Wireless OFDM Systems : How to make them work Wireless Local Area Networks (WLANs) experience a growing popularity recently. Where WLANs were primarily used for niche applications in the past they are now deployed as wireless extensions to computer networks. The increase of the datarates from 2 Mbps up to 11 Mbps for roughly a constant price has played a major role in this breakthrough. As a consequence an even greater success can be envisioned for the more recent OFDM based WLAN standards in the 5 GHz band which offer up to 54 Mbps. At IMEC we have realised this potential already several years ago and have established a successful research programme on OF based WLAN. In 1995 we started our research on wireless OFDM in the frame of a operation project with SAIT a Belgian telecom company. The goal of the project was to establish a robust network for industrial environments. This resulted in a first OFDM chip supporting QPSK for wireless networking at the end of the project (1999). 1999 was also the start of an intense co operation with National Semiconductor Inc. which resulted in a second generation ASIC in 2000. This OFDM processor supports up to QAM 64 and has a more optimal channel estimation algorithm. Understanding the indoor environment The OFDM Principle When people agree on OFDM Beating the wireless channel Avoiding a tower of Babel Living with a real radio Putting it all together.