Wireless communications with diffuse waves
  Diffuse, multiple-scattered waves can be very efficient for information transfer through disordered media, provided that antenna arrays are used for both transmission and reception of signals. Information capacity C of a communication channel between two identical linear arrays of n equally-spaced antennas, placed in a disordered medium with diffuse scattering, grows linearly with n and can attain considerable values, if antenna spacing a > lambda/2, where lambda is the wavelength. Decrease of a below lambda/2 makes the signals received by different antennas partially correlated, thus introducing redundancy and reducing capacity of the communication system. When the size of antenna arrays is well below lambda/2, the scaling of C with n becomes logarithmic and capacity is low. 
S.E. Skipetrov