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Pulse Or Digital Communications > Systems Using Alternating Or Pulsating Current > Plural Channels For Transmission Of A Single Pulse Train > Quadrature Amplitude Modulation Quadrature Amplitude ModulationQuadrature Amplitude Modulation patent applications listed are from June 2005 to current and include Date, Patent Application Number, Patent Title, Patent Abstract summary and are linked to the corresponding patent application page.11/22/07 - 20070268978 - Carrier offset estimator A system for estimating carrier offset includes includes a transmitter configured to transmit a quadrature modulated signal, and a receiver. The receiver includes an input configured to receive the quadrature modulated signal, a local oscillator configured to generate cosine and sine waves at a carrier frequency of the quadrature modulated ... 11/22/07 - 20070268977 - Method of utilizing and manipulating wireless resources for efficient and effective wireless communication A method of allocating symbols in a wireless communication system is disclosed. More specifically, the method includes receiving at least one data stream from at least one user, grouping the at least one data streams into at least one group, wherein each group is comprised of at least one data ... 11/08/07 - 20070258532 - Parallel bit interleaver for a wireless system Systems and methods are provided to process wireless data packets. A method includes determining a subset of data bits to be processed at a wireless transmitter and employing a clock edge to store the data. The clock edge allows parallel mapping of at least two bits from the subset of ... 11/08/07 - 20070258531 - Adaptive quantization method and apparatus for an ofdm receiver A quadrature frequency division multiplexing (“OFDM”) wireless receiver, including methods and devices for adaptive quantization of OFDM signals according to modulation and coding schemes and sub-carrier frequency responses, is provided. Efficient quantization may be utilized to reduce the large dynamic range of signals to achieve circuit simplification and chip area ... 10/25/07 - 20070248179 - Variable ofdm subchannel coding and modulation A system for selecting a modulation scheme and an error correction coding scheme for each subchannel in an OFDM system based on the energy detected on that subchannel. ... 10/11/07 - 20070237250 - Hybrid modulus blind equalization for quadrature amplitude modulation (qam) receivers Methods and apparatuses for blind equalizers with a hybrid adaptation error. In one embodiment, a Quadrature Amplitude Modulation (QAM) signal receiver, includes: a filter to reduce error in equalization, the filter to output a QAM signal; a decision engine coupled to the filter to determine a symbol based on the ... 08/30/07 - 20070201574 - Discrete multi-tone system having dht-based frequency-domain equalizer A discrete multi-tone (DMT) communication system is provided herein, replacing the conventional inversed discrete Fourier transform (IDFT) and DFT with IDHT (together with the complex-to-real transformation) and a DHT alone respectively at the transmitting end and the receiving end. A DHT-based frequency-domain equalizer (FEQ) at the receiving end equalizes each ... 08/23/07 - 20070195903 - Constellation location dependent step sizes for equalizer error signals An ATSC (Advanced Television Systems Committee-Digital Television) receiver comprises an equalizer and a controller. The equalizer provides a sequence of received signal points from a constellation space, the constellation space having an inner region and one, or more, outer regions. The controller provides a coefficient gain value for use in ... 08/09/07 - 20070183524 - Apparatus and method for interference cancellation in a wireless communication system A symbol demapping method and apparatus for efficient interference cancellation in a wireless communication system. Decision signal points are generated which include decision signal points based on a modulation scheme and a virtual signal point added to a zero point. A magnitude of a complex value of an input signal ... 06/28/07 - 20070147531 - Constellation rearrangement for arq transmit diversity schemes An ARQ (re-) transmission method of transmitting data in a wireless communication system wherein data packets are transmitted from a transmitter to a receiver, using a first transmission and a second transmission based on a repeat request. The method comprises the steps of modulating data at the transmitter using a ... 06/28/07 - 20070147530 - Bit-loading method and system for a dmt transceiver A system and method for a bit-loading algorithm based on an equal error rate principle for each sub-channel (bin) used in a discrete multi-tone modulation (DMT) system. The system and method of the present invention provides a bit-loading algorithm that provides long reach, high data rate and good error performance ... 04/12/07 - 20070081604 - Apparatus and method for reduced peak-to-average-power ratio in a wireless network A wireless transmission device capable of communicating with a receiver according to a DFT-spread OFDM protocol. The wireless transmission device comprises a configurable spectral shaping filter block capable of performing spectral shaping of an outgoing signal. The wireless transmission device configures the configurable spectral shaping filter block to perform spectral ... 04/05/07 - 20070076810 - System and method for selecting transmission format using effective snr Methods and systems are provided for determining a transmission format using an effective SNR. The method comprises determining (105) a pilot SNR for at least one time period in a frame, mapping (110, 115, 120, and 125) the scaled SNRs of the frame to a second SNR for at least ... 02/22/07 - 20070041462 - Method of transmitting captured image in digital broadcasting reception terminal A method of transmitting a captured image in a digital broadcasting reception terminal includes outputting digital broadcasting data being received as video and audio data in response to a digital broadcasting output request of a user; if a predetermined key is pressed while the digital broadcasting data is being output, ... 02/22/07 - 20070041461 - Multi-layer coded modulation for non-ergodic block fading channels A multi-layer coded modulation technique is disclosed for a wireless communication system with non-ergodic channels, which is particularly advantageous for multiple-input multiple-output (MIMO) systems. ... 02/08/07 - 20070030916 - System and method for demodulating multiple qam signals A system and method demodulate N QAM signals (N being a positive integer equal to or greater than 1) substantially simultaneously using, for example, one or two oscillators, regardless of how many QAM signals need to be demodulated. ... 02/08/07 - 20070030915 - Receiver block providing signal quality information in a communication system with signal constellation not having multiple symbols in same angle An aspect of the present invention provides signal quality information representing the angular deviations (i.e., based on the phase angle difference between the received symbol and the corresponding decoded symbol (i.e., selected symbol point in a signal constellation)). As a result, a relatively more accurate signal quality information is provided ... 01/25/07 - 20070019756 - Low complexity soft detection in multiple transmit and receive antenna systems with m-qam modulations This invention discloses a method for performing soft detection of transmitted signals modulated by M-QAM when a transmitter equipped with one or more transmit antennas, and the receiver has one or more receive antennas. This invention is built based on the fact that soft value of a single transmitted bit ... 12/21/06 - 20060285603 - Method and apparatus for performing channel compensation and symbol demodulation for coherent demodulation in an ofdm system A method and apparatus for performing channel compensation and symbol demodulation using an estimated channel impulse response during coherent demodulation of a received Orthogonal Frequency Division Multiplexing (OFDM) signal are provided. In the apparatus, an FFT processor IFFT-processes a received signal. A channel compensator generates a channel-compensated signal by multiplying ... 12/07/06 - 20060274845 - Quadrature amplitude modulation trellis coded modulation decoding apparatus and method thereof A quadrature amplitude modulation trellis coded modulation (QAM-TCM) decoding apparatus and the related method that receives and decodes a QAM signal. The QAM-TCM decoding apparatus includes an in-phase least significant bit (LSB) decoding path, which includes a in-phase Viterbi decoder for executing a decoding procedure on at least one LSB ... 11/23/06 - 20060262873 - Arrangements and methods for a digital communication system The present invention relates to methods, computer program products, a transmitter, a receiver and a transceiver including the transmitter and the receiver in a digital communication system for reducing the transmit power level when there is no user data is to send, i.e. when dummy data is sent instead. That ... 09/21/06 - 20060209977 - Global minimum-based mld demapping for soft-output mimo detection A method for generating soft bit values for a multi-bit symbol encoded in one or more received signals comprises (a) for a plurality of different combinations of multiple bit values, iteratively generating, for each combination, a metric value based on the one or more received signals. The method further comprises ... 07/20/06 - 20060159192 - Method and system for a robust initialization symbol for digital duplexing Provided is a method and system for increasing cyclic prefix and cyclic suffix based upon a fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT). The method includes representing at least one of the one or more DMT symbols in frequency domain to produce a frequency domain representation. The ... 07/20/06 - 20060159191 - Embedded keying Method of communicating digital data in which frames (8) are transmitted cyclically whereby a first number of symbols is transmitted according to a first keying mode (II) using a first constellation, and a second number of symbols is transmitted according to a second keying mode (L) using a second constellation. ... 06/29/06 - 20060140299 - Qam symbol mapping method and apparatus for downstream transmission of a cable modem Provided is a QAM (Quadrature Amplitude Modulation) symbol mapping method and apparatus for downstream transmission of a cable modem. The method includes the steps of: determining phase information on the basis of predetermined relations between two bits representing set partitioning information and two LSBs (Least Significant Bits) of bits representing ... 06/08/06 - 20060120474 - Mapping method for signal combining in a wireless communication system In a mapping method for signal combining in a wireless communication system, it is determined whether a full search is possible for an arbitrary mapping table. If the full search is possible, search metric values are computed for all possible constellation combinations and a constellation with a minimum value is ... 05/18/06 - 20060104378 - Method and system for computing log-likelihood ratios for coded quadrature amplitude modulated signals According to an embodiment of the invention, a method and system is disclosed for determining log-likelihood ratios for a coded set of individual bits (40) of a quadrature amplitude modulation (QAM) codeword. In the method at most two constant values (33,35) may be determined to perform a set of predetermined ... 05/18/06 - 20060104377 - Multiple output multicarrier transmitter and methods for spatial interleaving a plurality of spatial streams A multicarrier transmitter performs bit-interleaving suitable for transmitting more than one spatial stream over a multicarrier communication channel. The multicarrier transmitter may include a bit-grouping shifter to shift QAM symbol-bit groupings of a spatial stream among subcarriers of the multicarrier communication signal, and a bit-position permuter to rotate bits among ... 04/27/06 - 20060088117 - Correction-calculation algorithm for estimation of the signal to noise ratio in high bit rate dmt modulation A method for correcting signals received on a channel. Signals are received along the channel and it is determined how many of the signals are outside a predetermined range relative to a plurality of predetermined constellation points (i.e., erasures). Then, the noise power is estimated the noise power based on ... 04/13/06 - 20060078061 - Likelihood calculating method and communication method A likelihood calculating method, which uses a receiver having information data of plural signal points based on predefined data which consist of plural bits transmitted from a transmitter, comprises: receiving a reception signal from the transmitter; selecting a first signal point which, among the plural signal points, is the shortest ... 04/06/06 - 20060072679 - Method and device for modulation recognition of digitally modulated signals with multi-level magnitudes A modulation recognition method and device for digitally modulated signals with multi-level magnitudes are provided. The modulation recognition method includes selecting plural of quantization sizes used to construct plural of statistic histograms related to the magnitude of a sequence of data, setting up an off-line processing to extract plural of ... 03/09/06 - 20060050803 - Transmission system A transmission system for transmitting data over a channel in the form of a digital signal comprising bits of data, the system comprising an encoder for encoding the data prior to transmission, the encoder producing coding in the form of an overhead, and a decoder for decoding the data after ... 03/02/06 - 20060045197 - Ldpc (low density parity check) coded 128 dsq (double square qam) constellation modulation and associated labeling LDPC (Low Density Parity Check) coded 128 DSQ (Double Square QAM) constellation modulation and its associated labeling. A novel means is introduced by which a constellation may be arranged and mapping in its symbols may be determined to provide for improved performance. One application area in which this may be ... 03/02/06 - 20060045196 - Reduced state sequence estimator using multi-dimensional set partitioning A reduced state sequence estimator, and associated method, for equalizing data symbols communicated during operation of a communication system. The estimator is formed of multi-dimensional states of groups of symbols that are combined over more than one dimension to the multi-dimensional. Once the groups of symbols are formed, the groups ... 01/12/06 - 20060008020 - Method and apparatus for determining channel quality and performing adaptive modulation/coding within a multicarrier communication system In a multi-carrier communication system employing adaptive modulation and coding, a receiver feeds back channel quality information for a “binned” group of subcarriers instead of sending an individual quality report for each subcarrier. A transmitter will utilize the channel quality information for the bin to determine a set of γeff ... 01/12/06 - 20060008019 - Communications method The communications characteristics are improved with a communications method for carrying out communications using a plurality of M signal points to be placed on an I-Q plane. When the M signal points are spaced on the I-Q plane around a point of origin to have a uniform space a in ... 10/06/05 - 20050220204 - Device and method for management of the transmission of blocks of data in an hs-dsch downlink channel of a mobile communications network A device (D) is dedicated to managing transmission of digital data blocks in an HS-DSCH downlink transport channel set up between a base station of a communications network and a user equipment. It comprises processing means (MT) adapted, each time that a given block must be transmitted to the user ... 10/06/05 - 20050220203 - System & method for spreading on fading channels This disclosure describes a simple spreading technique that improves performance for communication over fading channels with QPSK or BPSK modulation. The technique may comprise combining two symbols at the transmitter by applying a 2×2 transform, resulting in a 4-PAM or 16-QAM constellation. The receiver may utilize a 2-dimensional soft de-mapper ... 09/22/05 - 20050207507 - Coded modulation device and method The present invention realizes a high coding gain employing a non-linear coding and a non-linear mapping. A converter converts one row of data that is inputted from a terminal into plural rows of data. The non-linear encoders non-linearly encode-lower level two rows of data in plural rows of converted data, ... 09/15/05 - 20050201479 - Multi-level modulation method and system Disclosed is a method and a system for performing N-ary modulation in which bit errors may be reduced against symbol error. A binary signal, a bit length thereof being n, is associated with N-ary signals arranged in first and second phase planes respectively for transmission, wherein N is not a ... 09/15/05 - 20050201478 - Modulation in a mobile telecommunications system A method of communication of data in a mobile telecommunications network involves at a transmitter first grouping the data into a first sequence of bits and a second sequence of bits. There is then a step of modulating a signal with the bits of the first sequence so that the ... 09/08/05 - 20050195911 - Communication system A data communication system is disclosed utilizing a transmitter and one or more receivers. The communication system may increase the data rate without requiring an increase in bandwidth. Additional advantages include an inexpensive encryption property, the incorporation of a simple adaptive synchronization scheme, and the incorporation of an effective error ... 08/25/05 - 20050185727 - Communication apparatus using a plurality of modulation schemes and transmission apparatus composing such communication apparatus A first signal generation section 11 generates a baseband modulation signal for an ASK modulation scheme from transmission data. A second signal generation section 12 generates a pair of baseband modulation signals for a non-ASK modulation scheme from transmission data. When performing non-ASK modulation, a switch 15 connects between an ... 08/04/05 - 20050169395 - Cost-effective multi-channel quadrature amplitude modulation A highly-efficient, cost-effective technique for multi-channel QAM modulation is described. The technique employs an inverse fast-Fourier transform (IFFT) as a multi-channel modulator. QAM encoding expresses QAM symbols as constellation points in the complex plane such that each QAM symbol represents a specific phase and amplitude of a carrier frequency to ... 08/04/05 - 20050169394 - Method and device for loop timing recovery based on maximum constellation signal A receiving device of a multiple communications channel system includes: a noise detector that detects channel noise among the received data signals and selects at least one channel among a plurality of channels in the multiple channel communications system on which the received data signals are largely unaffected by noise; ... 07/28/05 - 20050163242 - Bit mapping for variable-size higher-order digital modulations The invention is concerned with the mapping of m input bits to 2m modulation symbols of a two-dimensional symbol constellation. A quarter-quadrant constellation of 2m-4 modulation symbols that are located in a first quadrant of the two-dimensional signal plane is formed with each modulation symbol associated with a respective m-4 ... 07/21/05 - 20050157804 - Dsl rate adaptation A method for enhancing the bit rate and/or margin at which quadrature amplitude modulation (QAM) communication is performed includes the steps of varying a spectral allocation and constellation size with which communication is performed, so as to define a combination of spectral allocation and constellation size at which the bit ... 06/30/05 - 20050141628 - Fast soft value computation methods for gray-mapped qam A method and apparatus use unified equations to provide computationally efficient but exact solutions to bit soft value computations for Gray-coded QAM symbols in a received communication symbol as compared to carrying out region-specific equations that are keyed to particular regions of a nominal modulation constellation. Such unified equations further ... 06/09/05 - 20050123061 - Multidimensional signal modulation and/or demodulation for data communications Systems and methods are described for multidimensional signal modulation and/or demodulation for data communications. A method includes modulating a carrier signal in a first domain selected from the group consisting of phase, frequency, amplitude, polarization and spread; modulating the carrier signal in a second domain selected from the group consisting ... ### FreshPatents.com Support |