Accession Number : ADD008792

Title :   Sampled Speech Compression System.

Descriptive Note : Patent,


Personal Author(s) : Alsup,James M ; Whitehouse,Harper J

Report Date : 26 May 1981

Pagination or Media Count : 7

Abstract : A sampled speech compression and expansion system, for two-dimensional processing of speech or other type of audio signal, comprises transmit/encode apparatus and receive/decode apparatus. The transmit/encode apparatus comprises a low-pass filter, adapted to receive an input signal, for passing through low-frequency analog signals. A converter is connected to the low-pass filter for converting the analog signal into a digital signal. A buffer memory, whose input is connected to the converting means, stores the digitized signals. A correlator, having inputs from the A/D converter and the buffer memory, correlates the digital signal received directly from the converter with a delayed signal from the buffer memory. An 'interval-select' circuit, whose input is connected to the output of the correlator, uses the autocorrelation value as a basis for comparison with subsequent peaks in the correlation value which are greater than a specified fraction of the autocorrelation value. The interval-select circuit has an output which is connected to the buffer memory, the value of the fractional peaks and their timing being stored in the buffer memory.

Descriptors :   *Patents, *Speech compression, *Samplers, *Vocoders, Correlation techniques, Transmitter receivers, Analog systems, Audio frequency, Analog to digital converters, Signal processing, Memory devices, Analog signals, Buffer storage, Digital systems, Autocorrelation, Converters, Expansion, Input, Sampling, Value, Coders, Signals

Subject Categories : Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE