Re: OT: Distinguishable angular momentum in radio photons?

Posted by Sverre Holm (LA3ZA) on May 04, 2012; 7:57pm
URL: http://elecraft.85.s1.nabble.com/OT-Distinguishable-angular-momentum-in-radio-photons-tp7525974p7528491.html

This is the debunking saying that this is more or less a special case of MIMO - Multiple Input Multiple Output - communications, i.e. using multiple antennas on the rx and tx sides:

"Is orbital angular momentum (OAM) based radio communication an unexploited area?" Ove Edfors and Anders J Johansson, IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 2012

http://www.lunduniversity.lu.se/o.o.i.s?id=12683&postid=2062936

Abstract: "We compare the technique of using the orbital angular momentum (OAM) of radio waves for generating multiple channels in a radio communication scenario with traditional multiple-in-multiple-out (MIMO) communication methods. We demonstrate that, for certain array configurations in free space, traditional MIMO theory leads to eigen-modes identical to the OAM states. From this we conclude that communicating over the sub-channels given by OAM states is a subset of the solutions offered by MIMO, and therefore does not offer any additional gains in capacity."