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Class Information
Number: 375/261
Name: Pulse or digital communications > Systems using alternating or pulsating current > Plural channels for transmission of a single pulse train > Quadrature amplitude modulation
Description: Subject matter in which the transmitted signal can be represented as the superposition of two modulated signals, each being obtained by pulse amplitude modulation of a signal sequence on a sinusoidal carrier, the two signal sequences being generated in synchronization at the same rate, and the two carriers being of the same frequency but 90 degrees apart in phase.
Sub-classes under this class:
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| RE40978 |
Communication system |
Nov. 17, 2009 |
| 7616678 |
Multi-carrier constant envelope signal scheme for power and bandwidth efficient communications |
Nov. 10, 2009 |
| 7609757 |
DSL rate adaptation |
Oct. 27, 2009 |
| 7609776 |
Quadrature frequency changer, tuner and modulator |
Oct. 27, 2009 |
| 7599419 |
Method and apparatus for use of space time trellis codes based on channel phase feedback |
Oct. 6, 2009 |
| 7599441 |
Low complexity soft-input Viterbi decoding for digital communication systems |
Oct. 6, 2009 |
| 7593491 |
Quadrature single-mixer multi-mode radio frequency receiver |
Sep. 22, 2009 |
| 7590186 |
Orthogonal frequency division multiplexing (OFDM) system receiver using low-density parity-check (LDPC) codes |
Sep. 15, 2009 |
| 7590182 |
Method and apparatus for utilizing channel state information in a wireless communication system |
Sep. 15, 2009 |
| 7586995 |
Peak windowing for crest factor reduction |
Sep. 8, 2009 |
| 7583743 |
Method of differential-phase/absolute-amplitude QAM |
Sep. 1, 2009 |
| 7583802 |
Method for using a synchronous sampling design in a fixed-rate sampling mode |
Sep. 1, 2009 |
| 7577219 |
Apparatus for communications |
Aug. 18, 2009 |
| 7577207 |
Bit labeling for amplitude phase shift constellation used with low density parity check (LDPC) codes |
Aug. 18, 2009 |
| 7570711 |
Quadrature LINC transmission method and apparatus |
Aug. 4, 2009 |
| 7570699 |
QAM symbol mapping method and apparatus for downstream transmission of a cable modem |
Aug. 4, 2009 |
| 7570698 |
Multiple output multicarrier transmitter and methods for spatial interleaving a plurality of spatial streams |
Aug. 4, 2009 |
| 7570694 |
Backward compatible multi-carrier transmission system |
Aug. 4, 2009 |
| 7567501 |
Embedded keying |
Jul. 28, 2009 |
| 7558329 |
Systems and methods for implementing receiver transparent Q-mode |
Jul. 7, 2009 |
| 7555051 |
Method and device for estimating IQ imbalance |
Jun. 30, 2009 |
| 7555052 |
Method and system for a turbo trellis coded modulation scheme for communication systems |
Jun. 30, 2009 |
| RE40779 |
Communication system |
Jun. 23, 2009 |
| 7548597 |
Cascadable diversity receiving system and method thereof |
Jun. 16, 2009 |
| 7545882 |
Transmission apparatus, reception apparatus and digital radio communication method |
Jun. 9, 2009 |
| 7545873 |
Radio transmission apparatus, radio reception apparatus and radio transmission method |
Jun. 9, 2009 |
| 7545731 |
Virtual buffer size management system for the transmission of blocks of data bits in an HS-DSCH downlink channel of a mobile communications network |
Jun. 9, 2009 |
| 7542521 |
Direct-conversion frequency mixer |
Jun. 2, 2009 |
| 7539122 |
Device and method for management of the transmission of blocks of data in an HS-DSCH downlink channel of a mobile communications network |
May. 26, 2009 |
| 7539123 |
Subcarrier puncturing in communication systems |
May. 26, 2009 |
| 7539270 |
Method and apparatus to interleave bits across symbols from different constellations |
May. 26, 2009 |
| 7539273 |
Method for separating interfering signals and computing arrival angles |
May. 26, 2009 |
| 7535975 |
QAM mapping and bit labeling or bit-interleaved coded modulation |
May. 19, 2009 |
| 7535976 |
Apparatus and method for integration of tuner functions in a digital receiver |
May. 19, 2009 |
| 7532563 |
Mechanism to improve quality of channel estimates in OFDM transmissions |
May. 12, 2009 |
| 7526250 |
Apparatus, system and method for flip modulation in an impulse radio communications system |
Apr. 28, 2009 |
| 7515630 |
System for, and method of, processing quadrature amplitude modulated signals |
Apr. 7, 2009 |
| 7512186 |
Rate adaptation and parameter optimization for multi-band single carrier transmission |
Mar. 31, 2009 |
| 7505531 |
Signal communications system and method for noisy links |
Mar. 17, 2009 |
| 7505524 |
Receiver device and communication system |
Mar. 17, 2009 |
| 7505522 |
Spectral shaping in multiband OFDM transmitter with clipping |
Mar. 17, 2009 |
| 7502423 |
Digital modulator and digital modulation method |
Mar. 10, 2009 |
| 7496146 |
Communication system |
Feb. 24, 2009 |
| 7492832 |
Method and apparatus for digital vector QAM modulator |
Feb. 17, 2009 |
| 7492833 |
Method for digital wireless communications |
Feb. 17, 2009 |
| 7486608 |
Efficient implementation of low power mode in digital subscriber line (DSL) transceivers |
Feb. 3, 2009 |
| 7483491 |
Linear transformation circuits |
Jan. 27, 2009 |
| 7480338 |
Constellation mapping apparatus and method |
Jan. 20, 2009 |
| 7477694 |
Enhanced wireless packet data communication system, method, and apparatus applicable to both wide area networks and local area networks |
Jan. 13, 2009 |
| 7477695 |
Wireless communication system, wireless communication apparatus, wireless communication method, and computer program |
Jan. 13, 2009 |
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