| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 375334000 | Frequency shift keying | 24 |
| 20080240300 | METHOD OF PROCESSING ABNORMAL MODULATION SIGNAL, AND RECEIVER HAVING ABNORMAL MODULATION SIGNAL COMPENSATION FUNCTION - A method of detecting an abnormal modulation signal, and a receiver for compensating for an abnormal modulation signal are provided. The method includes demodulating an analog input signal, which has been modulated according to modulation parameters, using demodulation parameters corresponding to the modulation parameters to generate a baseband signal; sampling the baseband signal at a sampling rate; counting a number of samples having an amplitude greater than a threshold level during a detection window; and determining whether the analog input signal has been abnormally modulated, based on the number of samples counted. The receiver includes a baseband signal generator; a sampler; an abnormal modulation detector which counts a number of samples and determines whether the analog input signal has been abnormally modulated; a demodulation parameter modifier which modifies the demodulation parameters according to the determination result. | 10-02-2008 |
| 20080260071 | Methods and Apparatus for Frequency Synthesis with Feedback Interpolation - A frequency synthesis circuit includes a phase locked loop and an interpolator circuit. The phase locked loop circuit receives a reference clock and a feedback clock and generates an output clock with a frequency based on the reference clock and the feedback clock. An interpolator circuit is coupled in the feedback path of the phase locked loop circuit. An interpolator control circuit generates an interpolator control word that specifies a variable time delay for the interpolator circuit. The interpolator circuit receives the output clock, and generates the feedback clock by introducing a variable time delay in the output clock in accordance with the interpolator control word. The time variable delay varies the frequency of the output circuit. Embodiments for frequency synthesis circuits that include a spread spectrum frequency clock generator, frequency modulators, and a fixed frequency clock generator circuit are disclosed. | 10-23-2008 |
| 20090129510 | FREQUENCY SHIFT KEYING (FSK) DIGITAL SIGNAL RECEIVING APPARATUS - A frequency shift keying digital signal receiving apparatus includes a detecting portion detecting a new signal on the basis of a signal, from which a correlated ambient noise is filtered out by an adaptive filter, a holding portion holding a first electric power for the signal received before a new signal is detected, a calculating portion calculating a second electric power for the signal received after the new signal is detected, a comparing portion comparing levels of the first and second electric powers, a selector selecting the signal, from which the correlated ambient noise is filtered out, when the first electric power is higher than the second electric power and selecting the signal bypassing the adaptive filter when the first electric power is lower than the second electric power, and a demodulating portion demodulating a desired signal on the basis of the signal selected by the selecting portion. | 05-21-2009 |
| 20090238308 | Ultra low-power transmission system - An ultra low-power transmission system for use with a battery-operated device. The ultra-low power transmission system comprises an encoded transmitter and an addressable ultra -low power receiver. The ultra low-power receiver comprises an RF front-end block for receiving and demodulating an incoming RF signal. The RF front-end block includes an amplifier for amplifying the received RF signal and a frequency discriminator for demodulating the amplified RF signal to produce a baseband signal. The amplifier and the frequency discriminator are each comprised of enhancement mode, high-mobility electron transistors (E-HEMTs). The ultra low-power further receiver comprises a correlator for receiving the baseband signal from the frequency discriminator and detecting a codeword therein. The correlator comprises a plurality of switched capacitors for storing samples of the baseband signal. The correlator is operable to couple the plurality of switched capacitors in order to integrate the samples stored thereon. | 09-24-2009 |
| 20100158158 | WIDE-BAND SIGNAL PROCESSOR - A signal processor for processing a digital input signal including samples sampled at a sampling frequency, the signal processor comprising a plurality of filters arranged to divide the digital input signal into a first signal in a first frequency band below a first cut-off frequency, and a second signal in a second frequency band above a second cut-off frequency; first frequency shifting circuitry arranged to shift the second signal to a frequency band below the first cut-off frequency; decimation circuitry arranged to decimate the first signal and the shifted second signal; and processing circuitry arranged to process the decimated first and second signals. | 06-24-2010 |
| 20110038440 | Process for Receiving a Signal and a Receiver - A process for receiving a GMSK-modulated signal which, for simultaneously transmitting two services, has an in-phase signal with a pseudo-random code that differs from the quadrature signal. By means of a decomposition filter in a reference signal branch detects one service independently of the other during the correlating with the received signal. | 02-17-2011 |
| 20110129040 | METHOD OF ESTIMATING LOG-LIKELIHOOD RATIOS AND RELATIVE S-FSK RECEIVER - A method of estimating log-likelihood ratios for first and second streams of samples of a received S-FSK signal demodulated using first and second carriers includes estimating channel and noise parameters associated with first and second transmitted values for the first and second streams of samples obtained from the received S-FSK modulated signal. Current signal-to-noise ratios are estimated for current samples of the first and second streams of samples obtained from the received S-FSK modulated signal using the channel and noise parameters. The estimated current signal-to-noise ratios are compared with values of a discrete ordered set and respective pairs of consecutive values of the discrete ordered set between which the estimated current signal-to-noise ratios are comprised are identified. Log-likelihood ratios are estimated for the current samples of the first and second streams. | 06-02-2011 |
| 20110142173 | RECEIVERS AND SYMBOL DECODERS THEREOF - A receiver capable of decoding a symbol based on information on a previous symbol, the symbol and a next symbol in a Gaussian frequency shift keying (GFSK) communication system is provided. The receiver includes a discriminator to generate a symbol for each bit in a bit sequence, a first lookup table (LUT) to store a number of bit patterns and mapping patterns, wherein each of the bit patterns is in the form of a set of consecutive bits in the bit sequence and corresponds to a respective one of the mapping patterns, and wherein each of the mapping patterns includes a set of entries and each of the entries results from an operation of attribute values at a sample time in the waveform of a symbol, a calculator to receive a set of consecutive symbols from the discriminator and calculate a distance value between the set of consecutive symbols and each of the mapping patterns, and a comparator to identify one of the mapping patterns with a minimum distance value by comparing among the distance values from the calculator. | 06-16-2011 |
| 20110228882 | DECODING ALGORITHM FOR FREQUENCY SHIFT KEY COMMUNICATIONS - A method and apparatus for decoding binary frequency shift key signals in which an exclusive-OR of the sign of a real waveform with a sign of the imaginary waveform at a time shortly after the real (or, alternatively, the imaginary) waveform crosses zero is used to determine a bit represented by the signal. In some embodiments, particularly those in which the bit period is about one-half of the carrier signal frequency, both the real and imaginary waveforms are monitored to detect the zero crossing in order to account for the situation in which data transitions prevent zero-crossings on one of the waveforms. | 09-22-2011 |
| 20110243277 | DEVICES AND METHODS IMPLEMENTING FREQUENCY OFFSET DETERMINATION FOR FSK RECEIVERS - An RF receiver ( | 10-06-2011 |
| 20120027132 | GFSK RECEIVER ARCHITECTURE AND METHODOLOGY - A Gaussian Frequency Shift Key (GFSK) receiver includes a receiver front end to receive a GFSK-modulated signal and convert the received GFSK-modulated signal to a baseband frequency modulated signal, a channel filter to reduce channel interference which is adjacent to a desired channel of the baseband frequency modulated signal, a demodulator to demodulate the channel filtered baseband modulated signal and to recover a sequence of symbols, a digital filter to reduce inter-symbol interference (ISI) from the sequence of symbols, a slicer to produce symbol decisions based on the filtered sequence of symbols, and a symbol-to-bit mapper to map the symbol decisions to data bits. | 02-02-2012 |
| 20120045023 | LOW RATE, DIRECT CONVERSION FSK RADIO-FREQUENCY SIGNAL RECEIVER - The receiver ( | 02-23-2012 |
| 20120163506 | GFSK MODULATOR AND A METHOD FOR REDUCING RESIDUAL FREQUENCY MODULATION AND A DIGITAL ENHANCED CORDLESS TELECOMMUNICATION TRANSMITTER INCLUDING THE GFSK MODULATOR - A GFSK modulator comprises: a first compensation module, configured to receive a GFSK pulse signal, apply a first amplitude compensation and a first delay compensation to the GFSK pulse signal, so as to generate a first compensated control signal; a second compensation module, configured to receive the GFSK pulse signal, apply a second amplitude compensation and a second delay compensation to the GFSK pulse signal, so as to generate a second compensated control signal; a closed-loop PLL module including a closed-loop PLL, configured to receive and use the first and the second compensated control signals to generate a modulated signal. | 06-28-2012 |
| 20120177150 | RECEIVER - A receiver comprises an input-stage circuit, a filter circuit, an output-stage circuit and a digital control oscillator. The input-stage circuit has a mixer configured for mixing the GFSK signal and a feedback signal to generate an input-stage current signal to the filter circuit. Then the filter circuit filters the input-stage current signal, and converts it into a voltage signal. The output-stage circuit is coupled to the filter circuit, for converting the voltage signal into a digital output data. In addition, the digital control oscillator is coupled to the output-stage circuit, for outputting the feedback signal based on the digital output data. | 07-12-2012 |
| 20130051496 | SINGLE-PHASE DOWN-CONVERTER FOR TRANSLATING IMAGE INTERFERENCE TO GUARD BANDS AND MULTI-MODE WIRELESS COMMUNICATION RECEIVER INCLUDING SINGLE-PHASE DOWN-CONVERSION RECEIVING CIRCUIT AND DUAL-PHASE DOWN-CONVERSION RECEIVING CIRCUIT - A single-phase down-converter includes a mixer and a local oscillator (LO) signal generator. The mixer is arranged to generate a mixer output signal by mixing a radio frequency (RF) signal and an LO signal. The LO signal generator is coupled to the mixer, and arranged to generate the LO signal with a frequency shifted from an RF carrier frequency by a specific intermediate frequency, wherein when image interference exists, the specific intermediate frequency makes the image interference translated to guard band(s) of channel(s). | 02-28-2013 |
| 20130156132 | SYMBOL ERROR DETECTION FOR BLUETOOTH BASIC DATA RATE PACKETS - A symbol error detector can be configured to detect symbol errors of GFSK modulated portions of a Bluetooth packet without relying solely on a CRC error detection mechanism. The symbol error detector can operate on frequency error signals that are a difference between a frequency associated with a current symbol and predetermined frequency outputs from a bank of filters matched to a frequency response of the Bluetooth receiver for predefined combinations of three consecutive symbols (i.e., an estimated previously decoded symbol, an estimated current symbol, and an estimated subsequent symbol). The frequency error signals can be compared against a threshold and against each other to determine a potential unreliability in decoding the current symbol and to determine whether to generate a symbol error notification. The frequency error signals being within a threshold of each other can indicate potential unreliability in decoding the current symbol. | 06-20-2013 |
| 20140023164 | RECEIVING APPARATUS AND METHOD IN SMART UTILITY NETWORK COMMUNICATION SYSTEM - A receiving apparatus receives an FSK signal, converts the FSK signal into a phasor including amplitude and phase, estimates and compensates for a CFO (carrier frequency offset) from the converted phasor, and recovers a data bit from the converted phasor. | 01-23-2014 |
| 20150103957 | HART Sampling - A method for processing an electrical signal comprises receiving an electrical signal comprising a frequency modulated signal encoding digital data, sampling a first portion of the electrical signal to provide a first sample set, and determining an intermediate value from the first sample set. A first output value is selected from a plurality of stored output values based on the intermediate value, the output value indicating a frequency modulation encoded value within the first portion of the electrical signal. An indication of the obtained output value is output. | 04-16-2015 |
| 20150139363 | FREQUENCY-SHIFT KEYING RECEIVER - A frequency-shift keying (FSK) receiver includes an injection-locking oscillating circuit to receive a FSK input signal, and a phase detecting circuit. The injection-locking oscillating circuit outputs a locked signal having a phase that tracks a phase of the FSK input signal. A difference between the phases of the FSK input signal and the locked signal is associated with a difference between a frequency of the FSK input signal and a free-running frequency of the injection-locking oscillating circuit. The phase detecting circuit receives the FSK input signal and the locked signal, and outputs a baseband logic signal according to the difference between the phases of the FSK input signal and the locked signal. | 05-21-2015 |
| 20150146823 | Wireless Network Receiver - A wireless network receiver includes a detection module that uses preamble data in a data frame for signal processing functions and the detection module is configured to adjust the number of preamble data bits that are used based on the power of a received signal. | 05-28-2015 |
| 20160134439 | FREQUENCY SHIFTING A COMMUNICATIONS SIGNAL(S) IN A MULTI-FREQUENCY DISTRIBUTED ANTENNA SYSTEM (DAS) TO AVOID OR REDUCE FREQUENCY INTERFERENCE - Frequency shifting a communications signal(s) in a multiple frequency (multi-frequency) distributed antenna system (DAS) to avoid or reduce frequency interference is disclosed. Related devices, methods, and DASs are disclosed. Non-limiting examples of frequency interference include frequency band interference and frequency channel interference. As a non-limiting example, frequency interference in a multi-frequency DAS may result from non-linearity of a signal processing component generating an out-of-band harmonic of a first, in-use communications signal in a first frequency band, within different frequency band(s) of other in-use communications signal(s). To avoid or reduce such interference, embodiments disclosed herein involve predicting frequency interference that may result from processing received, in-use communications signals in multiple frequency bands to be distributed in a multi-frequency DAS. Frequency shifting is performed to avoid or reduce any interfering signal products produced from the signal processing of any in-use communications signals, from interfering in the frequencies of other in-use communications signals. | 05-12-2016 |
| 20160134451 | RECEIVING APPARATUS AND DEMODULATION METHOD - This receiving apparatus achieves circuit size reduction and consumption power reduction, while still having an advantage of high-speed processing. In a receiving apparatus ( | 05-12-2016 |
| 375335000 | More than two frequencies | 1 |
| 20080260072 | APPARATUS FOR RECEIVING AND RECOVERING FREQUENCY SHIFT KEYED SYMBOLS - A receiver architecture for receiving an FSK signal having a predetermined number of modulation levels includes a selectivity filter ( | 10-23-2008 |
| 375336000 | Minimum shift keying | 1 |
| 20140185710 | APPARATUS AND METHOD OF PROVIDING TRAFFIC INFORMATION USING RADIO TRAFFIC BROADCASTING - An apparatus and a method that provide traffic information using radio traffic broadcasting that provides corresponding traffic information to a driver when the driver requests the corresponding traffic information, without requiring a separate digital modulation module, by recording radio traffic broadcasting in a streaming scheme. In addition, corresponding traffic broadcasting is extracted and stored in a file form when a street name, a land mark, a location name, or the like, on a destination path set by the driver is recognized as an audio in the recorded radio traffic broadcasting. | 07-03-2014 |
