Vestigial Or Single Sideband, Or Suppressed Carrier Patents (Class 375/277)
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Patent number: 12184365Abstract: A dual-polarized multiple-input-multiple-output (MIMO) mobile device is provided that includes a first array of antennas and a second array of antennas. Based upon a blockage of at least one of the array of antennas being less than a blockage threshold, the mobile device operates in a default configuration in which a default polarization selection from the second array is used in combination with a fixed polarization selection from the first array to form a first MIMO layer signal and a second MIMO layer signal. Should the blockage exceed the blockage threshold and an optional performance threshold be satisfied, the mobile device may operate in a dynamic configuration in which a dynamic polarization selection from the second array is reversed as compared to the default polarization selection.Type: GrantFiled: June 2, 2023Date of Patent: December 31, 2024Assignee: QUALCOMM IncorporatedInventors: Vasanthan Raghavan, Sinan Adibelli, Mohammad Ali Tassoudji, Junyi Li
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Patent number: 9014293Abstract: Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.Type: GrantFiled: March 15, 2013Date of Patent: April 21, 2015Assignee: TM IP Holdings, LLCInventor: Richard C. Gerdes
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Patent number: 8861581Abstract: Provided is a receiver for processing VSB signal. The receiver includes a first equalizer/decoder unit and a second equalizer/decoder unit. The first equalizer/decoder unit performs a first equalizing operation, first TCM decoding and first RS decoding on a received symbol to output a first dibit. The second equalizer/decoder unit performs a second equalizing operation, second TCM decoding and second RS decoding on the received symbol to output a transport stream. The first dibit is provided as a priori information for a soft-decision operation of the second TCM decoding.Type: GrantFiled: April 5, 2011Date of Patent: October 14, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: DoHan Kim, Sergey Zhidkov, Beom kon Kim
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Patent number: 8767865Abstract: A wireless station of the present invention includes: a synchronization unit configured to synchronize with a transmission suspension period of a transmitting station of a wireless system, a measurement unit configured to measure a reception level of a wireless signal of said transmitting station in a transmission period and a reception level in the transmission suspension period, and an interference estimation unit configured to estimate an amount of interference to another wireless system according to the measured reception level in the transmission suspension period and reception level in the transmission period.Type: GrantFiled: September 21, 2011Date of Patent: July 1, 2014Assignee: NEC CorporationInventor: Kazushi Muraoka
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Patent number: 8717147Abstract: Disclosed are a passive RFID (Radio Frequency Identification) system and method capable of recognizing a great deal of tags at a high speed. A reader of a passive RFID system, including: a processor dividing slots and subchannels to configure a round, recognizing subchannels that are not involved in a collision and interference by the slots, and changing the subchannels that are not involved in a collision and interference, into a sleep state; a transmission unit encoding a command generated through the processor, performing an amplitude jitter modulation on the encoded command, and transmitting the modulated command; and a reception unit acquiring and demodulating tag signals received through a plurality of subchannels by the slots, and providing the demodulated tag signals to the processor.Type: GrantFiled: September 21, 2010Date of Patent: May 6, 2014Assignee: Electronics and Telecommunications Research InstituteInventors: Ji Hoon Bae, Cheng Hao Quan, Dong Han Lee, Chan Won Park, Won Kyu Choi, Kwang Soo Cho, Man Sik Park, Gil Young Choi, Jong Suk Chae
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Patent number: 8699600Abstract: A frequency and data synchronization control system through the 8VSB SFN DTx modulation prevents the deterioration of the digitally broadcasted receiving sensitivity caused by a discrepancy of the frequency or data between the receiver of the digital broadcasting signal and the distributed translator or between distributed translators.Type: GrantFiled: February 23, 2011Date of Patent: April 15, 2014Assignee: K-Tech Telecommunications, IncInventor: Steve Kuh
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Patent number: 8472544Abstract: A digital television (DTV) transmitter and a method of coding data in the DTV transmitter method are disclosed. A pre-processes enhanced data by coding the enhanced data for forward error correction (FEC) and expanding the FEC-coded enhanced data. A data formatter generates enhanced data packets including the pre-processed enhanced data and inserting known data to at least one of the enhanced data packets. A first multiplexer multiplexes main data packets with the enhanced data packets, and a data randomizer randomizes the multiplexed data packets. A Reed-Solomon (RS) encoder RS-codes the randomized data packets by adding first parity data, and a data interleaver interleaves the RS-coded data packets. A trellis encoder trellis-encodes the interleaved data packets, wherein the trellis encoder may be initialized when a known data sequence is inputted thereto.Type: GrantFiled: August 20, 2010Date of Patent: June 25, 2013Assignee: LG Electronics Inc.Inventors: In Hwan Choi, Kyung Won Kang, Kook Yeon Kwak, Young Jin Hong, Sung Ryong Hong
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Patent number: 8458752Abstract: A method for receiving a broadcasting signal and a broadcasting signal receiver are disclosed. Even when a cell is changed while an emergency alert is output, the emergency alert can be continuously output using emergency alert table information included in the broadcasting signal and channel information of the cell. The emergency alert table information may include a cell identifier and the channel information of the cell may include virtual channel information of the cell.Type: GrantFiled: May 10, 2011Date of Patent: June 4, 2013Assignee: LG Electronics Inc.Inventors: Chang Sik Yun, In Hwan Choi, Kook Yeon Kwak, Hyoung Gon Lee, Won Gyu Song, Jin Pil Kim, Jong Moon Kim, Jin Woo Kim, Byoung Gill Kim
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Patent number: 8432669Abstract: A signal receiving apparatus includes a main body for receiving control signals, and a cover covering the main body. The cover includes a receiving portion and at least one fixing portion. The receiving portion receives the main body, and the at least one fixing portion fixes the signal receiving apparatus to a housing of an electronic device. An electronic device using the signal receiving apparatus is also provided.Type: GrantFiled: June 1, 2011Date of Patent: April 30, 2013Assignees: Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd., Hon Hai Precision Industry Co., Ltd.Inventors: Ke-Hui Peng, Yong-Min Li, Li-Ni Liang
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Patent number: 8385250Abstract: A digital broadcasting system and a data processing method are disclosed. In an aspect of the present invention, the present invention provides a data processing method including receiving a broadcast signal in which main service data and mobile service data are multiplexed, demodulating the received broadcast signal, outputting demodulation time information of a specific position of a broadcast signal frame, and acquiring reference time information contained in the mobile service data frame, setting the reference time information to a system time clock at a specific time based on the demodulation time information and decoding the mobile service data according to the system time clock.Type: GrantFiled: June 21, 2010Date of Patent: February 26, 2013Assignee: LG Electronics Inc.Inventors: Chul Soo Lee, In Hwan Choi, Jae Hyung Song, Seung Jong Choi
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Patent number: 8344818Abstract: A single sideband mixer is constructed with digital logic elements such as T-type flip-flops and inverters and with FETs, and the resulting mixer circuit simultaneously improves control over the frequency resolution, noise floor and operating frequency range. The use of this group of elements also allows the mixer circuit to be easily realized in an integrated circuit.Type: GrantFiled: June 15, 2007Date of Patent: January 1, 2013Assignee: Scientific Components CorporationInventor: Doron Gamliel
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Patent number: 8199839Abstract: A digital broadcast transmitting/receiving system and a signal processing method thereof that can improve the receiving performance of the system. A digital broadcast transmitter has a randomizer to randomize an input data stream which has null bytes being inserted at a specified position, a multiplexer to output a data stream formed by inserting specified known data into the position of the null bytes of the randomized data stream, an encoder to encode the data stream outputted from the multiplexer, and a modulator/RF-converter to modulate the encoded data, RF-convert the modulated data and transmit the RF-converted data. The receiving performance of the digital broadcast transmitting/receiving system can be improved even in a multi-path channel by detecting the known data from the received signal and using the known data in synchronization and equalization in a digital broadcast receiver.Type: GrantFiled: October 1, 2009Date of Patent: June 12, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Hae-joo Jeong, Yong-deok Chang
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Patent number: 8165246Abstract: Use of a training sequence having terms that are orthogonal to each other are employed to considerably speed up execution of the LMS algorithm. Such orthogonal sequences are developed for a channel that is described as a finite impulse response (FIR) filter having a length Mnew from the already existing orthogonal training sequences for at least two channels that have respective lengths Mold1 and Mold2 each that is less than Mnew such that the product of Mold1 and Mold2 is equal to Mnew when Mold1 and Mo1d2 have no common prime number factor. More specifically, a set of initial existing orthogonal training sequences is found, e.g., using those that were known in the prior art or by performing a computer search over known symbol constellations given a channel of length M.Type: GrantFiled: August 28, 2000Date of Patent: April 24, 2012Assignee: Alcatel LucentInventor: Markus Rupp
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Patent number: 8149937Abstract: The invention provides a signal receiver. The signal receiver comprises a carrier removal module, a Fast Fourier Transformation (FFT) module, and a signal processor. The carrier removal module generates a carrier signal with a frequency of an estimated carrier frequency, generates at least one delta carrier signal with a frequency of the carrier frequency plus a delta frequency, removes the carrier signal from a first signal to obtain a second signal, and removes the delta carrier signal from the first signal to obtain a third signal. The FFT module derives a series of first FFT values from the second signal, and derives a series of second FFT values from the third signal.Type: GrantFiled: January 18, 2011Date of Patent: April 3, 2012Assignee: Mediatek Inc.Inventor: Kun-Tso Chen
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Patent number: 8130865Abstract: In one implementation, a polar transmitter includes a digital signal processing component that processes baseband signals and provides a baseband data signal with amplitude values; and a digital pre-distortion component that receives the baseband data signal with amplitude values, compensates for jitter error in the baseband data signal with amplitude values, and provides an adjusted modulated signal.Type: GrantFiled: October 31, 2008Date of Patent: March 6, 2012Assignee: Infineon Technologies AGInventors: Markus Schimper, Franz Kuttner
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Patent number: 7966633Abstract: A method for receiving a broadcasting signal and a broadcasting signal receiver are disclosed. Even when a cell is changed while an emergency alert is output, the emergency alert can be continuously output using emergency alert table information included in the broadcasting signal and channel information of the cell. The emergency alert table information may include a cell identifier and the channel information of the cell may include virtual channel information of the cell.Type: GrantFiled: March 19, 2010Date of Patent: June 21, 2011Assignee: LG Electronics Inc.Inventors: Chang Sik Yun, In Hwan Choi, Kook Yeon Kwak, Hyoung Gon Lee, Won Gyu Song, Jin Pil Kim, Jong Moon Kim, Jin Woo Kim, Byoung Gill Kim
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Patent number: 7940854Abstract: A digital television (DTV) transmitter and a method of processing data in the DTV transmitter are disclosed. A pre-processor pre-processes the enhanced data by coding the enhanced data for forward error correction (FEC) and expanding the FEC-coded enhanced data. A data formatter generates enhanced data packets including the pre-processed enhanced data and for inserting known data to at least one of the enhanced data packets. A first multiplexer multiplexes the enhanced data packets with main data packets including the main data. An RS encoder RS-codes the multiplexed main and enhanced data packets, the RS encoder adding systematic parity data to each main data packet and adding RS parity place holders to each enhanced data packet. And, a data interleaver interleaves the RS-coded main and enhanced data packets, wherein a known data sequence is included in every Nth enhanced data segment outputted from the data interleaver.Type: GrantFiled: August 30, 2006Date of Patent: May 10, 2011Assignee: LG Electronics, Inc.Inventors: Kyung Won Kang, In Hwan Choi, Kook Yeon Kwak
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Patent number: 7890980Abstract: A method for receiving a broadcasting signal and a broadcasting signal receiver are disclosed. Even when a cell is changed while an emergency alert is output, the emergency alert can be continuously output using emergency alert table information included in the broadcasting signal and channel information of the cell. The emergency alert table information may include a cell identifier and the channel information of the cell may include virtual channel information of the cell.Type: GrantFiled: March 19, 2010Date of Patent: February 15, 2011Assignee: LG Electronics Inc.Inventors: Chang Sik Yun, In Hwan Choi, Kook Yeon Kwak, Hyoung Gon Lee, Won Gyu Song, Jin Pil Kim, Jong Moon Kim, Jin Woo Kim, Byoung Gill Kim
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Patent number: 7779327Abstract: Provided are a Vestigial Side Band (VSB) Digital Television (DTV) transmitter and receiver based on the Advanced Television System Committee (ATSC) A/53, and a method thereof. The present invention provides 8-VSB DTV transmitter and receiver that can improve reception performance of the receiver by transmitting and receiving robust data mixed with P-2VSB, E-4VSB, and/or E-8VSB. The DTV transmitter includes an input means for receiving a digital video data stream including normal data and robust data; an encoding means for coding the digital video data stream into data symbols; and a transmitting means for modulating and transmitting an output signal of the encoding means, wherein the encoding means performs trellis coding on the robust data by sequentially applying a plurality of trellis coding methods.Type: GrantFiled: April 1, 2005Date of Patent: August 17, 2010Assignee: Electronics and Telecommunications Research InstituteInventors: Jae-Young Lee, Kum-Ran Ji, Sung-Hoon Kim, Seung-Won Kim, Soo-In Lee, Chieteuk Ahn
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Patent number: 7664203Abstract: Methods and systems for processing a single sub-channel that includes two or more combined channels. Using intermediate frequency sub-sampling, two or more channels from a broad band signal are combined into a single sub-channel for further analog and digital processing. Each of the two or more channels is down converted to an intermediate frequency, filtered to remove certain undesired channels, and combined such that the two or more channels are adjacent to each other. A digital representation of the sub-channel is produced from the combined intermediate frequency channels. Each channel within the digital representation is down converted to baseband, and the in-phase and quadrature components are separated from each other. Compared to one direct down conversion technique, intermediate frequency sub-sampling as described in the application may reduce the number of analog to digital converters and control amplifiers used in analog processing by a factor of four.Type: GrantFiled: February 14, 2005Date of Patent: February 16, 2010Assignee: Microsoft CorporationInventors: Dan Q. Tu, Louis F. Coffin, III
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Patent number: 7515641Abstract: Disclosed is an apparatus and method for processing a ranging channel in an OFDMA system. The apparatus converts received ranging complex signals to polar coordinate signals having a signal magnitude and a phase, and the received converted signals are each represented by a signal magnitude component and a phase component. A predetermined phase component of a signal according to a phase rotation is used to estimate a time delay by an addition operation of the phase of the received signal and the phase according to the phase rotation. Accordingly, the time delay and the power of each reverse link user of the OFDMA mobile communication system can be calculated by arithmetic operations of addition components instead of multiplication components, resulting in the reduction of complexity.Type: GrantFiled: August 19, 2004Date of Patent: April 7, 2009Assignees: Electronics and Telecommunications Research Institute, Samsung Electronics Co., Ltd., SK Telecom Co., Ltd., KT Corporation, KTFreetel Co., Ltd., Hanaro Telecom, Inc.Inventors: Chang-Wahn Yu, Kyung-Yeol Sohn, Youn-Ok Park, Seung-Ku Hwang
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Patent number: 7433417Abstract: The invention relates to a receiver (1, 49, 51, 52, 54) for receiving RF signals. The known receiver comprises a phase-locked loop which is controlled by the stereo pilot. Because of unwanted frequency changes, a sampling rate converter precedes the stereo decoder. Filtering operations within a complex range can be performed by means of the invention.Type: GrantFiled: February 17, 2003Date of Patent: October 7, 2008Assignee: NXP B.V.Inventors: Wouter Joos Tirry, Ludovic Albert Jozef Van Paepegem
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Patent number: 7177609Abstract: A chopper-direct-conversion (CDC) radio receiver includes a phase-alternating mixer receiving an antenna input signal and at least one local oscillator signal and generating a double sideband signal in a single mixing step. The phase-alternating mixer may be implemented by two parallel mixers each mixing the input signal with one of two local oscillator signals and an adder receiving and summing outputs from the two parallel mixers, by a track-and-hold circuit sampling the input signal based upon the local oscillator signal, or by a window averaging circuit averaging the input signal across a period of the local oscillator signal. The CDC architecture is suitable for fabrication on a single chip and offers solutions to virtually all problems found in conventional direct-conversion receivers.Type: GrantFiled: May 16, 2003Date of Patent: February 13, 2007Assignee: National Semiconductor CorporationInventor: Hee Wong
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Patent number: 7050511Abstract: The in-band adjacent-channel digital audio broadcasting system includes a scrambling unit for scrambling a signal to be broadcasted, thereby generating a scrambled signal; an outer coding unit for performing a first encoding of the scrambled signal, thereby generating an outer encoded signal; an outer interleaving unit for performing a first interleaving of the outer encoded signal a byte by byte basis, thereby generating an outer interleaved signal; an inner coding unit for performing a second encoding the outer interleaved signal, thereby generating an inner encoded signal; an inner interleaving unit for performing a second interleaving of the inner encoded signal, thereby generating an inner interleaved signal; a modulating unit for modulating the inner interleaved signal, thereby generating an orthogonal frequency division multiplexing (OFDM) symbols; a guard interval inserting unit for inserting a guard interval between the OFDM symbols in order to eliminate an inter-symbol interference, thereby generatiType: GrantFiled: September 28, 2001Date of Patent: May 23, 2006Assignee: Electronics and Telecommunications Research InstituteInventors: Young-Ho Jeong, So-Ra Park, Geon Kim, Soo-In Lee
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Patent number: 6891898Abstract: The system for recovering symbol timing offset and carrier frequency error from an orthogonal frequency division multiplexed (OFDM) signal includes a receiver circuit for receiving an OFDM modulated signal representing a series of OFDM symbols, and providing a received signal to an output thereof. A peak development circuit is included for developing a signal having a plurality of signal peaks representing symbol boundary positions for each received OFDM symbol, where each of the signal peaks is developed responsive to an amplitude and phase correspondence produced between the leading and trailing portions of each of the received OFDM symbols. The system includes a circuit for enhancing the signal peak detectability, which includes a circuit for additively superimposing and then filtering the signal peaks, to produce an enhanced signal peak having an improved signal-to-noise ratio.Type: GrantFiled: October 23, 2002Date of Patent: May 10, 2005Assignee: iBiquity Digital CorporationInventors: Paul James Peyla, Joseph Bertram Bronder
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Patent number: 6771707Abstract: A vestigial-sideband (VSB) signal is down-converted to generate a VSB signal including a carrier frequency offset from zero frequency by an amount greater than the bandwidth of the VSB signal. The carrier of this final I-F signal has a carrier offset from zero-frequency, which carrier offset exceeds the highest modulating frequency of the VSB signal and is adjusted to a prescribed carrier offset value. The down-converted VSB signal is digitized to generate a digital multiplicand signal for a digital multiplier circuit. The digital multiplier circuit is supplied a digital multiplier signal descriptive of a system function composed of a constant term and a second harmonic of the carrier frequency offset from zero frequency. Digital product signal from the digital multiplier circuit is descriptive of a double-sideband amplitude-modulation final I-F signal in the digital regime, which DSB AM final I-F signal is subsequently detected to generate a baseband demodulation result.Type: GrantFiled: May 11, 2000Date of Patent: August 3, 2004Inventor: Allen LeRoy Limberg
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Patent number: 6539063Abstract: The system for recovering symbol timing offset and carrier frequency error from an orthogonal frequency division multiplexed (OFDM) signal includes a receiver circuit for receiving an OFDM modulated signal representing a series of OFDM symbols, and providing a received signal to an output thereof. A peak development circuit is included for developing a signal having a plurality of signal peaks representing symbol boundary positions for each received OFDM symbol, where each of the signal peaks is developed responsive to an amplitude and phase correspondence produced between the leading and trailing portions of each of the received OFDM symbols. The system includes a circuit for enhancing the signal peak detectability, which includes a circuit for additively superimposing and then filtering the signal peaks, to produce an enhanced signal peak having an improved signal-to-noise ratio.Type: GrantFiled: February 18, 1999Date of Patent: March 25, 2003Assignee: Ibiquity Digital CorporationInventors: Paul James Peyla, Joseph Bertram Bronder
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Publication number: 20020186790Abstract: A digital VSB transmission system that is able to send supplemental data along with MPEG image/sound data is enclosed. The system initially encodes the supplemental data symbol to generate a parity bit, and it multiplexes the parity bit with a predefined sequence and transmits the multiplexed data to a receiver. The system is compatible with the existing ATSC 8T-VSB receivers that are already on the market. It can have advantages over the other types of VSB transmission systems that transmit only the predefined sequence. In addition, the system according the to the present invention results an improved robustness against ghost and noise signals in a channel compared to systems using only the ½ rate convolutional encoding.Type: ApplicationFiled: November 16, 2001Publication date: December 12, 2002Applicant: LG Electronics Inc.Inventors: In Hwan Choi, Young Mo Gu, Kyung Won Kang, Kook Yeon Kwak
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Patent number: 6430228Abstract: The efficient quadrature amplitude modulator of the present invention allows from 6 to 8 independent compressed channels to occupy a 6 MHz bandwidth while reducing processing power by 33 percent for 8 levels of modulation offered by 64-QAM and by 25 percent for 16 levels of modulation offered by 256-QAM. The modulator achieves this efficiency using an improved digital filter architecture combining the modulation and filtering with post filtering carrier combination. The QAM modulator presented is implemented with a reduction in the total number of binary parallel multipliers. To increase operational throughput, the speed of operation increases with the use of LUTs (look-up tables) storing precomputed filter weighting coefficients. The reduction in multipliers is also achieved by using post filtering carrier combination which similarly reduces the number of MAC operations performed during filtering.Type: GrantFiled: October 10, 2000Date of Patent: August 6, 2002Assignees: Motorola, Inc., General Instrument CorporationInventor: Qin Zhang
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Patent number: 6426780Abstract: A digital television receiver converts very-high-frequency intermediate-frequency digital television signal to a band with uppermost frequency in the lower portion of the high-frequency range. This facilitates RLC analog filtering, such as a Butterworth-Thomson-transition filter or a bridged-T trap filter, being used for suppressing the frequency-modulated audio carrier of co-channel NTSC analog television signal prior to the digital television signal being synchrodyned to baseband for recovering symbol code. The delay distortion introduced by this analog filtering is compensated for in substantial part in surface-acoustic-wave bandpass filtering of the very-high-frequency intermediate-frequency digital television signals. Remnant delay distortion is reduced by channel equalization filtering carried out in the digital regime.Type: GrantFiled: September 15, 1999Date of Patent: July 30, 2002Assignee: Samsung Electronics Co., Ltd.Inventors: Allen LeRoy Limberg, Chandrakant B. Patel
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Patent number: 6141387Abstract: The efficient quadrature amplitude modulator of the present invention allows from 6 to 8 independent compressed channels to occupy a 6 MHz bandwidth while reducing processing power by 33 percent for 8 levels of modulation offered by 64-QAM and by 25 percent for 16 levels of modulation offered by 256-QAM. The modulator achieves this efficiency using an improved digital filter architecture combining the modulation and filtering with post filtering carrier combination. The QAM modulator presented is implemented with a reduction in the total number of binary parallel multipliers. To increase operational throughput, the speed of operation increases with the use of LUTs (look-up tables) storing precomputed filter weighting coefficients. The reduction in multipliers is also achieved by using post filtering carrier combination which similarly reduces the number of MAC operations performed during filtering.Type: GrantFiled: March 19, 1998Date of Patent: October 31, 2000Assignees: Motorola, Inc., General Instrument CorporationInventor: Qin Zhang
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Patent number: 6075822Abstract: A traceback device for grand Alliance 8 Vestigial Side Band using Viterbi decoding algorithm. The traceback device includes a control unit, traceback device and delaying unit, wherein the control unit generates an activating signal.sub.-- 1 to read survivor path stored value one time per four symbol data inputs and a reading address signal, while also generating an activating signal.sub.-- 2 to delay read survivor path stored value. The traceback device reads stored survivor path information according to the activating signal.sub.-- 1 and the address signal from the control unit and performs traceback based on the read survivor path information. The data-delaying unit sequentially delays decoded data from the traceback device up to the predetermined bit according to the activating signal.sub.-- 2 from the control unit to output one byte decoded data per one time traceback.Type: GrantFiled: March 31, 1999Date of Patent: June 13, 2000Assignee: Hyundai Electronics Industries, Co., Ltd.Inventor: Dae Il Oh
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Patent number: 5987070Abstract: VSB data is transmitted in a frame which includes a frame sync, a segment sync, a mode control, and a plurality of data symbols. The mode control indicates the number of modulation levels of the data symbols and includes 2-level symbols forming the following byte: PABCPABC. P is a parity bit, and ABC represents a selected one of a plurality of data constellations defining the modulation levels of the data symbols.Type: GrantFiled: November 17, 1997Date of Patent: November 16, 1999Assignee: Zenith Electronics CorporationInventors: Mark Fimoff, Timothy G. Laud
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Patent number: 5930303Abstract: A method for transmitting "biphase" encoded digital signals including the steps of setting an aperture corresponding to a data bit; dividing said aperture into a plurality of segments; setting a first segment, selected from said plurality of segments of said aperture, dependent upon whether the bit is a digital one or zero; setting a second segment, selected from said plurality of segments of said aperture, so as to fit the remaining aperture of the data bit; and, transmitting said first and second segments of said data bit; wherein a narrow spectrum results containing no low frequency components and separated from 0 Hz by an amount equal to the data rate or 1/2 the data rate.Type: GrantFiled: November 3, 1997Date of Patent: July 27, 1999Inventor: Harold Walker
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Patent number: 5694419Abstract: A common transceiver circuit for use as either a modulator or demodulator and that is implemented through a shared resource approach. This approach is particularly, though not exclusively, suited for vestigial sideband (VSB) signals. Specifically, a VSB transceiver circuit (700), through strategically located multiplexing stages, physically re-uses a complex vestigial Nyquist filter (610), a complex mixer (620) and an equalizer (785) during demodulation and modulation. The VSB transceiver also selects a particular configuration of a common complex Hilbert transform circuit (720) for use during either demodulation or modulation. In addition, the same equalizer selectively provides both channel equalization, during de-modulation, and (sin x)/x compensation, during modulation, through use of differing corresponding sets of tap coefficients.Type: GrantFiled: November 7, 1995Date of Patent: December 2, 1997Assignee: Hitachi America, Ltd.Inventors: Koslov Joshua Lawrence, Frank Anton Lane, Carl G. Scarpa
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Patent number: 5692013Abstract: A common transceiver circuit for use as either a modulator or demodulator and that is implemented through a shared resource approach. This approach is particularly, though not exclusively, suited for with quadrature amplitude modulated (QAM) or vestigial sideband (VSB) signals. Specifically, a QAM transceiver circuit (400), through strategically located multiplexing stages, physically re-uses both a complex Nyquist filter (310, 320) and an equalizer (140) for demodulation and modulation. Additionally, tap coefficients of the complex Nyquist filter are set such that a center frequency of an otherwise baseband Nyquist filter is translated upward to a symbol rate in order to eliminate a separate complex mixer (250, 260). Similarly, a VSB transceiver circuit (700), also through strategically located multiplexing stages, physically re-uses a complex vestigial Nyquist filter (610), a complex mixer (620) and an equalizer (785) during demodulation and modulation.Type: GrantFiled: November 7, 1995Date of Patent: November 25, 1997Assignee: Hitachi America, Ltd.Inventors: Joshua Lawrence Koslov, Frank Anton Lane, Carl G. Scarpa
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Patent number: 5508748Abstract: A system for determining the data bits represented by the received symbols of one or more data constellations includes converting the received symbols into multi-bit values (preferably in two's complement form), selecting a number of the most significant bits of each of the multi-bit values and inverting the most significant bit thereof to derive the data bits represented by the respective symbol.Type: GrantFiled: April 8, 1994Date of Patent: April 16, 1996Assignee: Zenith Electronics CorporationInventors: Gopalan Krishnamurthy, Timothy G. Laud
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Patent number: RE40241Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the siganl points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.Type: GrantFiled: February 4, 1999Date of Patent: April 15, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Mitsuaki Oshima, Seiji Sakashita
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Patent number: RE40242Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second band streams respectively.Type: GrantFiled: September 21, 2000Date of Patent: April 15, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Mitsuaki Oshima, Seiji Sakashita
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Patent number: RE40779Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.Type: GrantFiled: February 20, 2004Date of Patent: June 23, 2009Assignee: Panasonic CorporationInventors: Mitsuaki Oshima, Seiji Sakashita