Date Added: Dec 2012
Orthogonal Frequency-Division Multiplexing (OFDM) uses a large number of closely spaced orthogonal sub-carrier signals to carry data. The orthogonality allows for efficient modulator and demodulator implementation using the Fast Fourier Transforms (FFT) algorithm on the receiver side, and inverse FFT on the sender side. The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions without complex equalization filters by converting a frequency-selective channel into a parallel collection of frequency flat sub channels. Hence, OFDM has developed into a popular scheme for wideband digital communication. Here an effort is made to further improve the performance by utilizing the frequency diversity across the OFDM subcarriers.