Popular Convolutional Codes
An especially popular Viterbi-decoded convolutional code, used at least since the Voyager program has a constraint length k of 7 and a rate r of 1/2.
- Longer constraint lengths produce more powerful codes, but the complexity of the Viterbi algorithm increases exponentially with constraint lengths, limiting these more powerful codes to deep space missions where the extra performance is easily worth the increased decoder complexity.
- Mars Pathfinder, Mars Exploration Rover and the Cassini probe to Saturn use a k of 15 and a rate of 1/6; this code performs about 2 dB better than the simpler k=7 code at a cost of 256× in decoding complexity (compared to Voyager mission codes).
Read more about this topic: Convolutional Code
Famous quotes containing the words popular and/or codes:
“What is saved in the cinema when it achieves art is a spontaneous continuity with all mankind. It is not an art of the princes or the bourgeoisie. It is popular and vagrant. In the sky of the cinema people learn what they might have been and discover what belongs to them apart from their single lives.”
—John Berger (b. 1926)
“I cannot help thinking that the menace of Hell makes as many devils as the severe penal codes of inhuman humanity make villains.”
—George Gordon Noel Byron (1788–1824)