Entries |
Document | Title | Date |
20080225988 | LOW NOISE LOGARITHMIC DETECTOR - A logarithmic detector circuit including a drive circuit to receive a modulated input signal and generate a buffered modulated signal, a signal shaping circuit coupled to the drive circuit and configured to shape a voltage range of the buffered modulated signal to generate a shaped modulated signal, and a detecting circuit to detect the shaped modulated signal to generate an output signal substantially proportional to a logarithm of an amplitude of the modulated input signal. | 09-18-2008 |
20080247490 | Receiver For Amplitude-Modulated Signals - In a receiver, a synchronization circuit (MIX | 10-09-2008 |
20080292024 | AMPLITUDE-SHIFT-KEYING (ASK) RADIO-FREQUENCY (RF) SIGNAL DECODING DEVICE AND METHOD THEREOF - An amplitude-shift-keying radio-frequency (ASK RF) signal decoding method includes separating a low frequency and a high frequency from an ASK RF signal, which includes a pause section and a non-pause section, generating a divided signal by dividing the high frequency signal, counting the divided signal for the non-pause section of the low frequency signal, and decoding the ASK RF signal based on a result of the counting. | 11-27-2008 |
20080298507 | Electronic Quadrature Device - An electronic quadrature device is provided comprising at least one I signal path (I) and at least one Q signal path (Q); at least one first sigma-delta modulator (DSDMI) and at least one first digital/analog converter unit (DACI) arranged in the at least one I signal path (I); and at least one second sigma-delta modulator (DSDMQ) and at least one second digital/analog converter unit (DACQ) arranged in the at least one Q signal path (Q). The at least one first sigma-delta modulator (DSDMI) is coupled to the at least one second sigma-delta modulator (DSDMQ) via at least one complex signal path (C | 12-04-2008 |
20080298508 | RECEIVER FOR ESTIMATING SIGNAL MAGNITUDE, NOISE POWER, AND SIGNAL-TO-NOISE RATIO OF RECEIVED SIGNALS - An improved receiver and method estimate one or more parameters, such as amplitude and signal-to-noise ratio, of a received signal, such as an M-QAM or q-ASK signal. The amplitude of an M-QAM signal is estimated based upon known or ascertainable phase information regarding a plurality of transmitted symbols. The amplitude of a q-ASK signal is estimated based upon known or ascertainable magnitude information regarding a plurality of transmitted symbols. In another embodiment, the amplitude of an M-QAM or q-ASK signal is estimated based on statistical knowledge of the amplitude of the transmitted symbols. Other embodiments estimate amplitude, noise power, and signal-to-noise ratio of a received signal utilizing second-order and fourth-order moments of received samples, a maximum likelihood searching process, or a Kurtosis estimation process. | 12-04-2008 |
20080298509 | RF Power Transmission, Modulation, and Amplification, Including Embodiments for Generating Vector Modulation Control Signals - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion. | 12-04-2008 |
20080310551 | Decoder for 4QAM-NR and method thereof - A 4QAM-NR decoder and decoding method are disclosed. The 4QAM-NR decoder, obtains original data corresponding to receiving data received by a receiving terminal. The 4QAM-NR decoder comprises a determining device, an improving device and a corresponding device. The determining device provides a determining method to determine whether the receiving data is improved or not. The improving device improves the receiving data. The corresponding device obtains the approximate original data corresponding to the receiving data. | 12-18-2008 |
20090034658 | Self-mixing Receiver and Forming Method Thereof - This invention is primarily a circuit structure of self-mixing receiver, and the methodology of circuit structure is described as follows. The first stage is a high input impedance voltage amplifier utilized to amplify the received RF carrier signal from the antenna. Besides, there are no any inductors required. The second stage is a multi-stage amplifier to amplify the output signal of first stage to rail-to-rail level, which is quite the same with supply voltage. The third stage is a mixer adopted to lower the signal frequency. The fourth stage is a digital output converter, which is proposed to demodulate the electric signals and convert the demodulated signal to digital signal. | 02-05-2009 |
20090110118 | ADAPTIVE DEINTERLEAVER MEMORY ALLOCATION - A receiver for use in a wireless network comprising a communications channel and a method of allocating deinterleaver memory usage in the receiver, wherein the receiver comprises a processor adapted to organize subchannels of the communications channel and set a number (N) of data bits per soft decision, wherein the soft decision is represented by N data bits; an address decoder adapted to decode the subchannels; a demapper adapted to receive QAM symbols and demap the QAM symbols to soft decisions; a deinterleaver adapted to perform deinterleaving on the soft decisions, wherein the deinterleaver comprises a memory component having a storage size that is a function of the number (N) of bits per soft decision; and a Viterbi decoder adapted to decode the deinterleaved soft decisions. | 04-30-2009 |
20090141830 | RECEIVER AND METHOD FOR RECEIVING WIRELESS SIGNALS - A receiver and method for receiving wireless signal are characterized in that a multi-branch correcting and switching module ( | 06-04-2009 |
20090154599 | Apparatus and method for detecting communications from multiple sources | 06-18-2009 |
20090154600 | QRD-QLD searching based sphere detector for MIMO receiver - An apparatus includes a receiver configurable to receive signals from y pairs of antennas, where y is greater than one, and where the received signals convey coded bits of information. The apparatus further includes a detection block that includes a plurality of search modules configurable to process signals received from pairs of the antennas in parallel to find partial Euclidian distances and determine valid partial candidates for individual antennas; and a plurality of sort modules configurable to sort the valid partial candidates to find M best partial candidates to be combined into M | 06-18-2009 |
20090185640 | DEMODULATION CIRCUIT, DIGITAL MICROWAVE SYSTEM AND DEMODULATION METHOD - A demodulation circuit, a digital microwave system including the demodulation circuit, and a signal demodulation method are provided. The demodulation circuit includes a first circuit, a second circuit, a third circuit, and a fourth circuit connected in turn. The fourth circuit includes a pulse counting unit and a data decision unit connected in turn. The signal demodulation method includes: performing bandpass filtering on input signals; increasing gains of the bandpass filtered signals; extracting pulse signals are extracted from the gain-increased signals; counting the extracted pulse signals; filtering the pulse signals having counting values falling outside of a predetermined range, and outputting the filtered pulse signals. | 07-23-2009 |
20090213964 | RADIO DETECTION DEVICE AND METHOD - A radio detection device includes two or more reception antennas, for detecting a detecting object by a mono-pulse method; the radio detection device including: a variable gain unit for discretely changing respective signal intensity of a difference signal and a sum signal of each reception signal received by the two or more reception antennas; an A/D conversion unit for performing A/D conversion process on the difference signal or the sum signal, the difference signal or the sum signal having the signal intensity changed by the variable gain unit; an angle calculating portion for calculating an angle by the mono-pulse method using the difference signal and the sum signal after the A/D conversion process by the A/D conversion unit; and a control unit for performing a control of individually switching a conversion magnification of the signal intensity by the variable gain unit with respect to the difference signal and the sum signal. | 08-27-2009 |
20090232255 | QAM SYMBOL SLICING METHOD AND APPARATUS - A method for slicing a symbol in a QAM digital demodulator, includes acquiring a digital integer value by sampling a symbol signal in an in-phase coordinate or a quadrature-phase coordinate; and extracting a symbol bit sequence in the in-phase coordinate or the quadrature-phase coordinate from a whole bit sequence of the digital integer value by using an LSB thereof. Further, a symbol slicer for detecting a QAM symbol, includes digital sampling units, each of which acquires a digital integer value by sampling a symbol signal in an in-phase coordinate or a quadrature-phase coordinate; and a symbol bit sequence extracting unit that extracts a symbol bit sequence in the in-phase coordinate or the quadrature-phase coordinate from a whole bit sequence of the digital integer value by using an LSB thereof. | 09-17-2009 |
20090257529 | LOW POWER, INTEGRATED RADIO TRANSMITTER AND RECEIVER - A low power (optionally, self-powered) integrated transceiver using on-chip antennas is provided. The transmitter and receiver utilize phase-locked loops (PLLs) which initially, in a closed-loop state, pre-tune (i.e. phase-lock) voltage controlled oscillators (VCOs) before opening the loops to allow them to transmit and receive data. The TX, in the opened-loop state, disables the loop components while (FM) modulating the VCO. The RX, in the opened-loop state, injection-locks the VCO with the incoming (FM) modulated signal while the remaining loop components serve to demodulate the signal. For both the TX and RX an integrated antenna can be used and, advantageously, the TX comprises a dual purpose inductor which functions as both an inductor in the voltage-controlled oscillator (i.e. in the resonant tank thereof) and the integrated antenna. | 10-15-2009 |
20090296856 | CARRIER PHASE SYNCHRONIZATION SYSTEM FOR IMPROVED AMPLITUDE MODULATION AND TELEVISION BROADCAST RECEPTION - Systems and methods are described for carrier phase synchronization for improved AM and TV broadcast reception. A method includes synchronizing the phase of a carrier frequency of a broadcast signal with the phase of a remote reference frequency. An apparatus includes a receiver to detect the phase of a reference signal; a phase comparator coupled to the reference signal-phase receiver; a voltage controlled oscillator coupled to the phase comparator; and a phase-controlled radio frequency output coupled to the voltage controlled oscillator. | 12-03-2009 |
20090310715 | RECEIVER AND METHOD FOR PROCESSING RADIO SIGNALS USING SOFT PILOT SYMBOLS - A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16QAM or 64QAM. The receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. | 12-17-2009 |
20090316835 | POWER SAVINGS IN HIERARCHICALLY CODED MODULATION - A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator. | 12-24-2009 |
20100002808 | SYSTEMS AND METHODS FOR PERFORMING SISO DETECTION IN A WiMAX ENVIRONMENT - In accordance with some embodiments, a communication system is described that comprises a soft-output detector configured to receive a transmit signal and output reliability information regarding the received signal. In accordance with such embodiments, the detector comprises a symbol combiner configured to operate in both a repetition mode and a non-repetition mode, wherein repetition mode comprises receiving a plurality of signals for the transmit signal. | 01-07-2010 |
20100002809 | PHY sub-channel processing - Physical layer (PHY) sub-channel processing. A soft symbol decision stream is arranged into a number of sub-channels to reduce substantially the processing performed within a communication receiver on data that is not intended for that communication receiver. In other embodiments, a predetermined approach is employed to arrange the soft symbol decision stream into one or more frames; each frame may have one or more soft symbol blocks; and each soft symbol block may have one or more symbols. Each of the soft symbol blocks, within a frame, may be assigned to a sub-channel. Only the soft symbol blocks that contain information destined for the communication receiver need be decoded. Only the sub-channel that includes these soft symbol blocks, destined for this communication receiver, need be decoded. The soft symbol blocks not within the sub-channel may be discarded thereby recovering some of the processing capabilities of the communication receiver. | 01-07-2010 |
20100014612 | QAM DEMODULATION - A method of demodulating a signal on which is modulated, using a quadrature amplitude modulation scheme, a plurality of information symbols, the method including: determining at least one QAM detection threshold corresponding to one or more of said information symbols; and demodulating each information symbol on the basis of at least one respective QAM detection threshold. | 01-21-2010 |
20100046673 | RECEIVER FOR ESTIMATING SIGNAL MAGNITUDE, NOISE POWER, AND SIGNAL-TO-NOISE RATIO OF RECEIVED SIGNALS - A method and apparatus for estimating attributes of a received signal that includes a plurality of transmitted signals are provided. The amplitude of the received signal is estimated by performing a method of demodulation based on known signal information. The amplitude of an M-ary quadrature amplitude modulated signal is estimated based upon known or ascertainable phase information regarding a plurality of transmitted symbols. The amplitude of a q-ary amplitude shift keyeing signal is estimated based upon known or ascertainable magnitude information regarding a plurality of transmitted symbols. Statistical information is also used for amplitude estimation. | 02-25-2010 |
20100054365 | Multilevel Cluster-based MIMO Detection Method and MIMO Detector Thereof - A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation. | 03-04-2010 |
20100074373 | BROADCAST RECEIVER AND CHANNEL SEARCHING METHOD USING THE SAME - Disclosed is a broadcast receiver. The broadcast receiver comprises a signal receiver for tuning and outputting a Q channel of a digital broadcasting signal, a demodulator for demodulating a signal of the received channel and checking a lock state M or an unlock state of a gain control signal and a timing control signal of the channel, and a demodulation controller for controlling o an operation of the demodulator and detecting a lock state of the channel based on the lock state of the gain control signal and the timing control signal. | 03-25-2010 |
20100119010 | Control Modules - A circuit is provided comprising detector circuitry, calculating circuitry, and determining circuitry. The detector circuitry is figured to generate an I data signal magnitude value of a sampled I data signal and a Q data signal magnitude value of a sampled Q data signal. The calculating circuitry is configured to calculate a phase shift angle φ | 05-13-2010 |
20100142649 | SYSTEM AND METHOD OF GENERATING SOFT BITS - A receiver receives a received signal from a communication link, the received signal comprising a stream of symbols modulated onto a carrier, each of the stream symbols selected from a constellation of symbols to represent a plurality of encoded data bits. The receiver comprises a demodulator to produce a stream of received symbols derived from the received signal; a channel decoder to produce a received stream of data bits derived from the stream of received symbols; and a memory device to store information related to the plurality of symbols in the constellation. For each of the symbols in the stream of received symbols, the demodulator: determines which of the plurality of symbols in the constellation is a respective closest symbol to that received symbol; identifies a respective nearest neighbor symbol for each data bit represented by the closest symbol for that received symbol based on the information stored in the memory device; and for each data bit represented by the respective closest symbol for that received symbol, subtracts the distance between the respective closest symbol and that received symbol from the distance between the respective nearest neighbor symbol and that received symbol in order to produce respective soft bits for that received symbol. | 06-10-2010 |
20100158157 | ASK DEMODULATOR, COMMUNICATION MODULE, COMMUNICATION DEVICE, AND ASK DEMODULATION METHOD - According to one embodiment, an ASK demodulator includes a rectifier, a first low-pass filter, a second low-pass filter, a comparator, and a threshold controller. The rectifier rectifies an ASK signal. The first low-pass filter outputs a signal corresponding to an envelope curve output from the rectifier. The second low-pass filter outputs an integrated signal of the signal output from the first low-pass filter. The comparator detects an output logic in accordance with comparison between the signal output from the first low-pass filter and a threshold obtained by adding a predetermined hysteresis width to the integrated signal output from the second low-pass filter. The threshold controller controls the threshold by setting the predetermined hysteresis width based on a direct current offset voltage caused by element dispersions of the comparator. | 06-24-2010 |
20100172443 | SYSTEMS AND METHODS OF CLASSIFYING AND DECODING WIRELESS SIGNALS - Systems and methods of classifying and decoding wireless signals are disclosed. A receiver may receive wireless signals from multiple transmitters. The receiver may use sphere decoding to classify the wireless signals (e.g., determine the modulation scheme of the wireless signals) and decode the wireless signals (e.g., determine the symbol and/or symbols transmitted using the wireless signals). | 07-08-2010 |
20100172444 | METHOD FOR DIGITAL WIRELESS COMMUNICATIONS - In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established. | 07-08-2010 |
20100189196 | AMPLITUDE SHIFT KEYED (ASK) DEMODULATION PATTERN AND USE IN RADIO FREQUENCY IDENTIFICATION (RFID) - A demodulation circuit for an Amplitude Shift Keyed (ASK) modulated signal includes an envelope detector, an alternating voltage amplifier, a differentiator circuit, and a comparator having a hysteresis connected in series. The envelope detector produces an envelope signal from the received ASK signal. The amplifier blocks the DC component of the envelope signal and amplifies AC components of the envelope signal to obtain a steeper slope of the rising and falling edges. The differentiator circuit then processes the transition edges to provide a differentiated signal having positive and negative electrical pulses. The comparator converts the pulses into a binary data stream which corresponds to the transmitted data stream. The combination of the differentiated signal and comparator having a hysteresis enables better stability and sensitivity of the ASK demodulation circuit. | 07-29-2010 |
20100195768 | VITERBI EQUALIZATION WITH DETECTION OF THE NEAREST CONSTELLATION POINTS FOR STAGE REDUCTION - The device is used for decoding convolution-encoded reception symbols. In this context, transmission data are modulated with a modulation scheme to form symbols, which are encoded with a transmission filter to form convolution-encoded transmission symbols. A convolution-encoded transmission symbol contains components of several symbols arranged in time succession. These transmission symbols are transmitted via a transmission channel and received as reception symbols. The Viterbi decoder decodes the reception symbols by use of a modified Viterbi algorithm. Before running through the Viterbi decoder, the reception symbols are processed by a state-reduction device, which determines additional items of information relating to possible consequential states of the decoding independently of the decoding through the Viterbi decoder in every state of the decoding. The state-reduction device uses the additional items of information to restrict the decoding through the Viterbi decoder to given consequential states. | 08-05-2010 |
20100195769 | Method And Apparatus For Generating M-ary CPM Waveforms From A Superposition Of PAM Waveforms - To reflect advantages of a constant phase modulation waveform, the invention provides a pulse amplitude modulated PAM waveform that is a superposition of Q | 08-05-2010 |
20100208846 | RADIO RECEIVING APPARATUS AND RADIO RECEIVING METHOD - A radio receiving apparatus and a radio receiving method wherein synchronization is established at a high speed with high reliability. An IR receiver ( | 08-19-2010 |
20100232547 | CIRCUIT AND METHOD FOR CONTROLLING A RECEIVER CIRCUIT - A method for controlling a receiver circuit and circuit with a receiver circuit and with a control circuit is provided, whereby a received signal is demodulated and filtered. An amplitude value of the demodulated and filtered signal is compared with thresholds of a window comparator. A zero crossing of the demodulated and filtered signal is compared with time thresholds of a time window by a comparison unit. A first output value of the window comparator and a second output value of the comparison unit are logically combined, and wherein, via the logical combination, the receiver circuit is turned off if, within a period of time, the amplitude value is determined to be outside a window formed by the thresholds of the window comparator, or a zero crossing is determined to be outside the time window. | 09-16-2010 |
20100278284 | METHOD AND SYSTEM FOR SYMBOL DETECTION USING SUB-CONSTELLATIONS - Systems and methods for symbol detection using sub-constellations are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process received chips into received symbols for a plurality of users, a first detection unit configured to detect first components of user symbols for the plurality of users based on the received symbols and a computation unit configured to compute a portion of the received symbols due to the first components of the user symbols. The apparatus further comprises a second detection unit configured to detect second components of the user symbols based on the received symbols with the computed portion removed and a combining unit configured to detect the user symbols by combining the first components of the user symbols with the respective second components of the user symbols. | 11-04-2010 |
20100290565 | CONSTELLATION RECOVERY FOR QUADRATURE AMPLITUDE MODULATION - Methods and apparatus are provided for receiving an input signal. In an embodiment of the invention a current candidate QAM constellation can be selected. A mean squared error of a signal responsive to the input signal can be computed based on the current candidate QAM constellation. The computed mean squared error can be compared to a threshold error value. The invention advantageously allows for relatively efficient and relatively reliable equalization of signals transmitted with an unknown QAM constellation, and allows for relatively efficient and reliable recovery of the unknown QAM constellation. | 11-18-2010 |
20100296608 | METHOD AND ARRANGEMENT RELATING TO RADIO SIGNAL TRANSMISSIONS - The present invention aims to provide a method for fast and exact ML low-complexity demodulation in for example MIMO systems. The present invention relates to a method and arrangement for processing signals, especially a Maximum Likelihood (ML) demodulation of Quadrature Amplitude Modulation (QAM) signals, in a digital communications system, having a number of transmit antennas transmitting n | 11-25-2010 |
20110051851 | DEMODULATION USING SERIAL LOCALIZATION WITH INDECISION - A receiver includes a constellation processing module and a plurality of demodulation stages. The constellation processing module groups points of a constellation associated with a transmitted signal into a plurality of subsets, were at least two adjacent ones of the subsets have one or more common constellation points so that the at least two adjacent subsets overlap. The constellation processing module also determines a centroid-based value for each of the subsets of constellation points and groups the centroid-based values into one or more sets. Each of the demodulation stages except for the last demodulation stage localizes a search for a final symbol decision using the set of centroid-based values input to or selected by the demodulation stage as constellation points. The last demodulation stage determines the final symbol decision using the subset of constellation points input to or selected by the last demodulation stage. | 03-03-2011 |
20110051852 | JOINT DEMODULATION AND INTERFERENCE SUPPRESSION USING SERIAL LOCALIZATION WITH INDECISION - A receiver includes a constellation processing module and a multi-stage demodulator having a plurality of non-final demodulation stages and a final demodulation stage. The constellation processing module derives a set of centroid-based values from subsets of constellation points associated with a plurality of transmitted signals for input to each of the non-final demodulation stages. Each of the non-final demodulation stages demodulates a group of signals input to the non-final demodulation stage using the set of centroid-based values as constellation points and suppresses residual interference associated with using the set of centroid-based values as constellation points for signal demodulation. The final demodulation stage demodulates a group of modified signals input to the final demodulation stage using the subset of constellation points input to the final demodulation stage to determine a final symbol decision for the plurality of transmitted signals. | 03-03-2011 |
20110090990 | DEMODULATION APPARATUS, DEMODULATION METHOD, AND ELECTRONIC DEVICE - Disclosed herein is a demodulation apparatus including: an operation determination block configured to determine whether the demodulation apparatus operates as part of either a first device or a second device with which the demodulation apparatus communicates, the first device being configured to ASK-modulate and transmit data, the second device being configured to load-modulate and transmit data; and first and second demodulation control blocks. | 04-21-2011 |
20110129038 | RADIO COMMUNICATION METHOD, RADIO TRANSMITTING APPARATUS, AND RADIO RECEIVING APPARATUS - A duplicating section duplicates a bit sequence to be input, and a 16 QAM section modulates a bit sequence of a duplicating source to form a symbol, a 16 QAM section modulates the duplicated bit sequence to form a symbol, an S/P section parallel converts the symbol sequence input in series, an S/P section parallel converts the symbol sequence input in series, and an IFFT section | 06-02-2011 |
20110164704 | Amplitude Modulation Demodulating Circuit and Method Thereof - An amplitude modulation (AM) demodulating circuit applied to a radio frequency identification (RFID) system attenuates carrier signals by a notch filter to increase a signal-to-carrier ratio and to reduce complexity and cost of circuit design. The AM demodulating circuit includes an envelope detector, a notch filter, a low-pass filter, and a comparing circuit. The envelope detector performs envelope detection on an AM signal modulated by a carrier frequency to generate an envelope signal. The notch filter filters the envelope signal to generate a first filtered signal, and a zero point of the notch filter corresponds to the carrier frequency of the AM signal. The low-pass filter filters the first filtered signal to generate a second filtered signal, and the carrier frequency of the AM signal corresponds to a stop band of the low-pass filter. The comparing circuit converts the second filtered signal to a digital signal according to a level value. | 07-07-2011 |
20110188613 | Compact pulse shaping for QM-MSK and PAM/QAM reception - Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B | 08-04-2011 |
20110206164 | SIGNAL SPACE EXPANSION FOR A 16 QAM SCHEME - The invention relates to methods for transmitting and receiving a data bit stream in a communication system using a 16-QAM constellation. Further, an apparatus for performing the methods is provided. To provide a modulation and coding scheme using a signal space expansion and 16-QAM which improves the bit-error rate in comparison to QPSK modulated signals and still provides the possibility to implement coders and decoders with low complexity the invention suggests the use a 16-QAM constellation with specially selected mapping rules together with repetition coding (signal space expansion) and interleaving of the data stream to be transmitted. | 08-25-2011 |
20110293044 | Method and System for Channel Estimation in a Spatial Multiplexing MIMO System - Aspects of a method and system for channel estimation in a SM MIMO communication system may comprise receiving a plurality of spatially multiplexed communication signals from a plurality of transmit antennas. A plurality of baseband combined channel estimates based on phase rotation may be generated in response to the received plurality of spatially multiplexed communication signals. An estimate of the channel matrix may be determined based on the baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated in response to receiving the estimate of the channel matrix. An amplitude and a phase of at least a portion of the received plurality of spatially multiplexed communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively. | 12-01-2011 |
20120008720 | AMPLITUDE-SHIFT-KEYING (ASK) RADIO-FREQUENCY (RF) SIGNAL DECODING DEVICE AND METHOD THEREOF - An amplitude-shift-keying radio-frequency (ASK RF) signal decoding method includes separating a low frequency and a high frequency from an ASK RF signal, which includes a pause section and a non-pause section, generating a divided signal by dividing the high frequency signal, counting the divided signal for the non-pause section of the low frequency signal, and decoding the ASK RF signal based on a result of the counting. | 01-12-2012 |
20120027129 | DEMODULATION CIRCUIT, DIGITAL MICROWAVE SYSTEM AND DEMODULATION METHOD - A demodulation circuit, a digital microwave system including the demodulation circuit, and a signal demodulation method are provided. The demodulation circuit includes a first circuit, a second circuit, a third circuit, and a fourth circuit connected in turn. The fourth circuit includes a pulse counting unit and a data decision unit connected in turn. The signal demodulation method includes: performing bandpass filtering on input signals; increasing gains of the bandpass filtered signals; extracting pulse signals are extracted from the gain-increased signals; counting the extracted pulse signals; filtering the pulse signals having counting values falling outside of a predetermined range, and outputting the filtered pulse signals. | 02-02-2012 |
20120063549 | SIGNAL RECEIVING APPARATUS, SIGNAL RECEIVING METHOD AND SIGNAL RECEIVING PROGRAM - A signal receiving apparatus has: a radius identifying section configured to identify a radius representing a distance from an origin on an IQ plane of signal points each corresponding to a symbol obtained from a received signal modulated by adoption of an APSK modulation method; and a parameter outputting section configured to output a control parameter related to a demodulation or decoding process of the received signal on the basis of the identified radius. | 03-15-2012 |
20120069935 | SYMBOL-LEVEL COMBINING FOR MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) SYSTEMS WITH HYBRID AUTOMATIC REPEAT REQUEST (HARQ) AND/OR REPETITION CODING - Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. The symbols of the received signal vectors are combined, forming a combined received signal vector that may be treated as a single received signal vector. The combined signal vector is then decoded using a maximum-likelihood decoder. In some embodiments, the combined received signal vector may be processed prior to decoding. Systems and methods are also provided for computing soft information from a combined signal vector based on a decoding metric. Computationally intensive calculations can be extracted from the critical path and implemented in preprocessors and/or postprocessors. | 03-22-2012 |
20120076243 | METHOD FOR LIMITING INTERFERENCE RECEIVED BY A PLURALITY OF DESTINATIONS - The present invention concerns a method for limiting interference received by a plurality of destinations, the interference being generated by plural flows of complex modulation symbols transferred by a plurality of sources on same resources of a wireless telecommunication network. The method comprises the steps executed by a relay of:
| 03-29-2012 |
20120082268 | METHOD FOR DIGITAL WIRELESS COMMUNICATIONS - In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established. | 04-05-2012 |
20120106678 | METHOD AND APPARATUS TO IMPROVE ACQUISITION OF A QUADRATURE AMPLITUDE MODULATED (QAM) SIGNAL HAVING A FREQUENCY OFFSET - A method and apparatus are described that result in an improved acquisition of a received communication signal containing a large frequency offset. The method and apparatus raises a derotated sequence of data to a power of an integer provide a sinusoidal spectral component. The method and apparatus determines a cross product based upon the sinusoidal spectral component to provide a phase error. The method and apparatus determines an oscillator signal based upon the phase error. The method and apparatus adjusts the received communication signal based upon the oscillator signal to compensate for the large frequency offset to provide the derotated sequence of data. | 05-03-2012 |
20120128101 | METHOD AND APPARATUS FOR ROBUST AND HIGH EFFICIENCY FEC FRAME HEADER RECOVERY - Methods and apparatus for FEC frame header detection are provided, suitable for use in a DVB-C2 receiver. A first method comprises demodulating with a quadrature phase shift keying (QPSK) demapper, followed by correlation and symmetry measures for detection of a robust FEC header. A second method comprises demodulating with a 16 quadrature amplitude modulation (QAM) demapper, followed by correlation and symmetry measures for detection of a high efficiency FEC leader. Another embodiment comprises using both the first and second methods to find the FEC header because the first symbol of the FEC frame header may be sent either in robust mode or in high efficiency mode. There is also provided a method and apparatus for generating an alternate decision statistic for determining detection of the FEC frame header. | 05-24-2012 |
20120134444 | Semiconductor Device Having First and Second Demodulation Circuits for Wireless Communication - A device receives ASK signals by using an ASK signal receiving circuit that is different from an ASK signal receiving circuit for R/W mode, when an NFC-enabled semiconductor device operates in a mode other than the R/W mode. An ASK signal receiving circuit for 100% ASK is provided on the side of a pair of transmitting terminals. This arrangement eliminates the influence of an ESD provided within an ASK signal receiving circuit for 10% ASK coupled to a pair of receiving terminals. There is no need for management of threshold values that are different according to type of ASK and it is possible to support different modulation schemes by a smaller circuit configuration. | 05-31-2012 |
20120134445 | RECEIVING APPARATUS AND RECEIVING METHOD - A duplicating section duplicates a bit sequence to be input, and a 16QAM section modulates a bit sequence of a duplicating source to form a symbol, a 16QAM section modulates the duplicated bit sequence to form a symbol, an S/P section parallel converts the symbol sequence input in series, an S/P section parallel converts the symbol sequence input in series, and an IFFT section | 05-31-2012 |
20120134446 | METHOD AND APPARATUS FOR RECEIVING DATA - Modem coding and modulation techniques have greatly improved the transmission and reception of signals. A method is described including receiving a signal de-mapping the signal into a first and second substream, decoding the first and second substream using a low density parity check decoding process, and combining the first and second decoded substream into a single data stream. An apparatus is described including a symbol de-mapper that receives a signal de-maps the modulation symbols in the signal into a first and second substream, a first decoder that decodes the first substream using a low density parity check coding process at a first decoding rate, a second decoder that decodes the second substream at a second encoding rate, and a combiner that combines the first substream and the second substream into a single data stream. | 05-31-2012 |
20120155574 | RECEIVER AND METHOD FOR PROCESSING RADIO SIGNALS USING SOFT PILOT SYMBOLS - A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. | 06-21-2012 |
20120170687 | Device and A Method for Obtaining a Radio Controlled Clock Signal - A device for obtaining a RCC signal and related methods are described herein improves the reliability of the RCC signal reception and demodulation. In one aspect, a device configured to obtain a RCC signal includes: a receiving circuit to receive an analog AM RCC signal and to process said analog AM RCC signal to generate a digital AM RCC signal; and a demodulation circuit in connection with said receiving circuit, to demodulate said digital AM RCC signal to generate the RCC signal. In another aspect, a method for obtaining a RCC signal includes: processing a received analog AM RCC signal to generate a digital AM RCC signal; and demodulating said digital AM RCC signal to generate said RCC signal. Since the digital processing method is more reliable than the analog processing method, the reliability of RCC signal reception and demodulation are improved. | 07-05-2012 |
20120183100 | Detector Circuit, Transponder and Method for Detecting Signal Amplitudes - A transponder circuit for receiving and processing an ASK signal having modulated communication information is provided. The transponder circuit includes a data receiver configured to receive the ASK signal. A reference clock extractor coupled to the data receiver is configured to extract a reference clock signal from the ASK signal. An amplitude determination unit is coupled to the data receiver and the reference clock extractor, and is configured to determine at least one amplitude value of the received ASK signal in at least one clock cycle of the extracted reference clock signal based on the extracted reference block. A processing unit, which is coupled to the amplitude determination unit, processes the amplitude value such that the communication information is retrieved. | 07-19-2012 |
20120243639 | DATA COMMUNICATION DEVICE, AIR PRESSURE MONITORING SYSTEM USING THEREOF, AND DATA COMMUNICATION METHOD - A data communication device includes: an antenna resonance circuit; a detection circuit; an arithmetic processing device; and a first switch. The antenna resonance circuit receives a signal in the ASK (Amplitude Shift Keying) format. The detection circuit demodulates a digital baseband signal based on the reception signal. The arithmetic processing device detects an appearance time of an edge in the demodulated digital baseband signal based on a preamble part of the reception signal. The first switch short-circuits both end of the antenna resonance circuit at first timing in synchronization with the appearance time of the edge. | 09-27-2012 |
20120250798 | MAXIMIZING DATA RATE BY ADJUSTING CODES AND CODE RATES - The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment. | 10-04-2012 |
20120257692 | RECEIVER SYSTEM AND METHOD OF OPERATION THEREOF - A method of operation of a communication system includes: utilizing an estimation module estimating a log-likelihood ratio for a transmission; and utilizing a slicing module, coupled to the estimation module, slicing a constellation by: reading the log-likelihood ratio from the estimation module, defining a threshold within the constellation, and adjusting the threshold based on the log-likelihood ratio for determining a symbol. | 10-11-2012 |
20120307941 | RADIO RECEIVER, METHOD OF CALIBRATING RADIO RECEIVER, METHOD OF CORRECTING TIME-INDUCED DEVIATION IN RADIO RECEIVER, AND RADIO BASE STATION APPARATUS - A radio receiver includes a signal divider that divides an intermediate frequency signal obtained by converting a frequency of a radio frequency signal received at an analog reception circuit, into a plurality of signal fragments based on an amplitude, and outputs the signal segments; and a plurality of analog to digital converters that perform an analog to digital conversion on the respective signal fragments divided by the signal divider, and output the signal fragments toward a digital reception circuit. | 12-06-2012 |
20120307942 | APPARATUS AND METHOD FOR SOFT DEMAPPING - Provided is a soft demapping apparatus that may detect a log likelihood ratio (LLR) value of a quadrature amplitude modulation (QAM) signal, using a shifted table scheme, may designate a sub-region of the QAM signal corresponding to bit information that is obtained by decoding the LLR value, and may calculate an LLR value of other bit information included in the designated sub-region. | 12-06-2012 |
20120328053 | Orthogonal Frequency Division Multiplexed (OFDM) Demodulator Imbalance Estimation - Techniques are provided for generating an estimate of the phase and magnitude imbalance of a receiver in a communication device. For each of a plurality of symbols in a signal received by the communication device, a plurality of tones that make up the symbol are obtained. For each of the plurality of symbols, each tone is multiplied by its respective mirror tone to produce a plurality of mirror tone multiplication results, and the plurality of the mirror tone multiplication results are summed over tones to produce a sum of multiplication results for each symbol. The total power of all tones for each symbol is obtained to produce a tone power quantity for each symbol. The estimate of the phase and magnitude imbalance in the received signal is generated based on the sum of the multiplication results for each of the plurality of symbols and the tone power quantity for each of the plurality of symbols. | 12-27-2012 |
20130044837 | RECEIVER AND INTEGRATED AM-FM/IQ DEMODULATORS FOR GIGABIT-RATE DATA DETECTION - Provision of gigabit-rate data transmission over wireless radio links, using carrier frequencies in the millimeter-wave range (>30 GHz). More specifically, a circuit for detection of amplitude-shift keyed (ASK) or other amplitude modulations (AM) which can be easily incorporated into an integrated circuit receiver system is described, making the receiver capable of supporting both complex IQ modulation schemes and simpler, non-coherent on-off or multiple-level keying signals. Several novel radio architectures are also described which, with the addition of a frequency discriminator network, have the capability of handling frequency shift keyed (FSK) or other frequency modulations (FM), as well as AM and complex IQ modulation schemes. These radio architectures support this wide variety of modulations by efficiently sharing detector hardware components. Disclosed herein are architecture for supporting both quadrature down-conversion and ASK/AM, ASK/AM detector circuit details, AM-FM detector architecture, and an AM-FM/IQ demodulator system and FSK/FM detector circuit details. | 02-21-2013 |
20130101071 | SIGNAL MONITORING PLATFORM - Aspects of the disclosure relate to signal monitoring at edge of a network domain in a network. A monitoring device can evaluate communication quality of information streams in downstream frequency channels, and operation conditions in a telecommunication network. In one aspect, communication quality can be evaluated at the physical layer level or at a higher-layer level containing payload data. In response to an operation issue, the monitoring device can transmit a notification to a node of a distribution platform of the telecommunication network. | 04-25-2013 |
20130107989 | Process for Performing Log-Likelihood-Ratio Clipping in a Soft-Decision Near-ML Detector, and Detector for Doing the Same | 05-02-2013 |
20130136210 | Metric Corrections for Demodulators Using Serial Localization with Indecision - Demodulation methods and apparatus for a multi-stage SLI demodulator are disclosed. Residual signals from each demodulation stage are modeled as finite sets of unresolved signals and a new metric is introduced for use in search of best candidate symbol estimates. The metric may be evaluated based on a probability distribution function of the residual signals or a probability mass function of the unresolved signals. The metric may also be approximated by the sum of a conventional Euclidean metric and a correction metric. The best candidate symbol estimates generated from each stage of the multi-stage SLI demodulator are summed to form cumulative symbol estimates. | 05-30-2013 |
20130156131 | METHOD AND APPARATUS FOR CORRECTING SIGNAL DEPENDENT DUTY CYCLE ERRORS IN AMPLITUDE SHIFT KEYING RECEIVERS - An apparatus for demodulating an Amplitude Shift Keying (ASK) encoded signal is provided. The apparatus comprises a peak detector, a first comparator, a threshold generator, a delay circuit, and a second comparator. The peak detector is configured to detect a peak voltage, and the first comparator is coupled to the peak detector and receives a first threshold voltage. The threshold generator is coupled to the peak detector and is configured to generate a second threshold voltage that is proportional to peak voltage. The delay circuit is coupled to the first comparator, and the second comparator is coupled to the delay circuit and that is coupled to the threshold generator so as to receive the second threshold voltage. | 06-20-2013 |
20130182797 | AMPLITUDE SHIFT KEYING DEMODULATOR AND METHOD FOR DEMODULATING AN ASK SIGNAL - An ASK demodulator comprises a rectification circuit which receives and rectifies an ASK signal to generate a rectified current; an active load circuit is coupled to the rectification circuit and receives the rectified current and present an impedance which is inversely proportional to at least a part of the rectified current when a frequency of a base band signal meets a preset condition; a comparator is coupled to the rectification circuit and the active load circuit and receives a reference voltage and a voltage generated based on, at least in part, the rectified current and the impedance, and compares the reference voltage and the generated voltage to generate a demodulated signal. | 07-18-2013 |
20130243129 | QUADRATURE ERROR COMPENSATING CIRCUIT - According to one embodiment, a quadrature error compensating circuit for acquiring an in-phase component signal and a quadrature component signal, includes a first filter, a first multiplier, a first subtractor, a second filter, a correlation calculating circuit. The first multiplier multiplies the in-phase component signal by a control value. The correlation calculating circuit calculates a cross-correlation value between an output of the first filter and an output of the second filter, and uses the cross-correlation value as the control value. | 09-19-2013 |
20130287146 | RECEIVER DEVICE, SYSTEM, AND METHOD FOR LOW-ENERGY RECEPTION OF DATA - A receiver device, A system and a method for reception of a signal having an amplitude that has been modulated with information, wherein a resistive element is provided that converts an electrical quantity into a physical parameter. | 10-31-2013 |
20130322569 | Digital Mobile Passive Leak Detection for Broadband Communication System - Passive detection of a quadrature amplitude modulated (QAM) signal amid noise is achieved by detection of a spectral component of a detected signal that corresponds to a known QAM symbol rate in, for example, a QAM modulated broadband communication system (BCS). Improved authentication can be provided by simultaneously detecting symbol rate components in two or more QAM bands. No modification of a broadband communication system such as by including a marker signal is required and thus there is no requirement for dedication of a portion of the broadband communication system spectrum or problem of marker signal interference with BCS signals. | 12-05-2013 |
20130343489 | DEMAPPER FOR ROTATED QAM CONSTELLATIONS - A method includes receiving a symbol modulated with multiple bits according to a signal constellation including multiple constellation points. A soft metric is computed for a given bit in the symbol: A first constellation point closest to the received symbol according to a distance measure is found. A row or column of the constellation points, which is closest to the first constellation point according to the distance measure, and over which a value of the given bit is constant and is opposite to the value of the given bit in the first constellation point, is identified. At least the identified row or column is searched for a second constellation point that is closest to the received symbol according to the distance measure. The soft metric is calculated based on the first and second constellation points. The value of the given bit is reconstructed based on the soft metric. | 12-26-2013 |
20140050285 | DATA RECEIVING CIRCUIT AND SEMICONDUCTOR DEVICE - A data receiving circuit that can accurately obtain a data signal corresponding to information data from a high speed high density transmitted signal, and a semiconductor device including the data receiving circuit. The amplitude of a first differential signal corresponding to a level difference between a pair of received differential signals, generated in a first differential stage, is amplified and binalized to obtain a received data signal. A second differential signal corresponding to the level difference between the received differential signals, and a third differential signal which is a phase-inverted signal of the second differential signal are generated in a second differential stage provided separately, and a current corresponding to the second differential signal and a current corresponding to the third differential signal are discharged into the respective ones of the pair of transmission lines, thereby suppressing the amplitudes of the received differential signals. | 02-20-2014 |
20140056386 | AMPLITUDE/ORTHOGONALITY ERROR COMPENSATOR - An amplitude/orthogonality error compensator includes: an amplitude corrector configured to perform an amplitude correction on an in-phase component and a quadrature component of an input complex signal based on amplitude error information, and to output a complex signal obtained through the amplitude correction; an orthogonality corrector configured to perform an orthogonality correction on the complex signal, obtained through the amplitude correction, based on orthogonality error information, and to output a complex signal obtained through the orthogonality correction; a filter section configured to allow a predetermined frequency component included in the complex signal obtained through the orthogonality correction to pass through the filter section; an amplitude error detector configured to obtain the amplitude error information based on the complex signal that has passed through the filter section; and an orthogonality error detector configured to obtain the orthogonality error information of the complex signal. | 02-27-2014 |
20140112416 | RECEIVING APPARATUS AND RECEIVING METHOD - An object of the present invention is to provide a receiving apparatus and a receiving method capable of preventing phase rotation of a signal after FFT from occurring on a frequency domain. Further, the receiving apparatus according to the present invention is provided with: a window control unit configured to control a position of an FFT window in which FFT is performed to the time domain signal, and output FFT data corresponding to the FFT window; a signal delaying unit configured to generate, from the time domain signal, a plurality of delay signals with different delay amounts; and a signal switching unit having a switch for outputting by switching between two of the time domain signal and the plurality of delay signals based on a predetermined switch timing, the signal switching unit being configured to output the FFT data including the output signal of the switch. | 04-24-2014 |
20140140443 | INJECTION-LOCKED RF RECEIVER HAVING TRIFILAR TRANSFORMER SPLITTER - The present invention relates to an injection-locked RF receiver having trifilar transformer splitter. The injection-locked RF receiver includes a trifilar transformer splitter, an injection-locked oscillator and a phase detector. The trifilar transformer splitter includes a primary winding, a secondary winding and a tertiary winding. RF input signal is input to the primary winding. The secondary winding outputs a first differential signal to the injection-locked oscillator. The tertiary winding outputs a second differential signal to the phase detector. Using the trifilar transformer splitter of the invention, the frequency-shift keying demodulation with high sensitivity is achieved, and the number of amplifier can be reduced so as to lower the power consumption of the injection-locked RF receiver and reduce the complexity of the involved system. | 05-22-2014 |
20140140444 | COMPENSATION APPARATUS, SIGNAL GENERATOR AND WIRELESS COMMUNICATION EQUIPMENT - A compensation apparatus compensates a quadrature-demodulated signal output from a quadrature demodulator | 05-22-2014 |
20140153672 | ENHANCED DECODING AND DEMAPPING METHOD AND APPARATUS FOR QAM DATA SIGNALS - A receiver circuit, including a multi-stage QAM de-mapper, for receiving a QAM data signal is disclosed. A first de-mapper circuit recovers a set of encoded data bits from the QAM data signal by calculating a plurality of distances between a received QAM symbol and each of a plurality of possible constellation points. A second de-mapper circuit then generates a set of unencoded data bits for the received QAM symbol based, at least in part, on the plurality of distances calculated by the first de-mapper circuit. The receiver circuit may further include a decoder circuit to decode the set of encoded data bits recovered by the first de-mapper circuit. The second de-mapper circuit may identify a subset of the plurality of possible constellation points based on a result of the decoding and select a constellation point that is associated with the shortest distance of the plurality of distances. | 06-05-2014 |
20140153673 | Adaptive decoding based on signal to noise ratio (SNR) - A communication device is configured adaptively to process a receive signal based on noise that may have adversely affected the signal during transition via communication channel. The device may be configured to identify those portions of the signal of the signal that are noise-affected (e.g., noise-affected sub-carriers of an orthogonal frequency division multiplexing (OFDM) signal), or the device may receive information that identifies those portions of the signal that are noise-affected from one or more other devices. The device may be configured to perform the modulation processing of the received signal to generate log-likelihood ratios (LLRs) for use in decoding the signal. Those LLRs associated with noise-affected portions of the signal are handled differently than LLRs associated with portions of the signal that are not noise-affected. The LLRs may be scaled based on signal to noise ratio(s) (SNR(s)) associated with the signal (e.g., based on background noise, burst noise, etc.). | 06-05-2014 |
20140192931 | RECEIVER AND METHOD FOR NEAR FIELD COMMUNICATION - In one embodiment, an apparatus is provided that includes a first circuit configured and arranged to provide a modulated carrier signal in response to a signal provided from the antenna. The modulated carrier signal conveys data using peaks or amplitudes of the carrier signal. A second circuit is configured to rectify the modulated carrier signal and integrate the rectified signal in response to a first clock signal. A third circuit is coupled to an output of the second circuit and is configured to sample the integrated signal values and provide therefrom a sample-based approximation of the modulated carrier signal. | 07-10-2014 |
20140192932 | Method and System for Implementing a Single Weight Spatial Multiplexing (SM) MIMO System - Certain aspects of the method may comprise generating at least one control signal that may be utilized to control at least a first of a plurality of received spatially multiplexed communication signals. An amplitude and/or phase of the first received spatially multiplexed communication signal may be adjusted via the generated control signal so that the amplitude and/or phase of the first received spatially multiplexed communication signal may be equivalent to an amplitude and/or phase of a second received spatially multiplexed communication signal. The amplitude of the first received spatially multiplexed communication signal is adjusted within the processing path used to process the first received spatially multiplexed communication signal. | 07-10-2014 |
20140219396 | Methods and QAM Receiver for Performing Timing Recovery - A method in a QAM receiver ( | 08-07-2014 |
20140270000 | Computation of Reliability Values - There are disclosed systems and methods for computing a reliability value for a bit of a received symbol value y associated with a constellation. In one embodiment, the method comprises computing the reliability value by obtaining a first minimum distance value, the first minimum distance value being a function of an absolute magnitude of an initial value associated with the bit, and combining the first minimum distance value with a second minimum distance value, the second minimum distance value being a function of a distance between the received symbol value y and a symbol x | 09-18-2014 |
20140270001 | QUADRATURE ERROR DETECTION AND CORRECTION - In an example, there is disclosed a system and method for detecting and correcting error in a quadrature receiver (QR). The QR may include a receiver channel operable to divide a received RF signal into I and Q channels. The receiver channel may include error sources, such as (in sequence) pre-demodulation (PD) error, LO mixer error, and baseband (BB) error. Test tones may be driven on the receiver channel at a plurality of test frequencies, and a quadrature error corrector may be provided to detect error from each source. Upon receiving an RF signal, the quadrature error corrector may apply correction coefficients to correct each source of error in reverse sequence (BB, LO, PD). | 09-18-2014 |
20140270002 | SYSTEM AND METHOD QUADRATURE ERROR DETECTION AND CORRECTION - In an example, there is disclosed a system and method for detecting and correcting error in a quadrature receiver (QR). The QR may include a receiver channel operable to divide a received RF signal into I and Q channels. The receiver channel may include error sources, such as (in sequence) pre-demodulation (PD) error, LO mixer error, and baseband (BB) error. Test tones may be driven on the receiver channel at a plurality of test frequencies, and a quadrature error corrector may be provided to detect error from each source. Upon receiving an RF signal, the quadrature error corrector may apply correction coefficients to correct each source of error in reverse sequence (BB, LO, PD). | 09-18-2014 |
20140301505 | RECEIVING DEVICE AND RECEIVING METHOD - A receiving device including: a demodulation circuit configured to generate first likelihood data of reception symbols based on a transmission format of the reception symbols, the transmission format being selected from transmission formats and including a modulation scheme applied to the reception symbols, the modulation scheme being one of amplitude modulation schemes, a processor configured to estimate a scale ratio of an implementation scale to a theoretical scale, the implementation scale being a scale of the first likelihood data, the theoretical scale being a scale of second likelihood data of the reception symbols, the second likelihood data being defined by a theory and not depending on an implementation of the receiving device, and to generate the second likelihood data based on the first likelihood data and the scale ratio, and a decoding circuit configured to decode the second likelihood data based on the transmission format. | 10-09-2014 |
20140369445 | DECISION CIRCUIT, RECEIVER DEVICE, AND PROCESSOR - A decision circuit includes: a first decision block to distinguish a first bit of bits using an amplitude of an analog signal as a discrimination point, the analog signal being an amplitude shift keyed signal; a superposition block to acquire an absolute value of a difference of the analog signal in respect to an amplitude center value of the analog signal by superposing divided analog signals; an inversion block to control inverting of the signal based on a first distinction result of the first decision block; a second decision block to distinguish a second bit of the bits based on an amplitude of an output signal from the inversion block and the discrimination point; and an output buffer to output the first distinction result and a second distinction result of the second decision block in synchronization with a clock. | 12-18-2014 |
20140376666 | RECEIVING STAGE AND METHOD FOR RECEIVING - A receiver stage for receiving a receive signal comprises M receiving paths, each receiving path comprises a signal processor and K comparators. The signal processors of the M receiving paths are configured to generate, for each of the M receiving paths, an amplified version of the receive signal, such that an amplification gain of the respective receiving path increases from a first of the M receiving paths to a last of the M receiving paths. For each of the M receiving paths the K comparators of the respective receiving paths are configured to compare the amplified receive signal of the respective receiving path with a respective threshold value. For each of the M receiving paths the threshold value increases from a first of the K comparators to the last of the K comparators. | 12-25-2014 |
20150023452 | OPTICAL COMMUNICATION INTERFACE UTILIZING N-DIMENSIONAL DOUBLE SQUARE QUADRATURE AMPLITUDE MODULATION - The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using nDSQ format(s) over optical communication networks. In certain embodiments, the communication interface is used by various devices, such as spine switches and leaf switches, within a spine-leaf network architecture, which allows large amount of data to be shared among servers. | 01-22-2015 |
20150098528 | BASE STATION FOR RF COMMUNICATION | 04-09-2015 |
20150124907 | Hardware-Efficient Signal-Component Separator For Outphasing Power Amplifiers - Described herein is a fixed-point piece-wise linear (FP PWL) approximation technique for computations of nonlinear functions. The technique results in circuit designs having relatively few and simple arithmetic operations, short arithmetic operands and small-sized look-up tables and the circuits resultant there from can be efficiently pipelined to run at multi-GSamples/s throughputs. In one exemplary embodiment, the FP PWL approximation technique was used in the design of an energy-efficient high-throughput and high-precision signal component separator (SCS) for use with in an asymmetric-multilevel-outphasing (AMO) power amplifier. The FP PWL approximation technique is appropriate for use in any application requiring high-throughput, area and power constrained hardware implementations of nonlinear functions. | 05-07-2015 |
20150312084 | Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same, and Aperture Relationships - Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal. | 10-29-2015 |
20150312085 | Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same, and Aperture Relationships - Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal. | 10-29-2015 |
20160006590 | Carrier Recovery in a QAM Receiver - The present invention relates to inspection apparatus for use in wellbores in the oil and gas industries. In particular the invention relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method an apparatus for receiving data from a telemetry module, the data being modulated according to a quadrature amplitude modulation coding scheme, in which a receiver has a carrier recovery circuit comprising a phase detector, a loop filter and a signal synthesiser generating an inphase and a quadrature demodulation signal. The method comprises receiving a preamble sinusoidal signal representing a symbol; determining the cross product of the received inphase and quadrature components and ideal inphase and quadrature components; indexing a look up table with said cross product to determine a phase adjustment and adjusting the phase of the demodulation signals in accordance with said determined phase adjustment. | 01-07-2016 |
20160080182 | DEMODULATION OF ON-OFF-KEY MODULATED SIGNALS IN SIGNAL ISOLATOR SYSTEMS - A receiver system for an on-off key (“OOK”) isolator system may include a receiver that generates an intermediate current signal based on an OOK input signal. The intermediate current may be provided at a first current level when the input signal has a first OOK state and a second current level when the input signal has a second OOK state. The system also may include an output driver to generate a voltage representation of the intermediate current signal. Performing signal processing in a current domain permits fast transitions between OOK states. | 03-17-2016 |
20160080183 | DEMODULATION OF ON-OFF-KEY MODULATED SIGNALS IN SIGNAL ISOLATOR SYSTEMS - A receiver system for an on-off key (“OOK”) isolator system may include a pair of receivers. A first receiver may generate a first current signal representing a received OOK signal, and a second receiver may generate a second current signal from a common mode representation of the received OOK signal. The receiver system may include circuitry to compare the first and second current signals and generate an output signal therefrom. | 03-17-2016 |
20160080184 | CONFIGURATION OF A NEAR-FIELD COMMUNICATION ROUTER ACCORDING TO THE MODULATION TYPE - A first near-field communication device is configured according to a modulation type transmitted by a second device. A decoder of the first device decodes a received signal using type-A modulation during a first time slot corresponding to the duration of a first type-A symbol. The first device determines the modulation type transmitted by the second device according to the value of the decoded symbol. | 03-17-2016 |
20160094379 | SYSTEM FOR THE CORRECTION OF AMPLITUDE AND PHASE ERRORS OF IN-QUADRATURE SIGNALS, CORRESPONDING RECEIVER AND METHOD - A system may be for the correction of phase and amplitude errors. The system may receive a first input signal and a second input signal and supply a first output signal and a second output signal. The system may include two adders that supply the first and second output signals, respectively. The two adders may be configured for computing a sum of the first and second input signals, and multiplying the weighted sum by a third coefficient. Moreover, the first coefficient or the second coefficient of the first adder may be variable to enable correction of the phase errors, and the third coefficient of the second adder may be variable to enable correction of the amplitude errors. | 03-31-2016 |
20160127161 | Weather Band Receiver - A weather band receiver, which may be part of an FM receiver, is disclosed. FSK-encoded data units in an alert packet transmission are detected using a quadrature matched filter circuit. At least one FSK-encoded data unit is captured from the alert packet transmission. Soft quantized bits are extracted from the FSK-encoded data units. The soft quantized bits are saved to memory and used to recover an alert message. Soft quantized bits from two or more FSK-encoded data units may be combined before recovering the alert message. | 05-05-2016 |
20160182107 | METHOD AND APPARATUS FOR COMPENSATING FOR A LOSS OF LOW-FREQUENCY SIGNAL CONTENT OF AN INPUT SIGNAL AT A RECEIVER INPUT | 06-23-2016 |
20160182264 | DIGITAL DECODING OF BACKSCATTER MODULATED DATA | 06-23-2016 |
20160182273 | METHOD AND APPARATUS OF 128-DSQ DE-MAPPING IN 10GBASE-T SYSTEM | 06-23-2016 |
20160204973 | SIGNAL RECEIVER WITH ADAPTIVE SOFT INFORMATION ADJUSTMENT AND ASSOCIATED SIGNAL PROCESSING METHOD | 07-14-2016 |
20170237599 | APPARATUS AND METHODS FOR SIGNAL GENERATION, RECEPTION, AND SELF-CALIBRATION | 08-17-2017 |
20180026780 | SIGNAL DEMODULATION APPARATUS AND METHOD IN CLOSED COMMUNICATION SYSTEM | 01-25-2018 |