Comments on: Its all about the O.. OFDM http://gigaom.com/2004/11/21/its-all-about-the-o-ofdm/ Trusted Insights and Conversations on the Next Wave of Technology Wed, 25 Nov 2009 07:36:02 +0000 http://wordpress.com/ hourly 1 By: Glenn Fleishman http://gigaom.com/2004/11/21/its-all-about-the-o-ofdm/#comment-4666 Glenn Fleishman Wed, 30 Nov -0001 00:00:00 +0000 http://gigaom.wordpress.com/2004/11/21/its-all-about-the-o-ofdm/#comment-4666 <p>OFDM is also in the middle of a patent dispute with Wi-LAN of Canada claiming broad patents on OFDM technology, including some rights they bought from Hedy Lamarr (which are expired, but are intended to be moral rights, I believe).</p> <p>OFDM is a very simple idea at heart. Instead of trying to encode data at a very fast rate monolithically (across all frequencies), you divide the amount of spectrum you have into small channels that each run much more slowly. It's a lot easier to deal with signal reflection and synchronization many different slower channels. Combine those channels and you get the full data rate. Make those sub-channels wider in worse conditions and you reduce speed, but not remarkably.</p> OFDM is also in the middle of a patent dispute with Wi-LAN of Canada claiming broad patents on OFDM technology, including some rights they bought from Hedy Lamarr (which are expired, but are intended to be moral rights, I believe).

OFDM is a very simple idea at heart. Instead of trying to encode data at a very fast rate monolithically (across all frequencies), you divide the amount of spectrum you have into small channels that each run much more slowly. It’s a lot easier to deal with signal reflection and synchronization many different slower channels. Combine those channels and you get the full data rate. Make those sub-channels wider in worse conditions and you reduce speed, but not remarkably.

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