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Viterbi parameter issue

Honored Contributor II

I am trying to generate a Viterbi entity with 3 different codes, all at 1/2 rate. The constraint lengths include 5, 7, and 9, so I design the block for CONSTRAINT_LENGTH_M_1 = 8. However, when I run the block to use the constraint 5 code, the last 4 bits are always zeroed out. When I rebuild the decoder to ONLY use the constraint length 5 code, and set CONSTRAINT_LENGTH_M_1 = 4, only then does the decoder work. I want to avoid instantiating multiple Viterbi decoders for each constraint length....the documentation indicates that a single decoder should be able to support multiple lengths at runtime. 


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