Patents Assigned to SPATIAL DIGITAL SYSTEMS
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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
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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
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Publication number: 20120328036Abstract: 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. In addition, a wireless communications system with access points featuring multiple beams that exhibit directional discrimination that can concurrently support multiple users with multi-beam terminals via a common frequency channel.Type: ApplicationFiled: October 17, 2011Publication date: December 27, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120326925Abstract: 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: ApplicationFiled: July 16, 2012Publication date: December 27, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120319885Abstract: 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: ApplicationFiled: June 17, 2012Publication date: December 20, 2012Applicant: Spatial Digital SystemsInventor: Donald C. D. Chang
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Publication number: 20120319772Abstract: This invention aims to present a smart and dynamic power amplifier module that features both power combining and power sharing capabilities. The proposed flexible power amplifier (PA) module consists of a pre-processor, N PAs, and a post-processor. The pre-processor is an M-to-N wavefront (WF) multiplexer (muxer), while the post processor is a N-to-M WF de-multiplexer (demuxer), where N?M?2. Multiple independent signals can be concurrently amplified by a proposed multi-channel PA module with a fixed total power output, while individual signal channel outputs feature different power intensities with no signal couplings among the individual signals. In addition to basic configurations, some modules can be configured to feature both functions of parallel power amplifiers and also as M-to-M switches. Other programmable features include configurations of power combining and power redistribution functions with a prescribed amplitude and phase distributions, as well as high power PA with a linearizer.Type: ApplicationFiled: July 12, 2011Publication date: December 20, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120301136Abstract: A communication system and method that allows a transmitter segment (ground end of uplink segment) to dynamically combine power from a plurality of propagation channels (transponders) to improve power levels of signals being transmitted, without affecting the receiver segment (user end of downlink segment) and the propagation segment (space segment), and without modifying propagation apparatus configurations (satellite). Specifically, the transmitter segment generates mixtures of input signals by using Wavefront-Multiplexing and transmits wavefront-multiplexed (WFM) signals through propagation channels to a receiver segment that coherently separates the mixtures of received WFM signals by using adaptive equalization and Wavefront-De-Multiplexing.Type: ApplicationFiled: November 23, 2011Publication date: November 29, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120274499Abstract: The proposed MIMO radar imaging method takes advantages of measurement techniques of spatial frequency components of an RF area image from radar returns. To minimize size, weight and power (SW&P), minimum redundancy arrays (MRAs) for both Tx and Rx with unique geometries are proposed. MIMO waveforms are utilized to index the radiated illuminations to a targeted area in the forms of 1-D spatial frequency components. Consequently, the corresponding radar returns from the targeted field of view (FOV) are captured by the Rx MRA. With the knowledge of uniquely designed MRA array geometries, virtual beams are synthesized in Rx processor; usually one Tx and many contiguous Rx fan beams. These virtual beams may be dynamically “moved” to different beam positions. The elongated beam direction for Tx fan beam and that for Rx fan beams are perpendicular to one another. Thus intersections of the Tx fan-beam and many Rx fan-beams are the very areas of radar returns. We refer those areas as virtual beam crosses.Type: ApplicationFiled: April 29, 2011Publication date: November 1, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120212371Abstract: 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: ApplicationFiled: February 9, 2011Publication date: August 23, 2012Applicant: Spatial Digital SystemsInventor: Donald C. D. Chang
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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
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Publication number: 20120183295Abstract: 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: ApplicationFiled: September 13, 2011Publication date: July 19, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120069918Abstract: The present invention features novel methods of implementing configurable arrays for personal portable devices including hand-held mobile devices and re-locatable wireless devices, utilizing a wireless communications system that employs multiple individual hubs and/or base-stations. The digital beam forming (DBF) methodology utilizes multiple low gain elements conformal to the mechanical contours of handheld devices to function as arrays. The distributed N element arrays dynamically provide the options of reconfigurable shaped beams with near hemispheric radiation patterns for various handheld orientations and conditions by various users, while also supporting operations of multiple orthogonal beams concurrently connecting to multiple hubs. The larger the N becomes, the more flexibility the residing devices can provide.Type: ApplicationFiled: September 19, 2011Publication date: March 22, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120064759Abstract: A retractable mobile device power module comprises of a plug to power outlet, a retractable power cord, an adapter, and a retractor. With this design, power supply for mobile devices can be compact and low profile. Besides providing power, this design can be used for data transmission as well.Type: ApplicationFiled: November 22, 2010Publication date: March 15, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventors: Yuanchang Liu, Donald C. D. Chang, Derrick Chu
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Publication number: 20120051284Abstract: 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: ApplicationFiled: November 8, 2011Publication date: March 1, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: Donald C. D. Chang
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Publication number: 20120026937Abstract: 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: ApplicationFiled: June 29, 2011Publication date: February 2, 2012Applicant: SPATIAL DIGITAL SYSTEMSInventor: DONALD C. D. CHANG
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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
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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
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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
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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
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Patent number: 7786933Abstract: 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: May 5, 2008Date of Patent: August 31, 2010Assignee: Spatial Digital Systems, Inc.Inventor: Donald Chin-Dong Chang