The guard interval is provided in Orthogonal Frequency-Division Multiplexing (OFDM).
MH SET - 2023, SET Exam - 2023,
Answer: D
The guard interval serves both (A) and (B).
In OFDM, a guard interval (usually a cyclic prefix, a copy of the end of each symbol placed at its start) is inserted between symbols. Delayed copies of the previous symbol arriving by multipath fall into this interval, so they do not overlap the useful part of the next symbol, which eliminates inter-symbol interference (ISI). Because each symbol is then effectively isolated, OFDM also does without the pulse-shaping filter that single-carrier systems need for ISI control.
The guard interval does not raise the symbol rate; it lowers it slightly, since part of each symbol period carries no new data.
Please log in or register to report this question.