In the case of PAM with correlated noise, the correlation metrics in the Viterbi algorithm may be expressed in general as (Unger boeck, 1974)
![958_62e66ab0-b098-4aed-a52f-f359109e8634.png](https://secure.tutorsglobe.com/CMSImages/958_62e66ab0-b098-4aed-a52f-f359109e8634.png)
where xn = x(nT ) is the sampled signal output of the matched filter, {In} is the data sequence, and {rn} is the received signal sequence at the output of the matched filter. Determine the metric for the duobinary signal.