Terahertz Communications: An Array-of-Subarrays Solution

Enabling terahertz communications will alleviate the spectrum limitation of current wireless systems. This article presents an indoor multiuser terahertz system with array-of-subarrays architecture to accommodate hardware constraints as well as channel characteristics in the terahertz band. Specifically, the difference between terahertz and millimeter-wave communications is first clarified. Then the advantage of the array-of-subarrays structure is explained through comparison with the fully connected structure in both spectral and energy efficiency. Furthermore, a distance-aware multi-carrier scheme with the array-of-subarrays structure is introduced for wideband terahertz communications. Finally, the associated open issues and future research directions are discussed.