Patents by Inventor Donald C. D. Chang

Donald C. D. Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11914539
    Abstract: An input switching circuit dynamically connects, based on an input mapping table, input streams to inputs of a wavefront pre-transform circuit. An output switching circuit dynamically connects, based on an output mapping table, output data at outputs of the wavefront pre-transform circuit to transport streams. A controller controls, based on a wiping command, at least one of the input and output switching circuits to alter at least one of the input and output mapping tables such that the at least one of the input and output switching circuits is disabled for connection. A first subset of the transport streams operates in a foreground mode available to a user and is transported for storage in remote storage sites at a network and a second subset of the transport streams operates in a background mode available to an administrator and is not transported for storage in the remote storage sites.
    Type: Grant
    Filed: March 6, 2023
    Date of Patent: February 27, 2024
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Juo-Yu Lee, Donald C. D. Chang, Steve K. Chen
  • Patent number: 11887575
    Abstract: A system for generating and injecting acoustic interference signals to mitigate undesired acoustic noise over a target zone. M pickup sensors pick up acoustic noise signals from one or more noise sources in real time and generate M noise signals, M>1. A beam forming network includes M acoustic beam forming modules to process the M noise signals respectively and generate N acoustic interference signals. N acoustic injectors condition, amplify and inject the N acoustic interference signals over the target zone, N>1. Each of the M acoustic beam forming modules includes a 1-to-N distribution network to transform a respective one of the M noise signals into N signals, and N finite-impulse-response filters to perform amplitude and phase weighting on the respective N signals and generate N intermediate signals which are combined respectively with corresponding intermediate signals generated by remaining M?1 acoustic beam forming modules to generate the N acoustic interference signals.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: January 30, 2024
    Inventors: Donald C. D. Chang, Steve K. Chen
  • Patent number: 11831363
    Abstract: A communications system includes at least one receiver having receiving elements and a transmitter having transmitting elements to transmit signals to the receiving elements via wireless propagation channels. The transmitter includes a beam-forming network and a channel measurement unit. The beam-forming network receives input signal streams at its input ports and outputs one or more signals as shaped beams based on a set of composited transfer functions. The channel measurement unit performs measurements of components of channel status information to generate a set of point-to-point transfer functions and generates the composited transfer functions by computing linear combinations of the point-to-point transfer functions. Each of the point-to-point transfer functions characterizes propagation paths from one of the transmitting elements to one of the receiving elements.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: November 28, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Juo-Yu Lee
  • Patent number: 11782945
    Abstract: An apparatus includes N audio receivers positioned in a pre-defined geometry with respect to P audio sources to receive P audio signals from the P audio sources; N data sets coupled to the N audio receivers to sample the received P audio signals into N data streams; a plurality of storage devices coupled to the N data sets to store the N data streams; and a post processor coupled to the plurality of storage devices to generate output signals corresponding to reconstituted P audio signals using a wavefront demultiplexing transformation, wherein N and P are positive integers and N?P. The post processor has inputs receiving data retrieved from the plurality of storage devices and outputs providing the output signals.
    Type: Grant
    Filed: December 11, 2018
    Date of Patent: October 10, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Juo-Yu Lee, Steve K Chen
  • Patent number: 11770181
    Abstract: A source terminal, for communications with a destination terminal via satellite links to two clusters of satellites, comprises a transmitter and a multibeam antenna system. The transmitter includes a preprocessor and a bank of modulators. The preprocessor performs a K-muxing transform, which has an inverse transform, on M concurrent input data streams to generate concurrently M output data streams, M>1. Each output data stream is a linear combination of the M concurrent input data streams. The bank of modulators transforms N of the M output data streams into N signal streams, N?M. The multibeam antenna system transforms the N signal streams into N shaped beams and radiating N1 of the N shaped beams towards the first cluster of satellites and N2 of the N shaped beams towards the second cluster of satellites, where N1 and N2 are positive integers and N1+N2=N.
    Type: Grant
    Filed: June 30, 2022
    Date of Patent: September 26, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Steve K. Chen
  • Publication number: 20230229613
    Abstract: An input switching circuit dynamically connects, based on an input mapping table, input streams to inputs of a wavefront pre-transform circuit. An output switching circuit dynamically connects, based on an output mapping table, output data at outputs of the wavefront pre-transform circuit to transport streams. A controller controls, based on a wiping command, at least one of the input and output switching circuits to alter at least one of the input and output mapping tables such that the at least one of the input and output switching circuits is disabled for connection. A first subset of the transport streams operates in a foreground mode available to a user and is transported for storage in remote storage sites at a network and a second subset of the transport streams operates in a background mode available to an administrator and is not transported for storage in the remote storage sites.
    Type: Application
    Filed: March 6, 2023
    Publication date: July 20, 2023
    Applicant: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Juo-Yu Lee, Donald C.D. Chang, Steve K. Chen
  • Patent number: 11677725
    Abstract: A communications system between a source and a destination includes a transmitter at the source and a communication connectivity. The transmitter comprises a preprocessor and a candidate envelope folder to provide M known a priori digital envelopes, M?1. The preprocessor has N input ports and N output ports, N>M, performs at least one wavefront multiplexing (WFM) transform on N inputs received at the N input ports to generate N outputs at the N output ports. The preprocessor performs the at least one WFM transform by calculating, for each of the N outputs, a linear combination of the N inputs using one of the M digital envelopes such that a digital format of one of the N outputs appears to human sensors as having features substantially identical to a digital format of the one of the M digital envelopes.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: June 13, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Juo-Yu Lee, Steve K. Chen
  • Publication number: 20230145659
    Abstract: A communication system comprises a remote digital beam-forming network configured to receive a set of input signals destined for a set of user devices and generate element signals to be radiated by a set of remote antenna array elements; a pre-processor coupled to the remote digital beam-forming network, configured to perform a wavefront multiplexing transform on signal waveforms including the element signals and generate wavefront multiplexed signals; an optical line terminal coupled to the pre-processor, configured to process the wavefront multiplexed signal streams to generate optical waveform streams; and optical fibers coupling the optical line terminal to a set of optical network units.
    Type: Application
    Filed: January 9, 2023
    Publication date: May 11, 2023
    Applicant: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C.D. Chang, Juo-Yu Lee, Steve K. Chen
  • Patent number: 11599492
    Abstract: An input switching circuit dynamically connects, based on an input mapping table, input streams to inputs of a wavefront pre-transform circuit. An output switching circuit dynamically connects, based on an output mapping table, output data at outputs of the wavefront pre-transform circuit to transport streams. A controller controls, based on a wiping command, at least one of the input and output switching circuits to alter at least one of the input and output mapping tables such that the at least one of the input and output switching circuits is disabled for connection. A first subset of the transport streams operates in a foreground mode available to a user and is transported for storage in remote storage sites at a network and a second subset of the transport streams operates in a background mode available to an administrator and is not transported for storage in the remote storage sites.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: March 7, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Juo-Yu Lee, Donald C. D. Chang, Steve K. Chen
  • Patent number: 11552699
    Abstract: A MIMO basestation for a cellular communications system comprises a remote indoor processing facility coupled to an outdoor RF tower via optical fibers. The remote indoor processing facility includes a bank of RF modulators to modulate signal streams; a remote MIMO transmitting processor that includes a remote digital beam-forming network to transform the modulated signal streams into transmit beam signals; a pre-processor to perform a wavefront multiplexing transform on the transmit beam signals to generate wavefront multiplexed beam signals, each of the wavefront multiplexed beam signals being a linear combination of the transmit beam signals; and RF-to-optical drivers to perform optical modulating functions on the wavefront multiplexed beam signals to generate optical waveform streams.
    Type: Grant
    Filed: November 18, 2019
    Date of Patent: January 10, 2023
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C.D. Chang, Juo-Yu Lee, Steve K. Chen
  • Publication number: 20220337312
    Abstract: A source terminal, for communications with a destination terminal via satellite links to two clusters of satellites, comprises a transmitter and a multibeam antenna system. The transmitter includes a preprocessor and a bank of modulators. The preprocessor performs a K-muxing transform, which has an inverse transform, on M concurrent input data streams to generate concurrently M output data streams, M>1. Each output data stream is a linear combination of the M concurrent input data streams. The bank of modulators transforms N of the M output data streams into N signal streams, N?M. The multibeam antenna system transforms the N signal streams into N shaped beams and radiating N1 of the N shaped beams towards the first cluster of satellites and N2 of the N shaped beams towards the second cluster of satellites, where N1 and N2 are positive integers and N1+N2=N.
    Type: Application
    Filed: June 30, 2022
    Publication date: October 20, 2022
    Applicant: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Steve K. Chen
  • Publication number: 20220329294
    Abstract: An active scattering device comprises a set of N identical single chain RF devices functioning as repeaters or transponders, which are placed adjacent to each other and in parallel over an area of active scattering, where N is an integer ?2. Each of the N identical RF devices includes a receiving aperture, having a first coverage, for receiving a first signal within the first coverage; and a transmitting aperture, having a second coverage, for re-radiating a second signal within the second coverage, the second signal being received by one of the respective receiving apertures of the N identical RF devices. In various embodiments, the active scattering device is configured to function as a reflective directional repeater/transponder, or a retro-directive repeater/transponder, or a 2-D directional repeater/transponder that is retro-directive in a first dimension and reflective in a second dimension perpendicular to the first dimension.
    Type: Application
    Filed: June 20, 2022
    Publication date: October 13, 2022
    Applicant: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C.D. Chang, Juo-Yu Lee
  • Patent number: 11381302
    Abstract: A source terminal for communications with a destination terminal, both located near or on earth surface, via satellite links to a cluster of satellites in corresponding slightly inclined Geostationary Satellite Orbits (GSOs). The source terminal comprises a transmitter which includes a preprocessor to perform a K-muxing transform on M concurrent input data streams to generate concurrently M output data streams, M>1, each of the M output data streams being a linear combination of the M concurrent input data streams, the K-muxing transform having an inverse transform; a bank of modulators to transform the M output data streams into N signal streams destined for the destination terminal, N?M; and a multibeam antenna system to dynamically track and communicate with the cluster of satellites. The multibeam antenna system transforms the N signal streams into shaped beams and radiates the shaped beams towards the cluster of satellites.
    Type: Grant
    Filed: April 28, 2021
    Date of Patent: July 5, 2022
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Steve K. Chen
  • Patent number: 11368195
    Abstract: Embodiments of a communications system with multiple active scattering devices to service multiple users either indoor or outdoor over same spectrum in a communication network and a method for the system are generally described herein. Signals streams for transmission to users in spoke-and-hub configurations will utilize multiple active scattering devices. Three categories of operational concepts are presented: (1) multiple scattering devices arranged geometrically bundled together to function as active mirrors or retro-directive repeaters, (2) distributed man-made scattering devices placed to enhance channel bandwidth in between a hub and a common service area via frequency re-use, and (3) organizing distributed active scattering devices by remote beamforming for servicing a small common coverage area indoor or outdoor with enhanced bandwidth.
    Type: Grant
    Filed: May 28, 2014
    Date of Patent: June 21, 2022
    Assignee: Spatial Digital Systems, Inc.
    Inventors: Donald C. D. Chang, Juo-Yu Lee
  • Patent number: 10911121
    Abstract: A communication system includes a transmitter and remote receivers having each a set of receive elements. The transmitter includes a preprocessor and a set of transmit elements which radiate shaped beams including probing signals through a multipath communication channel. The preprocessor computes channel state information based on received responses to the probing signals, generate composited transfer functions based on the channel state information, generate the shaped beams based on the composited transfer functions, and process a plurality of input signals to be transmitted via the shaped beams to the remote receivers. The channel state information includes transfer functions, each characterizing at least one propagation path from one transmit element to one receive element. Each composited transfer function is a linear combination of the transfer functions. Each receive element is identified by a user element identification index in the transfer functions.
    Type: Grant
    Filed: September 4, 2018
    Date of Patent: February 2, 2021
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Juo-Yu Lee
  • Patent number: 10902138
    Abstract: One embodiment provides a storage management system. During operation, the system identifies a data file of a user. The system obtains an encrypted client registry from a primary cloud provider in a plurality of cloud providers that provide cloud storage to the user and retrieves a key associated with a device of the user by decrypting the encrypted client registry using a hash of a password associated with the user. The system obtains credentials of the plurality of cloud providers by decrypting a locally stored cloud configuration using the key and generates a plurality of coded fragments from the data file based on a generator matrix of erasure encoding. The number of coded fragments is determined based on a number of the cloud providers associated with the user. The system selects a respective coded fragment for uploading to a corresponding cloud provider in the plurality of cloud providers.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: January 26, 2021
    Assignee: PhazrlO Inc.
    Inventors: Chi-Kwan J. Cheung, Donald C. D. Chang, Juo-Yu Lee, Steve K. Chen, Tzer-Hso Lin
  • Patent number: 10904334
    Abstract: For data writing, a first input device performs a first wavefront multiplexing transform on a first input stream and a first probing stream to generate L first intermediate streams. An en-route processing device generates J output streams from the stored L first intermediate streams and at least a second probing stream. For data reading, an en-route processing device generates L first intermediate streams and at least a first recovered probing stream from J input streams including a first stored probing stream. The L first intermediate streams are stored in a first storage site. A first output device performs a first wavefront demultiplexing transform on the L first intermediate streams to generate a first output stream and a second recovered probing stream. The J input streams are stored in a distributed storage structure having at least a second storage site that stores P of the J input streams.
    Type: Grant
    Filed: January 17, 2018
    Date of Patent: January 26, 2021
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Juo-Yu Lee
  • Patent number: 10903565
    Abstract: An antenna system includes N movable antenna elements configured to generate concurrently M receiving beams pointing respectively at M satellites radiating in a common frequency band, N and M being integers and N?M?2. A beam forming system is coupled to the N movable antenna elements and configured to shape the M receiving beams using weights inputted from a beam controller. The beam controller optimizes the M receiving beams by computing spatial displacements to spatially reposition the N movable antenna elements relative to each other, using an iterative optimization processing to satisfy a plurality of constraints concurrently. A position driver system spatially re-positions the N movable antenna elements in accordance to the spatial displacements inputted from the beam controller.
    Type: Grant
    Filed: July 29, 2019
    Date of Patent: January 26, 2021
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Tzer-Hso Lin, Eric Hu
  • Patent number: 10892819
    Abstract: A communications system includes a ground hub, mobile airborne platforms, and a user terminal. The ground hub includes an antenna system, a beam-forming system and a baseband processor. The antenna system receives return-link signals radiated respectively by the mobile airborne platforms. The return-link signals correspond to signal streams transmitted by the user terminal and received by the mobile airborne platforms. The signal streams correspond to data streams including a known pilot code stream. The beam-forming system forms beams to receive the return-link signals and transforms the received return-link signals into baseband signals. The baseband processor includes adaptive equalizers to equalize the baseband signals and a wavefront demultiplexing processor to perform a wavefront demultiplexing transform on the equalized baseband signals to produce recovered versions of the data streams.
    Type: Grant
    Filed: July 22, 2019
    Date of Patent: January 12, 2021
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 10784896
    Abstract: One embodiment provides a system that facilitates numerical operation-based erasure coding. During operation, the system determines the bit-width of processing capability of the computing system. The system then determines, based on the bit-width, a number of bits for representing a respective data element from a data stream and a number of data elements based on a number of a dimension of a generator matrix of erasure encoding. The system then obtains the number of data elements from the data stream and converts a respective obtained data element to a corresponding numerical representation. Here, a respective obtained data element is represented by the determined number of bits. The system then generates a code word, which comprises a plurality of coded fragments, of erasure encoding from the numerical representations based on the generator matrix of the erasure encoding.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: September 22, 2020
    Assignee: PhazrlO Inc.
    Inventors: Donald C. D. Chang, Chi-Kwan J. Cheung, Lara Dolecek, Gary N. Jin, Rocky Chi-Ray Lin