Effect of cyclic prefix and zero-padding in OFDM

1. What is the effect of cyclic prefix and zero padding in OFDM?
2. What is benefit of cyclic prefix in OFDM?
3. What is the significance of zero padding?
4. What do you mean by cyclic prefix in OFDM system and explain the advantages of using cyclic prefix in OFDM signals?

What is the effect of cyclic prefix and zero padding in OFDM?

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. Circular convolution converts frequency selective multipath channel into flat fading channel.

What is benefit of cyclic prefix in OFDM?

The purpose of the cyclic prefix is to combat ISI and intra-symbol interference. The cyclic prefix is a guard time made up of a replica of the time-domain OFDM waveform. The basic premise is to replicate part of the back of the OFDM signal to the front to create the guard period, as shown in Figure 3.31.

What is the significance of zero padding?

Zero padding is a technique typically employed to make the size of the input sequence equal to a power of two. In zero padding, you add zeros to the end of the input sequence so that the total number of samples is equal to the next higher power of two.

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.