What does OFDM stand for in digital communications?

What does OFDM stand for in digital communications?

• A. Optical Frequency-Division Multiplexing
• B. Orthogonal Frequency-Domain Multiplexing
• C. Optical Frequency Division Modulation
• D. Orthogonal Frequency-Division Multiplexing

Answer: (C)

OFDM stands for Orthogonal Frequency-Division Multiplexing. The key idea is to split the available bandwidth into many closely spaced subcarriers that are orthogonal to each other. Because of this orthogonality, the subcarriers can overlap in frequency without causing interference, which greatly improves spectral efficiency and helps carry more data over a given channel. In practice, data is modulated onto a large number of subcarriers, typically using an inverse FFT to generate the time-domain signal and a cyclic prefix to combat multipath reflections. This structure makes OFDM particularly robust to multipath fading, since each subcarrier experiences a relatively flat channel, and data can be redistributed across subcarriers if some are degraded. A common source of confusion is naming: while you might hear terms that mention optical frequencies or a domain-focused phrasing, the standard expansion in digital communications is Orthogonal Frequency-Division Multiplexing. The option that uses an optical context or replaces Division with Domain does not describe OFDM in this setting.

OFDM stands for Orthogonal Frequency-Division Multiplexing. The key idea is to split the available bandwidth into many closely spaced subcarriers that are orthogonal to each other. Because of this orthogonality, the subcarriers can overlap in frequency without causing interference, which greatly improves spectral efficiency and helps carry more data over a given channel.

In practice, data is modulated onto a large number of subcarriers, typically using an inverse FFT to generate the time-domain signal and a cyclic prefix to combat multipath reflections. This structure makes OFDM particularly robust to multipath fading, since each subcarrier experiences a relatively flat channel, and data can be redistributed across subcarriers if some are degraded.

A common source of confusion is naming: while you might hear terms that mention optical frequencies or a domain-focused phrasing, the standard expansion in digital communications is Orthogonal Frequency-Division Multiplexing. The option that uses an optical context or replaces Division with Domain does not describe OFDM in this setting.