Patents Assigned to Spatial Digital Systems, Inc.
-
Patent number: 9621254Abstract: A communication system includes a transmitter segment at a source location inputting a plurality of input signals to be transmitted. The input signals are transformed to wavefront multiplexed signals (WFM signals), and the WFM signals are modulated into WFM waveforms. The WFM waveforms are transmitted through a segment of propagation to a receiver segment; wherein the segment of propagation includes a plurality of UAV based transmission channels among the WFM waveforms; wherein the WFM waveforms are transmitted over the transmission channels; wherein the receiver segment receives the WFM waveforms from the transmission channels. Demodulation is performed on the received WFM waveforms to convert the received WFM waveforms to received WFM signals individually. A wavefront de-multiplexing transform is performed on the received WFM signals to recover individual desired signals.Type: GrantFiled: February 27, 2013Date of Patent: April 11, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9608756Abstract: 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: GrantFiled: June 10, 2014Date of Patent: March 28, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9596024Abstract: Aircrafts flying near Earth or naval vessels are used as 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. When multiple antennas or signal sources exist, a ranking system is employed to optimize performance.Type: GrantFiled: February 27, 2013Date of Patent: March 14, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9559416Abstract: The invention is about a method and apparatus for grouping multiple satellite transponders with both (LP) polarization formats in different frequencies through Wave-Front (WF) Multiplexing (muxing) techniques for ground terminals with incompatible (CP) polarization formats. As a result of this invention, linear polarized (LP) transponders can be accessed and efficiently utilized by circularly polarized (CP) ground terminals and vice versa. This invention consists of conventional ground terminals, a unique organization of space assets, and a unique polarization alignment processor. The applications of wavefront multiplexing techniques to satellite communications offer many potential advantages, including improved flexibility and utility efficiency of existing space assets. Our proposed “Polarization Utility Waveforms” is an entirely new concept in VSAT and Earth Station Antenna diversity.Type: GrantFiled: July 10, 2013Date of Patent: January 31, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9502022Abstract: 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: GrantFiled: September 2, 2010Date of Patent: November 22, 2016Assignee: Spatial Digital Systems, Inc.Inventors: Donald C. D. Chang, Michael T. H. Lin, Steve Chen
-
Patent number: 9435893Abstract: 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: GrantFiled: July 16, 2012Date of Patent: September 6, 2016Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9065591Abstract: 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: GrantFiled: September 12, 2014Date of Patent: June 23, 2015Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 8981976Abstract: 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: GrantFiled: February 8, 2013Date of Patent: March 17, 2015Assignee: Spatial Digital Systems, Inc.Inventor: Donald C.D. Chang
-
Patent number: 8953728Abstract: 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: GrantFiled: June 17, 2012Date of Patent: February 10, 2015Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 8862050Abstract: 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: GrantFiled: September 13, 2011Date of Patent: October 14, 2014Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 8817694Abstract: 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: GrantFiled: November 8, 2011Date of Patent: August 26, 2014Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 8773307Abstract: 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: GrantFiled: November 22, 2010Date of Patent: July 8, 2014Assignee: Spatial Digital Systems, Inc.Inventors: Donald C. D. Chang, Yulan Sun, Yuanchang Liu
-
Patent number: 8767615Abstract: 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: GrantFiled: September 21, 2012Date of Patent: July 1, 2014Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 8395546Abstract: A receive only smart antenna with a command pointing option for communicating with geostationary satellites that autonomously detects the directions from which desired signal are received, and steer the multiple beams accordingly. An array feed is used to illuminate a parabolic reflector. Each feed element of the receive only smart antenna is associated with a unique beam pointing direction. As a receiver is switched to different feed elements, the far-field beam is scanned, making it possible to track a geostationary satellite in a slightly inclined orbit. This eliminates the need for mechanical tracking and maintains high antenna gain in the direction of the geostationary satellite. The receive only smart antenna also features capabilities to form multiple simultaneous beams supporting operations of multiple geo-satellites in closely spaced slightly inclined orbits. The designs can support orthogonal beams for enhanced bandwidth capacity via multiple beams with excellent spatial isolation.Type: GrantFiled: February 9, 2011Date of Patent: March 12, 2013Assignee: Spatial Digital Systems, IncInventor: Donald C. D. Chang
-
Patent number: 8384572Abstract: 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: GrantFiled: January 5, 2011Date of Patent: February 26, 2013Assignee: Spatial Digital Systems Inc.Inventors: Tzer-Hso Lin, Yuanchang Liu, Donald C. D. Chang
-
Patent number: 8232918Abstract: 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: GrantFiled: September 9, 2011Date of Patent: July 31, 2012Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang
-
Patent number: 8107569Abstract: A system is provided that enhances the throughput and reliability of wireless communications by providing multi-beam user terminals that exhibit directional discrimination. Multiple wireless communication channels are matched with multiple beams created from an array antenna by a beam-forming processor. The multiple wireless communication channels are bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and multi-path effects that can degrade communications. The beam-forming function may be performed in a dedicated beam-forming processor or may reside within a general-purpose microprocessor located in the user terminal.Type: GrantFiled: May 16, 2008Date of Patent: January 31, 2012Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang
-
Patent number: 8098612Abstract: A satellite broadcasting system is achieved in which remote beam forming processors located among distributed ground stations are used to control downlink beam footprints and pointing directions. Digital beam forming techniques allow a single satellite downlink broadcast antenna array to generate multiple simultaneous downlinks that can be pointed independently and that may contain distinct information content. By allocating some of the uplink back-channel elements as null channels, continuous calibration of the uplink channel can be performed, improving the performance of the downlink broadcast array and the quality of the broadcast for users. By wavefront multiplexing, all of the uplink channel elements propagate through the all of the available propagation channels simultaneously, eliminating the need for complex and costly individual array-element calibration equipment using on-board or ground-based references.Type: GrantFiled: May 16, 2008Date of Patent: January 17, 2012Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang
-
Patent number: 8035562Abstract: 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: GrantFiled: July 22, 2010Date of Patent: October 11, 2011Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang
-
Patent number: 7834807Abstract: A retro-directive antenna for communicating with a geostationary satellite autonomously detects the direction from which a signal is received, and transmits a beam that points back along the same direction. An array feed is used to illuminate a parabolic reflector. Each feed element of the retro-directive antenna is associated with a unique pointing direction of the beam in the far field. As the transmit energy is switched to different feed elements, the far-field beam is scanned, making it possible to track a geostationary satellite in a slightly inclined orbit. This eliminates the need for mechanical tracking and maintains high antenna gain in the direction of the geostationary satellite. The use of a toroidal reflector with multiple linear array feeds spaced in the azimuth direction enables multi-beam operation, allowing multiple geostationary satellites, spaced by up to fifteen beam widths in azimuth, to be tracked simultaneously and independently.Type: GrantFiled: May 16, 2008Date of Patent: November 16, 2010Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang