Sample rate converter with rational numerator or denominator

An interpolating sample rate converter that provides rate conversion by a factor of M/N comprising:

• an upsampler that upsamples an input data stream by a factor of M;
• a filter that shapes the upsampled data stream in accordance with a predetermined power spectrum;
• and
• a downsampler that downsamples the upsampled and shaped signal by a factor of N to produce an output data stream;
• wherein the upsampler and filter are implemented, at least in part, by a cascaded integrator-comb filter;
• and
• wherein the upsampling factor M is a natural number and the downsampling factor N is a rational number but not necessarily a natural number.

A decimating sample rate converter that provides rate conversion by a factor of M/N comprising:

• an upsampler that upsamples an input data stream by a factor of M;
• a filter that shapes the upsampled data stream in accordance with a predetermined power spectrum;
• and
• a downsampler that downsamples the upsampled and shaped signal by a factor of N to produce an output data stream;
• wherein the filter and downsampler are implemented, at least in part, by a cascaded integrator-comb filter;
• and
• wherein the upsampling factor M is a rational number but not necessarily a natural number and the downsampling factor N is a natural number.

A method for sample rate conversion of a digital input signal, the method comprising the steps of:

• (a) providing an input digital data stream at an input sample rate;
• (b) filtering and interpolating the input digital data stream by an integer value I utilizing, at least in part, a cascaded integrator-comb filter;
• and
• (c) decimating the interpolated input digital data stream by an instantaneously variable value V to provide an output digital data stream at an output sample rate.

A method for sample rate conversion of a digital input signal, the method comprising the steps of:

• (a) providing an input digital data stream at an input sample rate;
• (b) interpolating the input digital data stream by an instantaneously variable value V;
• and
• (c) filtering and decimating the interpolated input digital data stream by a value I utilizing, at least in part, a cascaded integrator-comb filter, to provide an output digital data stream at an output sample rate.

A sample rate converter for a digital input signal comprising:

• means for providing an input digital data stream at an input sample rate;
• means for filtering and interpolating the input digital data stream by an integer value I utilizing, at least in part, a cascaded integrator-comb filter;
• and
• means for decimating the interpolated input digital data stream by an instantaneously variable value V to provide an output digital data stream at an output sample rate.

A sample rate converter for a digital input signal comprising:

• means for providing an input digital data stream at an input sample rate;
• means for interpolating the input digital data stream by an instantaneously variable value V;
• and
• means for filtering and decimating the interpolated input digital data stream by a value I utilizing, at least in part, a cascaded integrator-comb filter, to provide an output digital data stream at an output sample rate.