The subtleties and intricacies of building a constraint length 15 convolutional decoder

A series of algorithms, circuit designs, and analytical techniques as well as a few tricks are presented. Each is essential to the design, which created a constraint-length-15, 1-Mb/s Viterbi decoder. The focus is the maximum-likelihood decoding of very-long-constraint-length convolutional codes, but many of the concepts will find other applications ranging from extremely fast constraint-length-7 decoders to software simulations of codes with constraint lengths even longer than 15. The constraint-length-15 decoder is now working and will form the basis for the coding system used in the next generation of deep space probes.<
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