Topic: Communication Systems
For a BER of $10^{-5}$ which modulation scheme will require minimal power?
- A. QPSK
- B. 8-PSK
- C. 16-PSK
- D. 16-QAM
Answer: A. QPSK
Explanation: The distance between the symbols in the constellation diagram determines the probability of error. As the distance is maximum in QPSK among the given higher-order schemes, for a given BER of $10^{-5}$, QPSK requires minimal power.