Concepts of Frequency Domain Equalization

The concepts of frequency domain equalization represent the most powerful strategies to combat time dispersion caused by multipath propagation in broadband wireless communication systems. Performing equalization in the frequency domain allows for a computational efficient implementation because the effort grows significantly lower with the bandwidth compared to equalization in the time domain. Two well known frequency domain concepts exist: OFDM (Orthogonal Frequency Division Multiplexing) and SC/ FDE (Single Carrier Transmission with Frequency Domain Equalization). While the interest on OFDM was almost overwhelming, the interest on SC/FDE has been growing rapidly only recently. A primary topic of this work is the extension and alternative formulation of the SC/FDE system as it is usually understood. Further more the basic concept is characterised in terms of equalization strategies, higher order modulation schemes, synchronization, channel estimation, channel coding or front-end implementation effort. Finally an overall comparison of OFDM and SC/FDE is carried out, characterising advantages and disadvantages.