Sample rate converter

Details Sample rate converter Sample rate converter

1989-11-02

1991-01-29

Ng, Jin F.

Pulse or digital communications

Repeaters

Testing

379406, 370 321, 375118, H04B 138

Patent

active

049892215

ABSTRACT:
A sample rate converter receives an input stream of samples representative of a time-varying signal and generates a corresponding output stream of samples which is also representative of the time-varying signal and in which each output stream sample appears at a desired time which may differ from the time when a sample appears in the input stream; filter circuitry receives the input stream and generates at least two intermediate samples which appear at different times, and interpolation circuitry combines selected intermediate samples to form a sample of the output stream at the desired time. In another aspect, an improvement is provided for a modem of the kind in which a line signal is sampled at times governed by an unstable clock to generate a first sample stream in which the samples appear with possibly changing sampling phases and a converter converts the first sample stream to a second stream of samples appearing at times that are possibly different from the times of appearance of the samples in the first sample stream; the improvement is means for providing to the converter signals representative of the changing phases of the samples in the first sample stream to cause the conversion to occur in a manner that reduces the contribution of the changing sampling phases to the times of appearance of the samples in the second sample stream.

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