Abstract: Systems and methods for detecting coolant leakage in direct liquid cooling systems are disclosed. Liquid coolant is flowed through cold plates that are attached to adjacent processors. Sensor readings of the processors are formed into a differential signal. Distribution of the differential signal is determined. Leakage of the liquid coolant is detected from the distribution of the differential signal.

Abstract: A method for adaptively estimating distortion coefficients of a power amplifier for compensating distortion of the power amplifier, the method has the steps of: estimating the power-amplifier distortion coefficients based on a first digital signal for generating a radio-frequency analog signal through the power amplifier, and a second digital signal obtained from the radio-frequency analog signal. The first digital signal has a length adaptively variable based on a predefined distortion-estimation accuracy.

Abstract: Methods and systems and devices for adaptively updating digital predistortion parameters for a power amplifier distortion model in a wireless communications network base station. The updated parameters are determined by a computing device separate from the base station. The base station monitors one or more operating conditions. When an operating condition differs from a stored operating condition by more than a threshold amount, the base station requests a parameter update from the computing device and receives a scheduled time to submit signals. Power amplifier input and output signals are provided to the computing device at the schedule time and the computing device determines the updated power amplifier distortion model and, consequently, the updated predistortion parameters, which it provides to the base station.

Abstract: There is provided a method of transmitting and receiving data across a network. A receiver device comprises a recovery module comprising a neural network trained to recover signals from clipped signals. The transmitter device may clip the original signal more aggressively due to the improved performance of the machine-learning based recovery module, thereby reducing the Peak to Average Power Ratio (PAPR) of the signal.

Abstract: A method for mitigating inter-mode interference (IMI) caused by antenna misalignment in an orbital angular momentum (OAM) mode multiplexing (OAM-MM) system and detecting a signal in an OAM beam. The method includes receiving an OAM beam bearing a signal, determining a phase-shifting value based on at least one of a type of the antenna misalignment and one or more antenna-misalignment parameters, wherein the phase-shifting value belongs to a beamforming (BF) codebook, shifting the phase of the received OAM beam using the determined phase-shifting value, and detecting the signal from the phase-shifted OAM beam.

Abstract: A method for mitigating inter-mode interference (IMI) caused by antenna misalignment in an orbital angular momentum (OAM) mode multiplexing (OAM-MM) system and detecting a signal in an OAM beam. The method includes receiving an OAM beam bearing a signal, determining a phase-shifting value based on at least one of a type of the antenna misalignment and one or more antenna-misalignment parameters, wherein the phase-shifting value belongs to a beamforming (BF) codebook, shifting the phase of the received OAM beam using the determined phase-shifting value, and detecting the signal from the phase-shifted OAM beam.

Abstract: A method and apparatus for mitigating the beam squint effect in a wideband wireless communication device involving a phased antenna array. Time delay units are operated in series with phase shifters to apply phase shifts to signals fed to or received from antenna elements. The array may be subdivided into sub-arrays each associated with its own time delay unit, and with each antenna element associated with its own phase shifter. The phase shifters are operated to compensate for location mismatch between time delay units and antenna elements, and also to compensate for practical limitations of the time delay units, such as length and quantization limitations.

Abstract: A method of beam steering is provided to address the squint effect that occurs in phased array antennas when wideband signals are transmitted. Beam steering weights are computed based on an optimization that takes into account performance at a set of frequencies across a bandwidth of interest, including at least endpoints of the bandwidth, and a design frequency.

Abstract: There is provided a method of transmitting and receiving data across a network. A receiver device comprises a recovery module comprising a neural network trained to recover signals from clipped signals. The transmitter device may clip the original signal more aggressively due to the improved performance of the machine-learning based recovery module, thereby reducing the Peak to Average Power Ratio (PAPR) of the signal.

Abstract: A method and apparatus for mitigating the beam squint effect in a wideband wireless communication device involving a phased antenna array. Time delay units are operated in series with phase shifters to apply phase shifts to signals fed to or received from antenna elements. The array may be subdivided into sub-arrays each associated with its own time delay unit, and with each antenna element associated with its own phase shifter. The phase shifters are operated to compensate for location mismatch between time delay units and antenna elements, and also to compensate for practical limitations of the time delay units, such as length and quantization limitations.

Abstract: Some aspects of the present disclosure relate to detection of a Phase Hit and, upon detecting the Phase Hit, determining the magnitude and location of the Phase Hit. Detecting the Phase Hit may involve comparing a phase offset difference for successive pilot symbol to a detection threshold. Determination of the detection threshold may involve a Neyman-Pearson binary hypothesis testing (NP-BHT) approach. Once the magnitude and location of the Phase Hit are known, data symbols received after the location may be processed to remove the magnitude of the Phase Hit.

Abstract: A method of beam steering is provided to address the squint effect that occurs in phased array antennas when wideband signals are transmitted. Beam steering weights are computed based on an optimization that takes into account performance at a set of frequencies across a bandwidth of interest, including at least endpoints of the bandwidth, and a design frequency.

Abstract: Aspects of the present application provide methods and devices for using a combined QAM and APSK modulation scheme in a hybrid modulation form in order to benefit from advantages of each respective modulation scheme. The proposed hybrid modulation scheme is less sensitive to phase noise and has lower PAPR than QAM and has very similar performance as QAM with respect to AWGN.

Abstract: Aspects of the present application provide methods and devices for using a combined QAM and APSK modulation scheme in a hybrid modulation form in order to benefit from advantages of each respective modulation scheme. The proposed hybrid modulation scheme is less sensitive to phase noise and has lower PAPR than QAM and has very similar performance as QAM with respect to AWGN.

Abstract: Some aspects of the present disclosure relate to detection of a Phase Hit and, upon detecting the Phase Hit, determining the magnitude and location of the Phase Hit. Detecting the Phase Hit may involve comparing a phase offset difference for successive pilot symbol to a detection threshold. Determination of the detection threshold may involve a Neyman-Pearson binary hypothesis testing (NP-BHT) approach. Once the magnitude and location of the Phase Hit are known, data symbols received after the location may be processed to remove the magnitude of the Phase Hit.

Abstract: The disclosed systems, structures, and methods are directed to a superposition based transceiver. The configurations presented herein employ a plurality of encoders configured to encode a plurality of input digital data streams, wherein each of the plurality of input digital data streams operates at different data rates, a plurality of modulators configured to modulate the plurality of encoded digital data input streams. In addition, a plurality of transmitter filters configured to perform up-sampling and filtering of the plurality of modulated digital data streams, and a signal mixer configured to combine the plurality of up-sampled and filtered digital data streams into a single aggregate digital data stream in a manner such that the single aggregate digital data stream contains spectral characteristics that substantially conform to both a central area and a skirt area of a unified spectral emission mask, as specified by European Telecommunications Standards Institute (ETSI).

Abstract: The disclosed systems, structures, and methods are directed to a superposition based transceiver. The configurations presented herein employ a plurality of encoders configured to encode a plurality of input digital data streams, wherein each of the plurality of input digital data streams operates at different data rates, a plurality of modulators configured to modulate the plurality of encoded digital data input streams. In addition, a plurality of transmitter filters configured to perform up-sampling and filtering of the plurality of modulated digital data streams, and a signal mixer configured to combine the plurality of up-sampled and filtered digital data streams into a single aggregate digital data stream in a manner such that the single aggregate digital data stream contains spectral characteristics that substantially conform to both a central area and a skirt area of a unified spectral emission mask, as specified by European Telecommunications Standards Institute (ETSI).

Abstract: Methods and devices for dynamic sensitivity control (DSC) in wireless networks are provided by adapting a clear channel assessment threshold (CCAT) on a frame-by-frame basis, based on a destination of a head-of-line (HoL) frame in a medium access control (MAC) layer transmission queue. Two different ways of protecting the communication range among devices in a basic serving set (BSS) are disclosed. In the first way, frames received from a node's BSS are differentiated, at the MAC layer, from frames received from an overlapping BSS (OBSS), and different CCATs are used for frames received from the node's BSS versus frames received from OBSS(s). In the second way, a lower bound on the CCAT value is defined based on the average received signal strength indicator (RSSI) of frames previously received from the node's BSS, and the CCAT is periodically reset to its minimum value.

Abstract: The disclosed systems, methods, and structures are directed to LoS MIMO communications that optimize spectral efficiency and include a precoding module to multiply an input transmit data vector with a precoding matrix to generate a precoded transmit data vector, a gain matrix calculation module to generate a gain matrix having optimal gain values that maximize the spectral efficiency, a transmit signal processing unit to convert the precoded transmit data vector into an analog signal, a receive signal processing unit to receive the analog signal and convert the analog signal into a receive data vector, an equalization module, a channel estimation module to estimate channel information to generate an estimated channel, and a singular value decomposition module to decompose the estimated channel matrix. The gain matrix calculation module calculates the optimal gain values of the gain matrix by maximizing an objective function encompassing the channel information provided by a fed-back diagonal matrix.

Abstract: Phase noise (PN) is suppressed in an OFDM signal. In an initial iteration, an estimation of the PN samples in an OFDM signal vector is produced and the OFDM signal is demodulated using the initial estimation of the PN to generate constellation symbols for the initial iteration. In an additional iteration, an Inverse Fast Fourier Transform of constellation symbols generated in a preceding iteration is calculated to reconstruct preceding samples of the transmitted signal vector. A PN effect on the reconstructed samples is estimated. A next estimation of the PN in a next signal vector is produced based on the estimated PN effect on the reconstructed samples. The next signal vector is demodulated using the next estimation of the PN to generate constellation symbols for the additional iteration. A predetermined maximum number of additional iterations may be used.