Systems and methods for implementing a sample rate converter using hardware and software to maximize speed and flexibility
First Claim
1. A sample rate converter comprising:
- a plurality of sample rate converter components, including;
a rate estimator;
a low pass filter, wherein an output of the rate estimator is passed through the low pass filter;
a phase selection unit, wherein an output of the low pass filter is provided to the phase selection unit;
a polyphase coefficient interpolator, wherein a set of interpolated polyphase filter coefficients is generated by the polyphase coefficient interpolator based upon an output of the phase selection unit;
a convolution unit configured to convolve the interpolated polyphase filter coefficients with a corresponding sample of an input data stream;
an input FIFO configured to receive samples of the input data stream and to provide the samples of the input data stream to the convolution unit;
an output FIFO configured to receive samples of an output data stream from the convolution unit; and
a FIFO management unit coupled to the input and output FIFOs and configured to provide feedback to the low pass filter;
wherein a first portion of the components comprise hardware components; and
wherein a second portion of the components comprise software components.
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Abstract
Systems and methods for converting a digital input data stream from a first sample rate to a second, fixed sample rate using a combination of hardware and software components. In one embodiment, a system includes a rate estimator configured to estimate the sample rate of an input data stream, a phase selection unit configured to select a phase for interpolation of a set of polyphase filter coefficients based on the estimated sample rate, a coefficient interpolator configured to interpolate the filter coefficients based on the selected phase, and a convolution unit configured to convolve the interpolated filter coefficients with samples of the input data stream to produce samples of a re-sampled output data stream. One or more hardware or software components are shared between multiple channels that can process data streams having independently variable sample rates.
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Citations
12 Claims
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1. A sample rate converter comprising:
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a plurality of sample rate converter components, including; a rate estimator; a low pass filter, wherein an output of the rate estimator is passed through the low pass filter; a phase selection unit, wherein an output of the low pass filter is provided to the phase selection unit; a polyphase coefficient interpolator, wherein a set of interpolated polyphase filter coefficients is generated by the polyphase coefficient interpolator based upon an output of the phase selection unit; a convolution unit configured to convolve the interpolated polyphase filter coefficients with a corresponding sample of an input data stream; an input FIFO configured to receive samples of the input data stream and to provide the samples of the input data stream to the convolution unit; an output FIFO configured to receive samples of an output data stream from the convolution unit; and a FIFO management unit coupled to the input and output FIFOs and configured to provide feedback to the low pass filter; wherein a first portion of the components comprise hardware components; and wherein a second portion of the components comprise software components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification