摘要 |
An analogue signal coder including circuitry for digitizing the analogue signal, deriving a long term correlation coefficient for the analogue signal and for deriving a number of short term coefficients. The coder also includes circuitry for deriving an excitation sequence which can be used to synthesize an approximation to the analogue signal. The circuitry for deriving a long term coefficient derives a plurality of sums of products of samples of the digitized signal and interpolates the sums of products. The long term correlation coefficient is derived from the interpolated plurality of sums of products with fractional resolution and reduced computational complexity.
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