787 results about "Pilot signal" patented technology

A method for target position estimation based on a distributed reconfigurable intelligent surface (RIS) transmissive array is provide, including: configuring distributed RISs as an RIS transmissive array, wherein the distributed RISs include two RIS transmissive array surfaces, a target source and receiving radio frequency (RF) chains are respectively disposed on two sides of the RIS transmissive array, the receiving RF chains are connected to receiving antennas, and the target source emits a pilot signal into space; transmitting the pilot signal through the RIS transmissive array to the receiving RF chains to obtain a received signal; determining an azimuth angle β and an elevation angle α of the target source relative to each of the two RIS transmissive array surfaces by processing the received signal; and constructing two rays respectively passing through centers of the two RIS transmissive array surfaces based on the azimuth angles β and the elevation angles α of the target source relative to the two RIS transmissive array surfaces, determining a median of a shortest distance between the two rays, and determining a position of the median as a position of the target source.

The invention discloses a channel estimation method and system with a limited backhaul network in a non-cellular large-scale MIMO (Multiple Input Multiple Output) system, and the method comprises the following steps: receiving a quantized pilot signal sent by an access point through the backhaul network, and taking the quantized pilot signal as a channel observation signal; updating the channel noise variance according to the channel prior mean value and the channel prior variance during the last iteration, and reducing the quantization noise of the channel observation signal according to the updated channel noise variance to obtain a received signal estimation value; inputting the channel noise variance and the received signal estimation value into the trained VAMP network to obtain an estimated channel state matrix, and calculating to obtain a channel prior mean value and a channel prior variance according to the estimated channel state matrix; and outputting the channel state matrix estimated at the moment as a final channel state matrix until the number of iterations reaches a preset number. The method is higher in robustness.

The invention relates to a channel estimation method based on frequency domain deviation compensation and dynamic DCT denoising, and belongs to the technical field of wireless communication. The method comprises the following steps: establishing a wireless channel model and an OFDM system model; estimating the frequency offset in the received signal by using the phase rotation characteristic of the pilot signal; calculating a preliminary channel frequency domain response # imgabs2 # at a pilot frequency position through a least square criterion based on the compensation signal # imgabs1 #; obtaining a receiving pilot frequency signal # imgabs4 # according to the sending pilot frequency Xp and the roughly estimated channel frequency response # imgabs3 #; estimating a current signal-to-noise ratio SNRest based on the pilot frequency signal # imgabs5 # and a noise power ratio; and establishing an adaptive DCT denoising strategy based on a signal-to-noise ratio threshold, and selecting different denoising strategies according to different signal-to-noise ratios to perform denoising processing on # imgabs6 # to obtain final channel estimation # imgabs7 #. The adaptive denoising strategy design of the invention effectively balances the relationship between noise suppression and channel structure fidelity, and improves the precision and stability of overall channel estimation.

The invention discloses a multi-modal data enhancement method and system based on feature space alignment. The method comprises the following steps: collecting modal original data streams of multiple unmanned aerial vehicles; reversely deducing an internal generation rule from a data final state, and constructing a sparse coding feature representation library through causal pilot signal extraction and singular trajectory analysis; constructing an adaptive weight map according to the feature representation library, and identifying a space alignment path through dynamic calibration processing to generate an alignment imbalance index; performing cross information entropy analysis to establish a collaborative enhancement chain, and identifying a collaborative enhancement mode based on the information coupling degree to generate a complementary enhancement vector; performing multi-dimensional projection reconstruction on the complementary enhancement vector, and determining feature mapping probability distribution through diffusion time inversion to obtain a multi-dimensional projection feature map; carrying out nonlinear enhancement processing to generate an enhancement expansion mode, and identifying an enhancement key node to construct an enhancement regulation and control sequence; and outputting hierarchical enhancement data based on the regulation and control sequence and the projection feature map, and realizing accurate space alignment and collaborative enhancement of multi-sensor data.

The present invention provides a new pilot pattern and channel estimation method involving such pilot for mmWave OTFS systems in high mobility scenarios with non-ideal power amplifier, which is applicable in the fifth generation (5G) and beyond networks. The pilot pattern for communication signal in wireless communications involving mmWave systems with non-ideal power amplifier comprises signal including a pilot signal element, information-bearing symbol and zero as guard, wherein, position of pilot and guard are arranged to combat the effect of inter symbol interference (ISI) from nonlinear impairment of the power amplifier for accurate channel estimation.

Methods, systems, and devices for wireless communications are described. A network entity may perform digital post distortion (DPoD) using signals transmitted from multiple user equipments (UEs) on adjacent frequency resources. Each UE may transmit, to the network entity, a data message on a first set of frequency resources and a pilot signal associated with the data message on a set of subcarriers within a second set of frequency resources. The first set of frequency resources may be a subset of the second set of frequency resources. The set of subcarriers includes one of odd or even indexed subcarriers within the second set of frequency resources. A first portion of the set of subcarriers may be within the first set of frequency resources and a second portion of the set of subcarriers may be within the second set of frequency resources and outside the first set of frequency resources.

The invention provides a phase tracking enhancement method, a storage medium and a product. The method comprises the following steps: processing a received signal by a receiver to obtain a channel estimation value on each subcarrier; acquiring a first pilot signal inserted on a preset position subcarrier of each OFDM symbol based on the received signal, and performing initial phase tracking according to the first pilot signal and the channel estimation value to obtain an initial phase parameter; based on the first result after channel equalization, the second result after demapping or the third result after error correction decoding, reconstructing to obtain a second pilot signal; and performing enhanced phase tracking according to the first pilot signal, the second pilot signal and the channel estimation value to obtain an updated phase parameter. Therefore, phase tracking can be performed based on more pilot signals, the accuracy of phase tracking can be improved, and the phase parameter estimation error can be reduced.

The invention provides a multi-antenna MIMO architecture synchronization method and device, a program product and a storage medium, and relates to the technical field of wireless communication. Receiving sampling signals through a plurality of receiving channels; performing down-sampling on each sampling signal to obtain a down-sampling signal; determining a plurality of cache regions to store each downsampling signal, and performing cross-correlation operation on each downsampling signal and a local synchronous time domain signal; when any receiving channel detects an effective peak value, determining the position of the effective peak value as a preliminary synchronization position; determining a corresponding search window range, and performing weighted stacking on the target cross-correlation results to obtain an overall correlation peak value; searching a maximum value in all the total correlation peak values, and determining a position corresponding to the maximum value as a final synchronization position; and calculating a frequency offset estimation value of each receiving channel according to each pilot signal, and carrying out weighted average on each frequency offset estimation value to obtain a final frequency offset estimation value. By adopting the method, the wireless frame synchronization precision can be improved.

Exemplary embodiments provide a device [e.g. a circuit, such as a control circuit] for generating a [e.g. time-variable] bias voltage VDC for an electro-optic modulator, wherein the device is configured to obtain an output power signal (I) dependent on an optical output power of the electro-optic modulator, wherein the device is designed to generate the bias voltage VDC on the basis of an amplitude ratio between the fundamental and the first harmonic of the output power signal (I) and on the basis of a phase angle of a pilot signal applied to the electro-optic modulator.

A channel state information determination method and device, in the method, a network device determines N rows of base vectors corresponding to N time units based on mobile state information and a channel map of a terminal device, each row of the N rows of base vectors comprises X base vectors, and the channel map is used for indicating channel characteristics based on a location area; the network equipment sends first indication information, wherein the first indication information is used for indicating N rows of base vectors; the network equipment respectively sends pilot signals in N time units; the network equipment receives second indication information, the second indication information is used for indicating weighting coefficients of Y base vectors in the X base vectors, and the weighting coefficients of the Y base vectors are determined based on the pilot signal; and the network equipment determines channel state information corresponding to M time units based on the weighting coefficients of the Y base vectors and the N rows of base vectors, and the M time units comprise N time units. The method can improve the accuracy of the channel state information.

A method for reporting channel status information (CSI) is performed by a terminal. The method includes: transmitting an uplink reference signal to a network device; receiving beamformed downlink pilot signals transmitted by the network device at T consecutive time points; estimating downlink effective channel information corresponding to the T consecutive time points according to the beamformed downlink pilot signals of the T consecutive time points; determining CSI corresponding to the T consecutive time points according to the downlink effective channel information corresponding to the T consecutive time points; and reporting the CSI to the network device.

The invention discloses a rail transit-oriented soft information codeword reconstruction security key extraction method and system, and relates to the field of digital information transmission, in the method, a sending end and a legal receiving end alternately send pilot frequencies to each other through a preset channel, and calculate a channel feature sequence of the preset channel; the sending end generates a master key from a preset random source, and encodes the master key to obtain a code word sequence; the sending end generates an information interaction sequence according to the first feature sequence and the code word sequence, and sends the information interaction sequence to a legal receiving end; after the legal receiving end receives the information interaction sequence, the legal receiving end reconstructs the second feature sequence according to the information interaction sequence to obtain a code word structure sequence; and the legal receiving end decodes the code word structure sequence to obtain a final key. The method and the device are used for improving the consistency rate of the secret keys among the legal users, so that the secret key generation and extraction efficiency is improved, and the safety of a rail transit system is improved.

The application discloses a channel estimation method for a millimeter wave frequency division duplex massive MIMO system based on compressed sensing and deep learning, and belongs to the technical field of wireless communication.The technical scheme is as follows: a received pilot signal is processed by using a compressed sensing method to extract a preliminary CSI matrix; a convolutional neural network and a long short-term memory network are combined to extract spatial features and capture time correlation; the preliminary estimated CSI matrix is input into a ConvLSTM layer, and the ConvLSTM network fuses time correlation information to improve the estimation accuracy of the CSI; the same padding, ReLU activation function and filter with appropriate size are used to obtain the same size as the input data; and dimension transformation and inverse normalization are used to obtain the final CSI estimation result.The application has the beneficial effects that the method for channel estimation by using compressed sensing and deep learning aims at reducing the overhead of channel estimation and improving the estimation accuracy in a time-varying channel, reduces the overhead of downlink training and uplink feedback, and improves the channel estimation accuracy in the time-varying channel.

The invention discloses an integrated waveform generation method and device based on transmission symbol compensation. The method comprises the following steps: generating an imitated radio frequency division multiplexing pilot signal; the simulated radio frequency division multiplexing pilot signal is sent to a receiving end, the receiving end is used for carrying out channel estimation on the simulated radio frequency division multiplexing pilot signal to obtain channel state information, and the channel state information comprises normalized time delay, normalized Doppler frequency shift or gain; according to the channel state information, pre-compensation processing is carried out on an imitated radio frequency division multiplexing information symbol on a target domain to obtain a compensation signal, and the target domain comprises a discrete affine Fourier transform domain or a time domain; and performing precoding processing on the compensation signal to obtain an integrated waveform. According to the invention, integrated waveform generation is realized, the efficiency is improved, and the signal processing complexity and resource overhead are reduced. The method can be widely applied to the technical field of wireless communication.

Systems, apparatus, articles of manufacture, and methods are disclosed to charge an energy storage device on a vehicle. The system includes instructions to detect direct current or alternating current on or at an input terminal of a vehicle electrical system, the input terminal to receive electrical energy to charge the energy storage device on the vehicle; based on detection of direct current, generate a first pilot signal that includes a first pulse width modulated signal associated with a first mode including a first duty cycle range; based on detection of alternating current, generate a second pilot signal that includes a second pulse width modulated signal associated with a second mode including a second duty cycle range, wherein the first duty cycle range is lower than the second duty cycle range; and charge the energy storage device based on detection of the first pilot signal or the second pilot signal.

A method and device for determining channel state information (CSI) are provided. The method includes: receiving uplink pilot signals sent by a terminal at T consecutive moments; performing uplink channel estimation on the uplink pilot signals to determine uplink channel information at each moment, wherein T is an integer greater than 1; determining a channel state information reference signal (CSI-RS) beam according to the uplink channel information; sending a beamformed CSI-RS to the terminal according to the CSI-RS beam; and receiving CSI reported by the terminal.

The invention provides a method for transmitting a binary data sequence on an OTFS communication channel influenced by Doppler spread. According to the method, the optimization of the pilot signal power ratio can be realized only by using the existing information of the transmitter end, and end-to-end simulation or test is not needed. A corresponding receiver executes two-stage iterative channel estimation, signal detection, demapping and data decoding, and iteratively feeds back information obtained from decoded data to channel estimation, signal detection, demapping and data decoding.

The invention discloses an underwater acoustic signal communication and positioning integrated method. The existing method does not jointly consider the problem of channel resource occupation caused by integration of communication and positioning. According to the method, mutually orthogonal Chirp subcarriers are used as communication signals, meanwhile, long Chirp signals are used as pilot frequency, and the pilot frequency and the communication signals are overlapped together to be sent at a sender, so that extra channel overhead caused by additional pilot frequency is saved, and the signal sending time interval is shortened. A receiver uses a plurality of pilot signals to perform joint Doppler estimation and compensation and time of arrival estimation, and the result of the time of arrival estimation is used for a positioning system and a communication system on the one hand. According to the demodulation mode, correlation calculation is carried out by using different Chirp subcarriers, and symbol demodulation is carried out according to correlation values. According to the communication and positioning integrated waveform design method, the signal sending time interval can be shortened, the system complexity can be reduced, and good communication performance is achieved.

The invention discloses a reconfigurable intelligent surface (RIS)-assisted multiple-input-multiple-output (MIMO) implicit channel estimation method based on a graph attention network, which is used for efficient downlink transmission in a multi-user scene. Firstly, a graph attention network is designed, user nodes and RIS nodes are modeled in a unified mode, received pilot signals serve as initial features, spatial feature expression is enhanced in combination with user three-dimensional position information, and therefore interference between users and a spatial correlation structure are accurately represented; secondly, end-to-end feature aggregation is achieved based on a message passing mechanism, a base station beam forming matrix and an RIS reflection coefficient are directly predicted under the condition that explicit channel estimation is not needed, and the total transmitting power constraint and the unit mode constraint are met through normalization processing so as to complete joint optimization; according to the method, the users and the speed of the system can be remarkably improved under limited pilot frequency overhead, and the method has excellent generalization performance and robustness in a multi-user complex propagation environment.

The invention relates to the technical field of optical communication, and discloses a multi-dimensional and multi-phase-based 50G PON signal noise compensation method, which comprises the following steps: S1, generating a mixed signal, including superposing a multi-phase orthogonal pilot signal into a data signal time domain at a transmitting end according to a preset proportion lower than the power of a data signal; and S2, transmitting the mixed signal in a polarization multiplexing mode, wherein the polarization multiplexing adopts double-channel parallel transmission of an X polarization state and a Y polarization state. Multi-phase orthogonal pilot signals are superposed to a data signal time domain in a low-power proportion at a transmitting end, polarization multiplexing dual-channel transmission is adopted, a narrow-band filter is utilized at a receiving end to separate pilots and calculate channel damage parameters, and a finite impulse response filter is configured to perform linear equalization compensation. And the simplified Kalman filtering algorithm is combined to estimate the phase noise and correct the phase, so that collaborative suppression of the linear channel damage and the phase noise in the 50G PON signal is facilitated.

The invention belongs to the technical field of wireless communication systems, and particularly relates to a GFDM waveform design method for a jungle communication system. The method mainly comprises two parts of performance test and waveform design, and in the GFDM jungle communication system, a receiving end tests the bit error rate and the symbol transmission rate of the GFDM jungle communication system according to a known pilot signal sent by a sending end; a utility function is confirmed, and waveform design parameters including a cyclic prefix and a roll-off coefficient are optimized step by step by applying a genetic algorithm; through careful construction and parameter optimization of each part, the invention aims to improve the overall performance of the jungle communication system, can give full play to the potential of the GFDM technology, and meets the diversified requirements of jungle communication.

Aspects of the subject disclosure may include, for example, determining a coherence block for each user equipment (UE) of a plurality of UEs being served by the first cell, resulting in a plurality of coherence blocks, responsive to the determining, identifying a smallest coherence block from the plurality of coherence blocks, identifying a pilot sequence length based on the smallest coherence block, determining a plurality of orthogonal pilot sequences based on the identifying the pilot sequence length, designating, from the plurality of orthogonal pilot sequences, a first group of orthogonal pilot sequences for use in the first cell, and distributing, to each neighboring cell of a plurality of neighboring cells adjacent to the first cell, a respective group of orthogonal pilot sequences from a remainder of the plurality of orthogonal pilot sequences, to prevent pilot contamination between the first cell and the plurality of neighboring cells. Other embodiments are disclosed.

The present invention discloses a MIMO-OFDM channel estimation method and device based on natural interpolation. The method comprises: obtaining a channel coefficient at a pilot signal based on least squares channel estimation; assigning weights to the channel coefficients at several pilot signals near each interpolation point according to the size of the Voronoi diagram grid area based on the natural interpolation method, and obtaining an interpolation formula at the interpolation point by weighted summation; and performing natural interpolation on each interpolation point using the interpolation formula to obtain a MIMO-OFDM channel estimation result. The method applies natural interpolation to channel estimation, and obtains a channel frequency response estimate at the interpolation point by weighting the values ​​at several pilot signals near the interpolation point. This method can simultaneously utilize the time and frequency correlation of the channel, significantly improve the channel estimation accuracy, reduce the channel estimation error, and have a smoother interpolation effect and better interpolation performance.

A communication frame for an OTFS transmission system includes first-type and second-type blocks. The first-type block includes pilot signals, guard signals, and data signals, the second-type block exclusively includes data signals. The pilot symbols, guard signals, and data symbols of the first-type block, and the data symbols of the second-type block, are arranged along the points of a grid in the delay-Doppler domain. In the communication frame, a first-type block is followed by a second-type block, and a second-type block is followed by a first-type block. In the first-type block at least one pilot symbol is surrounded on at least three sides by one or more guard symbols. Points of the grid of the first-type blocks in the delay-Doppler domain that are not occupied by pilot symbols or guard symbols are used for data symbols. The communication frame permits determining oscillator frequency offset and channel coefficients in a receiver.

The invention discloses an intelligent reflector assisted user arrival angle estimation method in a multi-carrier ISAC system. In the method, a plurality of users send pilot signals, and each IRS reflects the user signals to a remote radio access unit (RRH). The RRH uploads the received signal to a centralized baseband processing unit pool (BBU) through a forward link; the BBU performs joint processing on the received signals on the plurality of RRHs, and the observation dimension is increased by constructing the frequency domain snapshot observation matrix of the pilot signals on the plurality of subcarriers, so that the estimation precision of the arrival angle from the user to the IRS path is improved. According to the method, frequency domain snapshot information brought by pilot frequency subcarriers is fully utilized, and the angle estimation resolution and robustness are improved. By adopting the scheme of the invention, high-precision user positioning can be realized in a complex environment.

The invention relates to the field of digital information transmission, in particular to an OTFS channel estimation method based on dynamic sparse Bayesian under a low earth orbit satellite, which comprises the following steps of: converting an information symbol and a pilot symbol into a time delay Doppler domain sending matrix; sending the time delay Doppler domain sending matrix to a receiving end; dividing a pilot signal of a receiving end into a channel vector and a verification pilot signal; modeling a channel vector into a compressed sensing problem based on an OTFS system, and solving the compressed sensing problem by adopting dynamic sparse Bayesian channel estimation to obtain a posterior channel vector; iteratively updating the hyper-parameter of the posterior channel vector to obtain an optimal channel estimation result; performing iterative optimization on a channel estimation result by adopting a verification pilot signal to obtain an estimated channel vector; the OTFS channel estimation method designed by the invention has relatively strong anti-noise and anti-interference capabilities, and the estimation precision is remarkably superior to that of a traditional sparse Bayesian learning method.

A charging cable includes: an abnormality detection unit that detects an abnormality in a charging cable; and a CCID controller that outputs a first control pilot signal to a control pilot signal line to notify a vehicle about a rated current of the charging cable. The first control pilot signal provides a notification about the rated current in a state where a duty ratio of the first control pilot signal is controlled to fall within a prescribed range while a frequency of the first control pilot signal is fixed to a specific value. When the abnormality detection unit detects an abnormality, the CCID controller outputs a second control pilot signal for notifying the vehicle about details of the detected abnormality to the control pilot signal line. The second control pilot signal is different in duty ratio from the first control pilot signal.

The invention discloses a phase-free integrated sensing and backscatter communication method based on inverse scattering and a related device. According to the invention, the load impedance of the tag is dynamically modulated, so that a receiving antenna receives pilot signals in different modulation states to enhance backscattering; estimating a clutter tag structure combination power component and a tag antenna power component according to the RSSI of the collected pilot signal, thereby sensing and identifying a tag; and transmitting a data signal to a receiving antenna by adopting ASK modulation through the tag, collecting the received RSSI of the receiving antenna, and performing signal demodulation by utilizing a zero-forcing algorithm, thereby effectively enhancing the reliability of backscatter communication.

The disclosure relates to a method and a device for transmitting and receiving a signal by a base station or a terminal in a wireless communication system. Specifically, a method performed by a first device in a wireless communication system includes deriving an amplitude scaling factor based on a comparison between amplitude distribution of a pilot signal corresponding to a first time resource domain and the amplitude distribution of a data signal corresponding to a second time resource domain; and transmitting, to a second device, a physical channel including the pilot signal and the data signal and the amplitude scaling factor, wherein the pilot signal is transmitted with a power determined based on the amplitude scaling factor, and power compensation for the data signal is based on the amplitude scaling factor.

The invention discloses a synchronous perception and backscatter communication method and device based on spatial modulation and backscatter, and relates to the technical field of communication, and the method comprises the steps: transmitting a pilot signal to a label through a transmitting array, modulating the load impedance of the label, and then backscattering the signal to a receiving array; the receiving voltage generated by the receiving array and the original channel matrix are adopted to determine the reflectivity of the clutter tag and the reflectivity of the tag antenna; positioning and identifying the tag based on the reflectivity of the clutter tag; extracting a target channel matrix for constructing a tag from the original channel matrix according to the tag antenna reflectivity; performing spatial modulation on the information bits through a transmitting array, generating constellation symbols and determining an activation label; and backscattering the constellation symbols to the receiving array through the activation tag by adopting the transmitting array, and demodulating and decoding by combining the target channel matrix to output information bits. The backscatter label is accurately positioned and identified in a disordered environment, and spatial modulation is integrated into backscatter communication, so that the reliability of backscatter communication is improved.