Necessity of Cyclic Prefix in OFDM

Cyclic prefix is inserted to avoid intersymbol interference due to the multipath channel. In practice, CP-OFDM modulator is implemented via the computationally efficient fast Fourier transform (FFT).

1. What will happen if we append zeros instead of a cyclic prefix?
2. What do you mean by cyclic prefix in OFDM system and explain the advantages of using cyclic prefix in OFDM signals?
3. What do you mean by cyclic prefix?
4. How does the cyclic prefix remove ISI?

What will happen if we append zeros instead of a cyclic prefix?

The main idea of using Cyclic prefix in OFDM systems is because of 2 reasons, 1) To eliminate ISI from previous symbol. If an OFDM symbol is Zero padded instead of cyclic prefix, ISI due to adjacent symbol still gets eliminated, but it cannot be modeled using circular convolution.

What do you mean by cyclic prefix in OFDM system and explain the advantages of using cyclic prefix in OFDM signals?

Use of cyclic prefix is a key element of enabling the OFDM signal to operate reliably. The cyclic prefix acts as a buffer region or guard interval to protect the OFDM signals from intersymbol interference.

What do you mean by cyclic prefix?

In telecommunications, the term cyclic prefix refers to the prefixing of a symbol, with a repetition of the end.

How does the cyclic prefix remove ISI?

ISI effect can be reduced by interesting a guard interval (cyclic prefix). The cyclic prefix or guard interval is a periodic extension of the final section of an OFDM symbol that is appended to the forepart of the symbol in the transmitter, and is removed at the receiver before demodulation.