510 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 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 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.

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.

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.

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 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 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.

The invention discloses an intelligent fast beam training method for low-altitude millimeter wave communication, and belongs to the technical field of wireless communication. The method comprises the following steps: establishing a channel and transmission model of the low-altitude millimeter wave cellular-free large-scale MIMO system; in the channel estimation stage, a pilot signal is used for estimating a channel and preliminarily positioning the position of a user; in the beam training stage, firstly, customized three-dimensional beam codebook design is carried out based on obtained positioning information; and then, an enhanced multi-agent depth Q network algorithm is adopted to efficiently carry out beam search in the designed customized codebook, so that accurate three-dimensional beam alignment is realized. According to the method, the customized codebook and the intelligent learning algorithm are combined, the beam forming process is effectively optimized, the complexity and overhead of beam training are remarkably reduced, the convergence speed is increased, the system performance and reliability of downlink communication are improved, and the method is suitable for a high-maneuverability low-altitude unmanned aerial vehicle communication scene.

The invention provides a method for carrying out channel estimation on a large-scale MIMO-OTFS (Multiple Input Multiple Output-OTFS) system by utilizing a DML (Discrete Multiplexing Language) combined training layered global DLCE (Digital Light Control Element) network, which comprises the following steps of: 1, inputting a received pilot signal into a scene classifier to obtain a channel scene index; and inputting the pilot signal to a corresponding feature extractor to extract channel features based on the predicted channel scene index. And step 3, inputting the output of the feature extractor into a feature mapper to reconstruct the whole downlink cascade channel. The HGDLCE network extracts different channel characteristics for different channel scenes and finally reconstructs the channel, so that the channel estimation precision under different channel scenes is improved. Simulation results show that the scheme can obtain better channel estimation precision than a traditional scheme.

The invention discloses a large-scale MIMO multi-satellite positioning and direction estimation method and system based on angle information. The method comprises the following steps: firstly, obtaining channel matrix estimation between each satellite and a user by sending a pilot signal; then, obtaining estimated values of channel parameters by using a tensor-ESPRIT algorithm, wherein the estimated values comprise an angle of departure and an angle of arrival; according to the estimated departure angles, direction vectors between the user and all satellites are obtained, an optimization problem on spherical manifold is established, altitude constraints are considered, and a Riemann conjugate gradient method is used for solving and obtaining a user position estimation value; and finally, according to the estimated user position and arrival angle, establishing an optimization problem on the SO (3) manifold, and solving by using a Riemannian gradient descent method to obtain an estimated value of a user array rotation matrix. According to the method, positioning and direction estimation are performed by combining channel information between a plurality of satellites and users, and altitude constraints are considered during positioning, so that compared with single-satellite and non-constraint conditions, the positioning performance can be remarkably improved, and meanwhile, the method has good direction estimation performance.

A method for acquiring channel quality includes: receiving a pilot signal sent by a network device through a downlink channel; obtaining a first channel matrix according to the pilot signal, wherein the first channel matrix is used to represent channel quality of the downlink channel; obtaining a compressed target channel matrix by compressing the first channel matrix according to a channel state information (CSI) compression model and a CSI compression parameter, wherein the CSI compression model comprises a channel encoder, and the channel encoder comprises a plurality of sub-encoders; and different sub-encoders correspond to different CSI compression parameters; and sending the target channel matrix to the network device, such that the channel quality of the downlink channel is determined by the network device according to the target channel matrix.

The invention relates to the technical field of wireless communication, in particular to an angle-distance joint positioning method in a near-field communication system assisted by wave beam squint, which comprises the following steps of: determining a starting point (theta s, rs) and an end point (theta e, re) of a near-field sensing area, and determining a distance-to-angle joint in the near-field sensing area by adjusting parameters of a true time delayer and a phase shifter. Generating a beam squint focusing scanning track for joint angle-distance positioning; the method comprises the following steps: a base station sends a pilot signal, receives an echo signal of a user side on each subcarrier, and reversely deduces an initial angle estimation value and an initial distance estimation value of a target user by calculating receiving power and searching a subcarrier index corresponding to a power peak value; and a local search area is selected near the initial estimation value obtained in the coarse positioning step, angle and distance two-dimensional joint search is carried out based on an improved near-field multiple signal classification algorithm, and a high-precision final angle estimation value and a high-precision final distance estimation value are output.

The invention provides an intelligent electric meter interaction method and system based on dual-mode heterogeneous network communication, belongs to the field of power line carrier communication, and solves the problem of communication stability still existing in intelligent electric meter interaction under a dual-mode communication architecture. The method comprises the following steps: under the condition that a link layer of a high-speed power line carrier communication channel detects that a subcarrier-level bit error rate or a pilot signal-to-noise ratio has narrowband abnormality and lasts for a preset number of message periods, loading the link layer of the high-speed power line carrier communication channel through programmable impedance in a maintenance time slot, pilot frequency receiving results are collected under the disturbance condition and the non-disturbance condition, and a reflection mark memory function is formed; the reflection mark memory function obtained by maintaining the time slot each time is extracted and stored, a historical record is formed, and the historical record comprises channel frequency domain reflection coefficient changes and a group delay sequence; and identifying the arrival time of the main reflection component based on historical records, and converting the arrival time of the main reflection component into a suspected abnormal position interval.

The invention discloses a low-voltage power line power frequency communication interference suppression and adaptive demodulation method and system, and the method comprises the steps: firstly, detecting the voltage zero crossing of a power grid in real time, and dynamically calibrating a communication time slot based on an actually measured power frequency, thereby achieving the precise power frequency synchronization; injecting a pilot signal into the synchronous time slot window, and judging line topology mutation through coupling of pilot response and a preset signal-to-noise ratio threshold, thereby completing topology perception and verification; triggering channel reestimation in combination with a topological change result, rejecting fundamental wave and multi-order harmonic interference from channel response of least square estimation, and updating a channel model by adopting a time-varying smoothing algorithm; then, a low-noise time window is determined according to the corrected zero cross point, key data packets are scheduled preferentially, and high-reliability anti-interference transmission is achieved; and finally, dynamically and cooperatively adjusting the transmitting power, the receiving filter and the phase compensation based on the newest channel and topology state to form closed-loop self-adaption. According to the scheme, the intelligent degree is high, and the communication stability and the system maintainability are greatly improved.

A single-station positioning method based on Doppler frequency shifts and time difference information, and a system and an electronic device. The method comprises: acquiring an actual period of a pilot signal sent by an unmanned aerial vehicle (S1); on the basis of the actual period of the pilot signal sent by the unmanned aerial vehicle, determining two adjacent target signals sent by the unmanned aerial vehicle in a target area, and acquiring actual center frequencies of target signal information, an actual time difference of arrival between the two target signals at a receiving base station, actual angles of arrival, and actual Doppler frequency shifts of the unmanned aerial vehicle (S2); importing an actual range of the target area, the actual period of the pilot signal, the actual center frequencies of the target signals, the actual time difference and the actual angles of arrival into variables in a preset theoretical Doppler frequency shift model, so as to obtain a theoretical Doppler frequency shift value table, wherein the table comprises different theoretical Doppler frequency shift values corresponding to different distances from the unmanned aerial vehicle to the receiving base station (S3); performing error metric calculation processing on the actual Doppler frequency shifts and each theoretical Doppler frequency shift value, so as to obtain a theoretical Doppler frequency shift value corresponding to the minimum error metric (S4); and on the basis of the theoretical Doppler frequency shift value corresponding to the minimum error metric, determining the positions at which the unmanned aerial vehicle sends the target signals (S5). The method can ensure the accuracy of single-station positioning in a complex scenario.

A method, network node and wireless device (WD) for phase noise mitigation are disclosed. According to one aspect, a method in a network node includes receiving an orthogonal frequency division multiplex (OFDM) signal provided over a radio frequency (RF) channel that includes at least one guard band, the OFDM signal including at least one pilot signal. The method also includes mitigating phase noise based at least in part on the at least one pilot signal and further based on observations of signal content of the at least one guard band.

The invention relates to the technical field of satellite communication, and discloses a low-orbit satellite communication Doppler frequency offset processing method, system and device and a medium, and the method comprises the steps: separating a pilot signal from a received signal; taking the Doppler frequency as a first system state, taking the received signal as first observation data, and performing Doppler frequency offset estimation on the pilot signal by adopting a frequency offset estimation algorithm to obtain a frequency offset estimation value; taking the Doppler frequency as a second system state, taking the frequency offset estimation value as second observation data, and adopting a frequency offset tracking algorithm to perform Doppler frequency offset tracking on the pilot signal to obtain a frequency offset tracking value; and performing frequency offset compensation on the received signal according to the frequency offset tracking value to obtain the received signal after frequency offset compensation. According to the method, the Doppler frequency offset is subjected to streaming processing through Bayesian filtering in the estimation and tracking stages, the complexity of data storage and calculation is effectively reduced, the data updating rate is increased, and therefore the accuracy of low-orbit satellite data is effectively improved.

A channel estimator circuit receives in one slot a multiplexed representation of one or more time- domain code division multiplexed, TD-CDM, spread received signals. An initial estimator circuit processes a pre-estimation signal that is formed therefrom, uses a base pilot signal as a reference signal, and outputs an initial estimate signal. A frequency-domain processing circuit receives and processes a first set of one or more TD-CDM spread channel estimate signals that is representative of the initial estimate signal, and outputs a second set of signals. An interpolation buffer buffers the second set of signals. A TD-CDM de-spreading circuit de-spreads the buffered second set of signals and outputs TD- CDM de-spread channel estimate signals. In this manner, the frequency-domain-related signal processing and the time-domain-related signal processing are separated, and a significant reduction in the amount of hardware, energy and time resources required may be achieved, improving latency and reducing cost.

This invention provides an OTFS peak-to-average power ratio (PAPR) suppression method, apparatus, electronic device, and readable storage medium for high-reliability transmission, applied in the field of wireless communication technology. The method includes: embedding a pilot signal into an OTFS delay-Doppler domain signal frame and setting a guard interval to obtain an initial delay-Doppler domain transmitted signal; performing amplitude-limiting filtering on the transmitted signal to obtain amplitude-limited filtered noise; obtaining approximately iteratively ...

This invention discloses an echo channel estimation method based on adaptive filtering, belonging to the field of wireless communication. First, channel estimation of the mixed signal is performed using pilot signals. Then, a correlation algorithm is used to estimate the impulse response of the echo channel to obtain an estimated value of the echo channel. Next, the estimated echo channel value is used to calculate the echo signal and perform channel estimation of the near-end transmitted signal. This value is then subtracted from the first channel estimate to obtain a second estimate of the channel through which the near-end signal passes. Finally, a partial estimate of the near-end signal is calculated using the pilot signals and the second estimate, and this value is subtracted from the received signal to obtain an estimated value of the echo signal, which is then fed into an adaptive filter to update the filter coefficients. This invention fully utilizes pilot channel estimation in OFDM signals and combines it with adaptive filtering to achieve effective echo channel estimation in two-talk scenarios, reducing the bit error rate under echo interference.

The application discloses a kind of mobile communication base station and communication method, communication method includes: communication base station sends pilot configuration instruction to user, carries out estimation to Doppler frequency offset, obtains phase-compensated received pilot signal, and is converted into vectorization received signal;Linear regression model is constructed, adaptive sparse channel estimation is carried out based on variational bayes inference, and output downlink frequency domain channel matrix, angle domain channel matrix;Angle domain channel matrix is quantized using Lloyd-Max non-uniform quantizer, and the global channel matrix of base station end is obtained;Output optimal analog precoding matrix and digital precoding matrix;Communication base station generates radio frequency signal based on precoding after transmission signal vector, and sends to user.Communication base station includes distributed antenna unit, baseband processing unit, radio frequency link and central control unit.The technical scheme of the application covers the whole process signal processing link of mobile communication base station, and the calculation complexity is low, and can be directly adapted to existing 3GPP standard and hardware platform.

The invention discloses a pilot frequency transmission method and device. The method comprises the following steps: generating N pilot symbols; wherein a plurality of pilot symbols in the N pilot symbols are generated based on at least one Gray complementary sequence pair, each Gray complementary sequence pair in the at least one Gray complementary sequence pair comprises at least two Gray complementary sequences, and N is a positive integer greater than 1; and outputting the N pilot symbols. According to the scheme, the pilot symbol is generated based on the Gray complementary sequence pair, so that the finally sent pilot signal has low PAPR and has good flatness in the frequency domain, and the improvement of the channel estimation quality is facilitated.

The application relates to the technical field of wireless communication, in particular to a beam squint auxiliary angle-distance joint positioning method in a near field communication system, which comprises the following steps: determining the starting point (theta s ,r s ) and the ending point (theta e ,r e ) of the near field sensing area, generating a beam squint focusing scanning track for joint angle-distance positioning by adjusting the parameters of the true time delay device and the phase shifter; a base station sends a pilot signal, receives echo signals of a user terminal on each subcarrier, calculates the received power, finds the subcarrier index corresponding to the power peak value, and reversely deduces the initial angle estimation value and the initial distance estimation value of the target user; a local search area is selected near the initial estimation value obtained in the coarse positioning step, a two-dimensional joint search of the angle and the distance is carried out based on an improved near field multiple signal classification algorithm, and a high-precision final angle estimation value and a final distance estimation value are output.

This invention discloses a pilot-type carrier phase recovery circuit and a reverse antenna array system, belonging to the field of 5G millimeter-wave communication. The pilot-type carrier phase recovery circuit includes a digital phase detector, a quadrature mixer, a quadrature voltage-controlled oscillator, a low-pass filter, a high-pass filter, a polyphase filter, a loop filter, a first intermediate frequency amplifier, a second intermediate frequency amplifier, a first shaping circuit, and a second shaping circuit. Applied to a reverse antenna array system, this invention performs carrier phase recovery on the data signal and pilot signal output from the receiver, separating the data signal without spatial phase information and the spatial phase information used for reverse transmission. This invention enables high-order modulation full-duplex communication and real-time tracking of moving targets, featuring high integration, small area, high communication speed, and strong anti-interference capability.

A communication frame for an OTFS transmission system includes at least one first-type and at least one second-type block. At least the first-type block includes data signals two-dimensionally arranged along the delay domain and the Doppler domain of which at least one has a superimposed pilot signal. The second-type block includes data signals two-dimensionally arranged along the delay domain and the Doppler domain which may or may not have superimposed pilot signals. At least one second-type block is preceded and followed, in the delay-domain, by first-type blocks, the first-type blocks preceding and following a second-type block having at least one identical data symbol and associated superimposed identical pilot symbol at an identical location in the two-dimensional arrangement. An OTFS transmitter generates and transmits the communication frame, and a receiver uses its properties for compensating oscillator frequency offset and channel estimation.