14 results about "Complex gain" patented technology

The application provides a near-field channel parameter estimation method considering spatial non-stationary characteristics, which comprises the following steps: obtaining a multipath parameter initial value by using a far-field SAGE algorithm; calculating propagation distances of array elements at a transmitting end and a receiving end to scattering points, constructing a near-field channel response, and performing refined estimation on angle and distance parameters, time delay parameters and complex gain parameters of the multipath. Correlation operation is performed on a current residual signal and the near-field channel response in a frequency domain to obtain an array element level correlation metric. Continuous spatial non-stationary coefficients with a value of 0 to 1 are updated based on the correlation metric, and weighting iteration is performed on residual construction and parameter updating until a stop criterion is met, and near-field geometric parameters, time delay parameters, complex gain parameters of each multipath and spatial non-stationary coefficients of both transmitting and receiving ends are output. The method solves the problem of inconsistent multipath visible domains under XL-MIMO arrays, can suppress the influence of invisible array elements on parameter estimation, and improves the estimation accuracy and stability of the SAGE algorithm under the condition of near-field spatial non-stationary channels.

This invention provides a SIW TE20 and TM11 hybrid mode equalizer based on a three-dimensional multilayer substrate. The equalizer includes a multilayer dielectric substrate, an input / output transition structure, a substrate-integrated waveguide, a circular resonant cavity, and a dual-mode perturbation device. The physical structure of the equalizer consists of two dielectric substrates defined as an upper and lower dielectric layer, and three metal layers. This invention utilizes a stacked structure to vertically integrate the transmission layer and the resonant layer, reducing the device's planar area. Combined with the fully enclosed characteristics of SIW, it exhibits advantages such as low loss and high Q value at high frequencies. Furthermore, by utilizing the degeneracy of the TM11 mode and symmetrical via perturbation within the circular resonant cavity, two electrically independent resonant peaks are achieved within a single physical cavity, with adjustable frequency spacing. This allows for flexible fitting of complex gain curves. The antisymmetry of the TE20 mode excites the TM11 mode, naturally suppressing unwanted fundamental modes and improving the equalizer's response accuracy.

The invention discloses a beam forming method based on delay Doppler domain channel parameter prediction in a high-speed mobile communication system, and relates to the technical field of wireless communication, in particular to a beam forming method. The invention aims to solve the problem of wave beam mismatch at the future moment caused by CSI aging in high-speed mobile communication. The method comprises the following steps: 1, obtaining a channel response matrix and a power spectrum in a DD domain; 2, obtaining an estimated value of an angle of arrival, Doppler and time delay; 3, obtaining a final cluster set and an adaptive threshold; 4, calculating a space vector; calculating an angle of arrival based on the spatial vector; calculating a cluster direction vector based on the angle of arrival; calculating a sub-modal Doppler center and a sub-modal space vector; calculating sub-modal equivalent gain estimation of each group in each cluster; and 5, obtaining a prediction channel based on the complex gain propulsion prediction of each group in each cluster, and obtaining a prediction beam based on the prediction channel.

A method for cooperative multi-target uniform encirclement control of multiple unmanned surface vessels (USVs) is disclosed, relating to the field of cooperative multi-target encirclement technology. To address the shortcomings of existing cooperative multi-target encirclement technologies, such as low efficiency, insufficient encirclement accuracy and stability, and complex gain design that easily leads to excessive gain, this invention provides the following solution: It includes: constructing kinematic models of the multi-USV system and the multi-target system, defining the target state of the encirclement task; establishing a distributed target center estimator based on the kinematic model and target state; constructing an encirclement controller based on the target geometric center information provided by the distributed target center estimator; adjusting the angular velocity of the USVs to achieve consistency in phase interval angles based on the control strategy of the encirclement controller; dynamically adjusting the parameters of the encirclement controller and outputting the results to the multi-USV system. This method is suitable for application in cooperative multi-target uniform encirclement control of multiple USVs.

The invention discloses a feature construction and parameter joint optimization method for time delay-Doppler domain blind source separation. The method comprises the following steps: performing orthogonal time frequency space demodulation on a time domain mixed signal to obtain a time delay-Doppler domain received signal matrix; screening salient points according to a salient point detection threshold value; calculating a complex gain ratio of each receiving node relative to the reference node, and constructing a stable feature vector finally used for clustering based on complex gains; clustering is carried out on the feature vectors; constructing a global performance evaluation function integrating clustering quality, noise suppression and clustering number matching, and jointly optimizing a salient point detection threshold, a clustering radius and a minimum sample number; and reconstructing the desired signal by using the optimal parameter. According to the method, the problems of phase boundary discontinuity and amplitude scale difference are solved through refined feature construction, the overall performance of the system is optimal through parameter joint optimization, and the clustering precision and robustness of blind source separation are remarkably improved.

The embodiment of the invention provides a control parameter identification method and system of a wind power converter. Excitation signals (d-axis excitation and PLL excitation) with a frequency orthogonal characteristic are synchronously injected into a current loop and a phase-locked loop which are coupled with each other. Then, through one-time synchronous injection and response collection, a mixed response signal containing complete dynamic information of the two loops is obtained; and further, a synchronous demodulation and frequency response extraction algorithm is utilized to accurately separate complex gains of each loop on respective excitation frequency points from the mixed response, so that mutual interference between the loops is effectively decoupled and eliminated. Finally, based on the accurate and decoupled frequency response data, multi-loop parallel solution is carried out, all key control parameters are identified at a time, and rapid and accurate online identification of the control parameters of the wind power converter is achieved.

The invention belongs to the field of wireless communication, and discloses a pre-coding method for a multi-user MIMO-OTFS system. The method comprises the following steps: establishing an optimization problem according to a pre-coding matrix, a complete channel matrix, a system noise variance, a user weight and a total transmitting power constraint in a multi-user MIMO-OTFS communication model; a complete channel matrix in the optimization problem is approximated to be an LoS path approximation channel matrix, a matrix SVD is obtained, precoding matrix design is carried out based on a right singular matrix in an SVD decomposition result, and a directional component and a power component are included; substituting the designed precoding matrix into an optimization problem, constructing a sub-optimization problem about the power component and the complex gain of each sub-channel, optimizing the transmitting power of each sub-channel, and outputting the optimal power component; and constructing a final precoding matrix according to the direction component and the optimal power component. According to the method, efficient utilization of system resources can be realized, and the calculation complexity can be greatly reduced while the WSR performance is ensured.

The invention discloses a channel estimation method for an orthogonal time-frequency space modulation system. Aiming at the time-varying channel estimation problem in high dynamic scenes such as satellite communication and the like, the method comprises the following steps: firstly, inserting a single pilot symbol into a time delay-Doppler grid of a system transmission signal, and setting a protection symbol area; at a receiving end, traversing pilot frequency receiving signals according to time delay coordinates, detecting effective paths by setting a threshold value, performing correlation operation by using a Doppler domain basis function, and preliminarily estimating Doppler frequency offset and channel complex gain of each path; and gradually optimizing multi-path parameter estimation by adopting an iterative fitting mode and calculating and updating residual pilot response until a stopping criterion is met. According to the method, the calculation complexity is remarkably reduced while the estimation precision similar to that of a traditional method is kept, the method is particularly suitable for a multi-path sparse channel with fractional Doppler, and an efficient and reliable channel estimation solution is provided for an OTFS communication system with limited resources.

The invention relates to a nervous system function state evaluation method, system and device and a medium. The method comprises the steps that in a target monitoring time period, multi-channel original electroencephalogram signals of a target object and electrode-skin interface state parameters corresponding to all electroencephalogram signal collection channels are synchronously collected; inputting each electrode-skin interface state parameter into a pre-calibrated forward modulation model to obtain a complex gain estimation value prediction sequence; performing reverse demodulation processing on the multi-channel original electroencephalogram signals based on the complex gain estimated value prediction sequence to obtain electroencephalogram signals of each electroencephalogram signal acquisition channel; and performing time-frequency feature extraction on each electroneurographic signal, and evaluating the nervous system function state of the target object based on the extracted time-frequency features to obtain an evaluation result. By adopting the method, the endogenous modulation artifacts entangled with the neural signal spectrum characteristics can be effectively separated from the observation signals, and the evaluation accuracy of the functional state of the nervous system is remarkably improved.

The application provides an AGV communication channel modeling method and system based on an ellipsoid geometry random model, and belongs to the technical field of wireless communication channel modeling; the method comprises the following steps: a three-dimensional digital scene covering multiple frequency bands, AGV speeds and container densities is constructed, and a multi-dimensional channel data set is constructed based on ray tracing; a dynamic ellipsoid geometry model with a fixed base station and an AGV as the focus is constructed, and a time-varying characteristic is introduced by updating the AGV position in real time; the communication channel is divided into three parts, namely, a line-of-sight part, a ground reflection part and a non-line-of-sight part, the channel complex gains of the three parts are respectively modeled, and are superimposed to synthesize the channel impulse response under the FR3 frequency band. Through the introduction of the speed-dependent Doppler effect and the density-dependent metal scattering mechanism, the time-varying non-stationary characteristics of the AGV channel in the metal dense scene of the port can be accurately described, and efficient and accurate theoretical model support is provided for the intelligent port AGV communication design.

The application discloses a wireless communication system scene adaptive multipath time delay alignment method and device, the method uses SISO channel detection system to measure channel data, adopts a rectangular or RRC shaping filter to generate a CAZAC oversampling sequence as a template function, calculates the cross-correlation matrix of the IQ signal and the template function, calculates the noise threshold based on the median power and false alarm rate, executes dynamic threshold noise filtering, generates the cross-correlation matrix after noise reduction, and completes the preliminary estimation of the time domain impulse response; the SAGE algorithm is used to extract the multipath time delay and complex gain from the cross-correlation matrix; the channel impulse response is drawn to draw a power delay profile (PDP); and the PDP is aligned in combination with the geographic position information of the transceiver during actual measurement. The application solves the defects of traditional alignment in a bad scene, improves the statistical modeling accuracy, and can effectively align the multipath time delay through experiment verification, thereby providing reliable support for channel modeling.

This invention belongs to the field of integrated sensing technology for millimeter-wave communication, specifically relating to a sensing-assisted adaptive tracking method for millimeter-wave channels. The method includes: constructing a time-division duplex frame structure, divided into sensing time slots and communication time slots; in the downlink phase of each sensing time slot: updating the environmental scatterer set information through a multi-target tracking algorithm to construct the channel geometry, including determining multiple non-line-of-sight propagation paths and the path parameters of each path; constructing the geometry of each path based on its path parameters; in the uplink phase: acquiring the prior geometry of each path and the statistical prior of the complex gain of the current sensing time slot to obtain the updated complex gain of that path; in the uplink phase of each communication time slot: acquiring the prior geometry of each valid existing path and the statistical prior of the complex gain of the current communication time slot to obtain the updated complex gain of that path. This invention achieves adaptive channel tracking for dynamic scenarios with path creation and disappearance.

This invention relates to the field of physical layer secure communication technology, and provides a method and apparatus for synchronously generating group keys and paired keys. The method includes: a central node acquiring the azimuth angles and corresponding channel complex gains of each edge node, designing the switching array parameters of a time modulation array based on the azimuth angles of each edge node, calculating the average radiation pattern coefficients of all edge nodes, and transmitting them collectively; the central node generating a group key and modulating it into a modulated signal using the time modulation array and transmitting it; the central node generating corresponding paired keys for each edge node and encrypting them to obtain paired key ciphertext, which is then sent to the corresponding edge node; each edge node receiving the modulated signal performs coherent demodulation to obtain demodulated symbols, performs hard decision on the demodulated symbols, and obtains the group key; each edge node decrypts the paired key ciphertext using the average radiation pattern coefficients and the demodulated symbols to obtain the paired key.

The application provides a three-dimensional multilayer substrate-based SIW TE20 and TM11 mixed mode equalizer, which comprises a multilayer dielectric substrate, an input / output transition structure, a substrate integrated waveguide, a circular resonant cavity and a bimodal perturbation device, and the physical structure of the equalizer is composed of two layers of dielectric substrates defined as an upper layer of dielectric and a lower layer of dielectric and three layers of metal layers. The application scheme vertically integrates the transmission layer and the resonant layer by using the laminated structure, reduces the planar area of the device, combines the fully enclosed characteristics of the SIW, has the advantages of low loss and high Q value at high frequencies, simultaneously, the degenerate characteristics of the TM11 mode and the symmetric via perturbation are utilized in the circular resonant cavity, two electrically independent resonant peaks are realized in one physical cavity, the frequency interval is adjustable, the complex gain curve can be flexibly fitted, the TM11 mode is excited by using the antisymmetry of the TE20 mode, the unwanted base mode is naturally suppressed, and the response accuracy of the equalizer is improved.