Point of View: Spread-Spectrum Television Broadcasting

The terrestrial broadcast channel, plagued with ghosts, noise, interference, and frequency distortion, is the most difficult of all transmission media, but is nevertheless attractive because of its existing infrastructure, its low cost, and the fact that it is the means by which free and universal television service is made available to the public. To attain the maximum image quality, reliability, and spectrum efficiency in this medium, combined source and channel coding is proposed. Progressive or “multiresolution” source coding, together with a new form of spread-spectrum code-division multiplex (SS-CDM) channel coding, is used. The coded image information is divided into a large number of parallel data streams, each of which is spread to full channel bandwidth and becomes a component in the CDM multiplexing scheme. Each has a different priority and therefore a different carrier-to-noise ratio (CNR). In this article, CNR is reserved for channel conditions and SNR for signal-to-noise ratio of recovered signal The resulting signal occupies one standard 6-MHz channel and is expected to have excellent interference performance. (The opinions expressed herein are solely those of the author.)

Print ISSN

0036-1682

Published

1992-08

Content type

Original Research

DOI

10.5594/J06477