Techniques for variable sample rate conversion
AssigneeOctiv, Inc.
InventorRichard Hodges
Life of this patent
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Abstract
Methods and apparatus are described for performing a variable sample rate conversion. A difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal is tracked. A sample rate conversion ratio is adjusted in response to the difference. One of the first and second sample rates is converted using the conversion ratio.
Claims34
At least one computer readable medium having computer program instructions stored therein for performing a variable sample rate conversion, the computer program instructions comprising:
- first instructions for tracking a difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal;
- second instructions for adjusting a sample rate conversion ratio in response to the difference;
- and
- third instructions for converting one of the first and second sample rates using the conversion ratio.
A method for performing a variable sample rate conversion, comprising:
- tacking a difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal;
- adjusting a sample rate conversion ratio in response to the difference;
- and
- converting one of the first and second sample rates using the conversion ratio.
At least one computer readable medium having computer program instructions stored therein for performing echo cancellation, the computer program instructions comprising:
- first instructions for tracking a difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal;
- second instructions for adjusting a sample rate conversion ratio in response to the difference;
- third instructions for converting the first sample rate using the conversion ratio, thereby generating a modified first signal and facilitating synchronization of the modified first signal and the second signal;
- and
- fourth instructions for performing echo cancellation using the modified first signal and the second signal.
At least one computer readable medium having computer program instructions stored therein for performing echo cancellation, the computer program instructions comprising:
- first instructions for tracking a difference between a first sample rate associated with a first signal and a second sample rate associated with a second signal by tracking a sample count in which samples associated with the first signal make a positive contribution to the sample count and samples associated with the second signal make a negative contribution to the sample count;
- second instructions far adjusting a downsampling factor using a feedback signal generated by a third order control system with reference to the difference;
- third instructions for converting the first sample rate using an upsampling factor, a filter, and the downsampling factor, thereby generating a modified first signal and facilitating synchronization of the modified first signal and the second signal;
- and
- fourth instructions for performing echo cancellation using the modified first signal and the second signal.
At least one computer readable medium having computer program instructions stored therein for converting a sample rate using an upsampling factor, a filter, and a downsampling factor, the filter having a plurality of filter coefficients associated therewith, the instructions being operable to store the filter coefficients in consecutive memory locations in an order in which the filter coefficients are used.
Dependencies are inferred from the claim text.