Chapter 1
Introduction to OFDM and MIMO-OFDM
1.1 OFDM History
In recent years Orthogonal Frequency-Division Multiplexing (OFDM) [1–4] has emerged as a successful air-interface technique. In the context of wired environments, OFDM techniques are also known as Discrete Multi-Tone (DMT) [5] transmissions and are employed in the American National Standards Institute’s (ANSI’s) Asymmetric Digital Subscriber Line (ADSL) [6], High-bit-rate Digital Subscriber Line (HDSL) [7], and Very-high-speed Digital Subscriber Line (VDSL) [8] standards as well as in the European Telecommunication Standard Institute’s (ETSI’s) [9] VDSL applications. In wireless scenarios, OFDM has been advocated by many European standards, such as Digital Audio Broadcasting (DAB) [10], Digital Video Broadcasting for Terrestrial television (DVB-T) [11], Digital Video Broadcasting for Handheld terminals (DVB-H) [12], Wireless Local Area Networks (WLANs) [13] and Broadband Radio Access Networks (BRANs) [14]. Furthermore, OFDM has been ratified as a standard or has been considered as a candidate standard by a number of standardization groups of the Institute of Electrical and Electronics Engineers (IEEE), such as the IEEE 802.11 [15] and the IEEE 802.16 [16] standard families.
The concept of parallel transmission of data over dispersive channels was first mentioned as early as 1957 in the pioneering contribution of Doelz et al. [17], while the first OFDM schemes date back to the 1960s, which were proposed by Chang [18] ...
