Some Partial Unit Memory Convolutional Codes

K. Abdel-GhaffarUniversity of California, DavisR. J. McEliece 1G. Solomon 2This article presents the results of a study of a class of error-correcting codescalled partial-unit-memory convolutional codes, or PUM codes for short. This classof codes, though not entirely new, has until now remained relatively unexplored.This article shows that it is possible to use the well-developed theory of block codesto construct a large family of promising PUM codes. Indeed, at the end of thearticle the performances of several specific PUM codes are compared with that ofthe Voyager standard (2, i, 6) convolutional code. It was found that these codes canoutperform the Voyager code with little or no increase in decoder complexity. Thissuggests that there may very well be PUM codes that can be used for deep-spacetelemetry that offer both increased performance and decreased implementationalcomplexity over current coding systems.