An analog interpretation of compression for digital communication systems

The combination of a source coder and a digital modulator is in this article viewed as an analog-to-analog converter with signal compression ability. A reference-channel with defined available bandwidth, total received power, and noise statistics, can transmit one analog source signal. Compression is here defined as the number of such source signals that the digital system can transmit over the reference channel, and reconstruct with the same fidelity as the transmitted analog source signal. An image transmission example is provided where, for a given fidelity on a reconstructed image, the obtainable compression ratio is found for a digital compression system based on subband coding and pulse amplitude modulation