Abstract: A receiver comprises a matched filter bank, decision logic and a frequency offset estimator. The matched filter bank comprises an input for receiving data representative of a frequency- or phase-modulated signal. The decision logic generates a sequence of demodulated symbol values from outputs of the matched filter bank. The frequency offset estimator determines a first phase value from a first output and a second phase value from a second output of the matched filter bank, the second output being offset from the first by L symbol periods. It also determines a phase adjustment value from an L-symbol subsequence within the sequence of demodulated symbol values, each subsequence value being determined from values output by the matched filter bank between the first and second outputs. It estimates a frequency offset based on the difference between the first phase value plus the phase adjustment value, and the second phase value.

Abstract: Communication systems are described that use unequally spaced constellations that have increased capacity compared to conventional constellations operating within a similar SNR band.

Abstract: Systems and apparatuses for wireless power transfer system are described. A receiver may send an amplitude shift key (ASK) signal to a transmitter. The transmitter may receive the ASK signal from the receiver. The transmitter may perform a demodulation on the ASK signal. The transmitter may, in response to a failure to demodulate the ASK signal, encode a notification of failure in a frequency shift key (FSK) signal. The transmitter may transmit the FSK signal to the receiver. The receiver may receive the FSK signal. The receiver may perform a function to resolve the failure to demodulate the ASK signal.

Abstract: Disclosed are circuit and method for width measurement of digital pulse signals. The circuit comprises: a sample clock, used to drive all registers in the circuit; an edge detection and interrupt control unit, used to detect a rising edge and a falling edge of a pulse signal on an input pin Input to control signal collection; an integer encoding unit comprising a counter and registers and used to measure an integer part ? of the width of a high or low level on the input pin Input with one period 1/f of the sample clock as a reference unit; a signal capture chain, used to sample an output level of each delay cell DLL; a decimal encoding unit, used to find out and record the propagation position of the pulse edge on the signal capture chain; and a calibration control unit, used to perform calibration.

Abstract: A radar system is provided that includes a receive channel configured to receive a reflected signal and to generate a first digital intermediate frequency (IF) signal based on the reflected signal, a reference receive channel configured to receive a reflected signal and to generate a second digital IF signal based on the reflected signal, and digital mismatch compensation circuitry coupled to receive the first digital IF signal and the second digital IF signal, the digital mismatch compensation circuitry configured to process the first digital IF signal and the second digital IF signal to compensate for mismatches between the receive channel and the reference receive channel.

Abstract: In an embodiment a device includes a first circuit and a second circuit, wherein the first circuit is configured to generate a fourth signal and a fifth signal by applying the phase shift respectively to a first signal and to a second signal and deliver a sixth signal corresponding to a sampling over one bit of the fourth signal, a seventh signal corresponding to a sampling over one bit of the fifth signal, an eighth signal corresponding to a sampling over one bit of a difference between the fourth and fifth signals, and a ninth signal corresponding to a sampling over one bit of a sum between the fourth and fifth signals, wherein the second circuit is configured to receive the sixth, seventh, eighth, and ninth signals and determine, during a first phase where the first and second signals are representative of a first known symbol of a QPSK constellation, a state of a first bit from among a first state and a second state based on the eighth and ninth signals.

Abstract: A frequency modulated continuous wave (FMCW) radar system includes an antenna array having C antennas where (C=A+B?1), a first integrated circuit (IC) device including A first sensor inputs, and a second IC device including B second sensor inputs. The first sensor inputs are coupled to a first A of the antennas, and the second sensor inputs are coupled to a last B of the antennas such that a common one of the first sensor inputs and a common one of the second sensor inputs are both coupled to a common antenna. Each IC device receives reflected signals on each sensor input, and mixes the reflected signals to associated baseband signals based upon a local oscillator (LO) signal. Each LO signal has a different phase shift. The LO signals are based upon a common LO signal.

Abstract: The clock generation circuit outputs a clock signal with a constant cycle by repeating the following operations: when an enable signal becomes a H level, the clock signal immediately rises, and a sense end is changed to a L level via a first capacitor, then a voltage of the sense end is gradually increased via a resistor, and when the sense end reaches a predetermined potential, an output of a second inverter becomes the L level, the clock signal becomes the L level, an inverted clock signal becomes the H level, and accordingly the sense end becomes the H level; and thereafter, a current flows via the resistor so that the voltage of the sense end decreases gradually, when the sense end reaches a predetermined potential, the output of the second inverter becomes a H level, the clock signal becomes the H level, the sense end is changed to a L level via the first capacitor, then the voltage of the sense end is gradually increased via the resistor, and when the sense end reaches a predetermined potential, the out

Abstract: A wireless wideband transceiver may be able to communicate with multiple frequency-hopped spread-spectrum (FHSS) devices concurrently over multiple frequencies over a short range by including a plurality of digital chains corresponding to the FHSS physical channels, individually and dynamically compensated for in-phase/quadrature imbalance in the transmit and/or receive portion. To further improve communications the transceiver may also mitigate cross interference between adjacent channel signals that are received and/or transmitted simultaneously, avoid false reception and/or transmission of co-channel signals, delay respective FHSS channels transmissions relative to other channels transmissions, speed up connection to FHSS devices and coordinate Time Division Duplexing (TDD) operation according to application dependent TX/RX binary pattern.

Abstract: Systems and methods for classifying baseband signals include receiving, at a pre-processing stage of a neural network whose objective is modulation classification performance, a complex quadrature vector of interest including a plurality of samples of a baseband signal derived from a radio frequency signal of an unknown modulation type, providing the vector of interest to a plurality of FIR filters, each of which outputs a respective intermediate filtered version of the vector of interest, combining the outputs of two or more of the FIR filters to produce a filtered version of the vector of interest, including applying respective weightings to the outputs of the FIR filters, and providing the filtered version of the vector of interest to an analysis stage of the neural network for classification with respect to a plurality of known modulation types. The neural network may apply attention-based selection to learn the filters and respective weightings.

Abstract: A transmission interface between at least a master module and a slave module is proposed. The transmission interface includes a predetermined number of physical transmission medium(s). Each physical transmission medium is arranged to carry a multiplexed signal in which at least two signals are integrated, and the predetermined number is not smaller than a number of intermediate frequency (IF) stream(s) to be transmitted.

Abstract: A service transmission method and apparatus are provided. The method includes: a first mobile station acquiring N resource allocation parameter sets from a network device; the first mobile station sending first indication information to the network device, where the first indication information is used to indicate service information about a first service needing to be transmitted by the first mobile station; the first mobile station receiving second indication information sent by the network device, where the second indication information is used to indicate a first target resource; and the first mobile station determining, from the N resource allocation parameter sets, a first resource allocation parameter set adapted to the service information about the first service, and the first mobile station transmitting, according to the first resource allocation parameter set, the first service using the first target resource.

Abstract: A signal compensation device comprises a first filter circuit, for processing a broadband signal, to generate a first analog time-domain signal; a second filter circuit, for processing the broadband signal, to generate a second analog time-domain signal; a first transform circuit, for transforming the first analog time-domain signal to a first digital time-domain signal; a second transform circuit, for transforming the second analog time-domain signal to a second digital time-domain signal; a third transform circuit, for transforming the first digital time-domain signal to a first frequency-domain signal; a fourth transform circuit, for transforming the second digital time-domain signal to a second frequency-domain signal; and a processing circuit, for generating a time-domain compensation response according to the first frequency-domain signal and the second frequency-domain signal.

Abstract: A semiconductor device includes first to N-th PLL circuits configured to operate in synchronization with a common reference clock signal to output first to N-th clock signals, respectively; a majority circuit that performs a majority operation on the first to N-th clock signals to generate a majority clock signal; and a filter circuit to which the majority clock signal is provided, the filter circuit operating as a low-pass filter to output an output clock signal. N is an odd number of three or more.

Abstract: An IQ mismatch estimation circuit includes a raw channel estimation circuit, a reference channel estimation circuit, a digital predistortion (DPD) bin identification circuit, a channel estimate pruning circuit, and an IQ correction coefficient generation circuit. The raw channel estimation circuit generates raw channel estimates for a plurality of frequency bins of a baseband signal. The reference channel estimation circuit identifies a reference channel estimate based on the raw channel estimates. The DPD bin identification circuit identifies, based on the reference channel estimate, the frequency bins for which the raw channel estimates are based on a DPD expansion signal. The channel estimate pruning circuit generates pruned raw channel estimates by discarding the raw channel estimates of the frequency bins identified by the DPD bin identification circuit. The IQ correction coefficient generation circuit generates IQ mismatch correction coefficients based on the pruned raw channel estimates.

Abstract: A radar system is provided that includes a receive channel configured to receive a reflected signal and to generate a first digital intermediate frequency (IF) signal based on the reflected signal, a reference receive channel configured to receive a reflected signal and to generate a second digital IF signal based on the reflected signal, and digital mismatch compensation circuitry coupled to receive the first digital IF signal and the second digital IF signal, the digital mismatch compensation circuitry configured to process the first digital IF signal and the second digital IF signal to compensate for mismatches between the receive channel and the reference receive channel.

Abstract: A multiplexer includes: a low-pass filter that is connected between a common terminal and a first terminal and is formed of one or more first inductors and one or more first capacitors; a bandpass filter that is connected between the common terminal and a second terminal, has a passband higher than a passband of the low-pass filter, and is formed of one or more second inductors and one or more second capacitors; a high-pass filter that is connected between the common terminal and a third terminal, has a passband higher than the passband of the bandpass filter, and is formed of one or more third inductors and one or more third capacitors; and a fourth inductor that has a first end coupled to the common terminal and a second end coupled to the high-pass filter.

Abstract: In system for analyzing large data sets, document/file format can be discovered by attempting to parse the file using several parsers to generate a schema, assigning a score to each parsing, and selecting a parser based on the assigned scores. Schema element attributes, such as statistical parameters, can be derived and used in identifying schema elements associated with other files. Attributes of identified schema elements can be used to substitute missing data values with values based on such attributes. Data values corresponding schema elements can be selected and highlighted, and schema elements and/or attributes thereof can be highlighted based on selected data values. From a cluster of files, a lineage relationship between file pairs, indicating whether one file is derived from another, can be determined for several files. In reducing/compacting data, utilization of all available reducers can be optimized according to current utilization of one or more reducers.

Abstract: The present disclosure relates to a digital-to-analog converter (DAC) linearization system including a DAC, a summing buffer structure, an analog-to-digital converter (ADC), a calculation system, an error look-up table, and an adder. A combination of the DAC, the summing buffer structure, and the ADC sequentially provide first and second ADC output signals, both of which include DAC integral nonlinearity (INL). The calculation system calculates the DAC INL based on the first and second ADC output signals, the error look-up table provides a correction signal mapping to the calculated DAC INL, and the adder provides a calibrated digital input signal to the DAC based on the correction signal. The calibrated digital input signal ensures the DAC to generate an updated output signal with less nonlinearity and improved purity.

Abstract: In certain aspects, a circuit comprises a low noise amplifier (LNA) configured to receive a radio frequency (RF) signal, a first mixer coupled to the low noise amplifier (LNA), and a first trans-impedance filter coupled to the first mixer. The first trans-impedance filter comprises a tunable inductor and capacitor (LC) network configured to be a portion of a doubly terminated LC ladder filter and a trans-impedance amplifier (TIA) coupled to the tunable inductor and capacitor (LC) network. The circuit further comprises a second mixer coupled to the low noise amplifier (LNA) and a second trans-impedance filter coupled to the second mixer.

Abstract: Provided is a communication system in which one transmission path is shared by a plurality of communication devices, wherein the plurality of communication devices each includes a transmitter that repeatedly transmits one packet to the transmission path with a period of the communication device until a prescribed condition is satisfied, and a receiver that integrates a signal on the transmission path over a period of another communication device until a prescribed condition is satisfied.

Abstract: A method for processing a digital audio broadcast signal in a radio receiver, includes: receiving a hybrid broadcast signal; demodulating the hybrid broadcast signal to produce an analog audio stream and a digital audio stream; and using a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream. The time offset can be used to align the analog audio stream and the digital audio stream for subsequent blending of an output of the radio receiver from the analog audio stream to the digital audio stream or from the digital audio stream to the analog audio stream.

Abstract: Constant-envelope phase-optimized transmission methods and apparatus are disclosed. An example method includes determining initial values of modulation phases in a first quadrant, the modulation phases associated with binary codes to be transmitted; and optimizing the initial values to second values to enable a product of an objective function to be within a threshold value.

Abstract: Interference cancellation circuitry is provided for reconstructing a wirelessly transmitted modulated signal in a receiver using output of a decoder for calculating per-bit probabilities corresponding to bit-by-bit estimates of a coded message from which one bit hard decisions and multi-bit soft decision can be derived. A soft modulator reconstructs the transmitted modulated signal by calculating a weighted superposition depending upon the hard decisions and at least one combined value computed by combining two or more of the multi-bit soft decisions corresponding to different bits of the coded message. A soft modulation method using combined value(s) in a weighted superposition of hard decisions and computer program code for calculating the combined values and regenerated modulated signal are also provided. Other embodiments may be described and claimed.

Abstract: Described is a method and devices to determine root-mean-square of a delta-sigma modulated signal. The method includes filtering the delta-sigma modulated signal to produce a multi-bit filtered signal, delaying a copy of the delta-sigma modulated signal by a fixed number of samples to align with the filtered input, setting a sign of each multi-bit value of the multi-bit filtered signal based upon a corresponding sample value of the delayed copy of the delta-sigma modulated signal, to generate a hybrid signal, summing the hybrid signal to produce a summed signal, and determining the average of the summed signal and the square root of the average to produce a root-mean-square value.

Abstract: The present disclosure shows new mechanisms for sampling an input signal. In particular, some embodiments of the present disclosure include a new type of a level-crossing sampling mechanism called a derivative level-crossing sampling (D-LCS). At a high level, D-LCS involves quantizing the derivative of an input signal when the derivative of the input signal crosses one of the quantization thresholds. For certain class of signals, the derivative of the input signal can vary at a slower speed compared to the amplitude of the input signal. Therefore, by sampling the derivative of the input signal, instead of the input signal itself, the number of samples per unit time can be reduced.

Abstract: A plethysmographic respiration processor is responsive to respiratory effects appearing on a blood volume waveform and the corresponding detected intensity waveform measured with an optical sensor at a blood perfused peripheral tissue site so as to provide a measurement of respiration rate. A preprocessor identifies a windowed pleth corresponding to a physiologically acceptable series of plethysmograph waveform pulses. Multiple processors derive different parameters responsive to particular respiratory effects on the windowed pleth. Decision logic determines a respiration rate based upon at least a portion of these parameters.

Abstract: Provided is a radio receiver using a modulation scheme such as FSK or QPSK in which a transmission and reception frequency shift appears as DC offset in a demodulated signal, capable of increasing noise immunity while suppressing deterioration in sensitivity. A high-speed pull-in processing unit 102 that performs offset correction by subtracting a correction value Adj_DC obtained from transmission and reception frequency deviation from the demodulated (detected) signal and a low-speed pull-in processing unit 104 that feedbacks a correction value Adj_local(t) obtained from an average value of the demodulated (detected) signal to a local oscillator 1012 are used in combination. The correction value Adj_DC for the high-speed pull-in processing is reduced over time by subtracting a correction amount Adj_Del(t) from the correction value Adj_DC and the feedback is performed, so that, as a result, the correction value Adj_DC for the high-speed pull-in processing is given to the low-speed pull-in processing.

Abstract: Systems and methods for estimating IQ imbalance in a communication system are provided, where a first device is configured to perform a self-characterization. The self-characterization is performed by requesting an IQ probe from a second device. The first device receives tones via the IQ probe with frequency separation such that an image related to one IQ imbalance is separated from an image related to another IQ imbalance. IQ imbalance can be estimated by calculating tone to image ratio.

Abstract: Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.

Abstract: This disclosure provides systems, methods, and apparatus for receiving paging messages in fast fading scenarios. In one aspect, a method of demodulating a paging message during an assigned time slot by a wireless communications apparatus operating in an idle mode is provided. The method includes determining, in anticipation of the assigned time slot, an expected time position corresponding to a path of a pilot signal having a greater signal strength relative to other pilot signals. The method further includes assigning a first demodulation element to demodulate the pilot signal with reference to the expected time position and assigning a second demodulation element to demodulate the pilot signal with reference to a time offset from the expected time position. Other aspects, embodiments, and features are also claimed and described.

Abstract: A precoding method, a precoding apparatus, a Frequency Domain Equalization (FDE) method, and an FDE apparatus are provided in the embodiments of the present invention. The precoding method includes: performing offset modulation for a transmitting signal vector; calculating a precoding matrix according to the offset-modulated transmitting signal vector and a receiver decision signal vector, where the precoding matrix is used for performing precoding for the transmitting signal vector; and performing precoding for the transmitting signal vector according to the precoding matrix. Linear precoding is performed by using the offset-modulated signal on the transmitter, and therefore, the interference caused by multiple antennas and multipath propagation is reduced, the system BER is reduced, and the complexity of implementation is low.

Abstract: One aspect of the present invention includes a bi-phase communication receiver system. The system includes an analog-to-digital converter (ADC) configured to sample a bi-phase modulation signal to generate digital samples of the bi-phase modulation signal. The system also includes a bi-phase signal decoder configured to decode the bi-phase modulation signal based on the digital samples. The system further includes a preamble detector comprising a digital filter configured to evaluate the digital samples to generate an output and to detect a preamble of the bi-phase modulation signal for decoding the bi-phase modulation signal based on the output.

Abstract: A method may include receiving a positive in-phase (“I”)-channel signal (“I+ signal”), a negative I-channel signal (“I? signal”), a positive quadrature-phase (“Q”)-channel signal (“Q+ signal”), and a negative Q-channel signal (“Q? signal”). The method may further include outputting a truncated I+ signal, a truncated I? signal, a truncated Q+ signal, and a truncated Q? signal. The method may further include generating the truncated I+ signal based on the I+ and Q+ signals and a complement of the truncated Q? signal, generating the truncated I? signal based on the I? and Q? signals and a complement of the truncated Q+ signal, generating the truncated Q+ signal based on the I? and Q+ signals and a complement of the truncated I+ signal, and generating the truncated Q? signal based on the I+ and Q? signals and a complement of the truncated I? signal.

Abstract: Methods and apparatus for transferring data along a link with a 10GBASE-T transceiver at a variable data rate are disclosed. One exemplary method includes detecting a link quality metric; and selecting a symbol transmission rate and a data modulation scheme based on the detected link quality metric. In many implementations, for a selected symbol transmission rate, if the detected link quality metric is less than a link quality threshold, then the selecting of the data modulation scheme is performed such that a data bit per symbol value represented by the selected data modulation scheme is decreased by at least ½ data bit per symbol. The selected symbol transmission rate and the selected modulation together represent a selectable data rate from a selection of data rates.

Abstract: A method and apparatus for a receiver system in a receiver that includes at least two front end branches, each branch having its own intermediate frequency (IF) mixer to shift a received signal to an IF. When receiving multiple independent signals, the signals are digitized and the receiver performs a digital complex transform on each signal to obtain the corresponding quadrature component. When receiving a single signal the signal is routed to two mixers that are 90 degrees out of phase to obtain the quadrature signal components in the analog section of the receiver.

Abstract: A receiver apparatus includes a propagation channel estimating unit that estimates a propagation channel. The propagation channel estimating unit includes a path detector unit that repeatedly performs a process of detecting paths in the order of increase in a propagation channel goodness of fit. The receiver apparatus that estimates a propagation channel at a high accuracy level with a small amount of calculation operation involved is thus provided.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: The present invention discloses a method and system for adaptively identifying signal bandwidth. The method includes: performing digitizing intermediate frequency processing to the received signal and outputting in-phase/quadrature (I/Q) signals; identifying signal bandwidth of the I/Q signals according to at least two signal identification templates and outputting the synchronized signal flows after a successful identification. A system for adaptively identifying signal bandwidth is also disclosed. The present invention can be compatible with at least two bandwidth modes, and the software can automatically perform identification and switch of the modulation bandwidth, when manual invention is not necessary and the operation is simple.

Abstract: A system including a component of a transceiver, a comparator, a counter, and a calibration circuit. The component receives an input signal comprising packets and based on the input signal, generates output signals to transmit the packets. The comparator compares the output signals to generate a comparison signal. The counter counts cycles of a clock signal to provide a count value. The control device, based on the comparison signal, transitions the counter between incrementing the count value and decrementing the count value. The calibration circuit operates in first and second calibration modes; during the first calibration mode, calibrates the component until the counter transitions a predetermined number of times between incrementing the count value and decrementing the count value; and during the second calibration mode, calibrates the component until (i) the counter transitions between incrementing and decrementing the count value, or (ii) counts a predetermined number of cycles.

Abstract: Receiver design techniques are provided that are capable of producing relatively efficient, linear radio frequency (RF) receivers. During a design process, components of an analog receiver chain and digital nonlinearity compensation techniques are considered together to achieve reduced power consumption in the receiver.

Abstract: Data coding schemes perform level-based and/or transition-based encoding to avoid signaling conditions that create worst case crosstalk during transmission of multi-bit data from one circuit to another circuit via a parallel communication link. The coding schemes disallow certain patterns from being present in the signal levels, signal transitions, or a combination of the signal levels and signal transitions that occur in a subset of the multi-bit data that corresponds to certain physically neighboring wires of the parallel communication link.

Abstract: Embodiments of a method for processing a baseband signal in a Direct Current (DC)-suppressed system, a system for processing a baseband signal in a DC-suppressed system, and a smart card are described. In one embodiment, a method for processing a baseband signal in a DC-suppressed system involves processing the baseband signal in the analog domain with a first high pass filter (HPF), converting the processed baseband signal to a digital signal, and processing the digital signal in the digital domain with a second HPF to provide a discrete-time differentiation of the baseband signal. Other embodiments are also described.

Abstract: A time domain switching analog-to-digital converter apparatus and methods of utilizing the same. In one implementation, the converter apparatus comprises a carrier signal source, and at least one reference source. The carrier signal is summed with the input signal and the summed modulated signal is fed to a comparator circuit. The comparator is configured detects crossings of the reference level by the modulated waveform thereby generating trigger events. The time period between consecutive trigger events is used to obtain modulated signal deviation due to the input signal thus enabling input signal measurement. Control of the carrier oscillation amplitude and frequency enables real time adjustment of the converter dynamic range and resolution. The use of additional reference signal levels increases sensor frequency response and accuracy. A dual channel converter apparatus enables estimation and removal of common mode noise, thereby improving signal conversion accuracy.

Abstract: Certain disclosed embodiments pertain to suppressing interference in a wireless communication system. For example, a method of suppressing interference can include receiving one or more first signals including components from a plurality of sub-channels. Each of the first signals can be converted into a respective plurality of first sub-band frequency components. A respective spatial filter can be determined for each frequency sub-band using one or more corresponding first sub-band components for each respective spatial filter. One or more second signals including components from the plurality of sub-channels can be received. Each of the second signals can be converted into a respective plurality of second sub-band frequency components. A corresponding plurality of filtered sub-band components can be generated by applying the respective spatial filters to the corresponding second sub-band components for each of the second signals.

Abstract: Briefly, a method and apparatus to calculate cross-correlation values of complex binary sequences are provided. The apparatus may include a transformation unit and a cross-correlator. The cross-correlator may include a cross-correlation controller to provide, based on a type bit and a sign bit, a real component and/or an imaginary component of signals of complex binary sequences to a real accumulator and/or to an imaginary accumulator.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit information on different modulation layers using a carrier RF signal. Initially, first data to be transmitted is assigned to a first modulation layer and second data is assigned to a second modulation layer. In one embodiment of the present invention, the first and second data are assigned based on reliability criteria. The first and second modulation layers are hierarchical modulation layers of the carrier RF signal. Once assigned, the first data is transmitted using the first modulation layer of the carrier RF signal and the second data is transmitted using the second modulation layer of the carrier RF signal. In one embodiment of the present invention, information may be transmitted to one end user using one modulation layer, and information may be transmitted to a different end user using a different modulation layer.

Abstract: A channel estimation method and a channel estimation system based on time-domain training sequence are provided. The channel estimation system first acquires an initial channel vector used for channel estimation of a current frame, and calculates an algorithm initial vector based on a training sequence vector contained in a received receiving signal vector and the receiving signal vector, then performs estimation based on the initial channel vector and the algorithm initial vector and using a conjugate gradient method based on a preprocessing matrix to acquire each channel estimation value, and eventually perform noise reduction processing on each channel estimation value based on a first predetermined threshold value to acquire a final channel estimation value. Compared with the existing channel estimation methods, the present invention has a shorter delay and lower calculation complexity, and thus can be easily implemented.

Abstract: A method, an apparatus and a system for eliminating aliasing noise in a multi-carrier modulation system are disclosed. The method includes: acquiring a first power spectrum density template; acquiring information of in-band subcarriers whose aliasing noise is greater than background noise, and acquiring a difference between the aliasing noise and the background noise of the in-band subcarriers; adjusting the first power spectrum density template according to the information of the in-band subcarriers and the corresponding difference to obtain a second power spectrum density template; and sending signals according to the second power spectrum density template. The method, the apparatus, and the system disclosed herein eliminate the aliasing crosstalk noise, improve the performance and stability of in-band services without involving upgrade or modification of the Customer Premises Equipment (CPE), and are easy to implement.

Abstract: A method for processing a digital audio broadcast signal in a radio receiver, includes: receiving a hybrid broadcast signal; demodulating the hybrid broadcast signal to produce an analog audio stream and a digital audio stream; and using a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream. The time offset can be used to align the analog audio stream and the digital audio stream for subsequent blending of an output of the radio receiver from the analog audio stream to the digital audio stream or from the digital audio stream to the analog audio stream.