Abstract: A method for point cloud compression of an intelligent cooperative perception (iCOOPER) for autonomous air vehicles (AAVs) includes: receiving a sequence of consecutive point clouds; identifying a key point cloud (K-frame) from the sequence of consecutive point clouds; transforming each of the other consecutive point clouds (P-frames) to have the same coordinate system as the K-frame; converting each of the K-frame and P-frames into a corresponding range image; spatially encoding the range image of the K-frame by fitting planes; and temporally encoding each of the range images of the P-frames using the fitting planes.

Abstract: The present disclosure provides an analytical framework to investigate judicious topology reweighting of radio networks of clocks, when distributed time transfer and synchronization are based on physical layers and subject to the presence of false timing signals. Protagonist clocks exchange timing information pairwise, which is modeled as clocks tending to follow the majority of their neighbors. Antagonist clocks inject false timing signals, thereby, influencing the timing synchronization of (some of) the other protagonist clocks they meet. A class of pursuit-evasion graphical games subject to complete state observations and exploitation of phase noise disturbances, is proposed in designing clock steering protocols for resilient time metrologies that will be immune to erroneous timing signals injected into remote time dissemination networks.

Abstract: A system for hybrid modulation and demodulation includes a transmitter and a receiver. The transmitter is configured to receive a hybrid signal of a space-ground link system (SGLS), including a first component and a second component; perform a double sideband (DSB) modulation on the first component using a carrier frequency to obtain a first waveform; perform a single sideband (SSB) modulation on the second component using the carrier frequency to obtain a second waveform; mix the first waveform and the second waveform to generate a hybrid waveform; and transmit the hybrid waveform. The receiver is configured to receive the hybrid waveform; determine the carrier frequency; separate the first waveform and the second waveform; perform a DSB demodulation on the first waveform to obtain a first demodulated signal; and perform an SSB demodulation on the second waveform to obtain a second demodulated signal.

Abstract: A system for hybrid modulation and demodulation includes a transmitter and a receiver. The transmitter is configured to receive a hybrid signal of a space-ground link system (SGLS), including a first component and a second component; perform a double sideband (DSB) modulation on the first component using a carrier frequency to obtain a first waveform; perform a single sideband (SSB) modulation on the second component using the carrier frequency to obtain a second waveform; mix the first waveform and the second waveform to generate a hybrid waveform; and transmit the hybrid waveform. The receiver is configured to receive the hybrid waveform; determine the carrier frequency; separate the first waveform and the second waveform; perform a DSB demodulation on the first waveform to obtain a first demodulated signal; and perform an SSB demodulation on the second waveform to obtain a second demodulated signal.

Abstract: A method for emulating a communication system with fast changing link condition, applied to a testbed system including an interference emulator, a transmitter, and a receiver, includes: by the transmitter, generating code-word symbols, in an initial symbol sequence, according to information bits; evaluating an interference condition and a time duration for each code-word symbol; reordering the code-word symbols to a reordered symbol sequence based on interference conditions; evaluating a total time duration of code-word symbols under each interference condition; and transmitting the code-word symbols in the reordered symbol sequence. The method also includes: by the interference emulator, obtaining the total time duration of code-word symbols under each interference condition from the transmitter; and providing an emulated interference environment by ordering the time durations of different interference conditions.

Abstract: The present disclosure provides a high power amplifier (HPA) linearization method, applied to a ground hub which includes a predistorter and a PD controller. The ground hub is arranged in a satellite communication system together with a transmitter and a satellite transponder, and the satellite transponder includes an HPA. The HPA linearization method includes determining an initial correction signal based on a physical model with a plurality of PD parameters to compensate AM-AM and AM-PM characteristics of the HPA; receiving a signal from the satellite transponder; determining a reward function for an action taken by the PD controller; examining an action-value function for actions taken in a preset past period; taking an action to adjust the plurality of PD parameters for the PD to generate an updated correction signal; sending the update correction signal to the transmitter to compensate the AM-AM and AM-PM characteristics of the HPA.

Abstract: The present disclosure provides a method for wave propagation prediction based on a 3D ray tracing engine and machine-learning based dominant ray selection. The method includes receiving, integrating, and processing input data. Integrating and processing the input data includes dividing a cone of the original millimeter wave (mmWave) into a plurality of sub cones; determining a contribution weight of rays coming from each sub cone to the received signal strength (RSS) at a receiving end of interest; and determining rays coming from one or more sub cones that have a total contribution weight to the RSS larger than a preset threshold value as dominant rays using a neural network obtained through a machine learning approach. The method further includes performing ray tracing based on the input data and the dominant rays to predict wave propagation.

Abstract: Various embodiments provide a method for transmission control protocol (TCP) packet transmission. The method includes receiving, by a receiver performance enhancing node (PEN), one or more TCP packets each with a timestamp and a sequence number from a sender PEN; evaluating a packet delivery time from the sender PEN to the receiver PEN; detecting whether any TCP packet is lost based on a packet sequence and determining a delay shaping time for each TCP packet based on a maximum number of retransmissions and an evaluated delivery time distribution; in response to a lost TCP packet being detected, determining whether the lost TCP packet needs to be retransmitted based on the maximum number of retransmissions; and in response to the determined delay shaping time, determining when a received TCP packet needs to be forwarded based on the determined delay shaping time and a timestamp associated with the received TCP packet.

Abstract: Embodiments of the present disclosure provide a method, a device, and a storage medium for hybrid automatic gain control in a communication system. The method includes amplifying an input signal to generate an amplified signal which is converted into a plurality of output signals; obtaining a moving average amplitude of a plurality of output signals of a current input signal; and calculating a signal amplitude difference according to the moving average amplitude and a desired output signal amplitude level; calculating a signal amplitude ratio according to a plurality of output signals of two previous output signal blocks and AGC gains corresponding to the plurality of output signals of the two previous output signal blocks; obtaining a step size according to the signal amplitude difference and the signal amplitude ratio; and calculating an AGC gain of the current input signal according to the step size and a corresponding previous AGC gain.

Abstract: A method for emulating a communication system with fast changing link condition, applied to a testbed system including an interference emulator, a transmitter, and a receiver, includes: by the transmitter, generating code-word symbols, in an initial symbol sequence, according to information bits; evaluating an interference condition and a time duration for each code-word symbol; reordering the code-word symbols to a reordered symbol sequence based on interference conditions; evaluating a total time duration of code-word symbols under each interference condition; and transmitting the code-word symbols in the reordered symbol sequence. The method also includes: by the interference emulator, obtaining the total time duration of code-word symbols under each interference condition from the transmitter; and providing an emulated interference environment by ordering the time durations of different interference conditions.

Abstract: A satellite communications system is disclosed, the system comprising a ground controller, a decode-and-forward (DF) satellite transponder, and a digital high-power amplifier (HPA). The DF is further comprised of a transponder front end including a digital channelizer and a predistorter. The ground controller is configured to transmit multiple-access frequency-division-multiplexed signals to the DF, where the DF is configured to down-convert the signals received at the transponder front end. The digital channelizer is configured to convert the signals received into a single sample steam and feed the stream through the predistorter into the single digital HPA, wherein the HPA is configured to amplify each input sample of the stream in sample-by-sample fashion and generates a discrete output. The DF is further configured to convert the output of the digital HPA to a continuous time signal and up-convert the output with a main carrier frequency for down-link transmission to multiple-access ground users.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining breakpoints in a media item. Methods can include determining a candidate set of breakpoints within a media item. A machine learning model is used to generate a score for each particular candidate breakpoint in the set of candidate breakpoints based on presentation features of the media item. A subset of candidate breakpoints is selected from the set of candidate breakpoints based on the score. A final set of breakpoints is selected from the subset of candidate breakpoints based on a combination of the score for each particular candidate breakpoint and a location of the particular candidate breakpoint relative to a different candidate breakpoint. The final set of breakpoints is stored in a database and during playback of the media item, a digital component is presented when the media item reaches a stored breakpoint.

Abstract: Various embodiments of the present disclosure provide a method, a device, and a storage medium for performance prediction of a communication waveform in a communication system. The method includes measuring, by a receiver, an actual SNR distribution of a communication link between a transmitter and the receiver; further includes evaluating, by a waveform performance prediction device, a normalized minimum SNR shift required for the communication waveform to operate, where the normalized minimum SNR shift is obtained based on a normalized SNR distribution using a neural network (NN), the normalized SNR distribution corresponding to the actual SNR distribution; and further includes, according to the normalized minimum SNR shift, obtaining, by a waveform performance prediction device, an actual minimum SNR shift for the actual SNR distribution, where according to the actual minimum SNR shift, the communication system is adjusted for operation.

Abstract: An apparatus includes a camera for capturing an image at a first moment; a range finder for measuring a distance to an object at a center of the image; a rotatable mounting platform, fixedly hosting the camera and the range finder; and a controller. The controller is configured to receive the captured image and the measured distance; determine whether a target of interest (TOI) appears in the image; in response to determining a TOI appearing in the image, determine whether the TOI appears at the center of the image; calculate position parameters of the rotatable mounting platform for centering the TOI in an image to be captured at a second moment, separated from the first moment by a pre-determined time interval; control the rotatable mounting platform to rotate according to the calculated position parameters; and calculate and store the position parameters of the TOI with respect to the apparatus.

Abstract: Embodiments herein describe a video editor that can identify and track objects (e.g., products) in a video. The video editor identifies a particular object in one frame of the video and tracks the location of the object in the video. The video editor can update a position of an indicator that tracks the location of the object in the video. In addition, the video editor can identify an identification (ID) of the object which the editor can use to suggest annotations that provide additional information about the object. Once modified, the video is displayed on a user device, and when the viewer sees an object she can is interested in, she can pause the video which causes the indicator to appear. The user can select the indicator which prompts the user device to display the annotations corresponding to the object.

Abstract: A video segmenting system identifies a product for sale in a video and determines one or more attributes of audio and video content within the video. The video segmenting system determines a video segment within the video that is associated with the product for sale, based on the attributes. The video segmenting system generates a tag that associates the product for sale with the video segment and sends an indication of the tag to a user device. Once the video is played on a user device, the user device detects a search query about the product for sale. Using the tag, the user device can display a marker on the user device corresponding to the location of the video segment within the video.

Abstract: Systems, methods, and computer-readable media are disclosed for systems and methods for portable interactive product displays with region-specific products. Example methods may include determining a set of product identifiers of products to be positioned at an interactive display, the set of product identifiers including a first product identifier for a first product, determining a user identifier associated with a user device positioned within a distance of the interactive display, and determining a user interaction with the first product by a user of the user device. Certain methods may include determining a user interaction history for the user using the user identifier, and determining that an indication of the user interaction is to be added to the user interaction hi story.

Abstract: The present disclosure provides a high power amplifier (HPA) linearization method, applied to a ground hub which includes a predistorter and a PD controller. The ground hub is arranged in a satellite communication system together with a transmitter and a satellite transponder, and the satellite transponder includes an HPA. The HPA linearization method includes determining an initial correction signal based on a physical model with a plurality of PD parameters to compensate AM-AM and AM-PM characteristics of the HPA; receiving a signal from the satellite transponder; determining a reward function for an action taken by the PD controller; examining an action-value function for actions taken in a preset past period; taking an action to adjust the plurality of PD parameters for the PD to generate an updated correction signal; sending the update correction signal to the transmitter to compensate the AM-AM and AM-PM characteristics of the HPA.

Abstract: The present disclosure provides a method for wave propagation prediction based on a 3D ray tracing engine and machine-learning based dominant ray selection. The method includes receiving, integrating, and processing input data. Integrating and processing the input data includes dividing a cone of the original millimeter wave (mmWave) into a plurality of sub cones; determining a contribution weight of rays coming from each sub cone to the received signal strength (RSS) at a receiving end of interest; and determining rays coming from one or more sub cones that have a total contribution weight to the RSS larger than a preset threshold value as dominant rays using a neural network obtained through a machine learning approach. The method further includes performing ray tracing based on the input data and the dominant rays to predict wave propagation.

Abstract: A method for rapid discovery of satellite behavior, applied to a pursuit-evasion system including at least one satellite and a plurality of space sensing assets. The method includes performing transfer learning and zero-shot learning to obtain a semantic layer using space data information. The space data information includes simulated space data based on a physical model. The method further includes obtaining measured space-activity data of the satellite from the space sensing assets; performing manifold learning on the measured space-activity data to obtain measured state-related parameters of the satellite; modeling the state uncertainty and the uncertainty propagation of the satellite based on the measured state-related parameters; and performing game reasoning based on a Markov game model to predict satellite behavior and management of the plurality of space sensing assets according to the semantic layer and the modeled state uncertainty and uncertainty propagation.