Topic: Communication Systems
A 8 kHz communication channel has an SNR of 30 dB. If the channel bandwidth is doubled, keeping the signal power constant, the SNR for the modified channel will be
- A. 27 dB
- B. 30 dB
- C. 33 dB
- D. 60 dB
Answer: A. 27 dB
Explanation: $\frac{S}{N}=1000$\nNew $S/N$ ratio is here signal power is constant but by doubling channel B.W. noise will double, so\n$(\frac{S}{N})_{new}=(\frac{S}{2N})=\frac{1000}{2}=500$\n$(\frac{S}{N})_{new}=10 \log 500=26.98~dB\simeq27~dB$