Silicon Laboratories Inc.

Entropic Communications, Inc.

Carl Alelyunas

Branislav A Petrovic

Bradley Arthur Wallace

Thomas Glen Ragan

Russell Croman

David Anderton

Vladimir Mesarovic

Ken A Strickland

Tarang Shah

Nicholas R Berkner

Yue Zhao

In one embodiment, an apparatus includes first and second tuners to receive and process a radio frequency (RF) signal and output a first and second plurality of frequency domain sub-carriers. The apparatus may further include a combiner circuit to combine a first plurality of demodulated frequency domain sub-carriers and a second plurality of demodulated frequency domain sub-carriers into a plurality of combined frequency domain sub-carriers, and an output circuit coupled to the combiner circuit. In a first mode, the output circuit is to embed a format indicator with each of the plurality of combined frequency domain sub-carriers to indicate a frequency domain format, and to output the plurality of combined frequency domain sub-carriers with the embedded format indicator to a downstream processing circuit for channel decoding.

Interface to provide selectable time domain or frequency domain information to downstream circuitry

In one example, an apparatus includes: a wavelet transform engine to receive a first signal stream and perform a wavelet transform on a first time domain sample of the first signal stream, the first wavelet transform engine to output at least one first coefficient for a first frequency range; an energy calculation circuit to compute a first energy signature for the at least one first coefficient; and a correlation circuit to generate a correlation value using the first energy signature, a second energy signature and a plurality of previous energy signatures.

System, apparatus and method for time synchronization of delayed data streams by matching of wavelet coefficients

A method includes generating a two-dimensionally filtered pilot tone based on a plurality of received pilot tones received using a first subcarrier of each of a plurality of received OFDM symbols and a plurality of data symbols received using a second subcarrier of each of the plurality of received OFDM symbols. The plurality of OFDM symbols is received sequentially over a plurality of OFDM symbol times. The method may include generating inverse channel coefficients based on the two-dimensionally filtered pilot tone. The method may include applying the inverse channel coefficients to a subsequently received OFDM symbol to recover data encoded in the subsequently received OFDM symbol. Generating the two-dimensionally filtered pilot tone may use at least one least-mean-squares filter.

Two-dimensional filtering of pilots and carriers for OFDM channel estimation

In one embodiment, a noise cancellation circuit includes: a window generator to generate a window having a first set of samples; a band splitter to split the window into pairs of symmetric frequency components; a processing circuit, for each of the pairs, to: compare a first magnitude of a first symmetric frequency component to a second magnitude of a second symmetric frequency component and modify one of the components based at least in part on the comparison; an integrator to integrate the pairs output from the processing circuit; and a second window generator to generate a second window having a second set of samples.

Performing noise cancellation in radio signals using spectral duplication

Methods and systems are provided for spreading spectral density of digital-to-analog conversion output signals. A spreading circuit may spread a digital-to-analog converter (DAC) output signal over a particular frequency spectrum, with the spreading circuit receiving the DAC output signal; generating a plurality of internal control signals; and generating based on the DAC output signal and the one or more internal control signal a corresponding spread output signal. The Internal control signals may comprise at least a first control signal, generated based on sequences meeting at least one particular criterion, a second control signal, generated based on a feedback corresponding to an intermediate output generated within the spreading circuit. The spreading circuit may generate the first control signal based on zero-sum sequences. The spreading circuit may generate a stream of pulses based on the intermediate output, and may generate the feedback signal based on the stream of pulses.

Method and apparatus for spectrum spreading of a pulse-density modulated waveform

An apparatus includes a plurality of delay elements, a plurality of multipliers and an accumulator to form a biquad stage; and a precision logic circuit. The biquad stage includes feedback paths; at least one feedback path has an adjustable bit precision; and the precision logic is adapted to regulate the bit precision of the feedback path(s) based at least in part on at least one parameter that is associated with the biquad stage.

Biquad stage having a selectable bit precision

Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example system may comprise an accumulator circuit, a bit generator circuit, and a feedback circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and on one or more inputs generated within the system. The bit generator circuit may be operable to input into the accumulator circuit sequences meeting at least one particular criterion. The feedback circuit may be operable to apply an adjustment to a signal corresponding to an output of the accumulator circuit to generate a feedback signal, and input the feedback signal into the accumulator circuit.

Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example spreading circuit may comprise an accumulator circuit, a bit generator circuit, a comparator circuit, and an inverter circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and at least one other input. The bit generator circuit may be operable to input into the accumulator circuit zero-sum sequences. The comparator circuit may be operable to provide a stream of pulses based on the output of the accumulator circuit. The inverter circuit may be operable to invert output of the comparator circuit, wherein output of the inverter circuit is input into the accumulator circuit.

A spreading method and apparatus for spreading the spectral density of a pulse stream by summing a set of randomly selected zero-sum sequences to an incoming pulse stream and ensuring that the number of pulses output by the spreading method and apparatus is equal to the number of pulses input to the spreading method and apparatus.

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Austin, TX, United States of America

Carl Alelyunas