Custom NMOS LSI Channel Vocoder

Peter E. Blankenship

doi:10.1117/12.957309

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21 September 1979 Custom NMOS LSI Channel Vocoder

Peter E. Blankenship

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Proceedings Volume 0180, Real-Time Signal Processing II; (1979) https://doi.org/10.1117/12.957309
Event: Technical Symposium East, 1979, Washington, D.C., United States

Abstract

An advanced implementation of a full duplex, multiple transmission rate, high performance channel vocoder is described which draws upon charge coupled device (CCD), switched capacitor, and digital microprocessor NMOS LSI technologies. The heart of the transmitter is a 19 channel spectrum analyzer chip realized via FIR non-recursive filter design methods. Pitch and voicing are determined with a modified Gold type of algorithm requiring very few components to implement. The receiver consists mainly of a 19 channel synthesis filter bank, including exciter, realized via switched capacitor recursive filtering techniques. Transmit and receive control functions are implemented in an 8 bit microprocessor and rates of 1.2, 2.4, 3.6, 4.8 kbs are supported. The design requires 30 integrated circuits, dissipates 5 W, weighs 6.25 lbs, and occupies .12 cu. ft.

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Peter E. Blankenship "Custom NMOS LSI Channel Vocoder", Proc. SPIE 0180, Real-Time Signal Processing II, (21 September 1979); https://doi.org/10.1117/12.957309

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