|
|
Post by jackie on Dec 5, 2007 23:02:00 GMT -5
could anybody give me an example to demonstrate how multi-bits Viterbi soft-decoding works, say 3 bits? Suppose we use BPSK mapping the symbols, after AWGN channels, demapping and 3 bits quatization, how does Viterbi soft-decoding work? Also suppose rate R=1/2, constraint length is 3, convolutional code(2,1,3). Thank you very much.
|
|
|
|
Post by charan langton on Dec 16, 2007 17:40:39 GMT -5
I am not sure what you mean by the bits. If its BPSK, then it is one bit per symbol. How you multiplex symbols makes no difference to Viterbi decoding.
When you have a 2-D modulation such as 8-PSK, then both I and Q channel mappings are used in the soft-decision decoding. This is because there is no ONE number that we can use that would represent the 8-PSK symbol. We need two values. This is true for all 2-D modulation for all orders.
So I am not totally sure what you mean here about the bits.
|
|
