43 results about "Delay spread" patented technology

An apparatus configured to: receive a downlink signal; determine whether a TA stored at the apparatus is valid based, at least partially, on a reception timing of the received downlink signal and a delay spread value; and initiate small data transmission with a pre-configured uplink resource based, at least partially, on the determination that the TA is valid. An apparatus configured to: transmit, to a UE, a configuration comprising information related to TA validation for the UE, wherein the information comprises at least one of: an indication of a value configured to indicate a fraction of a cyclic prefix length of a symbol for reception of an uplink transmission from the UE, or a delay spread value; transmit a downlink signal; and receive a SDT based, at least partially, on the fraction of the length of the cyclic prefix, the transmitted downlink signal, and the delay spread value.

A system can utilize a first common physical uplink control channel (PUCCH) format 1 communication format for broadband cellular communications with user equipment via a channel. The system can estimate a first channel characteristic based on performing channel estimation on the channel over uplink signals, which comprises a Doppler spread. The system can estimate a second channel characteristic based on the performing of the channel estimation over uplink signals, which comprises a delay spread. The system can determine a number of symbols for a second common PUCCH format 1 communication format with the user equipment based on the first channel characteristic. The system can determine a group of initial cyclic shift indices for the second common PUCCH format 1 communication format with the user equipment based on the second channel characteristic. The system can communicate with the user equipment according to the second common PUCCH format 1 communication format.

The invention relates to the technical field of 5G communication security, and discloses a 5G short message encrypted transmission method, which comprises the following steps: acquiring time delay spread, angle spread and Doppler spread parameters of indoor multipath propagation, and generating a multi-dimensional channel characteristic matrix; acquiring a historical channel fingerprint database and a current channel feature matrix, and outputting a channel anomaly score; generating a three-dimensional decision space coordinate by using a threat-performance joint state space mapping algorithm; monitoring the real-time encryption queue length and the processing delay of each slice, calculating the actual SLA fulfillment rate and the security event interception rate, and generating a performance feedback vector; and inputting the performance feedback vector into a reward function calculation module of the reinforcement learning model, updating model parameters, and outputting an optimized decision strategy. According to the method, the interference of environmental noise on threat detection is avoided, the accuracy of pseudo base station attack identification is improved, and the problem of resource conflict arbitration in a multi-network slice scene is solved.

The invention discloses a channel time-frequency joint extrapolation method based on a multi-layer perceptron hybrid architecture. Aiming at the problems of high acquisition cost of actual communication scene channel data, high time consumption of model online training and difficulty in covering the actual communication scene by simulation data, the method comprises the following steps of: making a pre-training model by using a large-scale simulation channel data set to extract channel change characteristics; and carrying out online rapid adaptation according to the trace data of the actual measurement scene. Aiming at the characteristics that the time delay spread of an indoor wireless channel is relatively small and the number of antennas is relatively small, a multi-layer perceptron hybrid architecture is applied to the time-frequency domain extrapolation of a single-carrier broadband channel. The model can quickly adapt to an actual communication scene through fine tuning of a small amount of data. The method has the advantages of being high in adaptation speed, small in data dependence, high in scene migration capacity, high in calculation parallelism degree and the like, and is suitable for edge deployment and rapid adaptation to actual scenes.

The invention relates to the technical field of 5G communication channel estimation, and discloses a 5GMIMO channel estimation optimization method based on deep learning. According to the method, a deep learning model architecture is constructed, and model parameters are dynamically initialized according to channel coherence time so as to adapt to 5GMIMO channel multipath propagation characteristics. Received signal streams from a plurality of antenna elements containing different orthogonal frequency division multiplexing sub-carrier frequency sequences are processed, channel impulse response estimates are generated based on frequency domain correlation and input into a model for nonlinear transformation. And performing model parameter collaborative optimization, updating the network weight by calculating the gradient variation, constructing a target function according to channel delay extension and model depth association, and adjusting the estimation output towards the direction of minimizing the mean square error. And triggering model structure adaptation based on a norm of gradient variation, acquiring model copy parameters matched with the current channel state from an adjacent cell base station, normalizing the model copy parameters, and adjusting the number of attention heads or the number of residual blocks.

Disclosed are techniques for aliasing removal for wireless channel captures. In an aspect, a wireless station (STA) may estimate a wireless channel to produce a first frequency domain (FD) channel estimate. The STA may anti-alias the first FD channel estimate to produce a second FD channel estimate, wherein anti-aliasing the first FD channel estimate to produce a second FD channel estimate comprises removing, from the first FD channel estimate, signal energy associated with signals having a delay spread larger than a maximum tolerable delay spread. The STA may tone-decimate the second FD channel estimate to produce a third FD channel estimate. The STA may store the third FD channel estimate as a channel capture. In some aspects, the STA may send the channel capture to another entity as channel capture feedback, may performing a sensing operation using the channel capture, or both.

This disclosure provides methods, components, devices and systems for coordination for smooth beamforming. Some aspects more specifically relate to techniques to reduce phase misalignment and delay spread to beamformed messages such that a receiving device may apply channel smoothing filtering to the received beamformed message. In some examples, the transmitting device may ensure that the delay spread of the steered channel for a beamformed message is roughly matching the delay spread of an open-loop channel. The transmitting device may signal for the receiving device to perform channel smoothing filtering to a received beamformed message, for example, because the transmitting device applies techniques to reduce the phase misalignment and delay spread to the beamformed message. In some examples, based on the indication, the receiving device may apply channel smoothing filtering to a beamformed transmission received from the transmitting device.

The invention provides a channel estimation method for a minimum mean square error, which comprises the following steps of: performing Fourier transform on a received baseband signal to obtain OFDM (Orthogonal Frequency Division Multiplexing) frequency domain data, and obtaining frequency domain data of all symbols on a receiving side through solution resource mapping; the method comprises the following steps: processing by utilizing frequency domain data of a pilot symbol at a receiving side and a priori known pilot symbol sequence to obtain channel responses of SNR (Signal to Noise Ratio) estimation and LS (Least Square) channel estimation; processing according to the channel response of the LS channel estimation to obtain root-mean-square delay expansion; calculating a data-pilot frequency cross-correlation matrix and a pilot frequency self-correlation matrix according to root mean square time delay expansion, and calculating to obtain an MMSE filtering channel estimation coefficient according to the data-pilot frequency cross-correlation matrix and the pilot frequency self-correlation matrix; mMSE filtering is carried out according to the MMSE filtering channel estimation coefficient, and finally a final channel estimation value is obtained. According to the method, channel response is accurately estimated while operation is simplified, so that reliable communication and low operation delay are ensured.

Methods, systems, and devices for wireless communication are described. A network entity may indicate to a user equipment (UE) the ability of the network entity to disable a power amplifier for downlink transmissions (e.g., in a downlink control message). In response to the capability indication, the UE may estimate a delay spread and antenna array loss threshold for the downlink signal and report the delay spread and antenna array loss threshold to the network entity. Based on the reported delay spread and antenna array loss threshold, the network entity may determine a number of power amplifiers that may be disabled for downlink transmissions without reducing the received signal power at the UE below a minimum threshold. The power amplifier disabled by the network entity may be a power amplifier having an input power less than a threshold (e.g., one threshold less than the highest input power).

The application discloses a channel state information (CSI) measurement method, a terminal and a network side device, and belongs to the technical field of communication. The CSI measurement method comprises the following steps: a network side device sends CSI measurement configuration information to a terminal, wherein the CSI measurement configuration information is used for configuring target CSI measurement resources associated with target CSI information; and the network side device receives the target CSI information from the terminal. The target CSI information comprises at least one of the following: a Doppler frequency offset, a Doppler spread, a Doppler spectrum, a time domain channel correlation matrix, a delay spread, an average delay, a delay spectrum and a frequency domain channel correlation matrix.

This invention discloses a comprehensive evaluation method for wireless channel delay spread based on a dual correlation test in the field of wireless communication and channel modeling technology. This method includes the following steps: data acquisition and preprocessing, correlation calculation, data merging and trend analysis, and result presentation and decision-making basis. By combining Pearson and Spearman correlation coefficients, this method analyzes the impact of physical environment parameters on RMS_DS under LOS and NLOS conditions, improving the comprehensiveness and accuracy of correlation analysis and providing a reliable basis for wireless communication system design and optimization.

A device, such as a UE and a transmit / receive point (TRP), for providing network-assisted frequency offset compensation in a high-speed train single-frequency network (HST-SFN) is disclosed. The device includes a receiver that receives a first reference signal and a second reference signal transmitted from a first TRP via a wireless network. The first reference signal corresponds to the QCL RS of the second reference signal. The device receiver determines delay spread and average delay information of the path between the first TRP and the device based on the first reference signal. The device receiver also receives a third reference signal from the second TRP, which includes Doppler frequency shift and Doppler spread information and corresponds to the QCL RS of a fourth reference signal transmitted from the second TRP, or corresponds to the second reference signal transmitted from the first TRP in an SFN manner.

A generative neural network-based underwater acoustic OTFS communication transmission system and method are disclosed, relating to underwater communication transmission. Addressing the fractional spread problem caused by long delay spread and Doppler spread in broadband underwater acoustic channels, the system includes sequentially cooperating transmitter, receiver, channel estimation, and channel equalization units. The transmitter performs OTFS modulation, carrier modulation, and transmission; the receiver performs signal reception, preprocessing, and OTFS demodulation; the channel estimation unit combines a fractional-order dictionary matrix with a generative neural network, constructing a delay-Doppler domain refined grid and designing an unsupervised training model with double KL divergence constraints; and the channel equalization unit performs equalization processing and signal recovery. The method includes OTFS modulation transmission at the transmitter, underwater acoustic channel transmission, signal processing and demodulation at the receiver, generative neural network channel estimation, and equalization decoding. It requires no large number of labeled samples, has low computational complexity, short running time, and improves the transmission accuracy of underwater acoustic channels.

A terminal according to one embodiment of the present disclosure can: receive configuration information related to a wakeup signal (WUS) by means of higher-layer signaling; detect the WUS on the basis of the configuration information; determine a quasi co-location (QCL) type related to at least one from among Doppler shift, Doppler spread, average delay, delay spread and spatial Rx parameter on the basis of the capability of the terminal with respect to detection of the WUS; and detect the WUS on the basis of the QCL type.

This disclosure provides systems, apparatus, devices, and methods, including computer programs encoded on a storage medium, for switching waveforms in wireless communications. The UE (102) receives (434) a resume control message from the network entity (104) using the default waveform, the resume control message indicating a resume reference signal configuration and RACH resources. The UE (102) sends (440) a first report message on the RACH resource to the network entity (104) using the default waveform, the first report message indicating a delay spread and a Doppler spread measured from the recovery reference signal. The UE (102) receives (444) a RACH response from the network entity (104) using the default waveform, the RACH response comprising an indication of a configuration of an updated waveform for at least one of an uplink signal or a downlink signal based on the first report message.

The application relates to the technical field of wireless communication and machine learning cross-fusion, in particular to an industrial internet of things channel modeling method and system based on an interpretable random forest. The method comprises the following steps: constructing a channel data set containing multiple industrial scenes, a receiving point line-of-sight state and a three-dimensional position; after joint environment-height balance sampling and standardization preprocessing, a multi-output regression model is established by using a random forest, system parameters are taken as inputs, and a root mean square delay spread, an azimuth spread and an elevation spread are jointly predicted; further, the model efficiency and precision are improved by using a hyperparameter optimization with a time penalty term, and the model decision mechanism is explained from a global and local level by using permutation feature importance and SHAP value analysis, and the consistency with a physical propagation law is verified. The application realizes high-precision, stable and interpretable joint prediction of key statistical characteristics of an industrial wireless channel, and can support channel modeling, network planning and optimized deployment of an industrial internet of things communication system.

A method (400, 500) for an apparatus, such as a User Equipment, UE, (110) and a Network Entity, NE, (120), in a wireless network provides a mechanism for overhead reduction for uplink precoder indication when some of the groups of UE antenna ports have substantially the same channel properties. The channel properties may be one or more of quasi-co-location correlation properties, including delay spread, average delay, Doppler spread, Doppler shift, spatial transmission filter, or average gain. These mechanisms may be employed when the operability of one or more antenna ports changes.

The invention discloses a data transmission method, device and system of an OFDM (Orthogonal Frequency Division Multiplexing) system. The method comprises the following steps: acquiring a frequency domain received signal sequence of at least one receiving end; wherein the frequency domain receiving signal sequence comprises a useful signal, an interference signal and a noise signal; according to the signal power of the useful signal, the interference signal and the noise signal, determining the signal to interference plus noise ratio of the signal on each subcarrier, and determining the reachable secrecy rate of the OFDM system according to the signal to interference plus noise ratio of the signal on each subcarrier; determining a target cyclic prefix length and a target coding and modulation mode according to the reachable secrecy rate of the OFDM system and the maximum delay spread of a channel; and transmitting a to-be-transmitted data packet based on the target code and the modulation mode, wherein the to-be-transmitted data packet comprises to-be-transmitted data and a cyclic prefix with the target cyclic prefix length.

This invention belongs to the field of wireless ranging and positioning technology, specifically relating to a star-flash SLE phase ranging method based on average excess delay and the Rician K factor. The invention first constructs a bidirectional channel frequency response (CFR), maps it to a complex frequency domain sequence, and performs an IFFT to obtain the channel impulse response, constructing a power-delay distribution (PDP). Then, noise floor estimation and denoising are performed, followed by extraction of average excess delay, RMS delay spread, and Rician K factor estimates to form a joint discriminant index characterizing multipath and non-line-of-sight (NLS) levels. A dynamic peak value threshold is generated based on the joint discriminant index, the earliest valid path satisfying the dynamic threshold is selected, and the corresponding distance estimate is output. Compared with the traditional fixed-threshold complex-valued distance estimation (CDE) phase ranging method, this invention can suppress systematic deviations caused by misselection of strong reflection paths under strong multipath / NLS conditions, improving ranging accuracy and robustness, and is suitable for deployment on resource-constrained microcontroller platforms.

Provided are a method and device for estimating channel characteristics in a wireless communication system. The method comprises the processes of: estimating, on the basis of input data, the channel characteristics of a reception channel by using a plurality of extended convolutional blocks having a parallel connection structure in a convolutional neural network (CNN)-based model; and estimating the level of delay spread of the reception channel on the basis of the estimated channel characteristics.

The invention discloses a channel customization method based on an intelligent metasurface, a medium and a product, and relates to the technical field of wireless communication, and the method comprises the steps: executing a time delay extension calculation operation: receiving a signal which is transmitted to a target RIS by a transmitting end and is reflected by the target RIS through a receiving end of a target channel, and obtaining a received signal; the target RIS refers to a reconfigurable intelligent metasurface which sequentially takes each group of codebooks of L groups of codebooks generated in advance as a current codebook and configures the phase of each reflection unit of the reconfigurable intelligent metasurface of the target channel based on the current codebook; calculating the delay spread variance of the received signal; based on the time delay spread variance of each received signal, calculating a time delay spread variance average value of each reflection unit of the reconfigurable intelligent metasurface under different phase configurations; selecting the phase configuration with the minimum time delay spread variance average value of each reflection unit as the optimal phase configuration of each reflection unit; according to the invention, the channel quality of a broadband communication system can be improved.

The invention discloses a wireless communication quality prediction method and system based on static topographic features and dynamic time sequence fusion, and belongs to the technical field of geographic information systems and machine learning. The method comprises the following steps: extracting terrain perception characteristics between a transmitter and a receiver based on wireless channel simulation data, constructing a static input vector, and performing preliminary prediction on receiving power, path loss, channel capacity and time delay extension by adopting a cross-dimensional attention static prediction model; and then, current terrain perception features, static prediction results and historical signal sequence features are fused, dynamic prediction input is constructed, a dynamic cross-dimension attention network is input, and joint prediction of signal quality indexes is realized. A unified data standardization strategy is adopted in training, verification and test stages, and a controllable information interaction mechanism is introduced between feature dimensions, so that the prediction precision and generalization ability under a complex terrain are improved. Technical support is provided for wireless network planning, site deployment and system performance evaluation.

Methods, systems, and apparatus for wireless communication are described. Some systems can support wireless communication in high-frequency millimeter-wave (mmW) bands, such as frequency range 4 (FR4) or other frequency ranges. To support such communication, a base station can dynamically configure the cyclic prefix (CP) length for single-carrier waveform communication. The base station can determine the CP length to handle beam switching delay, physical propagation channel delay spread, or both. In some examples, a user equipment (UE) can provide feedback to the base station, and the base station can configure the UE with the CP length based on the feedback. The base station can send a configuration message to the UE indicating the configured CP length. A single-carrier waveform with the configured CP length can maintain symbol-level alignment with other supported waveforms, such as orthogonal frequency division multiplexing (OFDM) waveforms.

The invention relates to the technical field of communication, and discloses a channel estimation method and device, a storage medium and a program product. The channel estimation method comprises the following steps: acquiring a time domain OFDM signal transmitted through a wireless channel; converting the OFDM symbol to a frequency domain; extracting a pilot frequency sub-band and a pilot frequency symbol corresponding to the OFDM symbol; an extended pilot frequency sub-band set corresponding to each OFDM symbol is determined based on the extracted pilot frequency sub-bands, and the extended pilot frequency sub-band set corresponding to each current OFDM symbol is determined based on the pilot frequency sub-band corresponding to the current OFDM symbol and the pilot frequency sub-band corresponding to the OFDM symbol adjacent to the current OFDM symbol; after each extended pilot symbol set is converted to a time domain, performing time domain noise reduction processing to obtain time domain channel impulse response data; and converting the time domain channel impulse response data to a frequency domain, and performing interpolation processing to obtain a frequency domain channel estimation result. According to the technical scheme of the invention, ISI, ICI and channel aliasing effects caused by overlarge delay spread can be suppressed, and the spectrum efficiency and robustness of the system are improved.

The invention provides a broadband short wave channel modeling method and system, a medium and a product. In the method, a data processing unit firstly constructs a target time delay power distribution curve by using a shape parameter and a time delay spread parameter, the shape parameter can flexibly adjust an echo energy attenuation form, the time delay spread parameter can accurately reflect the duration of an echo cluster, and the combination of the shape parameter and the time delay spread parameter enables the constructed time delay power distribution to better fit an actual channel multipath structure. And the data processing unit combines a phase function for reflecting a signal frequency difference value and a random modulation function for reflecting the fading characteristic of the signal along with time, and a time-varying impulse response function obtained by multiplying the three functions comprehensively reflects the time-varying characteristics of the signal amplitude and phase on each path. And finally, the data processing unit sums all path impulse responses to obtain a total time-varying impulse response function, and actual channel characteristics such as multipath propagation and Doppler effect are integrated, so that the problem of inaccurate simulation precision of the model is effectively relieved, and the simulation accuracy of an actual physical process is improved.

Methods, systems, and devices for wireless communications are described. A network entity may indicate to a user equipment (UE) (e.g., in a downlink control message) a capability of the network entity to disable power amplifiers for downlink transmissions. In response to the capability indication, the UE may estimate and report to the network entity the delay spread and antenna array loss threshold of a downlink signal. Based on the reported delay spread and antenna array loss threshold, the network entity may determine a quantity of power amplifiers that may be disabled for downlink transmission without reducing the received signal power at the UE below a minimum threshold. The power amplifiers that the network entity disables may be the power amplifiers with input powers less than a threshold (e.g., less than a highest input power by a threshold).

This invention relates to the field of digital information transmission technology, specifically to a bandwidth-adaptive dynamic rate-limited data distribution system. The system includes a physical layer state acquisition front-end, a signal-to-noise ratio (SNR) trend prediction front-end, a cross-layer rate-limiting decision front-end, and a distribution execution front-end. The physical layer state acquisition front-end acquires the SNR sequence of the target distribution link; the SNR trend prediction front-end inputs the SNR sequence into a Kalman filter model and outputs a predicted value of the available bandwidth of the link, the state transition matrix parameters of which are dynamically determined by the multipath delay spread value of the current link; the cross-layer rate-limiting decision front-end compares the predicted value of the available bandwidth of the link with the current sliding window congestion window value of the transport layer and takes the smaller value as the dynamic rate-limiting threshold; the distribution execution front-end adjusts the data packet transmission interval of the transmission queue according to the dynamic rate-limiting threshold. This scheme reduces the transmission rate in advance based on the bandwidth prediction results before physical layer channel fading causes packet loss at the transport layer.

The invention discloses an underwater acoustic OTFS communication transmission system and method based on a generative neural network, and relates to underwater communication transmission. In order to solve the problem of fractional diffusion caused by broadband underwater acoustic channel long delay spread and Doppler spread, the system comprises a transmitting device, a receiving device, a channel estimation device and a channel equalization device which work cooperatively in sequence; the transmitting device completes signal OTFS modulation, carrier modulation and transmitting, the receiving device achieves signal receiving, preprocessing and OTFS demodulation, the channel estimation device combines a fractional order dictionary matrix and a generative neural network, a time delay-Doppler domain refinement grid is constructed, an unsupervised training model of double KL divergence constraint is designed, and the channel estimation device is used for estimating the channel. And the channel equalization device completes equalization processing and signal recovery. The method comprises the steps of transmitting end OTFS modulation transmission, underwater acoustic channel transmission, receiving end signal processing demodulation, generative neural network channel estimation and balanced decoding. A large number of labeled samples are not needed, the calculation complexity is low, the operation time is short, and the underwater acoustic channel transmission precision is improved.

This invention relates to an echo-assisted communication statistics modeling method, belonging to the field of wireless communication technology. The method of this invention proposes a way to predict the bistatic communication CCS (including communication path loss, delay spread, horizontal wave-off spread, pitch wave-off spread, horizontal wave-on spread, and pitch wave-on spread) from the monostatic sensing SCS (including sensed path loss, delay spread, horizontal wave-off spread, pitch wave-off spread, horizontal wave-on spread, and pitch wave-on spread) of an ISAC base station. This achieves complete and accurate prediction of communication channel statistics, solving the problem that existing ISAC channel modeling techniques cannot obtain large-scale link-level communication channel characteristics based on sensed data.