Trasmultiplexers Patents (Class 370/307)
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Patent number: 11245434Abstract: Advanced modulation and demodulation schemes for LoRa or equivalent chirp spread spectrum transmissions, with differential modulation and symbol repetition improve the sensitivity in combination with soft demodulation methods.Type: GrantFiled: December 8, 2020Date of Patent: February 8, 2022Assignee: Semtech CorporationInventor: Olivier Bernard André Seller
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Patent number: 10790931Abstract: Disclosed herein is a transceiver for a satellite, where the transceiver includes a receiver, a digital data stream processor and at least one transmitter. The receiver is configured to receive an uplink data stream from a satellite gateway or another satellite where the data stream carries a plurality of data packets. The digital data stream processor is configured to process the uplink data stream, to obtain the plurality of data packets, where at least one of the data packets includes payload data and error correcting data allowing a full error correction of the payload data. The data stream processor is further configured to perform no or only a partial error correction of the payload data of the at least one data packet, to obtain a downlink data stream. The transmitter is configured to transmit the downlink data stream to user terminal or another satellite.Type: GrantFiled: August 30, 2017Date of Patent: September 29, 2020Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.Inventors: Frank Mayer, Leo Frank
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Patent number: 10419034Abstract: Systems, methods, and apparatus for enhanced partial processing of satellite user data are disclosed. In one or more embodiments, a disclosed method for processing satellite data comprises encoding with an outer encoder in a transmitting terminal, modulating with a transmit modulator in the transmitting terminal, demodulating with a satellite demodulator in a satellite, encoding with an inner encoder in the satellite, modulating with a satellite modulator in the satellite, demodulating with a receive demodulator in a receiving terminal, decoding with an inner decoder in the receiving terminal, and decoding with an outer decoder in the receiving terminal. In one or more embodiments, the outer encoder and/or the inner encoder is operable to perform forward error correction (FEC) encoding. In at least one embodiment, the outer decoder and/or the inner decoder is operable to perform FEC decoding.Type: GrantFiled: January 30, 2018Date of Patent: September 17, 2019Assignee: The Boeing CompanyInventor: Matthew M. Everett
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Patent number: 10191954Abstract: A service is described that is able to analyze and prioritize media transcoding jobs. The determination of priority may be based on a feedback loop in which the system obtains request pattern information that indicates how end user devices consume the media content that has been transcoded. The historical request pattern information can be obtained by the service provider during the serving of the content to the requesting devices. Alternatively, the request pattern information may be obtained by receiving the information from a content publisher or other entities. Based on the request pattern associated with the media content, the system may assign higher priorities to formats that will be most frequently requested at specified time periods. The system may utilize higher number of resources, different types of resources or different configurations of resources to execute the high priority transcoding jobs.Type: GrantFiled: May 7, 2012Date of Patent: January 29, 2019Assignee: Amazon Technologies, Inc.Inventors: Jonathan B. Corley, Tal Saraf, Bradley E. Marshall
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Patent number: 10187141Abstract: Methods and systems are described for providing end-to-end beamforming. For example, end-to-end beamforming systems include end-to-end relays and ground networks to provide communications to user terminals located in user beam coverage areas. The ground segment can include geographically distributed access nodes and a central processing system. Return uplink signals, transmitted from the user terminals, have multipath induced by a plurality of receive/transmit signal paths in the end to end relay and are relayed to the ground network. The ground network, using beamformers, recovers user data streams transmitted by the user terminals from return downlink signals. The ground network, using beamformers generates forward uplink signals from appropriately weighted combinations of user data streams that, after relay by the end-end-end relay, produce forward downlink signals that combine to form user beams.Type: GrantFiled: September 25, 2017Date of Patent: January 22, 2019Assignee: VIASAT, INC.Inventors: Kenneth V. Buer, Mark J. Miller
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Patent number: 10079706Abstract: An apparatus, method and article of manufacture comprise a transceiver coupled to a phased array of antenna elements that are configured into pluralities of antenna elements to generate N modes of orthogonal radio waves where N is equal to or greater than 2. The coupling is via a plurality of 16-quadrature phase shift key (16-QPSK) modulators, each which is coupled to a respective one of the pluralities of antenna elements to modulate data onto a respective one of the N modes of orthogonal radio waves, to cause each of the N modes to operate as an independent data channel. For the case of N=2 modes, two 16-QPSK modulators generate independent 16-QPSK constellations, one for the first of the two modes and one for the second of the two modes, such that two 16-QPSK constellations are independent of each other, are orthogonal, and are on the same frequency.Type: GrantFiled: July 21, 2016Date of Patent: September 18, 2018Assignee: Raytheon CompanyInventors: Gary M. Graceffo, Andrew Kowalevicz
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Patent number: 10015038Abstract: A pulse quadrature modulator generates both alpha and beta binary signals, each one serial bit switched at an RF carrier frequency at a fraction of a high speed quantization clock. The alpha and beta binary signals each have respective alpha and beta pulse edges nominally occurring at two times the RF carrier frequency. The alpha and beta pulse edges alternate respectively. The alpha and beta pulse edges are each synchronized to the high speed quantization clock switched based on the baseband I and Q signal inputs. First and second switches gate a power signal using a respective of the alpha or beta binary signals to respectively produce first and second power outputs. The first and second switches differentially drive an RF load such as an antenna across the first and second power outputs having pulse edges at nominally at an integer multiple of four times the RF carrier frequency.Type: GrantFiled: December 28, 2016Date of Patent: July 3, 2018Assignee: ADX Research, Inc.Inventors: Pallab Midya, Brian D Lindemann, John Ribe
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Patent number: 9525454Abstract: A method of control of a plurality of end-points by a plurality of base stations, comprises issuing a frame by at least one end-point and sending the frame to at least one base station, sending a response frame from the base station to the end-point upon receiving the frame, the response frame comprising a plurality of downchirps, at least two sequences, each comprising a positive acknowledge and an increase rate and a positive acknowledgement and a decrease rate, and additional control sequences.Type: GrantFiled: September 9, 2015Date of Patent: December 20, 2016Assignee: Semtech CorporationInventor: Olivier Bernard Andre Seller
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Patent number: 9515789Abstract: A Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) system for inter-device communication is described. Information data from each neuromorphic chip is coded and modulated, on the basis of destination, into different channels. The parallel signals in different channels are sent serially using TDM to a central router. After signal grouping by a central switching controller, each group of signals may be delivered to corresponding transmitter in the central router for transmission to a corresponding receiver in the neuromorphic chip using TDM.Type: GrantFiled: February 27, 2013Date of Patent: December 6, 2016Assignee: HRL Laboratories, LLCInventors: Deying Zhang, Narayan Srinivasa
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Patent number: 9197164Abstract: Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.Type: GrantFiled: December 1, 2014Date of Patent: November 24, 2015Assignee: ParkerVision, Inc.Inventors: David F. Sorrells, Gregory S. Rawlins, Michael W. Rawlins
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Patent number: 8855189Abstract: Both live and offline transcoding of media is managed for storage in a cache. Requests for media are made by a client on a network and media taken from the cache and transcoded for delivery to the client. Media is also transcoded and stored in memory during idle request in anticipation of future requests during idle transcoder time between client requests. A prioritizer manages at least offline transcoding requests. A high priority queue operates at a higher priority than the low priority queue. The high priority queue receives live transcoding requests from a client on the network. A low priority queue receives offline transcoding requests. A media transcoder primarily transcodes media in accordance with requests from the high priority queue for delivery to a client on the network and then secondarily transcodes media in accordance with requests from the low priority queue when the high priority queue is empty.Type: GrantFiled: April 12, 2011Date of Patent: October 7, 2014Assignee: UV Networks, Inc.Inventors: Edward A Krause, Peter A Monta
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Patent number: 8451758Abstract: The invention relates to a method and a device for operation of two wireless services whereas a first service is broadcasting signals within burst with known time distances between the bursts and a second service is transmitting signals at least between a first partner and a second partner. The problem to be solved by the invention is to enable a user to use applications of at least to services concurrently at the same time with the same device. The problem is solved by an operation of one and the same device which is receiving bursts in a first mode of the first service and is switched from the first mode into a mode of the second service during the time between the bursts of the service.Type: GrantFiled: July 12, 2006Date of Patent: May 28, 2013Assignee: Entropic Communications, Inc.Inventor: Volker Aue
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Patent number: 8345884Abstract: A first matrix (W(k)) indicating frequency characteristics of a separation filter is calculated from input signals of a plurality of channels. A second matrix (Ws(k)) is calculated by using the restriction coefficients (Ci(k)) for restricting the separation filter and the first matrix, and separation filter coefficients (wsij(s)) are calculated by using the second matrix. With use of the separation filter coefficients, separation signals (ysi(t)) are then calculated from the input signals. A third matrix (Ws?1(k)) is then calculated by transforming the second matrix into an inverse matrix at each frequency, and reproduction filter coefficients (a?I1(s), a?I2(s)) are calculated by using the third matrix. With use of the reproduction filter coefficients, the synthesized signal of each channel is calculated by using the separation signals.Type: GrantFiled: December 7, 2007Date of Patent: January 1, 2013Assignee: NEC CorporationInventor: Toshiyuki Nomura
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Patent number: 8325647Abstract: Each of n signal transition detection sections detects a transition of the signal level of at least one of a first input signal or a second input signal corresponding to the signal transition detection section. A time-division control section outputs a control pulse according to a system clock when a signal transition is detected by at least one of the n signal transition detection sections. Each of n output switching sections outputs either the first or the second input signal corresponding to the output switching section as a multiplexed signal according to the control pulse.Type: GrantFiled: March 30, 2010Date of Patent: December 4, 2012Assignee: Panasonic CorporationInventors: Makoto Kawajiri, Norihide Kinugasa, Naohisa Hatani
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Patent number: 8271388Abstract: An image commercial transactions system and method, an image transfersystem and method, an image distribution system and method, and a display device and method are disclosed. A reception dealer accepts the transfer of an image recorded on a recording medium in a predetermined format with a handling condition intrinsic to the image, and transfers the image with the handling condition, and an advertisement, in digital data format, and a charge accounting dealer effects an electronic charge accounting transaction for the transfer of data of the image with the handling condition and the advertisement. Accordingly, a forwarding request user is helpful in making public the advertisement by having the data of the advertisement along with the data of the image forwarded, instead of the reception dealer, whereby a transfer fee for the data of image can be made lower. Consequently, it is possible to enhance the usability for the transfer significantly.Type: GrantFiled: August 29, 2006Date of Patent: September 18, 2012Assignee: Sony CorporationInventors: Hideki Toshikage, Shigeyuki Yoneyama
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Patent number: 8238275Abstract: An integrated circuit (IC) includes a processing module and main memory. The processing module includes a processing core and a first processing module millimeter wave (MMW) transceiver coupled to the processing core. The main memory includes memory and a first memory MMW transceiver coupled to the memory. At least one of an instruction and data is conveyed between the processing core and the memory via the first processing module MMW transceiver and the first memory MMW transceiver.Type: GrantFiled: August 30, 2008Date of Patent: August 7, 2012Assignee: Broadcom CorporationInventors: Ahmadreza (Reza) Rofougaran, Timothy W. Markison
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Patent number: 8204044Abstract: A method is performed by one or more network elements for voice-over-IP (VoIP) communications. The method includes receiving a request from a first mobile device to invite a second mobile device to participate in a VoIP session. The second device may be identified in the request by a network identifier. The network identifier is related to a mobile IP (MIP) address of the second device and a second IP address. An invitation is sent to the MIP address of the second device which may include a MIP address of the first device and a first IP address. A response to the invitation may be received from the second device. The response may be modified to include a first IP header that includes the MIP address of the second device and a second IP header to include the second IP address. The modified response is forwarded to the first device. After receipt of the modified response, the first device is configured to establish an IP connection for VoIP communication with the second device.Type: GrantFiled: September 21, 2009Date of Patent: June 19, 2012Assignee: Intel CorporationInventor: Gerald Lebizay
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Patent number: 8171495Abstract: Dispatching an incoming message from a queue into message transfer session(s) from which message consumers may draw messages. The message is reversibly received from the queue, whereupon a context of a message is identified. If the context correlates to an existing message transfer session, the message is ultimately assigned to a message transfer session. If the context does not correlate to an existing message transfer session, a new message transfer session is created, and the message is assigned to that new message transfer session. Upon receiving an acknowledgement of successful processing of the message, the removal of the message from the queue-like communication medium is assured. Upon receiving an acknowledgement of unsuccessful processing of the message, the message is restored to the queue-like communication medium.Type: GrantFiled: May 29, 2008Date of Patent: May 1, 2012Assignee: Microsoft CorporationInventors: Nicholas Alexander Allen, Edmund Samuel Victor Pinto, Karthik Raman, David Leon Stucki, John Anthony Taylor, Kenneth David Wolf
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Patent number: 8139517Abstract: The invention relates to a method of generating an optimized contribution signal comprising multiplexes. Each multiplex comprises global broadcasting services and its own combination of regional services. Each multiplex comprises stuffing packets and packets transporting signaling tables. The optimized contribution signal is generated by retaining only the global broadcasting services that are different from one another. The stuffing packets are marked and the packets transporting the signaling tables according to the multiplex to which they belong. Data bursts are constructed from the data streams corresponding to the global broadcasting services, to the regional services and to the marked stuffing packets and to the marked packets transporting the signaling tables. Another subject of the invention is a demultiplexing method, an optimized contribution signal and a regionalized data broadcasting system, and a receiver.Type: GrantFiled: October 13, 2006Date of Patent: March 20, 2012Assignee: Thomson LicensingInventors: Benoit Oger, Eric Lebars, Richard Lhermitte
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Patent number: 8045654Abstract: A method of detecting a signal in an input channel of a receiver includes applying each of a plurality of pre-detection bandwidths to an input signal. The method can include deriving, in a cascaded fashion, a plurality of pre-detection bandwidths for the input channel, and determining a temporal and spectral extent of pulsed energy in each of the plurality of pre-detection bandwidths. The derivation of the pre-detection bandwidths for the input channel can be performed by dividing the input channel into a sequence of smaller bandwidth sub-channels, so that the number of sub-channels is determined by how much bandwidth and pulse width range is able to be covered by a single detector.Type: GrantFiled: September 26, 2008Date of Patent: October 25, 2011Assignee: Lockheed Martin CorporationInventor: Robert Anderson
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Patent number: 7890048Abstract: A ground station multiplexes audio digital data of a plurality of audio broadcasts, GUI data, and download audio data and transmits the multiplexed signal to a receiving side through a satellite. The receiving side displays a GUI screen corresponding to an audio broadcast. When a music information selection command is input on the display screen, an audio broadcast of a music program corresponding to the music information is selected. When a music information download command is input on the display screen, download audio data corresponding to the music information is output. The download audio data is stored to a storage device so as to download audio data corresponding to a desired music title.Type: GrantFiled: November 10, 1998Date of Patent: February 15, 2011Assignee: Sony CorporationInventors: Tadaharu Koga, Satoko Nakatsuka, Yasushi Kikuta
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Patent number: 7675876Abstract: The preferred embodiment of the present invention provides an improved transport demultiplexor that can receive and filter different data types before sending the data to system memory. The preferred embodiment provides a string comparator to facilitate real time filtering of continuous incoming data before loading the data into system memory. The string comparator preferably uses a bit-maskable matching filter that filters system data in real time as the data is being delivered to system memory. When data matching the filter is located, the destination address of that data is determined and delivered to the processor. This allows the processor to quickly locate the desired data and thus facilitates the real time processing of that data.Type: GrantFiled: November 14, 2005Date of Patent: March 9, 2010Assignee: International Business Machines CorporationInventors: Eric M. Foster, Dennis E. Franklin, Bryan J. Lloyd
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Patent number: 7490182Abstract: A switching control circuit includes a serial-to-parallel converter, a rewritable storage device, and a decoder. The serial-to-parallel converter performs serial-to-parallel conversion for converting an inputted first control signal into a first parallel signal, and outputs the first parallel signal. The rewritable storage device has a write mode and a read mode selectively switched over in response to a storage mode switching signal, stores therein data of the first parallel signal in the write mode, and outputs the stored data as a second parallel signal in the read mode. In the read mode, the decoder decodes the first control signal and the second parallel signal to generate and output a plurality of element control signals to a plurality of elements, respectively. In the write mode, the decoder holds the plurality of element control signals generated in the read mode.Type: GrantFiled: April 7, 2006Date of Patent: February 10, 2009Assignee: Panasonic CorporationInventors: Shoji Yoshida, Kaoru Ishida, Hiroshi Yajima
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Publication number: 20090016244Abstract: Embodiments of the invention are generally directed to a system and method of implementing peer model architecture in integrated optical networks. In one embodiment, heterogeneous domains of nodes share a common control plane via routing and signaling adjacencies established through a network layer control channel. For example, in one embodiment, one or more Internet Protocol (IP) compliant routers, one or more Time Domain Multiplexing (TDM) switches, and one or more Wave Division Multiplexing (WDM) optical cross connects (OXC) run a common instance of an Interior Gateway Protocol (IGP).Type: ApplicationFiled: September 23, 2008Publication date: January 15, 2009Inventors: Vishal Sharma, Abhimanyu Das, Charles Chen
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Patent number: 7474635Abstract: A technique for reducing power requirements in a communication transponder by converting signals in multiple uplink channels carried in frequency division multiplexed (FDM) form on multiple uplink beams, to a lesser number of downlink beams that operate in time division multiplexing (TDM) but at a bandwidth different from and preferably greater than the bandwidth of the uplink channels. Because the TDM downlinks can utilize amplifiers operating at or near peak power, whereas conventional FDM downlinks must operate with amplifiers backed off to minimize intermodulation products, use of the TDM downlinks effects significant power savings.Type: GrantFiled: November 5, 2003Date of Patent: January 6, 2009Assignee: Northrop Grumman Corp.Inventors: Stuart T. Linsky, Harvey L Berger
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Patent number: 7460513Abstract: A radio base station (20) has an internal interface (26) which connects a radio equipment (22) and a radio equipment controller (24). At least one and preferably both of the example radio equipment (22) and radio equipment controller (26) comprises a framer (50, 70) which can be controlled for transmitting samples of different protocols over the internal interface. The framer (50, 70) facilitates (1) time multiplexing of N number of frames of a first protocol over the internal interface; (2) inserting L number of samples of a second protocol into M number of the frames of the first protocol, and (3) inserting a padding sample into each frame of the first protocol which does not include a sample of the second protocol. The first protocol has a frame rate; the second protocol has a sample rate which is different from the frame rate of the first protocol, and N is greater than L and M.Type: GrantFiled: August 3, 2004Date of Patent: December 2, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Jacob Kristian Osterling
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Patent number: 7450530Abstract: A cross link multiplexer bus comprising a plurality of cross link multiplexers and a plurality of interconnects. The plurality of cross link multiplexers has a destination port configured to receive a signal and an origin port configured to produce said signal. The plurality of interconnects has a set of interconnects coupled between a pair of adjacent cross link multiplexers. The signal is capable of being represented as a series of characters. A character is capable of being represented as a first data bit, a second data bit, and a control bit. A first interconnect is configured to convey the first data bit. A second interconnect is configured to convey the second data bit. A third interconnect is configured to convey the control bit. The third interconnect is positioned substantially between the first interconnect and the second interconnect.Type: GrantFiled: October 29, 2003Date of Patent: November 11, 2008Assignee: Broadcom CorporationInventors: Abbas Amirichimeh, Howard Baumer, Dwight Oda
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Patent number: 7450529Abstract: A cross link multiplexer bus comprising a plurality of cross link multiplexers and a plurality of interconnects. The plurality of cross link multiplexers has a destination port configured to receive a signal and an origin port configured to produce the signal. The plurality of interconnects has a set of interconnects coupled between a pair of adjacent cross link multiplexers. Preferably, the destination port is in a first cross link multiplexer, the origin port is in a second cross link multiplexer, and the first cross link multiplexer is configured to convey the signal toward the second cross link multiplexer in more than one direction. In an embodiment, the signal is capable of being represented as a series of characters, and a character is capable of being represented as a number of bits. Preferably, the plurality of cross link multiplexers includes a delay buffer to delay conveyance of a first bit so that it remains substantially synchronized with a second bit.Type: GrantFiled: October 29, 2003Date of Patent: November 11, 2008Assignee: Broadcom CorporationInventors: Abbas Amirichimeh, Howard Baumer, Dwight Oda
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Patent number: 7430254Abstract: A method of detecting a signal in an input channel of a receiver includes applying each of a plurality of pre-detection bandwidths to an input signal. The method can include deriving, in a cascaded fashion, a plurality of pre-detection bandwidths for the input channel, and determining a temporal and spectral extent of pulsed energy in each of the plurality of pre-detection bandwidths. The derivation of the pre-detection bandwidths for the input channel can be performed by dividing the input channel into a sequence of smaller bandwidth sub-channels, so that the number of sub-channels is determined by how much bandwidth and pulse width range is able to be covered by a single detector.Type: GrantFiled: August 6, 2003Date of Patent: September 30, 2008Assignee: Lockheed Martin CorporationInventor: Robert Anderson
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Patent number: 7356019Abstract: The invention relates to a conversion of a pulse modulated signal to a radio frequency signal enabling use of applications and protocols designed for wireless optical links on radio frequency channels. The method comprises receiving the pulse modulated input signal, decoding the received pulse modulated input signal into a decoded data bit-stream, encoding the decoded data bit-stream into a recoded data bit-stream, under use of the recoded data bit-stream modulating a radio frequency signal, and transmitting the modulated radio frequency signal. In the receiver path a received radio frequency signal is converted to a pulse modulated output signal by the steps of demodulating the received radio frequency signal into a demodulated data bit-stream, decoding the demodulated data bit-stream into a received data bit-stream, encoding the received data bit-stream into a pulse modulated output signal, and forwarding the pulse modulated output signal.Type: GrantFiled: March 8, 2004Date of Patent: April 8, 2008Assignee: International Business Machines CorporationInventors: Walter Hirt, Fritz Gfeller, Beat Weiss
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Patent number: 7123592Abstract: A head end is provided. The head end includes at least one modern for communicating with service units over a transmission bandwidth, the transmission bandwidth being divided into a number of subbands, each subband including a plurality of payload channels and at least one control channel and a control circuit, communicatively coupled with the at least one modem, that assigns each service unit to a subband such that the service units are substantially evenly distributed over the subbands.Type: GrantFiled: July 9, 2001Date of Patent: October 17, 2006Assignee: ADC Telecommunications, Inc.Inventors: Michael J. Geile, Brian D. Anderson, Jeffrey Brede, Robert J. Kirscht, Michael J. Fort, Mark D. Elpers
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Patent number: 7058150Abstract: A high-speed serial data transceiver includes multiple receivers and transmitters for receiving and transmitting multiple analog, serial data signals at multi-gigabit-per-second data rates. Each receiver includes a timing recovery system for tracking a phase and a frequency of the serial data signal associated with the receiver. The timing recovery system includes a phase interpolator responsive to phase control signals and a set of reference signals having different predetermined phases. The phase interpolator derives a sampling signal, having an interpolated phase, to sample the serial data signal. The timing recovery system in each receiver independently phase-aligns and frequency synchronizes the sampling signal to the serial data signal associated with the receiver. A receiver can include multiple paths for sampling a received, serial data signal in accordance with multiple time-staggered sampling signals, each having an interpolated phase.Type: GrantFiled: April 30, 2001Date of Patent: June 6, 2006Assignee: Broadcom CorporationInventors: Aaron W. Buchwald, Michael Le, Jurgen Van Engelen, Xicheng Jiang, Hui Wang, Howard A. Baumer, Avanindra Madisetti
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Patent number: 6940893Abstract: This invention modulates data onto a radio channel in such a way that the deleterious effects of the channel are reduced. This is accomplished in three steps: first, the information signal is modulated using a phase-differential modulation scheme. Second, the modulated signal is spread in both time and frequency by passing it through a dispersive filter, transmitting it through the channel, and removing the spreading using a dispersive filter in the receiver with the opposite characteristics of the filter in the transmitter. The third step, after demodulation, is to pass the signal through a low-pass filter to gather up the signal energy which has been dispersed by the channel. All three of these steps can be implemented with simple functional blocks, making this system very inexpensive to implement. Also included are two methods for enhancing the data throughput of the basic system, making it more bandwidth efficient.Type: GrantFiled: September 27, 1999Date of Patent: September 6, 2005Assignee: Telecommunications Research LaboratoriesInventors: John A. Pinkney, Spence T. Nichols
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Patent number: 6768434Abstract: A high speed x/sine(x) correction circuit for a digital to analog converter (DAC) functions by implementing a filter with an impulse response that approximates a sine(x)/x response. Each digital data value of an input signal to be converted by the DAC is considered a separate impulse. Each impulse, or initial pulse, is used to create a first reflection pulse by delaying the initial pulse by one clock cycle, inverting the delayed initial pulse and multiplying the delayed initial pulse by a constant less than one, such as dividing the delayed initial pulse by right-shifting the digital data value of the delayed initial pulse. The first reflection pulse is added to the input signal in the clock cycle it is generated prior to input to the DAC. A second reflection pulse may be generated in like manner from the first reflection pulse with an additional clock cycle delay for optimum results, both reflection pulses being added to the input signal in the clock cycle they are generated prior to input to the DAC.Type: GrantFiled: May 15, 2003Date of Patent: July 27, 2004Assignee: Tektronix, Inc.Inventor: Linley F. Gumm
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Patent number: 6731690Abstract: A transmultiplexer (202) is provided for transmultiplexing digitized signal samples (244) produced by a converter. The transmultiplexer (202) comprises a first Fourier transformer bank (304) configured to transform the digital signal samples (244) produced by the digitizer into frequency domain input signals (320). The transmultiplexer (202) also comprises a frequency domain shifter bank (306) configured to circularly shift the frequency domain input signals (320) to produce shifted signals (324). A frequency domain pre-filter bank (308) is configured to perform a first fast convolution with the shifted signals (324) and a first discrete Fourier transform of a first filtering function to produce filtered input signals (330), and a combining Fourier transformer (310) is configured to transform the filtered input signals (330) to produce output signals (348) containing a sample corresponding to a down-converted channel.Type: GrantFiled: December 1, 2000Date of Patent: May 4, 2004Assignee: Motorola, Inc.Inventor: Robert Mark Harrison
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Patent number: 6708029Abstract: A satellite-based communications system operating at high data rates includes a plurality of satellites each having uplink and downlink antennas for transmitting and receiving a plurality of signals utilizing a plurality of spot beams to and from a plurality of coverage areas at a predetermined range of frequencies. The system can include, or be combined with, other systems to enable increased capacity over high population areas and ubiquitous coverage over lower population areas. A portable antenna assembly can be coupled to a user's portable or mobile electronic device for coupling the electronic device directly to a satellite. A routing switch provides routing and switching on-board the satellite and routes signals according to their desired destination.Type: GrantFiled: May 2, 2001Date of Patent: March 16, 2004Assignee: Hughes Electronics CorporationInventor: Ellen K. Wesel
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Patent number: 6590871Abstract: A multi-carrier modulation apparatus to which transmultiplexers are applied. A multiplexing signal is treated as a synthesis of a plurality of multiplexed signals which are separated by a wider interval than the multiplexing frequency interval. Signals of channels 1 to M continuously frequency-multiplexed at a channel interval fB are treated as a synthetic signal of signals of channel 1 to channel 2N−1 and signals of channel 1 to channel 2N which are frequency-multiplexed at a channel interval 2fB. Individual multiplexed signals are synthesized by a plurality of transmultiplexers of less multiplexing number to make characteristics of polyphase filters required for the transmultiplexers less sharp.Type: GrantFiled: June 25, 1999Date of Patent: July 8, 2003Assignee: Hitachi Denshi Kabushiki KaishaInventor: Masaru Adachi
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Patent number: 6516438Abstract: The present invention provides a method for custom coding uplink signals and downlink beams in a satellite communications system. The method includes the step of applying, at a ground station (100), an outer code (102) to an uplink signal to produce an outer coded uplink signal. Next, the ground station (100) applies a selected reduced complexity inner code (104) to the outer coded uplink signal to produce a concatenated coded uplink signal. The ground station (100) transmits the concatenated coded uplink signal to a satellite (110). At the satellite (110), the inner code of the concatenated coded uplink signal is decoded (116) to produce an outer coded satellite data stream. Next, the satellite (110) applies a selected inner code (120) to a portion of the outer coded satellite data stream to produce a concatenated coded satellite data stream. The satellite (110) then transmits the concatenated coded satellite data stream in a downlink beam to a destination ground station (126).Type: GrantFiled: October 17, 2000Date of Patent: February 4, 2003Assignee: TRW Inc.Inventors: Donald C. Wilcoxson, Chamroeun Kchao, Eldad Perahia
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Patent number: 6456602Abstract: A physical layer device (PHY) device in a home LAN employs discrete multitone technology (DMT). The DMT system enables usage of existing residential wiring, which typically is telephone system grade twisted copper pair. The PHY device comprises a spectral image selection circuit to increase frequency diversity by examining all the images captured by a filter and restoring the transmitted signal based upon an image that may not be associated with the carrier frequency but its harmonics. Alternatively, the PHY device adjusts the sampling rate of its digital to analog convertor and accordingly filters to achieve desired grouping of spectral images.Type: GrantFiled: April 7, 1999Date of Patent: September 24, 2002Assignee: LegerityInventors: Chien-Meen Hwang, Muoi V. Huynh, Maged F. Barsoum, Hungming Chang, Eugen Gershon
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Patent number: 6449262Abstract: A physical layer device (PHY) device in a home LAN employs discrete multitone technology (DMT). The DMT system enables usage of existing residential wiring, which typically is telephone system grade twisted copper pair. The PHY device comprises an analog front end (AFE) circuit that frequency shifts the spectral images by using a clock signal. The multiplication of the clock signal is accomplished using a digital mixer or, in the alternative, an analog switch.Type: GrantFiled: April 7, 1999Date of Patent: September 10, 2002Assignee: LegerityInventors: Chien-Meen Hwang, Muoi V. Huynh, Maged F. Barsoum, Hungming Chang, Eugen Gershon
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Patent number: 6138261Abstract: The present invention provides a method for custom coding uplink signals and downlink beams in a satellite communications system. The method includes the step of applying, at a ground station (100), an outer code (102) to an uplink signal to produce an outer coded uplink signal. Next, the ground station (100) applies a selected reduced complexity inner code (104) to the outer coded uplink signal to produce a concatenated coded uplink signal. The ground station (100) transmits the concatenated coded uplink signal to a satellite (110). At the satellite (110), the inner code of the concatenated coded uplink signal is decoded (116) to produce an outer coded satellite data stream. Next, the satellite (110) applies a selected inner code (120) to a portion of the outer coded satellite data stream to produce a concatenated coded satellite data stream. The satellite (110) then transmits the concatenated coded satellite data stream in a downlink beam to a destination ground station (126).Type: GrantFiled: April 29, 1998Date of Patent: October 24, 2000Assignee: TRW Inc.Inventors: Donald C. Wilcoxson, Chamroeun Kchao, Eldad Perahia
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Patent number: 6020830Abstract: An efficient and cost effective analog telemetry system for transmitting receiving many individual data channels over long distances is provided by having each data channel signal modulate a pseudo-random number (PRN) signal which has been delayed for a distinct number of clock cycles for each data channel. The modulated PRN signals are then outputted to a single data line and summed. At the remote receiver, each data signal is recovered by cross correlating the modulated PRN signals with individual reference PRN signals. A synchronous delay generator in each data channel properly aligns each reference signal in time with its corresponding modulated PRN signal. Other modulated PRN signals, which are not aligned with the proper reference PRN signal, are rejected.Type: GrantFiled: October 14, 1997Date of Patent: February 1, 2000Assignee: The United States of America as represented by the Secretary of the NavyInventors: James M. Gannon, Robert M. Payton
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Patent number: 6009084Abstract: A transmultiplexer is connected between digital facilities and analog facilities for translating information between TDM and FDM formats on the digital and analog facilities, respectively. Information in the TDM format is representative of a plurality of digital telephone signal channels and information in the FDM format is representative of a plurality of analog telephone signal channels. The total capacity of the digital facilities is smaller than the total capacity of the analog facilities. Any one of the digital channels can be selectively coupled to any one of the analog channels. The transmultiplexer is installed at a telephone central office facility as an interface between a cable telephony transmission system and a digital telephone switch. A host computer controls both the transmultiplexer and the digital telephone switch.Type: GrantFiled: October 7, 1996Date of Patent: December 28, 1999Assignee: Nynex Science & Technology, Inc.Inventors: John D. Beierle, William C. G. Ortel
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Patent number: 5943315Abstract: A multiplex transmission system includes a multiplex transmission network through which normality and abnormality processing control specification information (PCSI) for loads are transmitted. A master load control unit (LCU) is connected to the multiplex transmission network. The master load control unit can multiplex the abnormality PCSi for a load as a main operation. A slave load control unit (LCU) is connected to the multiplex transmission network. The slave load control unit can multiplex the abnormality PCSI as a slave operation between itself and the main LCU. A storage device is mounted in the master and slave LCUs. The storage device can update and hold the information and read it at any time. In this multiplex transmission system, multiplexing abnormality can be detected and abnormality processing in the LCU in an abnormal state is controlled to urge its recovery of the LCU to a normal state.Type: GrantFiled: June 19, 1997Date of Patent: August 24, 1999Assignee: Yazaki CorporationInventors: Yoshio Iwasawa, Nobuhiro Imaizumi
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Patent number: 5889766Abstract: An FDMA (Frequency-Division Multiple Access) transmitter-receiver for use in an FDMA communication system which is capable of changing a bandwidth of a channel as required.Type: GrantFiled: January 14, 1997Date of Patent: March 30, 1999Assignee: Hitachi Denshi Kabushiki KaishaInventors: Makoto Ohnishi, Yukinari Fujiwara
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Patent number: 5715242Abstract: A system for voice distribution amongst a plurality of telephone subscriber locations operating on a broadband cable network wherein RF transmitting and RF receiving channels for carrying voice and signalling information are established at the subscriber locations and coupled with the broad band network and a central switch is also coupled with the broadband network and enables each RF transmitting channel to be selectively coupled to any of the RF receiving channels. Phase correction pilot tones having a known phase relationship are generated at the telephone subscriber locations and transmitted in one or more phase correction pilot tone channels separate from the RF transmitting channels to the central switch. At the switch, the phase correction pilot tones are recovered and the phases of the pilot tones are used to correct the phases of the transmitting channels.Type: GrantFiled: December 20, 1995Date of Patent: February 3, 1998Inventors: William C. G. Ortel, John D. Beierle
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Patent number: 5710763Abstract: A filter fast Fourier transmultiplexer divides a multi-channel communication signal into single channel communication signals through a cascade of filters and mixers. The output sample rate is maintained at the input sample rate and memory requirements and computations are substantially reduced.Type: GrantFiled: July 31, 1995Date of Patent: January 20, 1998Assignee: Motorola, Inc.Inventor: Robert Mark Harrison
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Patent number: 5699388Abstract: A system and method are shown for providing a fully synchronized two-way communication network having a number of transmission stations (10) and selective call receiving devices (27). Each transmission station (10) stores station identifying information and an updatable synchronization priority indicator. Periodically, each station (10) transmits a timing message that includes the station's identifying information, priority indicator, and information relating to the timing of the station's frame clock (45). When a given station receives a timing message transmitted from another station, it determines whether the other station is a direct upstream station thereof. The given station is responsive to a timing message from its direct upstream station for adjusting its frame clock (45) based upon the timing information contained in the message received from the direct upstream station. The given station thereby synchronizes itself with its direct upstream station.Type: GrantFiled: June 21, 1995Date of Patent: December 16, 1997Assignee: Motorola, Inc.Inventors: Zhonghe Wang, Morris Moore
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Patent number: 5627821Abstract: A defect notification method and apparatus for use in a multipoint ATM network so as to avoid the transmission of defect notification cells in an overlapped manner. In the invention when a connecting point detects a defect in a lower layer and when the connecting point is not a branching point the connecting point sends a first defect notification signal in the downstream direction of a first connection. When the connecting point receives the first defect notification signal and when the connecting point is a branching point, the connecting point terminates the first defect notification signal, sends a quasi-defect notification signal in the downstream direction of the first connection, and returns a second defect notification signal in the downstream direction of a second connection in the opposite direction of the first connection.Type: GrantFiled: March 15, 1995Date of Patent: May 6, 1997Assignee: Hitachi, Ltd.Inventor: Morihito Miyagi
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Patent number: 5625624Abstract: A satellite-based communication system providing high rate transfer of data between linked terminals. The system comprises a plurality of user terminals (VSAT's) that are linked by and that communicate with each other by way of a satellite-based relay system. A network control center provides configuration signals that control the satellite relay system and coordinate linking of terminals to each other. Frequency division multiplexing uplinks are used from the terminals and the network control center to the satellite relay system. Time division multiplexing are used on downlinks from the satellite relay system to the terminals and the network control center. Each user terminal comprises a data compression and decompression circuit, a transceiver, and an antenna for transmitting and receiving data to and from the satellite relay system. The satellite relay system comprises a satellite, a wide area antenna, a plurality of receive antennas, a plurality of transmit antennas, and a signal processor.Type: GrantFiled: October 21, 1993Date of Patent: April 29, 1997Assignee: Hughes Aircraft CompanyInventors: Harold A. Rosen, Victor S. Reinhardt, Parthasarathy Ramanujam, Gregory C. Busche, Andrew L. Strodtbeck, Jennifer L. Vollbrecht