Free-space optical communication technologies for next-generation cellular wireless communications

Abstract

To meet the ever-increasing demands for nextgeneration cellular wireless communications, the sub-THz bands (ranging from 0.1 to 1 THz) are being considered as one of carrier frequencies. However, the channel conditions of cellular networks are not only favorable to sub-THz bands, but the output power of devices operating at sub-THz frequency is also severely limited. Free-space optical (FSO) communications could be a promising technological alternative to sub-THz counterparts for cellular wireless communications. In this article, we identify a few technical challenges associated with the FSO communication for cellular wireless applications, such as direct impingement of solar irradiance onto the receiver, blockage of the line-of-sight path, and accurate beam alignment between the transmitter and receiver. We present potential solutions for those technical challenges.