Comparison Study of Unequal Error Protection Methods for One-Dimensional SignalConstellations

摘要

Unequal error protection is a method to improve bandwidth efficiency where thesource 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).