On the Information Entropy of Ray-Chaotic Indoor Environments

Indoor scenario has emerged as one of the most congested, contested, and competitive wireless environments. As the emergence of the Internet of Everything (IoE) and Fourth Industrial Revolution (Industry 4.0) infrastructures, the importance and relevance will continue to grow in the near future. Indoor wireless is qualitatively different than outdoor wireless. In the high-frequency regime, as the wavelength is much shorter than the typical size of indoor scatterers, the wave scattering process may exhibit chaotic ray dynamics. The reflections from irregular walls and scatterers superimpose and lead to speckle like, random wave fields. Due to the rich scattering phenomena, the signals relayed to individual receivers have high probability of being uncorrelated (or distinguishable). Thereby, the network capacity may proportionally increase with respect to a number of antennas or bandlimited parallel channels.