58 results about "Frequency grid" patented technology

The invention provides an OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization. According to the method, pilot symbol positions and densities are configured in an OTFS time-frequency grid according to channel time-varying characteristics and bandwidths, and a Doppler index range is set to optimize channel information acquisition; deploying a controllable reflecting surface, constructing a phase modulation matrix based on a target position and communication channel parameters, dynamically adjusting a phase gradient direction, and separating energy of a target echo and a communication signal; within a set Doppler index range, calculating frequency offset estimation, correcting a time domain sampling point of a received signal, and generating a phase correction vector; and positioning a spatial aliasing main interference area, and inhibiting symbol interference and spatial aliasing caused by a high-speed target through frequency domain beam forming weighting and phase rotation compensation in combination with a phase correction vector and a sub-Doppler parameter in the area. According to the invention, time-frequency-space domain cooperative efficient processing of OTFS radar communication integrated signals is realized.

The invention belongs to the technical field of quality detection, and discloses an electrical automation quality detection method and system. The method comprises the steps of collecting original voltage and current signals of a PCC point of a power grid and performing FFT to obtain a background harmonic frequency set and a background harmonic amplitude set; generating an initial frequency grid based on a preset target frequency band, and generating a sparse frequency grid in combination with the background harmonic waves; calculating the estimated signal-to-noise ratio of each candidate frequency, performing ascending sorting to obtain an injection sequence, injecting sinusoidal signals, collecting PCC point voltage response and total current, and calculating a frequency impedance data pair; performing rational function fitting based on the frequency impedance data to obtain a broadband impedance curve; analyzing the curve, extracting quality characteristic parameters, and performing quality judgment according to the parameters; according to the method, the technical problem that the grid-connected stability quality of a single new energy converter cannot be quickly and automatically qualified in a production line offline detection scene in the prior art is effectively solved.

The invention discloses an underwater sound double-expansion channel parameter estimation method based on Newton orthogonal matching pursuit. The method comprises the following steps: firstly, realizing frame synchronization by using a cross-correlation peak of an LFM signal and a received signal; a coarse estimation value of a Doppler coefficient is obtained on a discrete time frequency grid through an ambiguity function method by utilizing the self-correlation characteristic of m-sequence pilot frequency, multipath time delay of a channel is detected by utilizing a matched filtering peak value of a signal after frequency offset compensation, and a coarse estimation result of the channel is obtained; executing Newton iteration optimization in a continuous parameter space by adopting a Newton orthogonal matching pursuit algorithm to realize super-resolution off-grid estimation of the Doppler coefficient of the first data block; and finally, proposing an iterative block tracking strategy, initializing the compensation of the rear block through the estimated value of the front block, and updating the time-varying Doppler coefficient by using the balanced signal feedback to realize the dynamic tracking of the time-varying Doppler coefficient. According to the invention, the Doppler estimation root-mean-square error is obviously reduced, and the calculation efficiency is high.

Embodiments disclosed herein encompass methods, apparatus, and systems for interference management. First resource elements (REs) are configured to enable measurement of interference that affects communications between a first user equipment (UE) and a first network device in a wireless communication system. The first REs include REs that correspond to a subset of REs in a set of second REs, and the set of second REs includes all REs at a time position in a time-frequency grid that are muted for communications by a second UE. Interference mitigation based on the interference measurement may be applied to manage the interference. The interference may include cross-link interference between links in the same wireless communication system, or links in different wireless communication systems such as a terrestrial network and a non-terrestrial network.

A user equipment, UE, is configured for operating in a wireless communication network that utilizes resources of a time / frequency grid. The UE is adapted to report to the wireless communication network a connectivity information associated to a first connectivity option of the UE to the wireless communication network and associated to a second connectivity option of the UE to the wireless communication network; and / or is adapted to receive, during a same instance of time, and decode a first signal received from a first transmission / reception point, TRP, and a second signal received from a second TRP, the first signal and the second signal occupying resources in the same time / frequency grid.

A Global Navigation Satellite System (GNSS) receiver for processing GNSS satellite signals use a quasi-asynchronous sampling frequency grid to process the received signals. The GNSS receiver includes a plurality of RF paths configured to receive Global Navigation Satellite System (GNSS) signals from an antenna and transmit the GNSS signals in a frequency range for digitizing the GNSS signals. A phase-locked loop is configured to generate a clock signal and a plurality of clock dividers are configured to receive the clock signal and divide the clock signal. Each of a plurality of navigation systems receive a clock signal from one of the plurality of clock dividers.

The invention discloses an unknown radiation source individual identification system, method and equipment. The invention particularly relates to an unknown radiation source classification and identification method based on electromagnetic signal SLIB, time-frequency grid-energy feature fusion and entropy penalty K-means clustering. According to the method, time-frequency grid-energy features and contour integral bispectrum features divided by a time-frequency spectrum grid are subjected to PCA + t-SNE dual dimension reduction and splicing fusion to form a fusion feature vector, so that nonlinear high-order statistical features of signals are included, local fine-grained energy change information of a time-frequency domain is reserved, and the fusion feature vector is more accurate and efficient. Therefore, the essential characteristics of the signal can be represented more comprehensively. Secondly, a K-means clustering method based on entropy penalty is constructed, an unsupervised adaptive strategy is adopted, dynamic cluster center adjustment and an information entropy weight updating mechanism are combined, and the number of clusters is adaptively adjusted. Meanwhile, a Gamma dynamic adjustment factor and a Beta weight mechanism are introduced, sample attribution calculation is optimized, and the stability and robustness of clustering are improved.

First resource elements (REs) are configured for determination of different components of interference that affects communications between a first user equipment (UE) and a first network device in a wireless communication system. The first REs include REs that correspond to a subset of REs in a set of second REs, and the set of second REs includes all REs at a time position in a time-frequency grid that are muted for communications by a second UE. The first REs further include an RE that corresponds to an RE at a time position in the time-frequency grid, different from the time position of the REs that are muted. The interference may include cross-link interference between links in the same wireless communication system, or links in different wireless communication systems such as a terrestrial network and a non-terrestrial network.

Disclosed is a network device for a wireless integrated radar sensing and communication network, the network device comprising: a resource mapper configured for receiving a data resource allocation message and an enhanced sensing resource allocation message; wherein the resource mapper is configured for selecting a subset of resource elements for communication and coarse radar sensing from a time-frequency grid depending on the data resource allocation message; wherein the resource mapper is configured for selecting a subset of resource elements for enhanced radar sensing from the time-frequency grid depending on the enhanced sensing resource allocation message; wherein the resource mapper is configured in such way that the subset of resource elements for enhanced radar sensing is randomly distributed in the time-frequency grid.

The application discloses a variable-frequency-power-frequency automatic switching energy-saving system and method, and belongs to the technical field of motor control, which comprises the following steps: in the variable-frequency starting stage, a motor is driven to run at variable speed by a frequency converter; when the motor reaches full frequency, high power and stable operation, a control device controls the output voltage of the frequency converter to be synchronous with the grid voltage, and the switching to the power-frequency grid is completed when the phases are consistent; when the load decreases and needs to be reduced, the control device starts the frequency converter to make the output voltage of the frequency converter synchronous with the counter electromotive force of the motor in the power-frequency operation, then performs a back switching operation, the motor in rotation is smoothly connected by the frequency converter, and speed reduction control is implemented, and finally the variable-frequency speed regulation operation state is returned; the application realizes automatic selection of the optimal operation mode according to the actual load, avoids energy loss of the frequency converter in the high-speed area, and ensures that the impact on the motor and the grid in the switching process is minimum.

The utility model relates to the technical field of electric power systems, and discloses a gas turbine synchronous control system which comprises a power supply loop, an input loop, a control loop, a signal output loop and an alternating current loop, and the alternating current loop is connected with a synchronous locking detection relay TJJ used for detecting analog quantity of a generator side and analog quantity of a power grid side. The synchronous locking detection relay TJJ is connected with the control loop; according to the utility model, detection relays are reduced, the detection time is shortened, the detection precision is improved, wiring is simplified, the rotating speed and excitation of the generator are adjusted in time, same-frequency grid connection is ensured, and difference-frequency grid connection can be realized at the same time.

Methods and systems are described for accessing a network and differentiating a 5G network from a 6G network in a SSB. Methods can include searching for a SSB, detecting a valid PSS sequence, and decoding a SSS by matching a mapping of sequence elements of the SSS to resource elements of an OFDM time-frequency grid to a mapping of SSS sequence elements to resource elements of the OFDM time-frequency grid.

The invention relates to a motor fault diagnosis method based on sparse Bayesian and a one-dimensional neural network. The method comprises the following steps: S1, collecting a motor stator current signal, and carrying out filtering and preprocessing; s2, performing Hilbert transformation on the current signal to obtain an analysis signal; s3, constructing a sparse signal model in the truncated frequency domain and performing frequency grid division; s4, solving the sparse model based on sparse Bayesian learning, and correcting the deviation between the fault frequency and the grid by adopting an off-grid model to obtain an envelope spectrum; and S5, inputting the envelope spectrum into a one-dimensional convolutional neural network to output a motor fault diagnosis result. The method has higher frequency recovery precision, stronger robustness and fault recognition accuracy exceeding 98% in a complex environment.

A coordinated control method for fixed-frequency grid-connected power sources and grid-connected power sources in microgrids belongs to the field of power system automation. Its key features include the following steps: Step a, determining the I-V droop curve parameters of the fixed-frequency grid-connected power source and the P-V droop curve parameters of the grid-connected power source; Step b, data acquisition and processing in the microgrid; Step c, setting the microgrid voltage constructed by the fixed-frequency grid-connected power source and setting the grid-connected power source's grid-connected output power; Step d, coordinated adjustment of the fixed-frequency grid-connected power source and the grid-connected power source based on load characteristics. In this application's technical solution, the fixed-frequency grid-connected power source uses an I-V droop curve to output AC current with a fixed frequency and phase consistent with the synchronization signal. The grid-connected power source tracks the grid phase through a phase-locked loop and adjusts its active power output according to the P-V droop curve. Both the fixed-frequency grid-connected power source and the grid-connected power source allocate active power according to their respective capacities, and each fixed-frequency grid-connected power source allocates reactive power according to its capacity, jointly maintaining the power balance of the microgrid.

The invention discloses a flywheel hybrid offshore floating variable-speed constant-frequency wind power generation system, which relates to the technical field of wind power generation and comprises an impeller, a generator, a flywheel hybrid mechanism, a filter compensation mechanism and a control unit. The flywheel rotating at a high speed has a gyroscopic effect, stable torque generated by rotation of the flywheel can be used for resisting horizontal load effects of wind, waves, flow and the like, and swinging of the floating fan is reduced. And meanwhile, the flywheel hybrid mechanism and the filtering compensation mechanism can ensure that the generator obtains a constant synchronous rotating speed under the variable-speed wind condition, constant-frequency grid connection can be realized without a converter, and the stability and the electric energy quality of the system are improved.

Disclosed is a transceiver device such as a user equipment, UE, configured for operating in a wireless communication network providing a plurality of time resources in a time-frequency grid, the plurality of time resources having a first subset of time resources being sub-band full duplex, SBFD, time resources and a second subset of time resources being non-SBFD time resources; wherein according to a first configuration, the transceiver device restricts communication to one of the first type and the second type; and wherein according to a second configuration, the transceiver device uses both the first type and the second type for communication; wherein based on a received message, e.g., from a base station; and / or based on a determination result obtained by the transceiver device the transceiver device is to operate according to the first configuration or the second configuration.

Disclosed is a transceiver device such as a user equipment, UE, configured for operating in a wireless communication network providing a plurality of time resources in a time-frequency grid, the plurality of time resources comprising a subset of time resources being sub-band full duplex, SBFD, time resources; wherein a SBFD time resources provides for at least one uplink, UL, subband; and for at least one downlink, DL, subband. The transceiver device is to receive instructions indicating a link direction associated with whether to transmit UL or receive DL in a SBFD time resource; and to operate accordingly.

The application provides an evaluation method for power transmission distance of a medium-frequency offshore wind farm power collection line. Firstly, based on the structure parameters of the medium-frequency submarine cable, the equivalent thermal resistance method is used to calculate the rated current of each cross-section submarine cable, and the cross-section of the medium-frequency power collection line is preliminarily selected according to the rated current and the loop current. Then, according to the cross-section of the preliminarily selected power collection submarine cable, the reactive and active values of the power collection loop are calculated. When P 损 ≤ 5% P 额定 , it is considered that the active output is basically not affected; finally, the preliminary economic evaluation of the submarine cable is carried out. If the total investment of the medium-frequency power collection line submarine cable is not more than 110% of the power frequency scheme, it is considered that the power transmission distance of the power collection line is reasonable, otherwise the power transmission range of the power collection submarine cable or the medium-frequency frequency needs to be recalculated. The application provides a more accurate calculation method for the power transmission range and the cross-section selection of the medium-frequency grid-connected type offshore wind power project, thereby providing a basis for the design of the medium-frequency type offshore wind power project.

The invention discloses a method for controlling a controlled impedance source of a modular multi-level matrix converter for low-frequency power transmission. According to the control method, on the basis of the idea of a controlled impedance source, the sub-module is equivalently designed to be a frequency division controlled impedance source, energy transfer between impedances is achieved, namely, a power frequency impedance source obtains energy from a power grid, a low frequency impedance source transmits power to a low frequency power transmission system, and therefore stable control over the capacitor voltage of the converter sub-module is guaranteed. And meanwhile, non-communication power frequency / low frequency grid-connected synchronization of the M3C system and self-synchronization among the sub-modules are realized by utilizing the passive synchronization characteristic of the controlled impedance source. The control structure is simple, the information flow of controller interaction and centralized communication can be obviously reduced, and expansion to more quantum modules is easy. According to the control method provided by the invention, the efficiency and safety of the flexible low-frequency power transmission system can be improved, and large-scale grid connection and frequency division power transmission of offshore wind power are realized.

The application provides a non-destructive size measurement method for underground targets by combining frequency coding and half-integer phase control, and belongs to the field of non-destructive size measurement of underground targets. The method solves the problem that the prior art cannot effectively overcome the near distance blind area and suppress the frequency domain sidelobe. The method comprises the following steps: constructing an equal-interval frequency grid; generating a transmission frequency sequence by using a step parameter coprime with the total frequency point number for coding sorting; defining the effective transmission duration of each frequency point time slot, so that the near distance blind area range is determined by meeting the half-integer period condition; in each frequency point time slot, a linear sweep signal is generated, and the cumulative phase of the signal at the end of the time slot is controlled to meet the half-integer circle constraint; the signal is transmitted in sequence, and the echo signal is received synchronously; the complex frequency response of each frequency point is extracted, and after frequency domain coherent synthesis, the phase information is differentially approximated to obtain the group time delay; and the target geometric size is calculated according to the medium propagation speed and the group time delay. The method is used in the field of pipe network detection.

This application discloses a communication method, communication system, and related apparatus. The communication method includes: a first communication device sending first information to a second communication device at a first frequency position; the first information indicating that the first communication device has a first signal to send; the first frequency position is determined based on a first frequency grid, which includes multiple frequency positions, wherein the frequency interval between two adjacent frequency positions is greater than a first threshold; and the first communication device sending the first signal to the second communication device. Embodiments of this application can reduce the power consumption of network devices and terminal devices while ensuring a good network access experience for terminal devices.

An integrated sensing and communication, ISAC, transmitter device (110) comprises a communication interface (113) configured to transmit one or more data communication signals for data communication with an ISAC receiver device (120) using a subset of a plurality of time and frequency resources of a time-frequency grid. Moreover, the ISAC transmitter device comprises processing circuitry (111) configured to allocate a plurality of pilot signals to a further subset of the plurality of time and frequency resources based on a measure indicative of the importance of a sensing performance relative to a data communication performance of the ISAC transmitter device. The communication interface is further configured to transmit the plurality of pilot signals to the ISAC receiver device and / or to a further ISAC receiver device. Thus, the ISAC transmitter device allows adjusting pilot signal allocation depending on the data communication performance relative to the sensing performance.

The present invention discloses a method and system for improving the operational reliability of a flexible low-frequency power transmission system. The method for improving the operational reliability of the present invention comprises: when the number of faulty submodules in a single bridge arm of a modular multi-level matrix converter is greater than the number of redundant submodules, adjusting the reactive power on the power frequency grid side, the reactive power on the low-frequency grid side or the AC voltage amplitude on the low-frequency side, the submodule capacitor voltage and the active power of the new energy power generation system of the modular multi-level matrix converter, so that the modular multi-level matrix converter is not locked and maintains the voltage stability on its low-frequency grid side. The flexible low-frequency power transmission system can continue to operate, significantly improving the reliability of the flexible low-frequency power transmission system. The present invention enables the flexible low-frequency power transmission system to continue to operate when the number of faulty submodules in a single bridge arm of M3C exceeds the number of redundant submodules, thereby improving the operational reliability of the flexible low-frequency power transmission system.

This application relates to a grid frequency regulation method, apparatus, device, and medium based on a shared DC bus. The method includes: acquiring grid frequency data of each grid connected to a target inverter device; determining, based on the grid frequency data of each grid, whether there is a grid with abnormal frequency in each grid; and, if an abnormal frequency grid is determined to exist, using the target inverter device to adjust the frequency of the abnormal frequency grid. The target inverter device includes one grid-connected inverter and at least two grid-connected inverters, which are connected via a shared DC bus. This method can improve the reliability of grid frequency regulation.

The application discloses a method for estimating parameters of a water acoustic double-spreading channel based on Newton orthogonal matching pursuit, which comprises the following steps: first, frame synchronization is realized by using the cross-correlation peak of an LFM signal and a received signal; second, the coarse estimation value of a Doppler coefficient is obtained on a discrete time-frequency grid by using the autocorrelation characteristics of an m sequence pilot and a blurring function method, the multipath time delay of a channel is detected by using the matching filter peak value of a frequency offset compensated signal, and a coarse estimation result of the channel is obtained; third, the Newton orthogonal matching pursuit algorithm is used to perform Newton iteration optimization in a continuous parameter space, and the super-resolution off-grid estimation of the Doppler coefficient of a first data block is realized; and finally, an iterative block tracking strategy is proposed, the compensation of a latter block is initialized by using the estimation value of a former block, the time-varying Doppler coefficient is updated by using the feedback of an equalized signal, and the dynamic tracking of the time-varying Doppler coefficient is realized. The application significantly reduces the root mean square error of Doppler estimation and has high calculation efficiency.

The invention relates to a centralized photovoltaic low-frequency collecting and sending-out system, and the low-frequency collecting and sending-out system reduces the impedance power transmission loss of the sending-out system through a low-frequency photovoltaic module, a low-frequency collecting module, a low-frequency grid-connected module and a low-frequency power transmission system, and achieves the improvement of the sending-out distance and the sending-out capacity. Meanwhile, each photovoltaic field is prevented from being independently and directly connected with high voltage, the complexity of a power transmission line is reduced, the networking difficulty of the power transmission system is reduced, the operation mode of the low-frequency power transmission system is switched through the operation mode switching module, a sending-out channel of the low-frequency collecting and sending-out system plays a role in power regulation and control, and the power transmission efficiency is improved. The utilization rate of the photovoltaic low-frequency collecting and sending-out channel is improved, so that land centralized photovoltaic power generation is efficiently sent out to a load center, and the problem that the power transmission capacity of the photovoltaic channel at night is limited is effectively solved.

In some examples, a method comprises receiving, by a communication apparatus, a downlink transmission comprising a control resource set, wherein the control resource set comprises a set of resources designated for control signaling purposes within a time-frequency grid of the downlink transmission, detecting, by the communication apparatus, a downlink reference signal, DL-RS, transmitted within the control resource set, wherein the reference signal is associated with at least one reference signal configuration, wherein the reference signal configuration comprises a first reference signal configuration and / or a second reference signal configuration, and performing, by the communication apparatus, physical downlink control channel, PDCCH, decoding and / or calculating channel state information based on the detected reference signal.

The application discloses a meshless frequency estimation method for layout unconstrained blade tip timing signal and belongs to the technical field of array signal processing. The method comprises the following steps: setting a sampling model; setting the sampling model of the irregular layout of the blade tip timing signal according to the basic principle of the blade tip timing and the continuous compressive sensing theory; obtaining the rank constraint optimization problem description based on the atomic norm from the sampling model; obtaining the characteristic matrix through the irregular Vandermonde matrix decomposition; solving the rank constraint optimization problem based on the atomic norm through the alternating projection algorithm; and obtaining the frequency estimation value of the signal from the irregular Vandermonde matrix based on the polynomial root estimation method of the root multiple signal classification. The application is based on the basic principle of the blade tip timing and the continuous compressive sensing theory, and the frequency grid does not need to be divided in advance, so that the sensor layout is not restricted by the sparse linear array layout, and the blade tip timing signal obtained is uniform.

The invention discloses a hysteresis current control method and system for a fixed-frequency grid-connected converter, and belongs to the technical field of converter control. The method comprises the following steps: calculating single-cycle variation and influence quantity of voltage, current instruction and hysteresis width of a power grid; calculating a frequency loop compensation gain according to the converter topology; actual switching frequency is detected and compared with an instruction value, and a ring width control instruction is generated through a PI controller; and an actual loop width instruction is obtained by combining the compensation gain, and constant switching frequency control is realized. According to the invention, through multivariable compensation and closed-loop control, the influence of power grid voltage fluctuation, current instruction change and hysteresis width adjustment on the switching frequency is effectively suppressed, the problem of unstable switching frequency of traditional hysteresis control is solved, the advantage of fast dynamic response of hysteresis control is retained, accurate and stable control of the switching frequency is realized, and the switching efficiency is improved. The method is suitable for two-level and three-level converter topologies, and has important engineering application value.

A user equipment (UE) is configured to operate in a wireless communication network utilizing time-frequency grid resources. The UE is adapted to report to the wireless communication network connection information relating to a first connection option of the UE to the wireless communication network and to a second connection option of the UE to the wireless communication network; and / or adapted to receive and decode a first signal received from a first transmission / reception point (TRP) and a second signal received from a second TRP during the same time instance, the first signal and the second signal occupying resources in the same time-frequency grid.