940 results about "Pilot signal" patented technology

The invention provides a precise interference method and system for pilot signals of a remote controller of an unmanned aerial vehicle, and the method comprises the steps: receiving and processing an image transmission signal and a remote control signal of the unmanned aerial vehicle, and analyzing a starting time, a transmission period and different types of image transmission protocol classification results of the image transmission signal; extracting the time period of the remote control signal and the occurrence time of a pilot symbol in the remote control signal; generating optimized interference signal parameter configuration by utilizing a reinforcement learning algorithm, analyzing historical data by utilizing a long short-term memory network to obtain a historical analysis result, and predicting an optimal interference opportunity; monitoring a wireless communication environment around the unmanned aerial vehicle by using a real-time spectrum sensing technology so as to identify a potential conflict frequency band, and selecting a target interference frequency band by using a frequency agility technology; determining a precise interference method based on the historical analysis result, the optimal interference opportunity and the target interference frequency band; according to the invention, the interference precision and effect on the pilot signal of the remote controller of the unmanned aerial vehicle are improved.

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.

A method performed by a UE may include: receiving a pilot signal from a first number of first BSs; generating a serving BS matrix, wherein the serving BS matrix indicates that the UE accesses a second number of first BSs among the first number of first BSs; measuring CSI between the UE and each of the first number of first BSs; generating a CSI matrix based on the measured CSI between the UE and the first number of first BSs; encoding the serving BS matrix and the CSI matrix; and transmitting the encoded serving BS matrix and the encoded CSI matrix to one of the second number of first BSs.

The invention provides an OFDM signal receiving and processing system and method suitable for an NAVDAT system. According to the method, the characteristics that NAVDAT system signals have synchronous headers, pilot frequencies and the like are fully considered, firstly, the synchronous headers are used for carrying out correlation operation on received data to search a frame starting point, and a signal frame to be demodulated and decoded is obtained in combination with a constant false alarm detection algorithm; and subsequently, carrying out symbol synchronization to determine the FFT window position. Secondly, in combination with a discrete pilot signal, estimating an integral multiple frequency offset error, namely coarse synchronization, and further realizing estimation of a decimal multiple frequency offset error, namely fine synchronization, so as to realize frequency synchronization. And then, channel estimation is carried out by using the pilot signal and adopting a least square method to obtain the channel frequency response of the pilot, the frequency response of the complete signal is obtained through interpolation, and the rough estimation result is further processed through the designed RCAFCN network to obtain accurate channel estimation, so that the original OFDM signal is recovered. And finally, extracting a data part in the OFDM signal according to a frame structure, realizing soft demodulation through a log-likelihood ratio mode, decoding data of a signaling part by using a polarization code, and decoding data of a service part by using a low-density parity check code, thereby realizing complete demodulation and decoding. The method provided by the invention can effectively reduce inter-symbol interference and inter-carrier interference existing in OFDM signals, compensate channel distortion, reduce noise influence, improve decoding precision, improve communication quality, realize optimization of NAVDAT system baseband processing, and guarantee sailing safety of ships on the sea by combining with an existing marine broadcast system.

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 method for estimating the transmittance of a time-varying channel based on a frequency division multiplexing pilot frequency, and aims to solve the problem that the existing method for estimating the transmittance by adopting average transmittance does not have the capabilities of timely feedback and dynamic adjustment. The method comprises the following steps of: measuring a regular position component and a regular momentum component of a received signal by receiving a quantum signal and a pilot signal of frequency division multiplexing in a local local oscillator continuous variable quantum key distribution system generated by a transmitting end in real time; compensating phase noise caused by frequency offset and channel jitter due to different center frequencies of two independent lasers at a receiving end and a transmitting end by using a frequency offset compensation and phase recovery algorithm, and performing band-pass filtering to obtain a recovered pilot signal; and calculating the power ratio of the obtained pilot signal to the pre-calibrated pilot signal at each moment to obtain the time-varying free space transmittance. The performance change of the system in different time periods can be accurately reflected, the communication performance of the CVQKD system can be optimized, the success rate of key transmission can be improved, and the adaptability and robustness of the system can be improved.

The invention discloses a joint detection method for a satellite-ground downlink NOMA (Non-Orthogonal Multiple Access) system, which is characterized by comprising the following steps of: S1, inserting pilot frequencies in a time-frequency grid through pilot frequency signals which are sparsely and uniformly arranged in a sub-channel of a transmitting end; s2, extracting a pilot signal at a receiving end, and performing channel estimation based on a deep residual convolutional network; s3, performing multi-user signal detection based on an iterative retraining method of a deep neural network; s4, optimizing power distribution within a power distribution factor threshold range based on a sparrow search algorithm, and minimizing a system bit error rate; s5, combining the step S2, the step S3 and the step S4 to form a joint detection model based on deep learning; through combination of deep learning and a sparrow search algorithm, the problems of channel estimation precision, signal detection capability, power distribution optimization and the like in the system are solved, the overall performance and reliability of the system are improved, and the method is suitable for large-scale user access and efficient data transmission requirements in a modern satellite communication system.

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 discloses a time domain channel estimation method and device based on a multi-antenna diversity technology, and the method comprises the steps: mapping a bit stream into a symbol stream to construct a transmitting signal matrix, carrying out the STBC coding, inserting a time domain pilot signal, obtaining a matrix after insertion, selecting a vector in the matrix after insertion, and carrying out the time domain channel estimation. The method comprises the steps of obtaining a frequency domain receiving signal by combining with relevant parameters of Gaussian white noise and a Rayleigh fading channel, then performing matrix transformation to obtain an STBC decoding matrix, introducing a weight matrix to update an established MIMO-OFDM system input and output model to obtain a time domain channel estimation value, and finally performing FFT transformation on the time domain channel estimation value to obtain a frequency domain channel matrix estimation value. And substituting the frequency domain channel matrix estimation value into the STBC decoding matrix and then carrying out ML signal detection to obtain a final estimation value. A channel estimation algorithm is introduced to improve the estimation of a dynamic channel, a space-time block coding technology is combined to improve the demodulation signal precision of a MIMO system, and the full-state channel of the MIMO system is estimated.

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 relates to the technical field of intelligent power grids, in particular to an inspection vehicle tracking and communication optimization method and system, and the method comprises the steps: constructing an RIS-ISAC-NOMA system framework oriented to an intelligent power grid application scene, converting a non-line-of-sight NLOS path into an equivalent virtual line-of-sight LOS path through a reconfigurable intelligent metasurface RIS in a non-line-of-sight NLOS scene, and carrying out the tracking and communication optimization of an inspection vehicle through the virtual line-of-sight LOS path. A propagation path of an ISAC signal is adjusted in real time, and a vehicle tracking and predicting method based on an EKF algorithm is designed, so that efficient vehicle real-time sensing and communication are realized; a multi-inspection vehicle power distribution optimization scheme is provided in combination with the NOMA technology, the communication rate and the resource utilization efficiency of the system are further improved, meanwhile, the simulation result also verifies the advantages of the proposed system in the aspects of communication performance and resource utilization, and the overall efficiency of the system can be remarkably improved while the pilot signal overhead is reduced.

The embodiment of the invention provides a communication method and device, a storage medium and a program product, relates to the technical field of communication, and can improve the communication quality in a signal transmission process. The method is applied to a first node, and comprises: receiving a first signaling sent by a second node, the first signaling being used for determining an uplink transmission parameter of a transmission pilot frequency in an uplink transmission process; and transmitting a first signal to the second node based on the first signaling, the first signal comprising a pilot.

The invention discloses a direct sequence spread spectrum underwater acoustic communication Doppler rapid estimation method and system based on a GPU. The method comprises the following steps: modeling a received signal of a direct sequence spread spectrum underwater acoustic communication system; performing resampling and FFT operation on a local pilot signal in sequence, and storing an FFT operation result to obtain a Doppler matching matrix based on an equipment memory preloading method of a GPU (Graphics Processing Unit); a two-step Doppler estimation process is adopted, in the rough search stage, cross ambiguity function calculation is carried out based on GPU complex number multiplication, reduced module value normalization calculation is carried out based on GPU parallel, and a rough Doppler factor to be estimated is obtained through threshold detection; in the fine search stage, a plurality of Doppler branches near the coarse Doppler factor are selected, cross ambiguity function calculation is carried out based on GPU complex number multiplication, reduced module value normalization calculation is carried out based on GPU parallel, and a fine Doppler factor to be estimated is obtained through threshold detection.

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 belongs to the technical field of optical communication, and particularly relates to a low-complexity digital pre-equalizer based on frequency domain comb pilot channel estimation. The device comprises a data sending module, a channel response test module and a digital signal pre-equalization module, the data sending module comprises an initial comb signal generation part and a frequency component phase rotation part; the channel response test module comprises a signal frequency difference estimation and recovery part and a channel amplitude-frequency and phase-frequency response test part; the digital signal pre-equalization module comprises a filtering coefficient generation part and a sending signal convolution pre-equalization part; according to the invention, a frequency domain comb pilot signal is sent to analyze channel amplitude-frequency and phase-frequency response, so that a pre-equalizer for pre-compensating channel response at a sending end is generated; the method has the characteristics of high granularity, high precision, robust transmission signal system and the like, and can be applied to various scenes such as polarization multiplexing long-distance single-carrier coherent optical transmission, mode multiplexing short-distance intensity modulation direct detection systems and the like.

The invention discloses a channel characteristic map determination method and device, relates to the field of communication, and can determine a high-precision channel characteristic map. In the method, a terminal device and / or an access network device senses an environment based on sensing devices such as a radar, an infrared sensor, a camera, a point cloud laser scanner and the like and a communication pilot signal to sense material information of a scatterer and relative position information of the scatterer and the terminal device and / or the access network device; and the information is sent to the channel feature map management device through a first message, and the channel feature map management device determines a channel feature map according to the first message, so that a high-precision channel feature map is obtained.

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.

The embodiment of the invention provides a pilot signal transmission method, device and system, which are used for reducing the correlation of pilot signals in the same time period. The method can be applied to a first terminal device, and comprises: generating pilot signals respectively corresponding to at least two time units, the pilot signals respectively corresponding to the at least two time units being different; and respectively sending corresponding pilot signals to the network device on the at least two time units.

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 target detection and channel estimation method for a near-field sensing integrated system. The method comprises the following steps: a base station sends a downlink pilot signal to a sensing target and receives a corresponding echo signal; then, a user sends an uplink pilot signal to estimate a user channel; according to the characteristics of a near-field channel, a sensing and communication signal model based on a spherical wavefront hypothesis is established; according to the characteristics of a near-field channel, firstly, a near-field channel model is approximated by adopting Fresnel approximation, then a low-overhead dictionary based on near-field spherical wave approximation is provided, and on the basis, an improved orthogonal matching pursuit algorithm is designed for near-field communication perception to estimate parameters of a perception target and a communication channel. According to the invention, parameters of a near-field sensing target and a channel can be estimated with low overhead, and the estimation precision of the parameters in a near-field scene is improved.

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.