Apparatuses and methods for shifting a digital signal by a shift time to provide a shifted signal
AssigneeApple Inc.
InventorsThomas Bauernfeind, Andreas Menkhoff, Michael Bruennert
Life of this patent
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Abstract
An apparatus for shifting a digital signal having a first sample rate by a shift time to provide a shifted signal having a second sample rate is provided. The apparatus includes a sample rate converter configured to provide a value of an interpolated signal at a compensated sample time as a sample of the shifted signal, the interpolated signal being based on the digital signal. The sample rate converter is configured to modify a time interval between a sample time of the digital signal and the compensated sample time based on the shift time.
Claims7
An apparatus for time-shifting a digital signal by a shift time while converting a sample rate of the digital signal, the apparatus comprising:
- a sample rate converter configured to evaluate an interpolation function determined based on input samples of the digital signal at a compensated sample time to generate output samples, wherein the input samples have a first sample rate and the output samples have a second sample rate, and the compensated sample time is determined based on a shift time between the output samples and the input samples;
- wherein the sample rate converter comprises:
- a nominal sample time calculation unit configured to determine a nominal sample time corresponding to the second sample rate;
- and an adder for adding or subtracting the shift time to or from the nominal sample time to obtain the compensated sample time;
- wherein the sample rate converter comprises a format conversion unit to match a format of the shift time and the nominal sample time.
A transmitter comprising:
- a first circuitry configured to process a digital signal at a first clock rate;
- a digital modulator configured to time-shift an output of the first circuitry by a shift time while converting a sample rate of the digital signal;
- and a second circuitry configured to process an output of the digital modulator at a second clock rate;
- wherein the digital modulator comprises:
- a sample rate converter configured to evaluate an interpolation function determined from input samples of the digital signal at a compensated sample time to generate output samples, wherein the input samples have a first sample rate and the output samples have a second sample rate, and the compensated sample time is determined based on a shift time between the output samples and the input samples.
Dependencies are inferred from the claim text.