Question

To increase the rate of communication by log₂M in M-array communication, the power requirement increased by
1. 2^M
2. M²
3. M^M
4. 2M

Answer 1

Correct Answer - Option 2 : M²

Concept:

The bandwidth of the M-array communication is given by

\(BW=\frac{2R_b}{log_2M}\)

The distance of each signalling point from the origin is given by √E_s 

Where E_s = E_blog₂M.

Calculation:

Power in M-array communication is given by E_s

As Es = Eblog2M

To increase power by log₂M, 

Es = Eb(log2M)²

Es = Eblog2M²

Es = 2Eblog2M

Hence to increase the rate of communication by log2M in M-array communication,

the power requirement increased by M².