Question

According to Nyquist, the impulse response of the overall communication system should have ______ decay with _______ magnitude for sample values not equal to zero.

(a) Fast, small

(b) Slow, small

(c) Slow, large

(d) Fast. Large

The question was posed to me at a job interview.

This is a very interesting question from Pulse Shaping Techniques in section Modulation Techniques for Mobile Radio of Wireless/Mobile

Answer 1

Correct option is (a) Fast, small

To explain: According to Nyquist, the impulse response of the overall communication system should have fast decay with small magnitude for sample values not equal to zero. If the channel is ideal then it should be possible to realize approximate shaping filters at both transmitter and receiver.