OFDM and Multicarrier Signal Processing

Orthogonal Frequency Division Multiplexing (OFDM) is probably the topic that in the last two decades has motivated and attracted most of the research efforts and standardization activities for the physical layer of digital communication systems. Aim of this paper is to introduce the subject as a natural evolution from classical single carrier (SC) systems, by preserving intuition and links to the underlying physical phenomena. The first part of the paper is a thorough introduction to OFDM and multicarrier (MC) communications, with a special emphasis on the mathematical models used to describe, design signal processing algorithms for, and analyze the performance of these communication systems. The second part of the paper is dedicated to highlight characteristics, merits and drawbacks of OFDM and MC, with possible solutions to basic signal processing challenges, such as channel estimation and equalization, linear precoding, transmission in nonlinear channels, time-frequency synchronization, and bit/power loading algorithms.