Which of the following achieves high spectral efficiencies because the spacing of each carrier is as close as theoretically possible?
A)Direct-sequence spread spectrum (DSSS)
B)Quadrature amplitude modulation (QAM)
C)Orthogonal frequency-division multiplexing (OFDM)
D)Code-division multiple access (CDMA)

Question

Quizplus · Accepted Answer

Orthogonal frequency-division multiplexing (OFDM) achieves high spectral efficiencies because it uses a large number of carriers with narrow spacing, ensuring that each carrier is as close as theoretically possible. This results in efficient use of the available frequency spectrum.

Which of the Following Achieves High Spectral Efficiencies Because the Spacing