Abstract: A first electronic device includes: a first transceiver; a first memory storing at least one instruction; and a first processor operatively connected to the first transceiver and the first memory, the first processor being configured to execute the at least one instruction to: transmit, to at least one second electronic device, a non-high-efficiency (non-HE) announcement frame, and transmit, to the at least one second electronic device, a downlink (DL) multi-user (MU) extension (Ext) physical layer protocol (PPDU), wherein the DL MU Ext PPDU includes: a non-HE PPDU and a HE PPDU.

Abstract: A wavelength calibration method for a grating spectrometer is provided, including: moving a plurality of characteristic peaks of a calibration light source to a central position of a detector of the spectrometer respectively, and determining a functional relationship between a grating rotation angle of the rotatable grating and a central wavelength; and determining parameters ?, f, a, b, c in the following physical model, the physical model being used to calculate a corresponding wavelength at each pixel within an imaging range of the detector when the central wavelength is determined, ? ? = sin ? ( ? - ? 2 ) + sin ? ( ? + ? 2 + arctan ? ( a ? ( n ? x ) 2 + b ? ( n ? x ) + c f ) ) 1 ? 0 - 6 · m · N wherein ? is the grating rotation angle corresponding to the central wavelength as determined via the functional relationship, ? is built-in angle of the spectrometer, f is a focal distance of the spectrometer, m is grating diffraction order, N is the number o

Abstract: Methods and systems are described herein for determining data shifts using change point detection in time series datasets. The system receives, from a change point modelling system, a first model and a plurality of change points detected within a time series dataset using the first model. The system generates, for each change point, a second corresponding model that fails to detect a corresponding change point and inputs the time series dataset into the first model and into each second corresponding model. The system determines a performance difference between the first model and each second corresponding model and assigns severity metrics to the change points based on the corresponding performance difference. The system selects a subset of change points based on the severity metrics and determines a cause of each change point of the subset of change points.

Abstract: The present disclosure provides an auto-focus spectrometer, including: a grating element configured to split light; an imaging element configured to converge a light beam; a controller configured to move the imaging element to realize autofocus, and connected to the imaging element; and a detector; and an incident light is diffracted through the grating to the imaging element, and then converged to the detector through the imaging element to obtain spectrogram information. The present disclosure automatically adjusts the imaging element position according to the configuration and operation state of the spectrometer, so that the spectrometer can be automatically kept at an optimal imaging position and exert the best performance thereof.

Abstract: A method of digital memoryless pre-distortion includes receiving an input digital signal from a signal source, calculating a look-up table (LUT) address from the input signal and a power scale, updating an LUT value associated with the LUT address based on the input signal and an output signal that is output from a power amplifier to a wireless communications channel, linearizing the output signal with the updated LUT value, and outputting the output signal to the wireless communications channel. The steps of updating an LUT value associated with the LUT address and linearizing the output signal with the updated LUT value are repeated until a level of linearization is achieved that meets a pre-defined standard.

Abstract: Disclosed is a broad-spectrum imaging spectrometer based on reflection and transmission integrated structure, including a coaxial reflection outer cylinder and a coaxial transmission outer cylinder. A slit component is provided at an incident end of the coaxial reflection outer cylinder; a spherical mirror and a plane mirror are provided above the slit component; incident light passes through the plane mirror, reflects off the spherical mirror, and is further reflected by the plane mirror into the coaxial transmission outer cylinder; a grating prism module and a focusing inner cylinder are provided within the coaxial transmission outer cylinder along a transmission direction, and a cemented lens module is provided in the focusing inner cylinder; the cemented lens module is fixedly provided inside the focusing inner cylinder, the focus inner cylinder is placed within an adjustment chamber of the coaxial transmission outer cylinder.

Abstract: A computer-implemented method performed by a first electronic device for reducing a feedback overhead of beamforming in a wireless communication system, includes: transmitting a first data to a second electronic device; transmitting a data packet to the second electronic device; receiving a second data from the second electronic device; extracting a compressed steering matrix from the second data; obtain uncompressed steering matrix by using a decoder part of an autoencoder, based on the extracted compressed steering matrix; and transmitting, to the second electronic device, a third data via a radio signal beamformed based on the obtained uncompressed steering matrix.

Abstract: A distortion apparatus for a power amplifier comprises: pre-distortion circuitry that comprises a memory polynomial look-up-table (LUT) circuit; and post-distortion circuitry that updates the pre-distortion circuitry based on an output of the power amplifier. The pre-distortion circuitry comprises a plurality of LUTs. Each LUT corresponds to a different memory depth of a memory polynomial of a Volterra series. Each LUT indexed by an instantaneous power of an input sample delayed by an amount corresponds to a respective memory depth of each LUT. An output of the memory polynomial LUT circuit corresponds to a summation of an output of each LUT multiplied by the input sample delayed by the amount corresponding to the respective memory depth of each LUT, and an output of the pre-distortion circuitry is provided to the power amplifier.

Abstract: A second apparatus configured to communicate with a first apparatus in a wireless local area network (WLAN), including: a transceiver; and at least one processor configured to: receive, using the transceiver, a null data packet (NDP) from the first apparatus, generate a channel estimate based on the NDP, decompose the channel estimate to obtain a feedback matrix, based on the feedback matrix, obtain beamforming information to be used by the first apparatus to perform beamforming, transmit, using the transceiver, the beamforming information to the first apparatus, and receive, using the transceiver, a data transmission which is beamformed by the first apparatus based on the beamforming information, wherein the beamforming information includes at least one from among: a pair of angle indices which indicate a pair of angle vectors to be used by the first apparatus to beamform the data transmission, and a steering matrix index which indicates a steering matrix to be used by the first apparatus to beamform the dat

Abstract: A communication device, including a receiver configured to receive a signal comprising a plurality of training symbols and a data symbol; and at least one processor configured to: select, from among the plurality of training symbols, a first training symbol and a second training symbol based on a first parameter and a second parameter; obtain a first symbol difference corresponding to the first training symbol, and a second symbol difference corresponding to the second training symbol; estimate a carrier frequency offset based on the first symbol difference and the second symbol difference; obtain a compensated data symbol corresponding to the data symbol based on the estimated carrier frequency offset; and demodulate and decode the compensated data symbol to obtain decoded data.

Abstract: A one way ranging method estimates a distance between first and second wireless devices using a technique that involves exchanging dual tone RF signals between the devices and, at each of the first and second devices, maintaining “baseband coherence” between baseband signals carried by the RF signals transmitted and received by each respective device.

Abstract: Methods and systems for generating, storing, and modifying data for feature engineering purposes. In particular, methods and systems for automatically generating feature engineering pipelines by chaining multiple transformers (models and/or function trained to transform data in specific ways) and estimators (e.g., algorithms trained with input data to generate transformers) in a sequential order based on feature attributes. To determine the specific transformers and estimators, the system may access a shared knowledge database, graph engine, and pipeline engine.

Abstract: The present disclosure describes systems and methods for time-of-arrival (TOA) estimation techniques. Some embodiments of the disclosure provide for estimating radio propagation path parameters based on a training signal received over a set of active frequencies. The radio propagation path parameters (e.g., fading coefficients for each path) are used to reconstruct a channel frequency response on null frequencies (e.g., frequencies that did not include or carry the received training signal). A time-of-arrival parameter can then be estimated based on the estimated channel frequency response and the reconstructed channel frequency response (e.g., the channel frequency response estimated using both active frequencies and null frequencies).

Abstract: One or more aspects of the techniques and models described herein provide for bidirectional recurrent neural network (BiRNN)-based digital pre-distortion techniques for radio frequency (RF) power amplifiers (PAs). As an example, a digital pre-distorter (DPD) system may implement residual learning and long short-term memory (LSTM) projection layer features to reduce computational complexity and memory requirements. Implementing the described unconventional techniques of applying residual learning in RNN (e.g., in BiLSTM), using LSTM projection to develop a DPD structure, or both, may provide several advantages over preexisting techniques. For instance, the complexity in training and pre-distortion may be reduced and significantly less memory may be required to store the DPD neural network coefficients (e.g., while achieving similar or better linearization performance compared to other LSTM models). Further, faster training convergence speed may be achieved (e.g., compared to other LSTM models).

Abstract: A measurement method performed at a receiving device involves sequentially receiving RF signals, each comprising a different set of at least first and second tones at differing frequencies. Complex gain responses (CGRs) for each of the first and second tones of each of the RF signals are measured. A phase offset is determined between: i) a phase of the CGR of the second tone of a first RF signal, and ii) a phase of the CGR of the first tone of a second RF signal. A coherent channel frequency (CCF) response of the second tone of the second RF signal is computed by adjusting a phase of the CGR of the second tone of the first RF signal by the phase offset. A processor executes a signal paths calculation algorithm using the CCF response of the second tone of the second RF signal to determine an angle or time of arrival of the first RF signal.

Abstract: An electronic device may include conductive structures with a light-reflecting coating. The coating may have a two or four-layer thin-film interference filter. The two-layer filter may have a CrN layer and an SiCrN layer. The four-layer filter may have two CrN layers and two SiCrN layers. The two-layer filter may be used to coat relatively small conductive components. The four-layer filter may be used to coat a conductive housing sidewall. Both types of interference filter may produce a relatively uniform light blue color despite variations in coating thickness produced on account of the geometry of the underlying conductive structure.

Abstract: The present disclosure describes systems and methods for time-of-arrival (TOA) estimation techniques. Some embodiments of the disclosure provide for estimating radio propagation path parameters based on a training signal received over a set of active frequencies. The radio propagation path parameters (e.g., fading coefficients for each path) are used to reconstruct a channel frequency response on null frequencies (e.g., frequencies that did not include or carry the received training signal). A time-of-arrival parameter can then be estimated based on the estimated channel frequency response and the reconstructed channel frequency response (e.g., the channel frequency response estimated using both active frequencies and null frequencies).

Abstract: A method for detecting a modification, due to an interferer, of a wireless channel between a transmitting device and a receiving device. First and second samples of channel frequency response (CFR) of the wireless channel are measured within a time interval less than or equal to a pre-established static time interval throughout which the wireless channel is expected to exhibit a static characteristic in an environment without any interferer. An interferer is detected to have modified the wireless channel when a similarity condition reflecting a degree of similarity between the first and second CFR samples is not satisfied.

Abstract: A buckle type roller conveying slideway comprises a base, two ends and two side covers, the two ends are arranged at the front end and the rear end of the base respectively, and at least one end is assembled together with the end part of the base through a buckle connecting structure. During assembly, the ends and the base are firmly assembled and fixed together through the buckle connecting structures between the ends and the base, the whole assembling process is simple, easy and fast, and fasteners such as screws do not need to be additionally used or stamping and other procedures do not need to be additionally added for fixing, so that the assembling efficiency is improved, and the assembling labor intensity is also reduced.