Sample rate conversion method and apparatus
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorRichard Hellberg
Life of this patent
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Abstract
An arbitrary sample rate conversion apparatus is described. This apparatus includes a buffer for forming blocks of input samples having a first sample rate. For each block of input samples a subfilter is selected from a polyphase filter. Each block of input samples is convolved with the corresponding selected subfilter for producing blocks of output samples having a second sample rate.
Claims24
An arbitrary sample rate conversion method, including the steps of:
- forming blocks of input samples having a first sample rate;
- selecting, for each block of input samples, a subfilter from a polyphase filter;
- and
- block convolving each block of input samples with the corresponding selected subfilter to produce blocks of output samples having a second sample rate.
An arbitrary sample rate conversion method, including the steps of:
- forming blocks of input samples having a first sample rate;
- selecting, for each block of input samples, a subfilter from a polyphase filter;
- reversing an order of the samples in an input sample block if a delay associated with the corresponding selected subfilter is not less than half of a time separation between input samples;
- block convolving each block of input samples with the corresponding selected subfilter to produce blocks of output samples having a second sample rate;
- and
- reversing the order of the samples in an output sample block if the delay associated with the corresponding selected subfilter is not less than half of the time separation between input samples.
An arbitrary sample rate conversion apparatus, including:
- a block former, wherein the block former produces blocks of input samples having a first sample rate;
- a subfilter selector, wherein the subfilter selector selects, for blocks of input samples produced by the block former, subfilters from a polyphase filter;
- and
- a block convolver, wherein the block convolver convolves blocks of input samples with corresponding selected subfilters and produces blocks of output samples having a second sample rate.
An arbitrary sample rate conversion apparatus, including:
- a block former, wherein the block former produces blocks of input samples having a first sample rate;
- a subfilter selector, wherein the subfilter selector selects subfilters from a polyphase filter for corresponding blocks of input samples produced by the block former;
- an input order reverser, wherein the input order reverser reverses orders of samples in input sample blocks produced by the block former if delays associated with the corresponding selected subfilters are not less than half of a time separation between input samples;
- a block convolver, wherein the block convolver convolves blocks of input samples with corresponding selected subfilters to produce blocks of output samples having a second sample rate;
- and
- an output order reverser, wherein the output order reverser reverses orders of samples in output sample blocks if the delays associated with the corresponding selected subfilters are not less than half the time separation between input samples.
Dependencies are inferred from the claim text.