Orthogonal Frequency‐Division Multiplexing

The Orthogonal Frequency‐Division Multiplexing (OFDM) became the most popular transmission technique for a broadband communication system because it has many advantages such as robustness to multipath fading channels and high spectral efficiency. It allows multiple users to receive information at the same time on different parts of the channels. This chapter designs the OFDM system and discusses hardware implementation issues. The first design parameters of the OFDM system for wireless communications are Inter‐Carrier Interference (ICI) power, the size of the Discrete Fourier Transform (DFT), and the subcarrier spacing (or the OFDM symbol duration). The second design parameter is the guard interval and the cyclic prefix (CP). The third design parameter is the pilot subcarrier allocation. The fourth design parameter is windowing. The Fast Fourier Transform (FFT) and the Inverse Fast Fourier Transform (IFFT) are efficient algorithms to compute the DFT and IDFT.