Patents Assigned to Digital Systems, Inc.
-
Patent number: 9793977Abstract: A communications system for providing recovery communication service to users in a coverage area affected by an emergency disruption of normal communication services. The system comprises a ground hub serving as a gateway to terrestrial networks including a dispatch center and configured to communicate with at least three mobile airborne platforms roving over the coverage area via respective feeder-links in a Ku or Ka band. A first mobile airborne platform communicates in a first frequency band with emergency workers that are working in the coverage area and associated with the dispatch center. A second mobile airborne platform communicates, in place of at least one disrupted base station in the coverage area, with user mobile phones in mobile phone frequency bands or user personal devices in WiFi bands located in the coverage area. A third mobile airborne platform generates real-time imaging of surfaces located in the coverage area.Type: GrantFiled: April 11, 2017Date of Patent: October 17, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9780859Abstract: Aircrafts flying near Earth or naval vessels are used as active scattering platforms in a multipath communications channel in MIMO communications systems. These man-made platforms in a communications channel, with techniques of beam forming and wavefront multiplexing in both transmitters at source and receivers at destinations enhance the ability to coherently combine the power of the communication signals, and improve the signal-to-noise ratio in addition to the MIMO advantage of multiple times of channel capacity over a finite bandwidth via frequency reuse. These platforms may be stationary, mobile ground based, or ocean surface based. They may also be airborne, or space borne. A swarm of 10's micro-UAV based mini-transponders is an example through active scattering of these micro-UAV to generate 10× more available bandwidth between a base station and ground mobile users over same bandwidth.Type: GrantFiled: February 28, 2014Date of Patent: October 3, 2017Assignee: Spatial Digital Systems, Inc.Inventors: Donald C. D. Chang, Juo-Yu Lee
-
Patent number: 9762309Abstract: 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: GrantFiled: September 27, 2013Date of Patent: September 12, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9749033Abstract: 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: July 29, 2014Date of Patent: August 29, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9712235Abstract: A data communication system comprises a wave-front multiplexer configured to wave-front multiplex first electronic signals into second electronic signals. The data communication system further comprises an electronic-to-optical converter configured to convert a third electronic signal carrying information associated with the second electronic signals into a first optical signal; and an optical transferring module 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. The data communication system further comprises optical-to-electronic converters configured to convert the second optical signals into fourth electronic signals; and wave-front demultiplexers each configured to wave-front demultiplex one of the fourth electronic signals into fifth electronic signals equivalent to the first electronic signals respectively.Type: GrantFiled: December 22, 2015Date of Patent: July 18, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9692549Abstract: Presented are methods that utilize wavefront multiplexing for enabling linearly-polarized terminals to access circularly-polarized satellite transponders. The methods disclosed herein feature (1) polarization formation capability that renders transmitted signal conditioned on circularly-polarized channels through multiple linearly-polarized feeds, and (2) polarization-conversion capability that compensate path differentials introduced by electromagnetic wave propagation channels. Data streams to be transmitted are pre-processed by a wavefront multiplexer into multiple wavefront components in linear polarization formats, where signals from respective data streams are replicated into linearly-polarized sub-channels. These replicated data streams are linked via a unique complex weighting vector (amplitude and phase or their equivalents), or “wavefront”, which are also linked by various spatially independent wavefronts.Type: GrantFiled: June 2, 2015Date of Patent: June 27, 2017Assignee: Spatial Digital Systems, Inc.Inventors: Juo-Yu Lee, Donald C. D. Chang, Tzer-Hso Lin
-
Patent number: 9647347Abstract: 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: GrantFiled: October 17, 2011Date of Patent: May 9, 2017Assignee: Spatial Digital Systems, Inc.Inventor: Donald C. D. Chang
-
Patent number: 9628250Abstract: An advanced digital beam forming technique is achieved that is capable of simultaneously forming multiple beams and attenuating the cross-pol component at multiple locations. The proposed invention, comprising a series of signal inputs, optimization loops and weighting processes, successfully eliminates the side effect of an increase of the cross-pol in the process of beam-forming, thus reducing potential interference. This technique utilizes the orthogonally polarized signal component which is already available and can minimize both the horizontally polarized and vertically polarized cross-pol at the same time. The complexity of computation can be reduced by using only part of the orthogonal polarized components in the optimization.Type: GrantFiled: March 24, 2011Date of Patent: April 18, 2017Assignee: Spatial Digital Systems, Inc.Inventors: Donald C. D. Chang, Frank Lu, Yulan Sun
-
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: 9565239Abstract: Aspects of the disclosed subject matter are directed to facilitating peer-to-peer data exchange in a common domain. In accordance with one embodiment, a method is provided for obtaining content from one or more peers that are connected to the domain. The method includes registering a peer with a super-peer when a connection to the domain is established. Then, the connecting peer obtains data that describes various network conditions and identifies chunks of content available from other peers. In downloading content from other peers, heuristics are applied to select between available chunks that are potentially encoded at different bitrates. The heuristics account for the network conditions between peers and balance the potential need to quickly access content with the desire to obtain high quality content.Type: GrantFiled: June 1, 2010Date of Patent: February 7, 2017Assignee: Orions Digital Systems, Inc.Inventors: Nils B. Lahr, John Morris, Aj Gregory, Robert Green
-
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: 9294132Abstract: A method and system for decoding information read from a non-volatile memory uses a two stage decoding algorithm, where the first stage is a high-speed, low precision decoder and the second stage is a low-speed, high precision decoder. Most of the time only the first stage of the decoder is used, which lowers the average power consumption of the decoding process.Type: GrantFiled: November 8, 2012Date of Patent: March 22, 2016Assignee: Proton Digital Systems, Inc.Inventors: Borja Peleato-Inarrea, Andrei Vityaev, Nenad Miladinovic
-
Patent number: 9160369Abstract: The proposed method presents a novel error correction scheme utilizing LDPC codes that provides desired error floor performance. The error floor performance is achieved through combination of the two design parameters of the method. Encoding a block of user data of length S*K bits includes (A) dividing the block into S sub-blocks of equal length, each sub-block having K bits; (B) encoding each of the sub-blocks using a first Error-Correcting-Code; (C) computing bit-wise XOR of all the sub-blocks, thereby generating a new sub-block of K bits; and (D) encoding the new sub-block using a second Error-Correcting-Code.Type: GrantFiled: February 27, 2014Date of Patent: October 13, 2015Assignee: Proton Digital Systems, Inc.Inventor: Nenad Miladinovic
-
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: 8965161Abstract: A decohered laser light production system is provided. The decohered laser light system comprises a laser source. The system further comprises a multi-mode fiber having an input face, an output face and a body for propagating light from the input face to the output face, the input face arranged to accept laser light from the laser source, the body comprising a length such that laser light is generally decohered when exiting the output face.Type: GrantFiled: October 5, 2011Date of Patent: February 24, 2015Assignee: Christie Digital Systems Inc.Inventor: John Domm