Citation
Abstract
Maximum likelihood decoding of short constraint-length convolutional codes is one of the likely candidates for implementing high-performance telemetry systems for future deep-space missions. It has, in fact, been considered to be the best choice for video missions, providing better performance at the design point of 5 X 10-8 than other systems of comparable complexity. Recent advances in knowledge of sequential decoding have posed the question as to whether sequential decoding might, in fact, be preferable to maximum likelihood decoding. The answer, developed here in terms of a hypothesized maximum likelihood decoder built technologically similar to the JPL high-speed multi-mission sequential decoder, is that maximum likelihood decoding is preferable to sequential decoding at a 5 X 10-8 bit error rate. The reverse is true at 10-° and below. Two code families of variable constraint length are also developed which permit easy implementation of encoders for this hypothesized maximum-likelihood decoder.
Details
- Volume
- IX
- Published
- June 15, 1972
- Pages
- 97–102
- File Size
- 549.4 KB