Abstract: A technique for reinitializing a coupled circuit, the technique including receiving a common configuration value associated with states of a coupled circuit, tracking states associated with the coupled circuit while the coupled circuit is in a low power state based on the common configuration value, receiving the tracked state associated with the coupled circuit, receiving a scaling value associated with the coupled circuit, determining a current state of the coupled circuit based on the tracked state and the scaling value, and transmitting an indication of the current state to the coupled circuit when the coupled circuit has exited the low power state.

Abstract: A circuit includes a capture subsystem and digital pre-distortion (DPD) circuitry. The capture subsystem is configured to capture a set of signal samples responsive to a capture enable signal. The DPD circuitry is configured to generate a signal statistics signal based on an input signal, generate a set of DPD coefficients based on the set of signal samples, and apply DPD correction to the input signal to produce an output signal based on the signal statistics signal and the set of DPD coefficients. The set of signal samples includes samples of the signal statistics signal.

Abstract: Methods, apparatus, systems, and articles of manufacture are described for dynamic digital pre-distortion correction. An example system includes programmable circuitry operable to execute computer readable instructions to at least: generate signal statistics based on an input signal; group the signal statistics into a first group of signal statistics or a second group of signal statistics based on time constants of the signal statistics; decimate the first group of signal statistics; generate a first predistortion term based on the decimated first group of signal statistics; generate a second predistortion term based on the second group of signal statistics; and generate an output predistortion terminal based on the first predistortion term and the second predistortion term.

Abstract: A circuit includes a first digital pre-distortion (DPD) corrector and a second DPD corrector. The first DPD corrector has an input, and an output. The second DPD corrector has an input coupled to the input of the first DPD corrector, and an output. A signal combiner has a first input coupled to the output of the first DPD corrector, a second input coupled to the output of the second DPD corrector, and an output. The second DPD corrector is configured to provide a signal at the output of the second DPD corrector based on a signal at the input of the second DPD corrector and one or more signal statistics related to the signal at the input of the second DPD corrector.

Abstract: An example method includes switching a first multiplexer circuit associated with first delay circuitry from (a) a first sub-lookup table (LUT) of a first LUT of digital pre-distortion (DPD) corrector circuitry to (b) a first corresponding sub-LUT of a second LUT of the DPD corrector circuitry, the first sub-LUT associated with the first delay circuitry, the second LUT storing updated values to compensate for non-linearity of power amplifier circuitry of a transmitter including the DPD corrector circuitry. The method includes, based on a value of a counter being equal to a difference between (1) a first delay of the first delay circuitry and (2) a second delay of second delay circuitry, switching a second multiplexer circuit associated with the second delay circuitry from (a) a second sub-LUT of the first LUT to (b) a second corresponding sub-LUT of the second LUT, the second sub-LUT associated with the second delay circuitry.

Abstract: Examples of this description provide for a method. In some examples, the method includes determining, via a circuit, an estimated value of harmonic coupling in a transmitted signal via a feedback signal path that receives the transmitted signal and performing pre-compensation for the harmonic coupling based on the estimated value, the pre-compensation performed in the circuit.

Abstract: A TX-TX pre-compensation system that estimates unwanted coupling in a victim transmit chain caused by an aggressor transmit chain and injects a pre-compensation signal to cancel out the estimated coupling. In some embodiments, a signal measurement module estimates the amplitude, phase, and envelope delay of the coupling and an isolation pre-compensation module generates the pre-compensation signal based on the estimated amplitude, the estimated phase, the estimated envelope delay, and the difference between the carrier frequencies of the transmit chains. Since the phase of the coupling may be affected by the carrier frequency of the transmit chains, in some embodiments the phase of the pre-compensation signal is adjusted in response to a change in carrier frequency. Since the amplitude of the coupling may be affected by attenuator gain settings, in some embodiments the amplitude of the pre-compensation signal may be adjusted in response to a change in attenuator gain setting.

Abstract: The disclosure provides a heart rate monitor (HRM) circuit. The HRM circuit includes an analog front end (AFE). The AFE receives a Photoplethysmographic (PPG) signal, and generates a fine PPG signal. A motion cancellation circuit is coupled to the AFE, and receives the fine PPG signal and an accelerometer signal. The motion cancellation circuit subtracts the accelerometer signal from the fine PPG signal to generate a coarse heart rate. A peak detector is coupled to the motion cancellation circuit and the AFE, and generates an instantaneous heart rate. A filter is coupled to the peak detector, and generates an estimated heart rate from the instantaneous heart rate, the estimated heart rate is provided as a feedback to the peak detector.

Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

Abstract: Dual mode filters having two reconfigurable multi-stage filters. In a dual band mode, each reconfigurable filter filters an input signal in a different band using every filter stage. In a single band mode, both reconfigurable filters are effectively divided into two sub-chains that include either the odd-numbered filter stages or the even-numbered filter stages. Together, the four sub-chains in the single band mode filter an input signal in a single band with a higher parallelization than each reconfigurable filter in the dual band mode. In some embodiments, the dual mode filter is a decimation filter. In other embodiments, the dual mode filter is a resampling filter. In still other embodiments, the dual mode filter is an interpolation filter.

Abstract: A radio frequency transmitter includes an upconverter that outputs in-phase (I) and quadrature (Q) signals, a digital timing offset circuit, first and second digital-to-analog converters (DACs), an analog timing offset removal circuit, first and second pulse shapers, and an adder. The digital timing offset circuit introduces a time offset between the I and Q signals. The first and second DACs output analog I and Q signals, respectively, and have first and second clock signals, respectively. The first and second clock signals have the same frequency and are offset relative to each other by the time offset. The analog timing offset removal circuit removes the time offset between the analog I and Q signals. The first and second pulse shapers receive the analog I and Q signals, respectively, and output pulse-shaped I and Q signals. The adder receives the pulse-shaped I and Q signals and outputs an intermediate frequency signal.

Abstract: One example includes a receiver system. The receiver system includes an analog-to-digital converter (ADC) configured to convert an analog input signal into a digital output signal at a sampling frequency. The receiver system also includes a spur correction system configured to receive the digital output signal and to estimate spurs associated with the digital output signal and to selectively correct a subset of the spurs associated with a set of frequencies that are based on the sampling frequency.

Abstract: A TX-TX pre-compensation system that estimates unwanted coupling in a victim transmit chain caused by an aggressor transmit chain and injects a pre-compensation signal to cancel out the estimated coupling. In some embodiments, a signal measurement module estimates the amplitude, phase, and envelope delay of the coupling and an isolation pre-compensation module generates the pre-compensation signal based on the estimated amplitude, the estimated phase, the estimated envelope delay, and the difference between the carrier frequencies of the transmit chains. Since the phase of the coupling may be affected by the carrier frequency of the transmit chains, in some embodiments the phase of the pre-compensation signal is adjusted in response to a change in carrier frequency. Since the amplitude of the coupling may be affected by attenuator gain settings, in some embodiments the amplitude of the pre-compensation signal may be adjusted in response to a change in attenuator gain setting.

Abstract: A system for generating secondary clock signals from a primary clock signal includes a dithered clock divider which has a first input adapted to receive the primary clock signal and a second input adapted to receive a random division ratio. The dithered clock divider provides a dithered clock signal. The system includes a multi-phase clock generator which has a first input adapted to receive the primary clock signal, a second input adapted to receive the dithered clock signal, and a third input adapted to receive a pseudo-random pattern. The multi-phase clock generator provides the secondary clock signals from multiple phases of the dithered clock signal. The system includes a pseuodo-random pattern generator which provides the pseudo-random pattern.

Abstract: A system for generating secondary clock signals from a primary clock signal includes a dithered clock divider which has a first input adapted to receive the primary clock signal and a second input adapted to receive a random division ratio. The dithered clock divider provides a dithered clock signal. The system includes a multi-phase clock generator which has a first input adapted to receive the primary clock signal, a second input adapted to receive the dithered clock signal, and a third input adapted to receive a pseudo-random pattern. The multi-phase clock generator provides the secondary clock signals from multiple phases of the dithered clock signal. The system includes a pseudo-random pattern generator which provides the pseudo-random pattern.

Abstract: Dual mode filters having two reconfigurable multi-stage filters. In a dual band mode, each reconfigurable filter filters an input signal in a different band using every filter stage. In a single band mode, both reconfigurable filters are effectively divided into two sub-chains that include either the odd-numbered filter stages or the even-numbered filter stages. Together, the four sub-chains in the single band mode filter an input signal in a single band with a higher parallelization than each reconfigurable filter in the dual band mode. In some embodiments, the dual mode filter is a decimation filter. In other embodiments, the dual mode filter is a resampling filter. In still other embodiments, the dual mode filter is an interpolation filter.

Abstract: A phase spectrum based delay estimating method of tracking channel responses, extracting phase responses from the tracked channel responses, and generating a delay estimate, wherein the delay estimate is based on a slope and intercept estimates of the extracted phase responses with high quality metric to improve delay estimation, and a system thereof.

Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

Abstract: A technique for reinitializing a coupled circuit, the technique including receiving a common configuration value associated with states of a coupled circuit, tracking states associated with the coupled circuit while the coupled circuit is in a low power state based on the common configuration value, receiving the tracked state associated with the coupled circuit, receiving a scaling value associated with the coupled circuit, determining a current state of the coupled circuit based on the tracked state and the scaling value, and transmitting an indication of the current state to the coupled circuit when the coupled circuit has exited the low power state.

Abstract: A channel response generating module and method for generating a channel response based on a ratio of a channel response corresponding to an image signal frequency bin in relation to a channel response corresponding to a traffic signal frequency bin, or a channel response corresponding to a first frequency bin in relation to a channel response corresponding to a second frequency bin, and a zero-IF signal transmitter employing the channel response generating module and method to efficiently suppress image signals or compensate traffic signals during transmission of IQ RF signals.