viterbi decoder

decoder2=vitdec(decode2,trel,20,'cont','hard');

here the length of decode2 is 75 bits. but we are getting the error as:Length of the input code vector must be a multiple of the number of bits in an input symbol. please help us.

Answer 1

[Walter Roberson]

log2(trel.numInputSymbols) must evenly divide length(decode2)

http://www.mathworks.com/help/toolbox/comm/ref/vitdec.html

Each symbol in the vector decoded consists of log2(trellis.numInputSymbols) bits.

[Abi Aarthy]

sir,

we donot know how to implement this function"log2(trellis.numinputsymbols)".

[Walter Roberson]

As I indicated at the beginning of my response,

log2(trel.numInputSymbols)

The trel here is the same as the trel variable you are passing as the second argument to vitdec .