Howtosignalprocessing
- Why do we use IFFT in OFDM?
- What is the purpose of IFFT?
- What is the need for using FFT in OFDM?
- Why orthogonality is important in OFDM?
Why do we use IFFT in OFDM?
Thus, the IFFT block provides a simple way to modulate data onto N orthogonal subcarriers. The block of N output samples from the IFFT make up a single OFDM symbol. After some additional processing, the time-domain signal that results from the IFFT is transmitted across the radio channel.
What is the purpose of IFFT?
IFFT stands for Inverse Fast Fourier Transform. IFFT converts frequency domain vector signal to time domain vector signal. It is used after the modulator block in the OFDM Transmitter.
What is the need for using FFT in OFDM?
Using FFT algorithms provides speed enhancements for data processing for OFDM systems. This technique is being used for Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), Wireless Local Area Network (WLAN), Wireless Metropolitan Area Network (WMAN), Multi Band-OFDM Ultra Wide Band (MB-OFDM-UWB) etc.
Why orthogonality is important in OFDM?
One of the key features of OFDM is the orthogonality of the subcarriers used to transmit data. The orthogonality of subcarriers results in more subcarriers in a given bandwidth. This improves spectral efficiency. It also eliminates the interference between subcarriers, often called Inter-Carrier Interference ( ICI ).
