiver performs channel estimation on the terahertz OFDM signal to obtain the channel frequency response. Based on this, it performs OFDM decoding on the received signal to obtain a signal with preliminary phase correction. Then, it inputs the signal to a phase noise neural network decoder to extract phase noise features, which are then input into a dual-branch processing network for parallel processing. This yields the phase noise-compensated signal output from the Transformer phase estimation branch and the enhanced signal output from the CNN signal enhancement branch. Adaptive fusion processing is then performed based on confidence scores. Finally, demapping is performed to obtain the final result. This invention mitigates the impact of phase noise on system performance and improves bit error rate performance.

The application discloses a dynamic interference suppression method of multipath channel phase focusing and harmonic reverse phase cancellation, relates to the technical field of interference suppression, and comprises a path characteristic extraction module, which extracts sampling data of a received signal, constructs a received signal matrix, generates a pilot signal, carries out filter processing on a noise matrix, calculates a channel frequency response matrix, and extracts path characteristics by using a peak value detection method. The method can comprehensively calculate the time delay component contribution of the channel time domain response by discretizing the channel frequency response matrix through limited sampling points and combining all frequency components in the frequency bandwidth, can enhance the dynamic response capability of the channel model by introducing time-varying environmental characteristics through a dynamic path time delay function, can improve the signal characteristic correction precision through dynamic compensation of path time delay error phase rotation, and can realize the channel description process with path grouping as the core.

The invention discloses a positioning method and electronic equipment based on multi-source information fusion, and the method comprises the steps: obtaining a plurality of classification regions and the number of classification types according to channel frequency response, received signal strength and angle time delay response; obtaining a target feature according to the channel frequency response, the angle time delay response, the first feature extractor and the second feature extractor; and carrying out regression operation on the target features according to the plurality of classification regions and the number of divided categories to obtain positioning information, so that the positioning precision can be improved.

The invention relates to the technical field of signal performance evaluation, in particular to a non-cooperative long code navigation signal performance evaluation method and related equipment, and the method comprises the following steps: obtaining a QPSK modulated non-cooperative long code navigation signal and a baseband code stream symbol; after the standard long code sequence is divided into equal-length signal segments, a sectional type parameter configuration correlation / integral method is used for capturing and tracking to obtain observed quantity information, and according to the standard long code sequence, the error performance of the non-cooperative signal code element sequence is evaluated, and the error rate and the position are counted; comparing the code element sequence after the baseband signal time domain waveform superposition with a local template, and evaluating time domain waveform distortion; the method comprises the following steps: quantifying non-cooperative signal channel characteristics, estimating digital distortion parameters through segmented accumulation of baseband signals, solving a response coefficient of an analog distortion filter by using a least square method, calculating an amplitude-frequency characteristic peak-to-peak value and a group delay variance, evaluating analog channel frequency response characteristics, and realizing accurate evaluation of non-cooperative long code signals.

In one aspect, a method comprises: receiving a data transmission containing at least one orthogonal frequency division multiplexing (OFDM) packet from a second wireless device in a first wireless device; processing the at least one orthogonal frequency division multiplexing (OFDM) packet to recover data and provide the data to a host processor of the first wireless device; encoding at least one decoded symbol of the at least one orthogonal frequency division multiplexing (OFDM) packet with forward error correction encoding in the first wireless device; processing the encoded at least one decoded symbol to recover at least one corresponding transmitted symbol of the at least one OFDM packet; and determining a distance estimate between the first wireless device and the second wireless device, at least partially based on the corresponding transmitted symbol.

This invention discloses a method for online monitoring of cable thermal aging based on power line communication technology, implemented according to the following steps: Step 1: Establish a power line channel model to obtain the broadband channel frequency response under high-frequency conditions; Step 2: Based on the different distribution parameters of the cable under different thermal aging types and degrees, obtain the power line channel model after the cable undergoes thermal aging, and obtain the broadband channel frequency response under thermal aging conditions; Step 3: Use a random forest classification algorithm to classify cable aging and obtain the aging type of the cable; Step 4: Use a random forest regression prediction algorithm to train the cable groups obtained in Step 3 that have undergone overall thermal aging and local thermal aging, and predict the degree of thermal aging of the cable. This method can not only identify whether the cable has undergone thermal aging, but also predict the degree of cable aging.

The invention belongs to the technical field of wireless multi-carrier communication and signal processing, and particularly discloses an LDPC (Low Density Parity Check) assistance-based iterative channel estimation method, which comprises the following steps of: performing LDPC low density parity check code coding, offset quadrature amplitude modulation and filter group multi-carrier modulation on information at a transmitting end; at a receiving end, initial channel estimation is calculated based on pilot symbols, interpolation is carried out, and initial channel estimation values at all data symbol positions are obtained; performing hard decision re-modulation reconstruction to obtain a reconstructed symbol after the data symbol is subjected to balanced demodulation by using the demodulation signal; calculating the updated channel estimation according to the receiving symbol and the reconstruction symbol; and combining the initial channel frequency response estimation value at the pilot frequency position and the updated channel estimation value at the data symbol position, carrying out Gaussian filtering processing on the combined channel estimation value, and outputting a final full frequency domain channel estimation value. According to the invention, the channel estimation accuracy of the FBMC-OQAM system can be effectively improved.

The invention discloses method of improving AUV wireless communications systems, including steps of: collecting the channel frequency response and receiving signal data in the electromagnetic environment where AUV works on the water surface,; constructing a multi-dimensional feature aggregation network model based on self-attention mechanism; training a multi-dimensional feature aggregation network; and preprocessing received AUV signals to obtain improved input data. The network model completed by offline training is loaded, and the input data is input into the network for channel estimation. The invention uses a self-attention mechanism in deep learning to build a multi-dimensional feature aggregation network model. The estimation performance is much higher than the traditional channel estimation method, and the space-time complexity of the network is very low, which can be applied to an AUV wireless communication system through offline training.

The invention provides a communication and sensing integrated sensing burst set design and signal parameter estimation method and device, and relates to the technical field of wireless communication. The method comprises the following steps: designing a general-inductance integrated sensing signal SSB burst set; describing transmission and receiving processes of sensing signals of the MISO system modulated by the OFDM in the dynamic multipath environment; the method comprises the following steps: initializing carrier frequency offset, channel frequency response and Doppler frequency shift estimation according to a digital baseband signal in a mobile mode of a receiver, constructing a mathematical expression for receiving a sensing signal in a stable state, and estimating a multipath number according to an MDL criterion; and designing a signal parameter estimation architecture of the receiver in a tracking state. The signal structure designed by the invention is compatible with the existing system, the coverage range of the sensing signal is improved, the provided signal parameter estimation architecture can effectively estimate the multipath propagation, AoD and ToA of the signal in a complex environment, and the method is suitable for accurate environment sensing and positioning in large-range mobile scenes such as intelligent traffic and the Internet of Vehicles.

The application provides a power line carrier communication method and device based on adaptive bit power allocation. In the application, the channel frequency response and noise power of each OFDM subcarrier are determined according to a preset signal sent to a target electric energy meter and a received signal accepted by the target electric energy meter on each OFDM subcarrier, so as to filter out the optimal active subcarrier number with better communication effect and the most suitable optimal power allocation reference value through the channel frequency response and the noise power, and then configure a target power and a bit number for each optimal active subcarrier, so that the data to be transmitted can be modulated to each optimal active subcarrier according to the target power and the bit number to communicate with the target electric energy meter. In the above method, the OFDM subcarriers with better communication performance can be selected from a plurality of OFDM subcarriers, and then a suitable power and bit number are configured for each OFDM subcarrier, so as to improve the communication quality of the intelligent acquisition terminal and reduce the probability of communication interruption.

The invention discloses a self-adaptive non-uniform pilot frequency design and channel estimation method and system for an HPLC (High Performance Liquid Chromatography) channel, and the pilot frequency design method comprises the steps: detecting the initial channel frequency response of all effective subcarriers in the full frequency band of the channel by using a lead code, and calculating statistical characteristics; dividing the effective subcarriers into a deep fading subcarrier set and a non-deep fading subcarrier set according to the statistical characteristics of the effective subcarriers; all subcarriers in the deep fading subcarrier set are configured as pilot subcarriers, and effective subcarriers are extracted from the non-deep fading subcarrier set in a sparse uniform distribution mode and configured as pilot subcarriers. The method can allocate the pilot frequency resource according to the channel state, and significantly improve the data transmission efficiency.

The invention discloses a low-altitude unmanned aerial vehicle sensing method based on a 5G signal and related equipment. The method comprises the following steps: acquiring a channel frequency response measurement value; performing static background elimination on the channel frequency response measurement value to obtain a dynamic channel component; obtaining dictionary incoherence and channel occupancy density of the channel segments to obtain channel scores; when the channel score is greater than or equal to a first preset threshold value, performing global estimation on the dynamic channel component to obtain a first target state estimation value at the current moment; when the channel score is smaller than a first preset threshold value and the target unmanned aerial vehicle does not exist at the previous moment, returning to the step of obtaining the channel frequency response measurement value; and when the channel score is smaller than a first preset threshold value and the target unmanned aerial vehicle exists at the previous moment, performing local estimation on the dynamic channel component to obtain a second target state estimation value at the current moment. The method can improve the continuity and accuracy of unmanned aerial vehicle perception, and can be widely applied to the technical field of unmanned aerial vehicle state estimation.

The application provides a positioning method based on a channel frequency response, an electronic device and a storage medium. The method comprises the following steps: performing conjugate multiplication on each second channel frequency response and a first channel frequency response respectively to obtain a target vector, and subtracting the mean value of multiple values in the target vector from each value in the target vector to obtain a cleaned channel frequency response corresponding to each second channel frequency response; constructing an observation matrix based on multiple cleaned channel frequency responses at the same observation time; determining the angle of arrival of a passive target relative to a second receiver and the channel length of a NLOS channel based on the observation matrix; and determining the target position information of the passive target according to the first position information of a transmitter, the second position information of the second receiver, the angle of arrival and the channel length. The present scheme can analyze the angle of arrival of the passive target relative to the receiver and the channel length of the NLOS channel by means of the noise-reduced channel frequency response, and realizes accurate positioning of the passive target.

The invention discloses a distance measurement method based on frequency domain super-resolution and path geometric constraint and related equipment, and relates to the field of distance measurement. The method comprises the following steps: receiving a broadband detection signal sent by a sending end to obtain a received signal; performing frequency domain coherent processing on the received signal and a pre-stored broadband detection signal copy to obtain channel frequency response data; according to the calculated signal-to-noise ratio of each frequency point in the channel frequency response data, filtering the frequency points with the signal-to-noise ratio lower than a preset signal-to-noise ratio threshold to obtain effective channel frequency response data; based on the effective channel frequency response data, adopting a preset time delay algorithm to calculate direct signal propagation time delay of the direct path; and calculating a physical distance based on the direct signal propagation time delay and a calculation rule corresponding to a preset distance measurement mode. By implementing the above technical scheme, the accuracy of distance measurement in a multipath signal propagation scene is improved.

A system and method for determining a distance between two wireless network devices is disclosed. The system utilizes a power ratio dependent algorithm. The power ratio may be calculated as a ratio of the test signal power to the total signal power. The test signal power is defined as a signal power associated with a particular distance. The algorithm calculates a channel frequency response and calculates a power ratio and a cumulative power ratio using phase signals at each frequency and distance. A line-of-sight distance is determined based on a slope of the cumulative power ratio curve. This approach does not depend on any priori estimation of feature vectors or number of signals, and thus can be calculated quickly and efficiently.

A method performed by a receiving end in a wireless communication system is provided. The method includes receiving one or more reference signals (RSs) from a transmitting end, identifying, based on channel frequency response (CFR) identified based on the received one or more RSs, one or more matrixes associated with a plurality of antennas, which are included in the receiving end or the transmitting end and are for transmitting downlink data, converting the identified one or more matrixes into values associated with angles of beams formed by the plurality of antennas, determining, based on the values associated with the angles of the beams, one or more precoding matrix indicators (PMIs), which can be applied to the plurality of antennas, and identifying a first PMI corresponding to a maximum downlink data throughput from among the one or more PMIs.

The invention discloses a non-orthogonal multiple access system communication method based on index modulation and constant envelope modulation. According to the method, the number of activated subcarriers is selected at a sending end according to the bit number of data needing to be transmitted by users, index modulation is carried out on the subcarriers of all the users, and OFDM signals are embedded into phases of constant envelope signals through phase modulation after signals of all the users are superposed; and at a receiving end, firstly eliminating the cyclic prefix of the received signal, then carrying out channel estimation and equalization processing through pilot frequency, then deducing channel frequency response corresponding to each symbol by adopting a cubic spline interpolation method, and finally demodulating the user signal. According to the method, the robustness of the non-orthogonal multiple access system can be enhanced, and the low bit error rate can still be kept when the power difference between the users is not significant. The peak-to-average power ratio of the non-orthogonal multiple access system is greatly reduced, and the power consumption cost is reduced. And the anti-interference capability of the communication system on the frequency selective fading under the Rayleigh channel is obviously enhanced.

The present application belongs to the technical field of underwater acoustic physical layer, and particularly relates to a kind of underwater acoustic physical layer key quantization method and device, to be used in the condition of underwater acoustic channel under high signal-to-noise ratio Quantization and key generation, legal communication parties complete channel sounding in channel sounding stage using OFDM signal, and extract the observation sequence containing channel frequency response characteristics;Communication parties use clustering method to complete clustering to obtain cluster center, then build quantization protection interval through membership discrimination, and remove the fuzzy boundary observation point in the protection interval.The present application can solve the problem of quantization error caused by the inconsistency of observation sequence due to local noise difference under high signal-to-noise ratio, and by using the idea of clustering and protection interval to build irregular quantization protection interval, the quantization boundary point is removed, and under the condition of underwater acoustic environment and / or high signal-to-noise ratio, a lower initial key mismatch rate can be obtained, which is convenient for practical scene application.

The invention provides a clock synchronization method and device, terminal equipment and a storage medium, and the method comprises the steps: carrying out the sampling through employing an independent clock, obtaining a discrete sampling signal, carrying out the cross-correlation operation, generating a frame starting point index, calculating the phase difference of two detection sub-blocks in each frame, so as to obtain a global carrier frequency offset estimation value, and carrying out the calculation of the global carrier frequency offset estimation value. Applying reverse frequency offset to the discrete sampling points to obtain a frequency offset compensation signal sequence; extracting a channel impulse response and reconstructing the channel impulse response into a continuous time waveform, taking a difference value between real peak time and the closest integer sampling point moment as sampling time offset, establishing a linear function according to the change of the offset along with a frame sequence, and performing fitting to obtain a time drift estimated value; and obtaining an original result of channel frequency response, and applying reverse phase rotation to the original result according to the time drift estimation value to obtain a channel frequency response sequence after phase correction. According to the invention, joint synchronization of detection signals in two dimensions of time and frequency can be realized on the premise of no external reference clock.

In an embodiment, an apparatus of a digital unit (DU) is provided. The apparatus can include a transceiver, a memory to store instructions, and a processor. The instructions, when executed by the processor, can direct the apparatus to obtain a channel frequency response from a reference signal from a terminal, obtain an eigenvector by eigen decomposition of the channel frequency response, obtain a transformed vector by performing a two-dimensional Fourier transform on the eigenvector, identify, according to the transformed vector, a basis vector of a plurality of basis vectors of an enhanced type 2 codebook by a decision metric, determine a precoding matrix using the identified basis vector, and transmit, by a radio unit (RU), downlink data to the terminal to which the precoding matrix is applied.