Abstract: The present disclosure relates to an electronic instrument for analyzing a device-under-test, DUT, comprising: a digital signal generator configured to generate a test signal having a first frequency; a signal output unit which is connected to the DUT, wherein the signal output unit is configured to convert the test signal to an analog signal and to forward said signal to the DUT; a signal input unit which is connected to the DUT and which is configured to receive a DUT response signal which is based on the test signal, wherein the signal input unit is configured to digitalize the DUT response signal; a signal processing circuity configured to receive the digitalized DUT response signal and to downconvert said signal using the first frequency of the test signal; and an analyzing unit configured to analyze the downconverted DUT response signal in order to determine a transfer function, an impedance and/or a loop stability of the DUT.

Abstract: Circuits, methods, and apparatus that can provide in-phase and quadrature LO signals having an accurate phase relationship and matching amplitudes. An example can provide a quadrature modulator having phase-correction circuitry and amplitude-correction circuitry. The quadrature modulator can include a quadrature hybrid to receive an LO signal from a phase-locked loop or other clock source. The quadrature hybrid can provide in-phase and quadrature LO signals to phase-correction circuitry, which can accurately align a difference in the phase of the in-phase and quadrature signals to 90 degrees. The amplitudes of the resulting signals can be adjusted to have a desired amplitude using amplitude-correction circuitry. The amplitude-and-phase-corrected LO signals can be used to modulate in-phase and quadrature components of a baseband signal. The modulated products can be combined, gained, and filtered as necessary for wireless transmission, device testing, or other purpose.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as long term evolution (LTE). Methods and systems for optimizing computation of log-likelihood ratio (LLR) for decoding modulated symbols. A method disclosed herein involves receiving at least one symbol transmitted from at least one device, wherein the received at least one symbol is encoded and modulated symbol including a plurality of data bits. The method further includes computing a log-likelihood ratio (LLR) of each bit in the received at least one symbol for decoding the received at least one symbol using a centroid method that involves exploiting a symmetry of a constellation of code words and/or a uncertainty region defined on a constellation of code words.

Abstract: Provided is an optical transmission device including: a symbol demapping unit; a likelihood generation circuit configured to generate likelihoods relating to the reception signal; and an error correction decoding unit configured to execute soft decision decoding. The likelihood generation circuit includes: a first one-dimensional-modulation lookup table configured to input the signal of the I-axis component as an argument to output a first likelihood; a second one-dimensional-modulation lookup table configured to input the signal of the Q-axis component as an argument to output a second likelihood; and a two-dimensional-modulation lookup table configured to input, as an argument, the signal being the concatenation of the signal of the I-axis component and the signal of the Q-axis component, to generate a third likelihood. The error correction decoding unit is configured to execute the soft decision decoding based on the first likelihood, the second likelihood, and the third likelihood.

Abstract: Read data associated with Flash storage that is in a Flash storage state is received. One of a plurality of log-likelihood ratio (LLR) mapping tables is selected based at least in part on: (1) the Flash storage state and (2) a decoding attempt count associated with a finite-precision low-density parity-check (LDPC) decoder. A set of one or more LLR values is generated using the read data and the selected LLR mapping table, where each LLR value in the set of LLR values has a same finite precision as the finite-precision LDPC decoder. The finite-precision LDPC decoder generates the error-corrected read data using the set of LLR values and outputs it.

Abstract: In one aspect, a radio device comprises: an analog front end (AFE) circuit to receive and process an incoming radio frequency (RF) signal comprising a packet; an analog-to-digital converter (ADC) coupled to the AFE circuit to receive and digitize the processed incoming RF signal into a digital signal; a detector coupled to the ADC to detect a carrier frequency offset (CFO) in the digital signal based at least in part on a preamble of the packet; and a controller coupled to the detector. The controller may generate a compensation value for the CFO based on the detected CFO and cause one or more components of the radio device to compensate for the CFO using the compensation value.

Abstract: A measurement system for determining a phase and amplitude influence of a device under test, comprising a measurement instrument having a signal generator, a local oscillator, a first mixer and an analysis unit is disclosed. The signal generator is configured to generate a source signal with a predetermined source frequency and a source phase, and to forward the source signal to the device under test, wherein the source signal is altered by the device under test in at least one of amplitude and phase, such that a measurement signal is generated and forwarded to the first mixer. The local oscillator is configured to generate a local oscillator signal with a predetermined local oscillator frequency and a local oscillator phase, and to forward the local oscillator signal to the first mixer. The first mixer is configured to mix the measurement signal and the local oscillator signal, thereby generating a first mixer signal.

Abstract: Read data associated with Flash storage is received. One of a plurality of LLR mapping tables is selected and a set of one or more LLR values is generated using the read data and the selected LLR mapping table, where each LLR value in the set of LLR values has a same finite precision as a finite-precision low-density parity-check (LDPC) decoder. Error-corrected read data is generated using the set of LLR values, where the finite-precision LDPC decoder has the same finite precision as the set of LLR values. The error-corrected read data is output.

Abstract: Technologies directed to improving signal quality in received wireless signals in the phase domain of shift keying demodulation are described. One method receives digital data, the digital data including a systematic error as a linear function of residual carrier frequency offset and phase noise (PN). The method extracts first phase data from the digital data, determines, in a phase domain, an estimate of the systematic error using historical phase error data of additional digital data received prior to the digital data, and generate second phase data by subtracting the estimate from the first phase data. The method determines a set of symbols from the second phase data and generates a bit sequence of a data packet from the set of symbols.

Abstract: An apparatus may include a sampling circuit configured to produce a sequence of input samples based on a continuous time input signal and a sample clock signal, the sampling phase of the sequence of input samples based on a phase control value output by a timing recovery circuit. In addition, the apparatus may include the timing recovery circuit configured to receive the sequence of input samples, detect, for a current sample of the sequence of input samples, a phase offset in the sampling phase of the sequence of input samples, the phase offset being a deviation of the sampling phase from an expected phase, and in response to detecting the phase offset, select a bandwidth for timing recovery. Further, the timing recovery circuit may generate an updated phase control value based on the selected bandwidth for timing recovery.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for compensating for frequency-dependent I-Q imbalance. In some implementations, a radio receiver includes an in-phase mixer configured to generate an in-phase (I) signal and a quadrature mixer configured to generate a quadrature (Q) signal. A first analog-to-digital (A/D) converter is configured to generate first digital samples from one of the I signal and the Q signal. A second analog-to-digital (A/D) converter is configured to generate second digital samples from the other of the I signal and the Q signal. A compensation system includes a feedback loop configured to compensate for frequency-dependent I-Q imbalance based on results, for each of multiple of the first digital samples, of cross-correlation of the first digital sample with each of multiple of the second digital samples.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for compensating for frequency-dependent I-Q imbalance. In some implementations, a radio receiver includes an in-phase mixer configured to generate an in-phase (I) signal and a quadrature mixer configured to generate a quadrature (Q) signal. A first analog-to-digital (A/D) converter is configured to generate first digital samples from one of the I signal and the Q signal. A second analog-to-digital (A/D) converter is configured to generate second digital samples from the other of the I signal and the Q signal. A compensation system includes a feedback loop configured to compensate for frequency-dependent I-Q imbalance based on results, for each of multiple of the first digital samples, of cross-correlation of the first digital sample with each of multiple of the second digital samples.

Abstract: A communication apparatus includes an input terminal, an output terminal, and an interference reduction circuit. The interference reduction circuit is coupled between the input terminal and the output terminal. The interference reduction circuit receives a time-varying data signal. The interference reduction circuit acquires first partial data from the data signal at a first time, and generates a first level-shifted result and a second level-shifted result according to the first partial data. The interference reduction circuit is further configured to acquire second partial data from the data signal at a second time. The interference reduction circuit selects one of the first level-shifted result and the second level-shifted result as a selected result according to the second partial data, and sends the selected result to the output terminal.

Abstract: An apparatus of a wireless device can include baseband processing circuitry configured to generate a digitized downconverted signal based on a received radio frequency (RF) signal. The apparatus can also include estimation circuitry configured to detect a blocker signal in the downconverted signal, the blocker signal having power that exceeds a pre-determined threshold, and map the detected blocker signal to a plurality of harmonic frequencies associated with two or more carrier frequencies. The apparatus can include reference signal generation circuitry configured to generate a reference signal based on the plurality of harmonic frequencies and the received RF signal. The apparatus can include cancellation circuitry configured to apply a pre-processed reference signal (based on the reference signal) to the digitized downconverted signal to remove distortion associated with the detected blocker signal. The digitized downconverted signal is a baseband signal or an intermediate frequency (IF) signal.

Abstract: Processing of a data packet within a received wireless signal includes determining a frequency modulation (“FM”) domain carrier frequency offset (“CFO”) estimate component from a plurality of samples of the received wireless signal, determining a phase domain CFO estimate component from the plurality of samples of the received wireless signal, and determining a CFO estimation as a function of the FM domain CFO estimate component and the phase domain CFO estimate component. The data packet may be a Bluetooth Low Energy data packet. The FM domain CFO estimate component and the phase domain CFO estimate component may be determined from samples of a preamble field of the data packet.

Abstract: An analog-to-digital converter includes a ring oscillator having an input for receiving an analog signal, a coarse Gray code counter having a first input coupled to a first output of the ring oscillator and a second input for receiving a clock signal, a fine counter having first inputs coupled to secondary outputs of the ring oscillator and a second input for receiving the clock signal, a first difference generator having an input coupled to the output of the coarse counter, a second difference generator having an input coupled to the output of the fine counter, and an adder having a first input coupled to the output of the first difference generator, a second input coupled to the output of the second difference generator, and an output for providing a digital signal corresponding to the analog signal.

Abstract: An active phased array transmitter includes: a transmission frequency signal source that generates a transmission frequency signal; a modulator that modulates the transmission frequency signal based on transmission data and outputs the modulated transmission signal; a plurality of transmitters that change the phase and intensity of the modulated transmission signal; a transmission phased array antenna including a plurality of transmission antennas; a local transmission frequency signal source that generates a local transmission frequency signal; a first mixer that generates a first intermediate frequency transmission signal from a received signal of the radio waves output from the transmission antennas and the local transmission frequency signal; a second mixer that generates a second intermediate frequency transmission signal from the modulated transmission signal and the local transmission frequency signal; a transmission correlation processing circuitry that detects a transmission correlation relationship;

Abstract: The present invention provides a digital video broadcasting-terrestrial (DVB-T) system and modulation method thereof. The system comprises a transmission module and a receiving module. The transmission module modulates a video signal to a DVB-T signal. The receiving module receives the DVB-T signal via a transmission line and demodulates the DVB-T signal to the video signal, and at the same time, monitoring the signal-to-noise ratio (SNR) or bit error rate (BER), and quantizes them to a reference data. The receiving module transmits the reference data to the transmission module through the same transmission line. The system can determine a control parameter according to the reference data to set the modulation parameter of the DVB-T signal.

Abstract: This disclosure generally pertains to volume control of audio output by a device. A piecewise curve may be used to implement volume control using two or more curves segments. The piecewise curve may be implemented by a signal converter. The curve segments may be selected to provide volume control that provides incremental changes in amplification at mid-level to high level volumes, while providing anticipated amplification at lower volumes which satisfy users' expectations. In some instances, different piecewise curves may be selected for different types of audio so that these different types of audio are provided to users at an expected volume and/or in a meaningful way. When multiple audio outputs occur at a same time, the piecewise curves associated with some of the audio outputs may be dynamically adjusted or updated based on the presence of the other ones of the multiple audio outputs and/or ambient noise.

Abstract: A method for compensating the frequency dependent phase imbalance in a receiver is provided. The receiver downconverts an input signal to generate the signal r(t). The signal r(t) has an in-phase component rI(t) and a quadrature component rQ(t). A first test signal with a first carrier frequency is applied as the input signal of the receiver to obtain a first phase imbalance I. A second test signal with a second carrier frequency is applying as the input signal of the receiver to obtain a second phase imbalance. An IQ delay mismatch ?t of the receiver according to the difference of the second and the first phase imbalances and the difference of the second and the first carrier frequencies is obtained. The in-phase component rI(t) and the quadrature component rQ(t) of the signal r(t) corresponding to other input signal is compensated according to the obtained IQ delay mismatch ?t.

Abstract: A robust time shift tracking UWB receiver. After translating in baseband by a quadrature demodulator, the received UWB pulsed signal is integrated on successive time windows, and then sampled. The complex samples are then correlated with a coding sequence from the transmitter and then transmitted on the one hand to a phase estimator and a demodulating/detecting module. The latter estimates the symbol emitted and provides it to the estimator which removes the modulation effect for estimating, at each time-symbol, the phase of the complex samples. A phase rotation follow-up module determines a compensated phase rotation and a non-compensated phase rotation from a reference instant. Controlling means deduce from the non-compensated phase rotation a time offset to be applied to the integration windows.

Abstract: A system and method are provided for calibrating the IQ-imbalance in a low-IF receiver. A Test Signal can be generated in a mirror frequency and conveyed to the receiver. The power of the signal produced in the receiver from the conveyed Test Signal can be measured. In the absence of an IQ-imbalance, the Test Signal can be completely eliminated in the receiver and the corresponding measured power of the produced signal can be minimized. Accordingly, a two dimensional algorithm is described for calibrating a receiver and correcting the IQ-imbalance by adjusting the phase and gain difference between the I and Q channels in the receiver based on the measured power of the signal produced in the receiver.

Abstract: A receiving circuit includes: an interpolation circuit that generates, by using an interpolation coefficient, output data including a data point and a boundary point from pieces of input data that are input in chronological order; a detection circuit that outputs a detection signal when the detection circuit detects a phase of the output data by using the boundary point of the output data; a low pass filter that filters the detection signal and generates the interpolation coefficient; and a modulation circuit that modulates, by using a modulation signal having a frequency different from a cutoff frequency of the low pass filter, the interpolation coefficient generated by the low pass filter, and outputs the modulated interpolation coefficient to the interpolation circuit.

Abstract: Methods and apparatuses are described for a User Equipment (UE) to receive enhanced Control CHannels (eCCHs), including enhanced Physical Downlink Control CHannels (ePDCCHs), transmitted in a set of Resource Blocks (RBs) over a Transmission Time Interval (TTI). A method includes transmitting a first control signal to a first UE over a first number of Resource Elements (Res) in a subset of the RBs and over a first number of the transmission symbols in the TTI; transmitting a second control signal to a second UE over a second number of the REs in the subset of the RBs and over a second number of the transmission symbols in the TTI; and transmitting a reference signal of the first type over a third number of the REs in the subset of the RBs and over a third number of the transmission symbols in the TTI.

Abstract: Integrated circuit transceiver circuitry (2) includes a first resonant circuit (3A) coupled to a narrowband interface (6,7A,7B,21) between a first amplifier (3,20) and an interfacing circuit (4,8,9,44), including a programmable first reactive element (C) and a second reactive element (L). Amplitude sensing circuitry (42) senses a maximum amplitude of an in-phase signal (I) or a quadrature-phase signal (Q). An on-chip first tone generation circuit (38,38A,38B,38C) generates tones for injection into the in-phase signal and the quadrature-phase signal and operates in response to frequency scanning circuitry (30) and the amplitude sensing circuitry to adjust the first reactive element (C) to calibrate the first resonant circuit to a desired resonant frequency by selectively coupling reactive sub-elements (1,2,4,8 . . . ×Cv) into the first reactive element (C).

Abstract: Methods, systems, and devices are described for mitigating phase noise. An output of a decoder is utilized to generate an estimation of a plurality of transmitted symbols. One or more phase errors of a plurality of received symbols are generated. The one or more phase errors are based at least in part on the estimation of the plurality of transmitted symbols. The one or more phase errors are generated by comparing angles between the plurality of received symbols and the estimation of the plurality of transmitted symbols. The output of the decoder used to generate the estimation is a plurality of a posteriori log-likelihood ratios (LLRs) of a plurality of transmitted bits. The estimation is generated by performing hard decision decoding on the output of the decoder and remodulating the hard decision decoding according to the modulation used by a transmitter on the plurality of transmitted bits.

Abstract: A receiver circuit includes: an input ADC configured to convert an input data signal to sample data in accordance with a clock; a boundary phase computation circuit configured to determine the boundary phase of the input data signal based on the sample data; an eye pattern computation circuit configured to compute a maximum amplitude phase of an eye pattern of the input data signal based on the sample data and the boundary phase; and a determination circuit configured to determine a value of the input data signal in the maximum amplitude phase based on the sample data and the maximum amplitude phase.

Abstract: There is provided a signal processing apparatus including an oscillating unit having a division ratio of an integer that performs oscillation at a predetermined oscillation frequency, a frequency transforming unit that transforms a frequency of a signal of a processing target using a signal of the oscillation frequency obtained by the oscillation of the oscillating unit, and a correcting unit that corrects an error of the frequency of the signal of the processing target transformed by the frequency transforming unit based on an error of the oscillation frequency.

Abstract: An image rejection (IR) circuit is configured to receive a complex signal from a radio frequency (RF) mixer, where the complex signal includes an in-phase signal portion and a quadrature signal portion. This IR circuit may include: an in-phase path to remove first mismatch information from the in-phase signal portion and associated with at least one in-phase multi-tap filter; a quadrature path to remove second mismatch information from the quadrature signal portion and associated with at least one quadrature multi-tap filter; and a correlation unit to independently update each of the multiple taps of the in-phase multi-tap filter and the quadrature multi-tap filter according to a priority scheme.

Abstract: A method for phase modulation of a carrier signal from a transmitter to a contactless transponder in which data is coded as consecutive symbols, each corresponding to a predefined number of carrier cycles, and in which a symbol time is at least two cycles of the carrier signal includes, at the transmitter, spreading a phase jump of a symbol in relation to a preceding symbol over a first part of the symbol time. The establishment of the phase jump is completed in the first part of the symbol time. The periods of the cycles are constant during a second part of the symbol time.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: Provided is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time, including the steps of selecting a matrix F[i] from among N matrices, which define precoding performed on the plurality of baseband signals, while switching between the N matrices, i being an integer from 0 to N?1, and N being an integer at least two, generating a first precoded signal z1 and a second precoded signal z2, generating a first encoded block and a second encoded block using a predetermined error correction block encoding method, generating a baseband signal with M symbols from the first encoded block and a baseband signal with M symbols the second encoded block, and precoding a combination of the generated baseband signals to generate a precoded signal having M slots.

Abstract: Embodiments of an apparatus for improving a gain imbalance between an in-phase and quadrature component recovered by a receiver are provided. The apparatus includes a first transition counter configured to count a number of bit transitions in a first sequence of one-bit values provided by a first sigma-delta modulator based on the in-phase component, and a second transition counter configured to count a number of bit transitions in a second sequence of one-bit values provided by a second sigma-delta modulator based on the quadrature component. The apparatus further includes a gain monitor configured to: (1) determine a first and second power level, proportional to a power of the in-phase and quadrature components respectively, using the number of bit transitions in the first and second sequences, and (2) adjust a gain of one of the in-phase and quadrature components based on a ratio between the first and second power levels.

Abstract: Symbol detection and soft demapping methods and systems are provided. Individual subset symbol detection according to one or more embodiments involves identifying a search subset of a transmission symbol set for a transmission symbol. For each other transmission symbol in communication signals, multiple search subsets of the transmission symbol set are identified. The multiple search subsets include respective search subsets based on each transmission symbol in either the search subset for the first identified one of the transmission symbols or each of the multiple search subsets identified for a different one of the other transmission symbols. Symbol detection errors may be detected by identifying competing symbols and computing competing distances. Soft demapping may be provided by calculating soft decision results based on detected symbols and weighting the soft decision result.

Abstract: A method for transmitting and receiving a signal and an apparatus for transmitting and receiving a signal are disclosed. The method includes receiving the signal from a first frequency band in a signal frame including at least one frequency band, demodulating the received signal by an orthogonal frequency division multiplexing (OFDM) method and parsing the signal frame, acquiring a symbol stream of a service stream from the at least one frequency band included in the parsed signal frame, demapping symbols included in the symbol stream and outputting the demapped symbols to sub streams, multiplexing the output sub streams and outputting one bit stream, and deinterleaving and error-correction-decoding the output bit stream.

Abstract: An transmitting apparatus is provided. The transmitting apparatus includes a modulator which performs a QPSK-modulation for original data by using a different constellation combination pattern by predetermined unit, and a transmitter which transmits the QPSK-modulated data. Accordingly, BEP performance may be improved by transmitting additional data according to a constellation combination patter in hidden form.

Abstract: Methods and systems to vary an erasure slicer threshold based on a measure computed from prior soft and/or hard symbol decisions, identify reliable symbol estimates based on the threshold, identify unreliable symbol estimates for erasure based on the threshold, modify the identified symbol estimates, output the reliable symbol estimates and the modified symbol estimates as erasure slicer decisions, and filter the decisions in a feedback filter of a decision feedback equalizer (DFE). The erasure slicer threshold may be based on signal-to-noise ratio (SNR) or mean-squared-error (MSE). A symbol estimate may be identified for erasure when a coordinate of the corresponding soft decision is within an erasure area defined by the threshold. Symbol modification may include replacing a corresponding coordinate of the symbol estimate with a coordinate of a decision boundary associated with the erasure area.

Abstract: A robust differential receiver is described that may be used in any frequency modulated system, including short-range radio frequency (RF) communication devices. The differential receiver provides a preamble detection approach that reduces false preamble detection, a fine carrier frequency (CFO) estimation approach that provides an extended estimation range, and robust in-band and out-of-band interference detection. The described differential receiver assures that preamble detections are not falsely triggered, and that CFO estimates are based on accurately modeled preamble waveforms that have not been distorted by phase ambiguities or in-band distortion.

Abstract: A digital receiver includes a radio frequency analog front end, a digital processing unit, a plurality of cascaded amplifier stages configured to receive output of the radio frequency analog front end, a first analog to digital converter configured to convert an analog signal output from the plurality of cascaded amplifier stages into a digital signal output to the digital processing unit, a first received signal strength indicator unit configured to receive outputs of each of the plurality of cascaded amplifier stages and output signal to the digital processing unit, a second received signal strength indicator unit configured to receive output of at least one amplifier stage in the plurality of cascaded amplifier stages, and a received signal strength indicator detection unit configured to activate and to deactivate digital units according to a comparison of output from the second received signal strength indicator unit to a predetermined threshold.

Abstract: 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.

Abstract: A circuit, use, and method for controlling a receiver circuit is provided, wherein a complex baseband signal is generated from a received signal, a phase difference between a phase of the complex baseband signal and a phase precalculated from previous sampled values is determined, the phase difference is compared with a first threshold, a number is determined by counting the exceedances of the first threshold by the phase difference, a number of the counted exceedances is compared with a second threshold, and the receiver circuit is turned off if the number of counted exceedances exceeds the second threshold within a time period.

Abstract: A method includes receiving a data unit that includes a signal (SIG) field and a data field. The SIG field provides information for interpreting the data field. The method also includes detecting a first symbol constellation rotation of at least a first orthogonal frequency division multiplexing (OFDM) symbol in the SIG field of the data unit, determining, based at least in part on the detected first symbol constellation rotation, a number of information bits per OFDM symbol in the SIG field of the data unit, processing the SIG field of the data unit according to the determined number of information bits per OFDM symbol in the SIG field, and processing the data field of the data unit according to the information for interpreting the data field as provided in the SIG field of the data unit.

Abstract: A method detects a threshold crossing instant at which a signal crosses a threshold, by: sampling the signal at plural sampling instants spaced from one another by a sampling period; detecting consecutive first and second sampling instants at which the signal has a first signal value lower than or equal to the threshold, and the signal has a second signal value higher than the threshold, respectively; calculating a first interval indicative of a time between the threshold crossing instant and the first sampling instant; setting a reference signal having a reference amplitude representing the first interval relative to a reference scale; generating a signal with a delay depending on said reference signal; generating a threshold crossing detection signal at an instant delayed by a second interval; calibrating the reference scale of the reference amplitude so that the second interval is substantially equal to the first interval.

Abstract: A system and method are provided for implementing a soft Reed-Solomon (RS) decoding scheme, technique or algorithm to improve physical layer performance in cable modems and cable gateways. The algorithm is implemented in a forward error correction (FEC) module connected to a QAM demodulator. The RS decoding scheme is implemented without significantly complicating hardware or processing overhead. The soft Reed-Solomon (RS) decoding scheme extracts candidate RS symbols and their Log Likelihood Ratios (LLRs) from QAM symbols. The set of highest probable candidate blocks are then chosen and these are decoded using a variant of the Chase algorithm until a valid codeword is detected at the decoder output.

Abstract: Provided is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time, including the steps of selecting a matrix F[i] from among N matrices, which define precoding performed on the plurality of baseband signals, while switching between the N matrices, i being an integer from 0 to N?1, and N being an integer at least two, generating a first precoded signal z1 and a second precoded signal z2, generating a first encoded block and a second encoded block using a predetermined error correction block encoding method, generating a baseband signal with M symbols from the first encoded block and a baseband signal with M symbols the second encoded block, and precoding a combination of the generated baseband signals to generate a precoded signal having M slots.

Abstract: Techniques for data transmission using high-order modulation are provided. According to one aspect, parameters of a transmission link are determined, and a multilevel coding scheme and a high-order modulation signal constellation are selected on the basis of the determined parameters. An information indicating the selected multilevel coding scheme and high-order modulation signal constellation and data symbols encoded according to the selected multilevel coding scheme and high-order modulation signal constellation are transmitted. In other aspects, QPSK data symbols are embedded between M-QAM data symbols or M-PSK data symbols with M>4. The QPSK data symbols may be used to improve the efficiency of the decoding process.

Abstract: A symbol error detector can be configured to detect symbol errors of a Bluetooth enhanced data rate (EDR) packet without relying solely on a CRC error detection mechanism. After a phase of a current symbol is demodulated to determine a demodulated current symbol, the phase of the demodulated current symbol can be subtracted from the phase of the current symbol prior to demodulation to yield a phase error. The phase error can be compared against a phase error threshold to determine a potential unreliability of the demodulated current symbol. The phase error being greater than the phase error threshold can indicate that the demodulated current symbol may be unreliable. Accordingly, a symbol error notification can be generated to indicate that the demodulated current symbol may be unreliable.

Abstract: A method and system for performing complex sampling of signals using two or more sampling channels and calculating time delays between these channels.

Abstract: A method for detecting a format of a frame in a communication system is presented. An embodiment of the method includes receiving the frame comprising a plurality of orthogonal frequency division multiplexing (OFDM) symbols. The plurality of OFDM symbols may include at least one signal field symbol. The method further includes determining a modulation associated with the at least one signal field symbol. The modulation may be a first modulation or a second modulation. Also, the method includes estimating a position of the at least one signal field symbol among the plurality of symbols, and extracting a coding rate of the received frame. The method then includes detecting the format of the received frame based on the determined modulation and the estimated position of the at least one signal field symbol, and the extracted coding rate of the received frame.

Abstract: A radio receiver comprising: an antenna for receiving a radio frequency signal amplitude modulated with an audio frequency signal; a digitizer for periodically sampling the radio frequency signal and generating a digital reception signal representative of the amplitude of the radio frequency signal; and a demodulator for demodulating the digital reception signal to generate a representation of the audio frequency signal.