Question

The number of possible signal in M-ary signalling is given by M and M = __________ where n is an integer.

(a) n

(b) 2n

(c) 2^n

(d) n^2

This question was addressed to me in examination.

Question is taken from Combined Linear and Constant Envelope Modulation Techniques topic in chapter Modulation Techniques for Mobile Radio of Wireless/Mobile

Answer 1

Correct choice is (c) 2^n

Easy explanation: Two or more bits are grouped to form a symbol in M-ary modulation. And the number of possible symbols should be equal to 2^n, where n is an integer.