14 results about "Channel inversion" patented technology

The invention discloses an inter-ice water channel inversion method based on multi-channel satellite data, and belongs to the technical field of satellite image processing, and the method comprises the steps: obtaining a reflectivity abnormal value of a visible light radiation brightness value and an initial value of a reflectivity abnormal threshold value, and obtaining a brightness temperature abnormal value BTA of a thermal infrared radiation brightness value and an initial value of a brightness temperature abnormal threshold value; step 2, acquiring a pixel credibility matrix; and step 3, adjusting a brightness temperature abnormal threshold value and a reflectivity abnormal threshold value by adopting an iterative dual-threshold adaptive optimization algorithm based on fuzzy classification, calculating a brightness temperature abnormal value membership degree and a reflectivity abnormal value membership degree, and judging the comprehensive probability that the pixel belongs to the inter-ice water channel according to each membership degree and the pixel credibility matrix. According to the method, the dynamic complexity of the polar region environment can be better adapted by utilizing the advantages of the visible light data in the aspect of identifying the boundary and texture of the ground features and the advantages of the thermal infrared data in the aspect of distinguishing the ground features at different temperatures, and the inversion precision of the inter-ice water channel is improved.

System and method for an over-the-air computation (AirComp) scheme for federated edge learning (FEEL) doesn't require channel state information (CSI) at the edge devices (EDs) or edge server(ES). The disclosure adopts the majority vote (MV) principle and defines multiple subcarriers and orthogonal frequency division multiplexing (OFDM) symbols for voting options, which reduces to frequency-shift keying (FSK) over OFDM subcarriers as a special case. Thus, FSK-based over-the-air computation is provided for federated edge learning without channel state information. Since the votes from EDs are separated on orthogonal resources, the scheme eliminates the need for truncated-channel inversion (TCI) at the EDs and allows the ES to detect MV with a non-coherent detector.

The invention relates to a groove type IGBT cellular structure, an IGBT device and a preparation method, the groove type IGBT cellular structure comprises an N-drift layer and an active region, and the active region is provided with a P-body region, a plurality of grooves and an N + emitter region; the trenches comprise a plurality of gate trenches and emitter trenches which are transversely arranged, and each trench vertically passes through the P-body region and enters the N-drift layer; the table board width on the two sides of the gate trench is set as a first value; at least two adjacent emitter trenches exist, the mesa width between the two adjacent emitter trenches is set as a second numerical value, the first numerical value is greater than the mesa threshold, and the second numerical value is smaller than the mesa threshold. By designing the gate trench and the emitter trench with specific mesa width distribution, the hole outflow path is balanced, the conductivity of the channel inversion layer is kept stable, the collector induced barrier lowering effect of the device is effectively improved, and the reliability of the device is improved.

The invention provides a method for protecting location privacy of both communication parties. The method comprises the following steps: S1, setting parameters such as a transmission period, a time slot, noise parameters of each node, the number of legal users and access points; s2, the central processing unit selects an optimal access point in each time slot, the access point broadcasts a pilot signal to a transmitter, and the transmitter sends hidden information to the access point; s3, after the access point sends a pilot signal to the receiver, the hidden information is forwarded to the receiver; s4, calculating the receiving rate of the receiver according to the preset fixed energy Q and the related channel gain; and S5, repeating the steps S2 to S4 until the transmission period is finished. According to the method, a deformed channel inversion power control (CIPC) strategy is adopted, a pilot signal is transmitted through a relay node to realize hidden protection of position information of a communication node, the error detection probability of an eavesdropper and the hidden transmission performance of a legal user under the strategy are improved, and the superiority of the method in the aspect of privacy protection is verified through a numerical experiment.

The present invention discloses a pre-stack AVA elastic parameter inversion method and system based on knowledge transfer. A forward model is constructed based on the exact Zoeppritz equation to implement multiple groups of differential evolution algorithms with mutation. By introducing the optimal solution information of the elastic parameters of the bypass channel through the idea of knowledge transfer, while accelerating the iteration convergence of the current channel, the lateral continuity of the inverted elastic parameter profile is ensured. By introducing the post-stack P-wave impedance information during the selection process of multiple groups of differential evolution algorithms with mutation, the relationship between parameters is constrained, and the correlation of the three inverted parameters is improved; thereby ultimately improving the accuracy of pre-stack AVA elastic parameter inversion and ensuring lateral continuity. The basis of the present invention is for the known pre-stack AVA forward angle gather in the model, and the single-channel inversion of elastic parameters is performed using the MMDE method based on the given initial model. Then, to ensure lateral continuity, knowledge transfer is used to map the results of the bypass channel to the inversion process of the current channel, and finally, a laterally continuous elastic parameter inversion result is obtained.

The application discloses a digital air computing method based on binary complement coding, comprising the following steps: linear scaling and down rounding quantization are performed on a continuous analog signal to be calculated at a distributed device end, and the quantized value is converted into a binary complement sequence with a fixed length; a decoder is designed at a base station end based on a superposition result of each binary bit; each bit of the binary complement sequence is subjected to binary phase shift keying (BPSK) modulation, a frequency band is divided into a plurality of subcarriers by using orthogonal frequency division multiplexing (OFDM) technology, and a plurality of devices superimpose transmission on the same subcarrier for the same binary bit; equal power allocation is performed according to the weight priority of the binary bit, a transmission signal is preprocessed based on channel state information by using a truncated channel inversion strategy; a linear minimum mean square error (LMMSE) detector is applied to each subcarrier received signal at the base station end to estimate a superposition result; a multi-subcarrier mean square error minimization problem is constructed, and a greedy algorithm is used to optimize an active device set and a transmission power factor; and the application significantly improves the real-time performance and reliability of multi-device cooperative computing in actual application.

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive an indication of a configuration for processing a data block into an uncoded uplink signal. The UE may determine pre - equalization parameters corresponding to the uncoded uplink signal based on the indication of the configuration. The UE may apply analog modulation and the pre - equalization parameters to the data block to form the uncoded uplink signal and transmit the uncoded uplink signal on overlapping time - frequency resources with one or more other UEs according to air computing operations. The UE may determine a plurality of channel inversion coefficients based on: an indication of a configuration for processing a data block into an uncoded uplink signal, measuring one or more reference signals, receiving an indication of an inversion granularity, receiving an inversion coefficient power threshold, or any combination thereof.

An embodiment of the present invention provides a multi-channel pre-stack waveform inversion method and apparatus, which solves the problems of large inversion error and insufficient inversion resolution. A multi-channel pre-stack waveform inversion method provided by an embodiment of the present invention includes: Step 1: Obtain an angle gather based on the elastic wave equation; Step 2: Obtain a multi-channel inversion objective function based on the angle gather; Step 3: Remove the correlation between elastic parameters from the multi-channel inversion objective function; Step 4: Select an initial model of elastic parameters, and obtain the perturbation amount of the elastic parameters relative to the initial model based on the multi-channel inversion objective function after removing the correlation between elastic parameters and the initial model of elastic parameters; Step 5: Repeatedly iterate Step 4 to obtain a multi-channel pre-stack waveform inversion result.

The invention discloses a digital air computing method based on binary complement coding, which comprises the following steps of: performing linear scaling and downward rounding quantization on a continuous analog signal to be computed at a distributed equipment end, and converting a quantized value into a binary complement sequence with a fixed length; designing a decoder at the base station end based on the superposition result of each binary bit; performing binary phase shift keying (BPSK) modulation on each bit of the binary complement sequence, and dividing a frequency band into a plurality of subcarriers by adopting an orthogonal frequency division multiplexing (OFDM) technology, so that the same binary bit of multiple devices is superposed and transmitted on the same subcarrier; performing equal-ratio power distribution according to the weight priority of the binary bit, and preprocessing a transmitted signal by adopting a truncated channel inversion strategy based on channel state information; a linear minimum mean square error (LMMSE) detector is applied to each subcarrier receiving signal at a base station end to carry out superposition result estimation; constructing a multi-subcarrier mean square error minimization problem, and optimizing an activation device set and a transmitting power factor through a greedy algorithm; according to the method, the real-time performance and reliability of multi-device cooperative computing under the actual application condition are remarkably improved.

The application discloses a dam seepage field reconstruction and leakage channel inversion method and equipment, and the method comprises the steps of: constructing a structured topological graph reflecting the adjacency relationship between measuring points according to the spatial distribution characteristics of the dam seepage pressure monitoring section, and converting the monitoring data into a multi-dimensional feature tensor containing seepage pressure values, change rates and environmental factors; constructing a topological constraint-based space-time graph attention network model, introducing a topological adjacency mask in the attention score calculation process of the model graph attention layer to force the model to only aggregate features between nodes that exist in the topological structure, and embedding the spatial geometric constraint into the deep learning weight updating process; analyzing the attention weight matrix obtained by model training to invert the dominant leakage path inside the dam body, and outputting the reconstructed three-dimensional seepage field distribution based on sparse measuring points. The application eliminates the pseudo-correlation interference in the data-driven model through the topological hard constraint mechanism, and can realize the diagnosis of the dam seepage state.

A method performed by a user equipment (UE) generates local gradients for a federated learning task. The method calculates a gradient Sum-Power level based on the local gradients. The method receives a mapping between gradient Sum-Power levels and scaling factors for channel inversion coefficients to process a data block into an unencoded uplink signal. The method also determines a channel inversion coefficient based on a scaling factor obtained from the mapping and the calculated gradient Sum-Power level. The method applies analog modulation and the channel inversion coefficient to the data block to form the unencoded uplink signal. The method further transmits, to a network, the unencoded uplink signal on shared uplink resources for an over-the-air computation of global gradients for the federated learning task.

A method performed by a user equipment (UE) generates local gradients for a federated learning task. The method calculates a gradient sum power level based on the local gradients. The method receives a mapping between the gradient sum power level and a scaling factor for a channel inversion coefficient to process a data block into an uncoded uplink signal. The method also determines the channel inversion coefficient based on the scaling factor obtained from the mapping and the calculated gradient sum power level. The method also applies an analog modulation and the channel inversion coefficient to the data block to form an uncoded uplink signal. The method also transmits the uncoded uplink signal on a shared uplink resource to the network for air computation of global gradients for the federated learning task.

Erase operations can be performed selectively on one of erase blocks or a memory array coupled to the same string by creating a pseudo PN junction that is located adjacent to the selected erase block. The pseudo PN junction is created by including channel inversion at least on those portions of the string coupled to unselected erase blocks, which further creates a flow of electrons. As a result of the channel inversion (along with channel accumulation created adjacent to the channel inversion), the flow of gate induced drain leakage (GIDL) holes are further generated from the pseudo PN junction and GIDL holes are induced to tunnel into memory cells of the selected erase block.

This invention relates to an elastic parameter identification method based on a multi-objective mayfly algorithm and Taylor expansion, comprising: S1: collecting well logging data and establishing an initial model based on the well logging data; S2: performing inversion based on the initial model to obtain the Pareto set under t iterations; S3: extracting the mayfly position at the center of the final Pareto set based on the Pareto set under t iterations; S4: completing a single-channel inversion based on the mayfly position at the center of the final Pareto set, and completing the inversion of the entire profile based on the single-channel inversion. This invention improves both the accuracy and stability of the inversion results in pre-stack AVA inversion, and derives a more reliable combined inversion method, improving the accuracy of the inversion and providing strong support for the accurate identification of high-quality reservoirs.