Question

A 30 channel PCM system samples voice at rate of 20 kHz. The minimum channel bandwidth required is 6 MHz. If the samples are encoded with n-bits/sample then

• A. the number of bits n is equal to 10.
• B. the bit rate is equal to the bandwidth of the signal
• C. the bit rate is directly proportional to the number of channels.
• D. the bandwidth of the signal depends upon the value of n.

Answer 1

Answer: (C), (D)

the bandwidth of the signal depends upon the value of n.

$R_b=Nn{f}_s=30\times n\times 20K$
Bandwidth $=\frac{R_b}{2}$
$6\times {10}^6=\frac{n\times 600\times {10}^3}{2}$
$n=20$