Question

The duobinary filter, He (f) is called as

(a) Sine filter

(b) Cosine filter

(c) Raised cosine filter

(d) None of the mentioned

I had been asked this question in a job interview.

I need to ask this question from Correlative Coding topic in section Formatting and Baseband Modulation of Digital Communications

Answer 1

Right choice is (b) Cosine filter

For explanation I would say: The transfer function is 2T cos(πfT) which is called as cosine filter.