It is, I've been doing a bit of poking around in the patent applications filed by this guy recently and that seems to be the gist of it. Unlike normal MIMO though, only the base station has multiple antennas, the mobile stations have one antenna each.
This leads to the downstream bandwidth being much higher than the upstream, but given that video is going to drive mobile bandwidth growth that is ok.
Basically what's happening is that a training signal from each of the base station antennas is constantly being monitored by the mobile station, channel information gets calculated and sent back to the base station.
The base station uses the channel vectors for each of the mobile stations (updated frequently because this is spatial multiplexing and mobile stations... move) to compute the signals for the entire antenna array.
The odd seeming stuff about energy not being transferred has to do with using a sort of inverse spatial coding where you can aim signal nulls at mobile stations that don't want to receive particular signals.
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It is, I've been doing a bit of poking around in the patent applications filed by this guy recently and that seems to be the gist of it. Unlike normal MIMO though, only the base station has multiple antennas, the mobile stations have one antenna each.
This leads to the downstream bandwidth being much higher than the upstream, but given that video is going to drive mobile bandwidth growth that is ok.
Basically what's happening is that a training signal from each of the base station antennas is constantly being monitored by the mobile station, channel information gets calculated and sent back to the base station.
The base station uses the channel vectors for each of the mobile stations (updated frequently because this is spatial multiplexing and mobile stations... move) to compute the signals for the entire antenna array.
The odd seeming stuff about energy not being transferred has to do with using a sort of inverse spatial coding where you can aim signal nulls at mobile stations that don't want to receive particular signals.
Relevant patents: http://patents.com/us-20110044193.html http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sec...
Can get the pdf here. Nice, Mvandenbergh! http://www.google.com/patents?hl=en&lr=&vid=USPAT741... and here http://www.google.com/patents?hl=en&lr=&vid=USPATAPP...