Patents Assigned to SPATIAL DIGITAL SYSTEMS
  • Patent number: 9502022
    Abstract: A quiet zone generation technique is proposed for interference mitigation for a receive antenna by injecting the very interference signals via iterative processing, generating quiet zones dynamically for receive (RCV) antennas. The receive antenna may feature multiple receiving apertures distributed over a finite area. Optimization loops consist of four cascaded functional blocks; (1) a pick-up array to obtain the interference signals, (2) element weighting and/or repositioning processors, (3) an auxiliary transmit (XMIT) array with optimized element positions, (4) a diagnostic network with strategically located probes, and (5) an optimization processor with cost minimization algorithms. To minimize interferences between transmit (Tx) and receiving (Rx) apertures in limited space of an antenna farm for communications and/or radar applications are very tough problems.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: November 22, 2016
    Assignee: Spatial Digital Systems, Inc.
    Inventors: Donald C. D. Chang, Michael T. H. Lin, Steve Chen
  • Patent number: 9435893
    Abstract: An advanced multiple-beam GPS receiving system is achieved that is capable of simultaneously tracking multiple GPS satellites independently, detecting multiple interference signals individually, and suppressing directional gain in the antenna pattern of each beam in the interference directions. The GPS receiving system can be used for both planar and non-planar receiving arrays, including arrays that are conformally applied to the surface of a platform such as an aircraft. The GPS receiver combines spatial filtering and acquisition code correlation for enhanced rejection of interfering sources. Enhanced gain in the direction of GPS satellites and the ability to shape the beam patterns to suppress gain in the direction of interfering sources make the GPS receiving system largely insensitive to interfering and jamming signals that plague conventional GPS receivers.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: September 6, 2016
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Patent number: 9356358
    Abstract: An antenna system comprises: multiple antenna elements; and multiple beam forming networks configured to produce radiation patterns for both receiving and transmission functions configured to be optimized by re-positioning said antenna elements, wherein said beam forming networks comprise a receiving beam forming network configured to combine multiple first inputs from said antenna elements into at least a first output, and a transmission beam forming network configured to divide a second input into multiple second outputs to said antenna elements.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: May 31, 2016
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Michael T. S. Lin, Eric Hu
  • Patent number: 9287961
    Abstract: A receive-only smart antenna with a directional-point command capability for communication with geostationary satellites, allowing autonomous detection of received signals in order to allow steerage of multiple beams. An array feed is used to illuminate a parabolic reflector, with each feed element of the smart antenna associated with a unique beam-pointing direction. As the receiver switches to different feed elements, the far-field beam is scanned, making it possible to track a geostationary satellite in slightly inclined orbits, eliminating the need for mechanical tracking mechanisms while maintaining high antenna gain in the direction of the satellite. The receive-only smart antenna also features capabilities for forming multiple simultaneous beams supporting operations of multiple geo-satellites closely space in slightly inclined orbits. The designs can support orthogonal beams for enhanced bandwidth capacity via multiple beams with excellent spatial isolation.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: March 15, 2016
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 9252799
    Abstract: A receiver with orthogonal beam forming technique is achieved that is capable of differentiating different signal components within the received composite signal. An adaptive processor is used to eliminate the signal component whose phase information is known or can be calculated. The phase information of the major component of a signal can be easily acquired by using a limiter. The phase information of other signal components can be acquired by their direction information and other characteristics, such as modulation scheme, etc. Multiple orthogonal beams can be formed by eliminating one unwanted signal component each time by the adaptive processor until all unwanted signal is eliminated. Thus, a composite signal from multiple sources can be broken down into their component signals.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: February 2, 2016
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Yulan Sun, Frank Lu
  • Patent number: 9246508
    Abstract: A novel noise injection technique is presented to improve dynamic range with low resolution and low speed analog to digital converters. This technique combines incoming signal and noise signal with wave front de-multiplexer and split into several channels. Then low resolution and low speed analog to digital converters are used to sample each channels. All signals are recovered using wave front multiplexer. For advanced design, ground diagnostic signals with optimizing processor can be added to guarantee recovery quality.
    Type: Grant
    Filed: March 4, 2015
    Date of Patent: January 26, 2016
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C. D. Chang, Tzer-Hso Lin, Yuanchang Liu
  • Patent number: 9231729
    Abstract: A data communication system comprises a wave-front multiplexer configured to wave-front multiplex first electronic signals into second electronic signals. An electronic-to-optical converter is configured to convert a third electronic signal carrying information associated with the second electronic signals into a first optical signal. An optical transferring module is configured to split the first optical signal into second optical signals, wherein each of the second optical signals carries the same data as the first optical signal carries. Optical-to-electronic converters are configured to convert the second optical signals into fourth electronic signals. Wave-front demultiplexers each are configured to wave-front demultiplex the fourth electronic signals into fifth electronic signals equivalent to the first electronic signals respectively.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: January 5, 2016
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 9166673
    Abstract: A direct broadcasting satellite (DBS) system features a capability of coherently combining amplified signals powers from various broadcasting transponders without modifying the satellite segment. Organized DBS transponders would function as an equivalent DBS transponder with a higher EIRP. Power allocations are via a mechanism in an uplink transmitter in a ground segment and power combining mechanisms are in user receivers in a user segment. Specifically, the transmitter generates mixtures of input signals by using Wavefront-Multiplexing and transmits wavefront-multiplexed (WFM) signals which are sent concurrently through multiple parallel channels of transponders in the satellite segment. A receiver in the user segment separates the mixtures of received amplified WFM signals and coherently combines amplified components by various transponders by adaptive equalizing and Wavefront De-Multiplexing processors.
    Type: Grant
    Filed: August 27, 2013
    Date of Patent: October 20, 2015
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 9100085
    Abstract: A system is provided for high speed optical fiber data transmission by generating artificial wavefronts along multiple paths exhibiting spatial mutual orthogonality. Multiple independent signal streams are “structured” over a group of different propagation paths that are coherently organized by wavefront multiplexing and de-multiplexing techniques. Therefore, signal streams with enhanced throughput and reliability may be fully recovered at destinations via embedded diagnostic signals and optimization loops. Multiple optical channels are matched with multiple orthogonal wavefronts created by a signal pre-processor. A receiving end signal post-processor dynamically aligns propagation paths via diagnostic signals and orthogonality of the propagation wavefronts electronically. The multiple optical channels are coherently bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and unwanted multi-path effects.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: August 4, 2015
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 9077427
    Abstract: A communication system and method for a deep space spacecraft receiver to perform post-processing to dynamically combine received signal power coherently for pre-processed signal streams radiated non-coherently from a distributed, multiple element, Ka-band transmitting array via multiple concurrent propagation paths. Mutually orthogonal data and pilot signals travel though the multiple propagation paths. A pre-processor utilizing wavefront multiplexing restructures signal streams on the ground into multi-channel wavefrom structures along with injections of pilot signals for diagnostic and probing purposes. These restructured, or “wavefront multiplexed” (WFM) signals are transmitted through propagation channels to a receiver on the spacecraft, wherein adaptive equalization and wavefront de-multiplexing coherently separates the mixtures of received WFM signals.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: July 7, 2015
    Assignee: SPATIAL DIGITAL SYSTEMS, INC.
    Inventor: Donald C. D. Chang
  • Patent number: 9065591
    Abstract: A novel terrestrial wireless communications technique for terrestrial portable terminals including hand-held mobile devices and fixed wireless instruments, utilizing a spoke-and-hub communications system, having a plurality of individual hubs and/or base-stations all in communications with the portable terminals. The portable terminals and the hubs are assigned to use incompatible polarity formats in terms of circularly polarity (CP) and linearly polarity (LP). In forward links, a signal processed by the LP ground telecommunications hubs is radiated through multiple antennas with various LP polarities to an individual CP user simultaneously. The multiple paths are organized via assignments of a plurality of polarities, frequency slots, and directions by wavefront multiplexing/demultiplexing techniques such that the same communications assets including frequency spectrum may be re-used by other users. The same polarity diversity methods can be extended to peer-to-peer communications.
    Type: Grant
    Filed: September 12, 2014
    Date of Patent: June 23, 2015
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Patent number: 8981976
    Abstract: A novel noise injection technique is presented to improve dynamic range with low resolution and low speed analog to digital converters. This technique combines incoming signal and noise signal with wave front de-multiplexer and split into several channels. Then low resolution and low speed analog to digital converters are used to sample each channels. All signals are recovered using wave front multiplexer. For advanced design, ground diagnostic signals with optimizing processor can be added to guarantee recovery quality.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: March 17, 2015
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C.D. Chang
  • Patent number: 8953728
    Abstract: A system for processing data streams or signals includes a wave-front multiplexer configured to process first and second input signals into first and second output signals each carrying information associated with the first and second input signals, a first processing unit configured to process a third input signal carrying information associated with the first output signal into a third output signal, a second processing unit configured to process a fourth input signal carrying information associated with the second output signal into a fourth output signal, and a wave-front demultiplexer configured to process fifth and sixth input signals into fifth and sixth output signals each carrying information associated with the fifth and sixth input signals. The fifth input signal carries information associated with the third output signal, and the sixth input signal carries information associated with the fourth output signal.
    Type: Grant
    Filed: June 17, 2012
    Date of Patent: February 10, 2015
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Patent number: 8862050
    Abstract: A novel terrestrial wireless communications technique for terrestrial portable terminals including hand-held mobile devices and fixed wireless instruments, utilizing a spoke-and-hub communications system, having a plurality of individual hubs and/or base-stations all in communications with the portable terminals. The portable terminals and the hubs are assigned to use incompatible polarity formats in terms of circularly polarity (CP) and linearly polarity (LP). In forward links, a signal processed by the LP ground telecommunications hubs is radiated through multiple antennas with various LP polarities to an individual CP user simultaneously. The multiple paths are organized via assignments of a plurality of polarities, frequency slots, and directions by wavefront multiplexing/demultiplexing techniques such that the same communications assets including frequency spectrum may be re-used by other users. The same polarity diversity methods can be extended to peer-to-peer communications.
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: October 14, 2014
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Publication number: 20140266895
    Abstract: A novel wide null forming system achieves both wide bandwidth and beam width null through employing an antenna array to receive and transmit signals to which a complex null weight vector, calculated by perturbation program, is applied. The novel wide null forming system includes a multiple-element antenna array for receiving or transmitting signals. Multiple conditioning units matching the number of elements is present to condition the signals for proper reception and analysis, after which a series of complex multiplier processors adds complex weights. After being weighted each constituent beam is combined in an adding processor to form one composite beam for use by the user.
    Type: Application
    Filed: June 2, 2014
    Publication date: September 18, 2014
    Applicant: SPATIAL DIGITAL SYSTEMS, INC.
    Inventors: Donald C.D. Chang, Yulan Sun, Yuanchang Liu
  • Patent number: 8817694
    Abstract: A satellite broadcasting system is achieved where remote beam forming processors combined with wavefront multiplexers located among distributed ground stations are used to control downlink beam footprints and pointing directions. Digital beam forming (DBF) techniques allow a single satellite download broadcast antenna array to generate multiple independently pointed simultaneous downlinks, which may contain distinct information content. Allocation of some uplink back-channel elements as diagnostic signals allows for continuous calibration of uplink channels, improving downlink broadcast array and user broadcast performance. Wavefront multiplexing/demultiplexing allows all array element signals to be radiated by the broadcasting antenna array, with simultaneous propagation from ground stations to the broadcasting satellites through available parallel propagation channels in the uplinks of feeder links, with equalized amplitude and phase differentials.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: August 26, 2014
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Patent number: 8773307
    Abstract: A novel wide null forming system achieves both wide bandwidth and beam width null through employing an antenna array to receive and transmit signals to which a complex null weight vector, calculated by perturbation program, is applied. The novel wide null forming system includes a multiple-element antenna array for receiving or transmitting signals. Multiple conditioning units matching the number of elements is present to condition the signals for proper reception and analysis, after which a series of complex multiplier processors adds complex weights. After being weighted each constituent beam is combined in an adding processor to form one composite beam for use by the user.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: July 8, 2014
    Assignee: Spatial Digital Systems, Inc.
    Inventors: Donald C. D. Chang, Yulan Sun, Yuanchang Liu
  • Patent number: 8767615
    Abstract: Aircrafts or unmanned air vehicles flying near Earth are used as airborne communications towers or relays. Using techniques of ground based beam forming and wavefront multiplexing enhance the ability to coherently combine the power of the communication signals, and improve the signal-to-noise ratio.
    Type: Grant
    Filed: September 21, 2012
    Date of Patent: July 1, 2014
    Assignee: Spatial Digital Systems, Inc.
    Inventor: Donald C. D. Chang
  • Publication number: 20130071105
    Abstract: A system is provided for high speed optical fiber data transmission by generating artificial wavefronts along multiple paths exhibiting spatial mutual orthogonality. Multiple independent signal streams are “structured” over a group of different propagation paths that are coherently organized by wavefront multiplexing and de-multiplexing techniques. Therefore, signal streams with enhanced throughput and reliability may be fully recovered at destinations via embedded diagnostic signals and optimization loops. Multiple optical channels are matched with multiple orthogonal wavefronts created by a signal pre-processor. A receiving end signal post-processor dynamically aligns propagation paths via diagnostic signals and orthogonality of the propagation wavefronts electronically. The multiple optical channels are coherently bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and unwanted multi-path effects.
    Type: Application
    Filed: October 25, 2011
    Publication date: March 21, 2013
    Applicant: SPATIAL DIGITAL SYSTEMS
    Inventor: Donald C. D. Chang
  • Publication number: 20130070677
    Abstract: Aircrafts or unmanned air vehicles flying near Earth are used as airborne communications towers or relays. Using techniques of ground based beam forming and wavefront multiplexing enhance the ability to coherently combine the power of the communication signals, and improve the signal-to-noise ratio.
    Type: Application
    Filed: September 21, 2012
    Publication date: March 21, 2013
    Applicant: SPATIAL DIGITAL SYSTEMS
    Inventor: Donald C. D. Chang