Software Defined Adaptive MIMO Visible Light Communications after an   Obstruction
  We experimentally demonstrate a software-defined 2x2 MIMO VLC system employing link adaptation of spatial multiplexing and diversity. The average error-free spectral efficiency of 12 b/s/Hz is achieved over 2 meters indoor transmission after an obstruction. 
Peng Deng and Mohsen Kavehrad
cs.IT math.IT