SRK 2012

OFDM is the technology at the heart of most of today’s communication systems. Initially proposed in the late 1950s, OFDM now prevails in almost all broadband technologies, from digital video broadcasting system to wired ADSL and powerline communications and from WiFi to WiMax and LTE. OFDM significant advantage in mitigating the effects of multi-path channels and channels with high interference created great interest in researching its signal design, system structures and applications. What seemed like a complex and cumbersome structure when it was first proposed led to a much simplified system using today’s DSP techniques.

The two lectures will cover the history of OFDM and the basics of multi-carrier systems and will discuss OFDM uses in various scenarios. Signal structure, generation and detection will be described and the use of channel estimation, guard band and cyclic prefix and frequency and time offsets issues will be discussed. In addition, the lecture will address the use of OFDM in different standards. Other multi-carrier systems will be introduced and the prospects of new systems that are based on or similar to OFDM will be outlined. Specifically, there will be a brief description of OFDMA, Multi-Carrier CDMA, Spectrally Efficient FDM (SEFDM), Faster than Nyquist (FTN) concepts.