Abstract: A method may include selecting, based on a condition of an electromagnetic load, a selected measurement technique from a plurality of impedance measurement techniques for measuring an impedance of the electromagnetic load and performing the selected measurement technique to generate an estimate of the impedance of the electromagnetic load.

Abstract: A method may include selecting, based on a condition of an electromagnetic load, a selected measurement technique from of a plurality of impedance measurement techniques for measuring an impedance of the electromagnetic load and performing the selected measurement technique to generate an estimate of the impedance of the electromagnetic load.

Abstract: The overall performance and power utilization of an audio device may be improved with an adaptive sidetone generation system that generates sidetones optimized for different application-specific problems. In particular, systems that include sidetone generation capabilities may be developed to include numerous microphones from which information may be received and processed to generate optimized sidetones. For example, the information from the microphones may be used to receive and/or determine the audio device's operating mode. The information from the microphones and the received and/or determined mode may then be used to generate a sidetone that is optimized for the particular mode and particular conditions in which the audio device is operating. Through the generation of optimized sidetones, the audio signal quality may be improved, thus reducing the amount of subsequent audio processing required, and resulting in improved performance and power utilization.

Abstract: The overall performance and power utilization of an audio device may be improved with an adaptive sidetone generation system that generates sidetones optimized for different application-specific problems. In particular, systems that include sidetone generation capabilities may be developed to include numerous microphones from which information may be received and processed to generate optimized sidetones. For example, the information from the microphones may be used to receive and/or determine the audio device's operating mode. The information from the microphones and the received and/or determined mode may then be used to generate a sidetone that is optimized for the particular mode and particular conditions in which the audio device is operating. Through the generation of optimized sidetones, the audio signal quality may be improved, thus reducing the amount of subsequent audio processing required, and resulting in improved performance and power utilization.

Abstract: A method for adjusting automatic gain control (AGC) of a radio receiver begins when a primary AGC module establishes an AGC setting for the radio receiver to produce a primary AGC setting. The method continues when a supervisory AGC module compares performance of the radio receiver utilizing the primary AGC setting with a plurality of performance thresholds. The method continues with the supervisory AGC module adjusting the primary AGC setting to produce adjusted AGC setting when the performance of the radio receiver utilizing the primary AGC setting compares unfavorable with a first performance threshold of the plurality of performance thresholds. The method continues with the supervisory AGC module overwriting the primary AGC setting with alternative AGC setting when the performance of the radio receiver utilizing the primary AGC setting compares unfavorable with a second performance threshold of the plurality of performance thresholds.

Abstract: A sample rate converter includes an up-conversion module, a linear interpolator module, and a parameter control module. The up-conversion module is operable to convert a first data rate to a second data rate of a data signal. The linear interpolator module is operable to receive the data signal at the second data rate and to produce therefrom a data signal at a desired rate based on at least one parameter. The parameter control module is operable to produce the at least one parameter based on the desired rate.

Abstract: A method for managing power of a battery-powered handheld audio device by receiving an indicia of signal quality for a received continuous-time radio signal. The method compares the indicia of signal quality to a signal quality threshold. Upon a favorable comparison, enacting a first analog signal conditioning setting. Upon an unfavorable comparison, enacting a second analog signal conditioning setting. The method further provides, upon the favorable comparison, disabling a digital filtering operation, and upon the unfavorable comparison, enabling the digital filtering operation.

Abstract: A stereo decoder includes a first digital filter for producing a first filtered composite audio signal and a second digital filter for producing a second filtered composite audio signal. A sum/difference network produces a left channel signal and a right channel signal. A processor executes operational instructions that calculate a first corner frequency of a first digital filter based on a signal quality of the FM signal, calculate a first set of filter coefficients for the first digital filter based on the first corner frequency and an approximation of a filter transform, calculate a second corner frequency of a second digital filter based on the signal quality, and calculate a second set of filter coefficients for the second digital filter, based on the second corner frequency and the approximation of the filter transform.

Abstract: A radio receiver, optionally used in conjunction with a handheld audio system, includes a radio stage for processing a received radio signal into an audio signal. An audio stage produces an audio output, based on the audio signal. An overload monitor detects an overload condition in the radio stage and generates an overload signal in response to the detected overload condition. A controller controls the audio output in response to the overload signal.

Abstract: In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters (36 and 38) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism (34). In one embodiment, two or more cascaded filters (20, 24 or 22, 26 or 30,32) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.

Abstract: Embodiments of the present invention relate generally to receivers. A frequency modulated (FM) receiver includes an equalizer control unit coupled to receive at least one FM signal quality indicator and provide a control signal based on the FM signal quality indicator. An adaptive equalizer coupled to receive the control signal from the equalizer control unit and an FM signal and provide a filtered FM signal corresponding to the received FM signal. Coefficients of the adaptive equalizer are reset in response to the control signal. Another embodiment relates to a method for processing a frequency modulated (FM) signal. An FM signal is received. At least one FM signal quality indicator is used to provide a control signal. Based on the control signal, the received FM signal is filtered using one of an adaptive filter and a static filter to provide a filtered FM signal.

Abstract: In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters (36 and 38) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism (34). In one embodiment, two or more cascaded filters (20, 24 or 22, 26 or 30,32) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.