Accession Number : ADA290386

Title :   Comparison Study of Unequal Error Protection Methods for One-Dimensional Signal Constellations.

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Yu, Christopher C. ; Newman, Daniel A.

PDF Url : ADA290386

Report Date : 31 JAN 1995

Pagination or Media Count : 18

Abstract : Unequal error protection is a method to improve bandwidth efficiency where the source data are characterized by having coded bits of varying sensitivity to channel errors. In this report, a framework for comparing the performance of two schemes for unequal error protection is developed. The first scheme (embedded) is based on a clever design of signal constellations with nonuniformly spaced signal points. The second scheme (time-sharing) is based on time-multiplexing concept. It is shown that in the presence of white Gaussian noise, the time-sharing scheme can achieve improved performance over the embedded scheme for one-dimensional signal constellations. This report also describes an application of unequal error protection for MPEG (Motion Pictures Experts Group) video transmission. Corruption in the visual quality of a single frame and the effect of propogatable errors for MPEG coding are both minimized by the use of unequal error protection. (MM)

Descriptors :   *TIME DIVISION MULTIPLEXING, *VIDEO SIGNALS, SIGNAL PROCESSING, ONE DIMENSIONAL, WHITE NOISE, GAUSSIAN NOISE, GAIN, BANDWIDTH, ERROR CORRECTION CODES, VIDEO FRAMES, PULSE AMPLITUDE MODULATION.

Subject Categories : Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE