USING ASICS TO IMPLEMENT A PROGRAMMABLE DIGITAL FM DEMODULATOR

Abstract

With the advancement in speed and complexity of Application Specific Integrated Circuits (ASICs), Digital Signal Processing (DSP) algorithms can now be used to achieve fully programmable, multiple channel demodulation of Frequency Modulation (FM) multiplexes. This paper describes the DSP algorithms and ASIC implementation used in the design of a digital FM demodulator system. Each digital demodulator has programmable subcarrier frequency demodulation to 4 MHz, programmable digital output filtering, and tape speed compensation (TSC). The demodulator output is available in both digital form for direct computer interface and in analog form for conventional analysis.