Differences between cyclic prefix, postfix and zeropadding [duplicate]

1. What is the difference between zero padding and cyclic prefix in OFDM?
2. What will happen if we append zeros instead of a cyclic prefix?
3. What is difference between normal and extended cyclic prefix?
4. What is benefit of cyclic prefix in OFDM?

What is the difference between zero padding and cyclic prefix in OFDM?

With Zero Padding, the prefix are simply as zeros of certain length. With Cyclic Prefix however, the prefix is taken from end part of the symbol itself. For this project the GI ratio are chosen to be varied from 1:1 to 16:1, each were applied to various length of packet data i.e. 32, 64 and 128 bit.

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 is difference between normal and extended cyclic prefix?

The normal CP length is designed to support propagation conditions with a delay spread up to 4.7 μs, while the extended CP is intended to support deployments where the delay spread is up to 16.7 μs.

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.