A Flexible High-Speed Sequential Decoder for Deep Space Channels

This paper describes a sequential decoding machine built at the Jet Propulsion Laboratory (JPL), which uses a 3-bit quantization of the code symbols and achieves a computation rate of MHz. This machine is flexible and can be programmed to decode any complementary convolutional code with rates down to 1/4 and contraint lengths up to 32. In addition, metric programmability is provided for optimization of decoder performance with respect to channel parameter variations.