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7561638 |
Demodulation apparatus and receiving apparatus
A demodulation apparatus that can support various oscillation frequencies. The portable phone device includes a frequency synthesizer for generating a local-oscillation signal having a local...
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7486131 |
Quadrature demodulator and interrogator
In a receiving section, a first mixer and a second mixer generate an I signal and a Q signal from a modulated reception signal, a local signal, and a local signal obtained by shifting a phase by 90...
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7469022 |
Methods and apparatus for symmetrical phase-shift keying
Methods and apparatuses employing symmetrical phase-shift keying (SPSK) for data modulation and demodulation. Each symbol in a transmission signal carries n-bit information and is transmitted with...
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7463692 |
Device and method for symbol clock recovery in digital television
A device and method for a symbol recovery in a digital television are disclosed. The device includes a symbol clock recovery device includes a remained phase error remover operating a digital...
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7456682 |
Demodulator and phase compensation method thereof
The exemplary demodulator of the present invention can eliminate effectively a phase fluctuation which cannot be fully eliminated by a carrier recovery loop (feedback loop), with subsequent...
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7426243 |
Preprocessing signal layers in a layered modulation digital signal system to use legacy receivers
Systems and methods for receiving non-coherent layered modulation signals are presented. An exemplary apparatus comprises a tuner for receiving a layered signal and producing a layered in-phase...
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7394874 |
Up/down conversion circuitry for radio transceiver
A multi-channel RF receiver uses an image rejection mixer (e.g. double quadrature mixer) in the IF down conversion stage for image side band rejection (whereby use of an IF narrow band filter for...
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7109787 |
High-efficiency circuit for demodulating carriers in quadrature
A demodulation circuit for demodulating a received signal including carriers in quadrature modulated by digital signals and/or in which the processing is performed on two carriers in quadrature....
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7019599 |
Apparatus for continuous phase quadrature amplitude modulation and demodulation
An apparatus for continuous phase quadrature amplitude modulation and demodulation to continuously process phases and amplitudes at symbol change points in an M-ary quadrature amplitude modulation...
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6980059 |
Data directed frequency acquisition loop that synchronizes to a received signal by using the redundancy of the data in the frequency domain
A data-directed frequency-acquisition loop capable of generating a frequency error having a magnitude and direction from a double sideband suppressed signal comprises a first multiplier that...
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6931082 |
Digital phase locked loop
A technique that enables the sine and cosine branches within a PLL module to be obtained relatively easily and efficiently is described. According to the technique, the computation operations...
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6895063 |
Frequency changer and digital tuner
A zero or near zero IF frequency changer for use in a digital tuner comprises multipliers which receive the RF input signal from an input. The multipliers receive quadrature local oscillator...
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6771713 |
Data aided carrier phase tracking system for precoded continuous phase modulated signals
Data aided carrier phase and symbol timing synchronizers are implemented at baseband as digital modulators isolating input signal inphase and quadrature component signals fed into inphase and...
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6757336 |
Device and method for performing a carrier recovery
A method of receiving a signal and performing a carrier recovery, the method comprising the steps of: (a) receiving a signal Xk. (b) rotating Xk by a previous correction angle θk−1 to generate a...
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6717462 |
QPSK and 16 QAM self-generating synchronous direct downconversion demodulator
A system for recovering and demodulating a carrier includes a carrier recovery loop and a data detector. The carrier recovery loop receives the carrier as an input and produces a recovered carrier...
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6707863 |
Baseband signal carrier recovery of a suppressed carrier modulation signal
A multidetector ( 40 ) circuit for use in a plurality of carrier recovery systems ( 10, 70 ) for recovery for a suppressed carrier modulated signal. The multidetector ( 40 ) receives demodulated,...
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6597900 |
Circuit arrangement providing impedance translation filtering
A circuit arrangement for providing impedance translation filtering comprises a first path and a second path. In a base band variant the first path is a feed forward path which comprises first and...
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6570441 |
Incoherent demodulator and method of incoherently demodulating an IF signal
A demodulator includes a pair of analog mixers for incoherently demodulating modulated orthogonal signals with orthogonal local carriers to produce a pair of analog baseband signals, there being a...
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6563894 |
Method and apparatus for acquiring and tracking the sampling phase of a signal
Apparatus for providing an optimized sampling phase to a received signal in a given channel, the received signal including inter-symbol interference. The apparatus includes a voltage controlled...
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6466086 |
Quadrature demodulator with phase-locked loop
A quadrature demodulator applicable to digital communication and digital broadcast is provided, which simplifies the circuit configuration of a quadrature demodulator section and which reduces the...
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6433630 |
Phase shifter, and demodulator employing it
In a demodulator, a local oscillator 7 feeds a local oscillation signal having a frequency of f/n to a phase shifter 8 . In the phase shifter 8 , all-pass filters 9 and 10 produce two...
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6356145 |
Demodulator circuit which demodulates a signal without any restriction from a clock signal
A demodulator circuit including: a signal generating circuit for generating a sine-wave signal and a cosine-wave signal whose frequencies are same as that of the carrier wave of a modulated signal,...
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6297691 |
Method and apparatus for demodulating coherent and non-coherent modulated signals
A receiver receives modulated message signals in non-coherent FSK and coherent 8PSK protocols. A selectively configurable processor demodulates the message signals, and includes a demodulator that...
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6294952 |
Quadrature demodulator quadrature demodulation method and recording medium
A quadrature demodulator capable of calibrating an I (Q) signal conversion section without stopping the receiving operation performed by the quadrature demodulator. The quadrature demodulator...
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6249559 |
Digital frequency phase locked loop (FPLL) for vestigial sideband (VSB) modulation transmission system
In a digital frequency phase locked loop (FPLL) for a grand alliance (GA) HDTV receiver using a vestigial sideband (VSB) modulation transmission system, the digital FPLL for a VSB transmission...
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6208201 |
Recovery of a carrier signal from a modulated input signal
The present invention relates to the use of complex non-linear elements in improvements to the recovery of a carrier phase reference from a modulated input signal where the modulation is in...
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6191649 |
Quadrature demodulator and method for quadrature demodulation
A quadrature demodulator detects a phase angle error determined from the phase angle supplied from constellation symbols of outgoing in-phase and quadrature components of a modulated signal and and...
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6147560 |
Method and device relating to supervision and control of an oscillator signal
The present invention relates to methods and devices for such control and supervision of an oscillator signal from a controllable oscillator that is done mainly to control the frequency variation...
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6125271 |
Front end filter circuitry for a dual band GSM/DCS cellular phone
A front end circuit for an RF dual band GSM/DCS phone includes a first channel including an elliptical high-pass filter, a first SAW filter, and a low noise amplifier and a second channel including...
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6104237 |
Method for estimating phase in demodulator
A signal from a local oscillator is separated by a 90° phase sifter into an in-phase component and an orthogonal component. Each of the components is multiplied by a received IF signal in a mixer...
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6100755 |
Phase decision circuit
A phase decision circuit that can reduce the memory capacity of a ROM forming a look-up table. The quadrant decision section judges the quadrant to which an input signal belongs. The address...
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6091306 |
Circuit configuration with main and subordinate oscillators
Parasitic feedback is prevented in a transmitter, a modulator, or a demodulator from having an interfering influence on the circuit section that generates the mixed frequency. The circuit has a...
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6069524 |
FPLL with third multiplier in an analog input signal
A FPLL has an I, a Q and a third multiplier, with the I multiplier supplying demodulated signals to a limiter and the Q multiplier supplying signals to a loop filter. A VCO and phase shift circuit...
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6055280 |
High data rate digital demodulator and bit synchronizer
Demodulation and bit synchronization apparatus that uses a plurality of field programmable gate arrays to provide parallel processing to implement demodulation and bit synchronization. An...
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5963597 |
Data transmission apparatus
A data transmission apparatus applicable to transmission of data by the use of a cable of a television camera system or the like and capable of ensuring simplified exact demodulation of data...
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5939951 |
Methods and apparatus for modulating, demodulating and amplifying
An apparatus is disclosed for processing an input signal. The apparatus includes two feedback loops for generating output signal components from the input signal. Each loop contains an oscillator,...
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5905405 |
Quadrature demodulation circuit with carrier control loop
In a quadrature circuit, when a large frequency variation is detected, the carrier reproduction is conducted by using the carrier reproduction loop having a signal distortion but a small delay, and...
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5896061 |
Homodyne receiver and process for correcting the converted received signal
The invention pertains to a homodyne receiver, in particular for angle-modulated carrier signals in which the converted signal (ZF) has a d.c. voltage portion, and a process for correcting the...
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5881107 |
Transmission system for digital signals, and transmitter and receiver therefor
Transmission system with a transmitter (T), a receiver (R), and a filter combination (FI1, FI2; FQ1, FQ2) for transmitting a digital signal (sr), encoded in symbols (Si), from the transmitter (T)...
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5861773 |
Circuit for detecting the locked condition of PSK or QAM
A method for detecting a locked condition of a demodulator of at least one signal that may have discrete levels defining a constellation of nominal points in a plane. The method includes the steps...
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5822366 |
Transceiver and method for generating and processing complex I/Q-signals
The invention relates to a transceiver for generating complex I/Q-signals on a transmission frequency (f TX ) and for receiving them on a reception frequency (f RX ). The device comprises a first...
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5815541 |
Digital phase locked loop assembly
A digital PLL apparatus includes a synchronization integrating circuit, an angle calculating circuit, and a digital PLL circuit. The synchronization integrating circuit determines a symbol timing...
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5812546 |
Demodulator for CDMA spread spectrum communication using multiple pn codes
The demodulator has a plurality of matched filters in parallel. Each matched filter has a different binary PN code, a plurality of sample holders, a plurality of multipliers, an adder, and a...
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5761251 |
Dual automatic gain control and DC offset correction circuit for QAM demodulation
A circuit arrangement capable of achieving both DC offset correction and automatic gain control for QAM demodulation. The QAM signal is digitized and then the positive signal samples are averaged...
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5748046 |
Phase locked loop with controllable response time
An arrangement for selectively controlling the response time of a type II phase locked loop (PLL), especially one which includes a phase detector and an amplifier of a feedback type of integrator...
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5745004 |
FPLL with third multiplier in an AC path in the FPLL
A FPLL has first second and third multipliers with the first multiplier supplying demodulated signals to a limiter and the second multiplier supplying signals to the loop filter. A VCO and phase...
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5729173 |
Demodulation of quadrature amplitude modulation signals
A quadrature amplitude modulation demodulator for receiving a quadrature amplitude modulated signal having a suppressed pilot signal. In the demodulator, a receiver unit converts received...
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5668498 |
Controlling FPLL polarity using pilot signal and polarity inverter
A biphase stable FPLL includes a polarity determination circuit that ascertains the lockup phase of the FPLL based upon the polarity of the pilot in the digital signal. A frequency lock circuit...
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5656971 |
Phase demodulator having reliable carrier phase synchronization
In a demodulation device for demodulating a phase-modulated wave, a baseband signal producing circuit produces a baseband signal having particular information which is dependent on the...
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5652769 |
Costas loop and data identification apparatus
A costas loop includes a comparator, and a BPSK-modulated signal which is converted into a binary signal by the comparator is latched by a D-FF according to an oscillation signal from a VCO. An...
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