_________ is a common modulation scheme used with OFDM.
A)QPSK
B)FFT
C)IFFT
D)ISI

Question

Quizplus · Accepted Answer

QPSK (Quadrature Phase-Shift Keying) is a common modulation scheme used with OFDM (Orthogonal Frequency Division Multiplexing). QPSK allows for two bits to be transmitted per symbol, which allows for higher data rates and improved spectral efficiency. Additionally, QPSK is relatively robust to interference and can be easily demodulated at the receiver. Therefore, QPSK is often used in OFDM systems, especially in wireless communication systems such as Wi-Fi, LTE, and 5G.

B) FFT (Fast Fourier Transform) and C) IFFT (Inverse Fast Fourier Transform) are mathematical operations used to implement OFDM. FFT is used to perform spectral analysis and break down the transmitted signal into orthogonal subcarriers, while IFFT is used to convert the subcarriers back into the time domain at the receiver. Therefore, they are not modulation schemes like QPSK.

D) ISI (Inter-Symbol Interference) is a type of signal distortion that occurs when multiple symbols interfere with each other in a communication channel. It is not a modulation scheme used with OFDM.

_________ Is a Common Modulation Scheme Used with OFDM