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Class 375/298 - Quadrature amplitude modulation


Subclass of Class 375 - Pulse or digital communications
Definition: Subject matter in which the transmitted signal can be represented
No. of patents: 640
Last issue date: 01/24/2012


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NumberTitleIssue Date
8102942VSB modulation apparatus and method for generating a VSB-modulated wave
A vestigial sideband (VSB) modulation apparatus includes a signal processing unit which extracts an I-axis data signal component and a Q-axis data signal component from a baseband signal with symbol data superimposed thereon, a band-limiting filter which frequency-s...
01/24/2012
8077800Transmitting apparatus with bit arrangement method
A transmitting apparatus, that includes a means for generating bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data in a first encoding process, to be equal or closer to ...
12/13/2011
8059750Method and apparatus for generating training sequence code in a communication system
A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero...
11/15/2011
8059751Frequency dependent phase rotation prior to mapping in an OFDM transmitter
An input bit stream is phase rotated by reversing bit pairs and inverting bits. The manipulated bit stream is mapped to a symbol and the mapped symbol is converted to the time domain such that an output of the time domain conversion is an ordered set of N samples th...
11/15/2011
8050355Transmitter and receiver using pseudo-orthogonal code
A transmitter using pseudo-orthogonal code includes a serial-to-parallel converter for converting serial transmission data into 9-bit parallel data, and a pseudo-orthogonal code memory for receiving the parallel data from the serial-to-parallel converter and outputt...
11/01/2011
8040974Shift space-time coding for digital video broadcasting systems
A shift space-time encoding scheme applies STBC over hierarchical modulation. A low-priority bit stream is modulated to complex symbols using STBC encoding and a high-priority bit stream is modulated to complex symbols without STBC encoding. Complex symbols from the...
10/18/2011
8005163Constellation rearrangement for transmit diversity schemes
A method of transmitting data in a wireless communication system from a transmitter to a receiver, comprising the steps of modulating data at the transmitter using a first signal constellation pattern to obtain a first data symbol. The first data symbol is transmitt...
08/23/2011
8000410Bit reliability equalization by modulation switching for HARQ
A method is disclosed for digital data transmission using higher order modulation schemes, wherein a plurality of bits is mapped to bit positions of a symbol and the transmission has different error probabilities for at least two out of said bit positions. A data bi...
08/16/2011
7983359Synchronization techniques for polar transmitters
Various techniques involving polar modulation are disclosed. For instance, an apparatus may include a storage medium and a calibration module. The storage medium stores multiple adjustment settings. Each of these adjustment settings corresponds to an operating condi...
07/19/2011
7965791Transmitting apparatus with bit arrangement method
A method of transmitting data including controlling generation of bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data, to be closer to an occupation rate occupied with p...
06/21/2011
7961814Method for using a symbol mapper using a symbol mapping scheme to generate modulation symbols according to a different symbol mapping scheme and a method for generating a symbol mapping scheme
The invention relates to method and apparatus for generating modulation symbols according to a second symbol mapping scheme by a symbol mapping unit being adapted to generate symbols according to a first symbol mapping scheme, wherein the first and second symbol map...
06/14/2011
7961813Multi-value modulation/demodulation method and multi-value modulation/demodulation device
N (integer equal to or above 3) quaternary phase shift keying (QPSK) outputs having different amplitude levels, i.e., r2=r1Ɨ2āˆ’(iāˆ’1), i=2 . . . N with respect to a maximum amplitude level r1 are superposed after power amplification to form M(=22N...
06/14/2011
7920645Data transmissions in a mobile communication system employing diversity and constellation rearrangement of a 16 QAM scheme
The invention relates to methods for transmitting and receiving a data bit stream in a communication system using 16-QAM constellations. Further, an apparatus for performing the methods is provided. To improve the bit-error rate performance of the communication usin...
04/05/2011
7903759Method for transmitting and receiving quadrature-amplitude modulation signals, system for implementing thereof, machine-readable medium, and application of the method for synchronizing reception of amplitude modulation signals
The invention relates to signal transmitting engineering. The use of the inventive method in systems for transmitting and receiving quadrature amplitude-modulation signals (QAM) exhibiting a low carrier frequency synchronization threshold makes it possible to decrea...
03/08/2011
7873120Forward error correction coding for AM 9kHz and 10kHz in-band on-channel digital audio broadcasting systems
A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plur...
01/18/2011
RE42043Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion
A radio frequency transmitter, of the type supplied with two signals in baseband and in quadrature, I(nT) and q(nT), which are images from two binary streams representing information to be transmitted, 1) provides a first transposition into the digital domain, at an...
01/18/2011
7864883Method and apparatus for modulating digital signal using equilateral triangular constellation
Disclose is a modulation method that transmits n bits per modulation symbol, comprising the steps of: (a) generating a constellation of which 2n constellation points are arranged to be angular point of equilateral triangle; (b) generating a modulation sym...
01/04/2011
7860186Transmitting apparatus with bit arrangement method
A transmitting apparatus comprising circuitry operable to generate a plurality of bit sequences using bits included in a first data block and a second data block, circuitry operable to control the plurality of bit sequences to correspond to a signal point on the pha...
12/28/2010
7852969System and method for dynamic calibration of a quadrature encoder
A system and method for real time calibration of a quadrature encoder. Errors from sources such as signal offsets, amplitude mismatches and phase errors are addressed. In one embodiment, the errors are addressed by determining and applying a dynamic operational set ...
12/14/2010
7848453Independent LO IQ tuning for improved image rejection
A transmitter includes a first amplifier to amplify an in-phase oscillator signal to produce an in-phase mixing signal and a second amplifier to amplify a quadrature-phase oscillator signal to produce a quadrature-phase mixing signal. A first mixer mixes the in-phas...
12/07/2010
7844015Method for calibrating a quadrature modulator and a modulation system
A method and system for calibrating a quadrature modulator. The method includes: determining a set of sideband calibration frequencies; for each sideband calibration frequency out of the set of sideband calibration frequencies: inputting an input signal having the s...
11/30/2010
7817747Precise delay alignment between amplitude and phase/frequency modulation paths in a digital polar transmitter
A novel apparatus for and method of delay alignment between amplitude and phase/frequency modulation paths in a digital polar transmitter. The invention provides a fully digital delay alignment mechanism where better than nanosecond alignment is achieved by accounti...
10/19/2010
7801246Multi-mode communication device for generating constant envelope modulated signals using a quadrature modulator
A quadrature modulated transceiver (102) is used to generate a constant envelope angle modulated signal for communications. To produce the required feedback when operating in the constant envelope mode, an orthogonal frequency division multiplexed receiver (
09/21/2010
7778354Communicating apparatus, method of calculating set value of orthogonal error compensation and orthogonal error compensation program
A communicating apparatus includes: a local signal generator, an orthogonal modulator, an orthogonal demodulator, and two orthogonal error compensators. The local signal generator generates a first local signal and a second local signal. The orthogonal modulator mod...
08/17/2010
7773693Apparatus and method for direct quadrature power amplifier modulation
A direct power amplifier modulator that accepts bipolar I and Q data, either baseband or multi-carrier digital IF, and generates the resultant magnitude and sign components. Also described is a direct power amplifier modulator that generates quadrature terms of the ...
08/10/2010
7769104System and method for scrambling the phase of the carriers in a multicarrier communications system
A system and method that scrambles the phase characteristic of a carrier signal are described. The scrambling of the phase characteristic of each carrier signal includes associating a value with each carrier signal and computing a phase shift for each carrier signal...
08/03/2010
7756217Method 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 pr...
07/13/2010
7742542Phase correlated quadrature amplitude modulation
A method for transmitting a base band digital data signal having a bit period and a first bandwidth, comprising providing a carrier wave having a carrier amplitude and a carrier frequency, and synchronously modulating both the carrier amplitude and carrier frequency...
06/22/2010
7672398Method and system for adjusting the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter
A method and system for determining amplitude and phase compensation values used to adjust the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter. The compensation values may be det...
03/02/2010
7653148System and method for delivery of video, content on demand and IP packets
A method and apparatus for modulating an input signal comprised of an ordered series of samples separated by a substantially constant period T comprising the steps of providing a carrier signal, the carrier signal comprised of a series of samples separated by a subs...
01/26/2010
7639756Apparatus and method for adjusting quadrature modulator, communication apparatus and program
Disclosed are an apparatus and a method for the adjustment time for IQ offset of a quadrature modulator of a transmission circuit. In adjusting the I-offset and the Q-offset of a quadrature modulator, supplied with an I-signal and a Q-signal output from an analog ba...
12/29/2009
7616702Transmission circuit and communication apparatus comprising the same
A transmission circuit is provided which can quickly and accurately control an output power of a transmission signal even when the transmission signal is output at a high modulation rate and in a wide dynamic range. A switching control section controls a modulation ...
11/10/2009
7596186Devices and methods of modulation and demodulation enabling the extension or replacement of a communications link, corresponding sender and receiver
A modulation device comprises for each carrier frequency: means of discrimination between a signal coming from a first channel of a communications link and a signal coming from a second channel of said link, so as to obtain differentiated first and second signals; f...
09/29/2009
7570711Quadrature LINC transmission method and apparatus
A quadrature LINC transmission system processes a baseband input signal for transmission as a linearly amplified RF signal. An in-phase LINC element processes an in-phase baseband signal into an in-phase RF signal. A quadrature LINC element processes a quadrature ba...
08/04/2009
7548591Quadrature modulator and calibration method
A quadrature modulator and a method of calibrating same by applying a first test tone signal to an in-phase modulation branch input of the modulator and a ninety degree phase-shifted version of the first test tone signal to a quadrature modulation branch input of th...
06/16/2009
7545882Transmission apparatus, reception apparatus and digital radio communication method
A transmission apparatus includes a frame configuration determiner that determines a modulation scheme, from among a plurality of modulation schemes. A first symbol generator modulates a transmission signal according the modulation scheme determined by the frame con...
06/09/2009
7539270Method and apparatus to interleave bits across symbols from different constellations
An encoded input bit stream is interleaved across a number of symbols having different bit sizes in a manner that ensures that the bits assigned to each symbol from the bit stream are separated by a minimum separation. In this manner, bits that are adjacent within t...
05/26/2009
7535975QAM mapping and bit labeling or bit-interleaved coded modulation
Methods and systems using a Gray-like labeled QAM cross-constellation are disclosed. In some embodiments a Gray-like labeled QAM cross-constellation is used in wireless communication systems. ...
05/19/2009
7505531Signal communications system and method for noisy links
A system and method for communicating signals over a noisy channel is provided wherein an input signal may be sampled and modulated to make the signal more noise insensitive. In accordance with one embodiment, of the invention, an signal code modulation (SCM) scheme...
03/17/2009
7499503Parallel concatenated code with soft-in soft-out interactive turbo decoder
A method for parallel concatenated (Turbo) encoding and decoding. Turbo encoders receive a sequence of input data tuples and encode them. The input sequence may correspond to a sequence of an original data source, or to an already coded data sequence such as provide...
03/03/2009
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