Tutorial

T2: OFDM and MC-CDMA for Future Broadband Wireless Communications

Sunday, 19 June 2005, 13:00-16:30
Room: Seminar 3+4

Stefan Kaiser
"OFDM and MC-CDMA for Future Broadband Wireless Communications"

The success of multi-carrier communications (OFDM) in high rate wireless communications started with its deployment in digital broadcasting standards like DAB and DVB-T. Followed by its promising application in wireless local area networks (WLANs) like IEEE 802.11a and HIPERLAN/2, OFDM is a key candidate for data transmission of next generation (4G) broadband mobile radio systems where data rates of 100 Mbit/s and higher are targeted. Furthermore, OFDM has been selected for broadband fixed wireless access systems like IEEE 802.16a and HIPERMAN. Recently, a research project investigates the suitability of OFDM for satellite communications where already promising results could be shown.

This tutorial provides an understanding of the principle of OFDM and gives an overview on multi-carrier based broadcasting and WLAN standards as well as on novel concepts for 4G mobile radio. Potential multi-carrier multiple access schemes for future wireless communications like MC-CDMA, OFDMA and derivatives are detailed and its signal design and multi-user detection techniques are explained. A comparative analysis with respect to performance and flexibility shows the strengths and weaknesses of the individual multiple access schemes. The exploitation of spatial diversity in OFDM and MC-CDMA systems by different MIMO concepts is presented and discussed. Important implementation issues in OFDM systems like synchronization and channel estimation as well as the effects of non-linear amplifiers and phase noise of the oscillators are addressed. The final part of the tutorial gives an overview on EU projects performing research on OFDM and MC-CDMA air interfaces.