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7298202 |
FSK demodulator
An FSK demodulator which outputs an enable signal in response to the detection of a data change point in a detected signal of an amplitude associated with the received frequency of an input FSK...
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7116964 |
Signal reception and processing method for cordless communications systems
Channel selection of a received signal is first of all carried out, in the process, by way of an analog channel selection filter. The signal is then converted to a digital discrete-time and...
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7026864 |
Non-coherent FSK demodulator
A non-coherent frequency shift key demodulator comprising an oversampling device, a chain of registers, and a threshold device is disclosed. The oversampling device receives an input digital...
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7015749 |
Frequency discriminator using replica compensated delay lines and method of operation
A frequency discriminator for detecting phase shifts between sequential pulses in a frequency-shift keyed (FSK) signal having a nominal frequency, f. The frequency discriminator comprises: 1) a...
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6990157 |
All-digital FSK demodulation with selectable data rate and adjustable resolution
All-digital FSK demodulation can be accomplished by producing in response to a received IF signal digital information ( 22 ) indicative of a frequency of the IF signal. A symbol represented by the...
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6933776 |
Signal demodulating method of a two-phase frequency shift keying (FSK) digital demodulator
There is provided a signal demodulating method of a two-phase frequency shift keying (FSK) digital demodulator. The method utilizes at least a detect circuit respectively detecting and collecting a...
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6836181 |
FSK demodulation system
A FSK demodulation system of the present invention has a means for comparing two preset values across 0, a positive side level shift amount and a negative side level shift amount, with an inputted...
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6703896 |
Method and demodulator for FSK demodulation, and receiver including such a demodulator device
In a method for demodulating an analog FSK signal (FSKin), a current sample (Id(k);Id i ) of the downconverted and digital inphase component is multiplied with a previous sample (Qd(k−1);Qd i−1...
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6639458 |
FM demodulator capable of providing demodulated data with high determination accuracy
An FM demodulator for reproducing data by performing FM demodulation of a received RF signal in a Bluetooth transmission system is provided. The FM demodulator includes a frequency discrimination...
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6396338 |
Variable delay line detector
A variable delay line detector ( 34, 48, 66 )includes a power splitter ( 36, 50, 68 ), a mixer ( 44, 62, 72 ) and a variable delay line ( 42,52, 70 ). Various devices are suitable for the variable...
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6288618 |
Logic-based architecture for FSK modulation and demodulation
A cost-effective continuous phase logic-based modulator and demodulator are provided to allow communications using binary frequency shift keying (BFSK) as well as M-ary FSK techniques. The...
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6144253 |
Digital FSK demodulator
A FSK demodulator which uses the combination of a digital phase comparator and a digital controlled oscillator (DCO) in the form of a state machine to demodulate an FSK signal. The phase comparator...
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6121829 |
Frequency demodulator
A frequency demodulator of the present invention includes: an amplification section for receiving a frequency-modulated signal and amplifying the frequency-modulated signal based on a gain so as to...
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6046628 |
Demodulating device comprising a small circuit and a small consumption power
In a demodulating device which comprises an orthogonal transforming circuit, an up-converting circuit, a pulse signal producing circuit, and a low-pass filter, the orthogonal transforming circuit...
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5999577 |
Clock reproducing circuit for packet FSK signal receiver
A circuit is provided by which in the case of the transmission of a short packet signal through an FSK transmission channel having a frequency error for transmission and reception, directly from...
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5966406 |
Method and apparatus for noise burst detection in signal processors
A method and apparatus for noise burst detection in a signal processor is provided. The method and apparatus is based on the zero-crossing rate (ZCR) of the received signal, which is defined as the...
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5949280 |
Multivalued FSK demodulation window comparator
A multivalued FSK demodulation window comparator includes an MSB comparator, an LSB comparator, a reception electric field strength detector, and a reference voltage generating circuit. The MSB...
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5942937 |
Signal detection circuit using a plurality of delay stages with edge detection logic
A signal detection circuit employs a delay line with edge detection logic for capturing and buffering timing information about an input signal. A plurality of comparators for comparing the input...
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5917871 |
Bit synchronization circuit and method capable of correct bit synchronization for both 2-value and 4-value FSK transmission signals
A bit synchronization circuit receives polarity-judged output signal and a level-judged output signal that are produced through demodulation of a 2-value FSK or 4-value FSK transmission signal....
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5903186 |
Demodulator of MSK signal
A demodulator for demodulating an MSK signal constituted by a sequence of MSK modulated symbols is disclosed. An exclusive OR signal obtained by delay detection is delayed by delay times shorter...
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5828238 |
Digital frequency discriminator
A frequency discriminator circuit that includes a signal shaping and power splitting circuit (20) responsive to a sinusoidal RF input signal for providing first and second substantially identical...
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5822378 |
Receiver, a demodulator, and a demodulation method
Known is a receiver having a demodulator for intermediate frequency modulated frequency shift keyed signals. The known demodulator applies absolute period time measurements expressing the period of...
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5818881 |
Digital frequency demodulator
A digital frequency demodulator includes a first counter and a second counter measuring the instantaneous and mean values of the period of a frequency modulated signal. A comparator compares the...
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5809097 |
Low jitter phase detector for phase locked loops
A digital phase detector which generates low jitter when the phase-locked-loop is in lock. A delay line, combined with an UP/DOWN phase detector causes substantial overlap in the UP and DOWN...
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5808509 |
Receiver and demodulator for phase or frequency modulated signals
In a quadrature receiver for phase and/or frequency modulated signals an intermediate phase signal is quantized to produce a quantized phase signal. The receiver includes a demodulator in which...
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5789991 |
FSK modulating and demodulating apparatus wherein each binary data is represented by same number of cycles of modulated signal
A signal FSK-modulated with a binary data signal has first signal portions representing first logical level data contained in the binary data signal and second signal portions representing second...
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5783967 |
Frequency shift keying demodulation circuit using logic circuitry
A miniaturized FSK demodulation circuit for accurately demodulating a signal having a small modulation index comprises a multiplier for multiplying a FSK modulated input signal by 4, an oscillator...
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5781064 |
Digital filtering system for filtering digital outputs of a four level FSK demodulator
A digital filtering system for filtering a first and a second digital signals inputted from a FSK (frequency-shift-keying) demodulator to generate a first and a second filtered digital signals. The...
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5724001 |
Method and apparatus for demodulating a frequency shift keyed signal
A receiver (100) is utilized for demodulating a multi-level frequency shift keyed (FSK) signal. The receiver (100) includes a mixer (102) for mixing the multi-level FSK signal to generate an...
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5686869 |
Pulse-width modulating device
A pulse-width modulating device comprises: a counter for generating a plurality of counter signals of n-bit, where n is an integer of 2 or more; a fundamental waveform generator for outputting a...
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5684837 |
Adjustable digital FSK demodulator
An apparatus and method for demodulating a frequency-shift keyed (FSK) signal to provide a data signal. An input FSK signal is processed in a waveform reshaper to generate a first pulse signal...
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5612976 |
Detectors
A direct conversion Binary FSK radio receiver has an AFC loop comprising an Exclusive-Or phase detector 104 responsive to the I 3 and Q 3 signals. I and Q filters 100, 101 are not identical but...
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5550505 |
Frequency shift keying (FSK) demodulator for use in low signal-to-noise ratio environments
A frequency-shift keying (FSK) demodulator demodulates a binary signal encoded in an FSK signal. The present invention employs a bandpass filter to filter out noise and pass the frequencies used in...
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5539355 |
Frequency-shift-keying detector using digital circuits
A signal modulated by frequency-shift keying is input to a detector consisting of an instantaneous phase detection circuit that detects the instantaneous phase of the input signal, a...
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5514998 |
Method and system for demodulating GMSK signals in a cellular digital packet data system
A decision feedback multiple symbol differential demodulator for Gaussian filtered Minimum Shift Keying (GMSK) has a performance very close to theoretical limit even under a fading channel. The...
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5453714 |
Binary FM demodulator with self-adjusting resonant operating frequency according to demodulated binary output signal duty cycle
A demodulator for demodulating a binary frequency-modulated signal includes a demodulator with a quadrature tank circuit and a duty cycle monitor circuit. The quadrature tank circuit has a...
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5450032 |
FSK data demodulator using mixing of quadrature baseband signals
A first demodulator for generating a demodulated signal by demodulating first and second baseband signals obtained from a received frequency shift keying signal, comprises: a first mixer for mixing...
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5446762 |
Data demodulation circuit for FSK modulated RF signal receiver providing wide-band 90° baseband phase shifting
An FSK radio receiver of direct conversion type, which derives baseband in-phase and phase quadrature signals from a received FSK RF signal in respective mixers by applying local oscillator signals...
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5444415 |
Modulation and demodulation of plural channels using analog and digital components
In the modulation and demodulation of a plurality of frequency separated channels on a radio frequency carrier by digitally coded speech or data, the speech or data is modulated on a digitally...
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5436589 |
Demodulator for frequency shift keyed signals
A demodulator (414) for improving bit error rate performance where alternating bit patterns produce the worst occurrences of bit errors. The demodulator (414) consists of a zero threshold...
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5436590 |
Digital FSK demodulator with automatic offset cancellation
A digital FSK demodulator used in e.g. a telephone loop produces unequal amplitudes in detected mark and space tones. The inequality or offset must be cancelled so that a proper timing signal can...
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5373533 |
FSK signal receiving device
An FSK signal receiving device is constituted by a first phase shifting circuit for applying a first phase shift to a first reception base band signal of first and second reception base band...
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5333151 |
High speed frequency-shift keying decoder
A frequency-shift keying (FSK) signal detector splits an FSK signal into two paths. In one path, a phase-altering circuit having a variable frequency characteristic between the two encoding...
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5311556 |
Digital FSK transmitter receiver and method of operating same
A digital FSK receiver includes a zero-crossing detector which detects the zero crossings in an FSK signal having at least two signal frequencies. The time interval between zero crossings is then...
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5309113 |
FSK data demodulator
An FSK demodulator for demodulating first and second baseband signals obtained from a received frequency shift keying signal, the first and second baseband signals having a quadrature relation...
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5293408 |
FSK data receiving system
A data receiving system comprising an I base-band signal and a Q base-band signal which are used in a quadrature demodulation operation. Zero-crossing points of respective base-band signals are...
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5278514 |
MSK demodulator using one synchronous detector
An MSK signal demodulating circuit including a carrier reproducing circuit for reproducing a carrier phase-synchronized with a component of a mark frequency or a space frequency of an MSK signal, a...
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5197085 |
Radio receiver
A receiver for FSK signals produces quadrature related first and second frequency down-converted difference signals (I and Q), which are amplitude limited to form respectively first and second...
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5155446 |
Digital FSK demodulator
Digital FSK demodulators to be used in the telephone environment are disclosed. The demodulator according to one embodiment uses the sequential processing of a digital signal encoded in the...
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5150382 |
Frequency error detecting apparatus
A frequency error detecting apparatus for an FSK signal communication system in which data symbols are represented by frequencies displaced from a center frequency, includes a counter for counting...
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