Capacity of Terahertz Line-of-Sight UCA-MIMO Channels with One-Bit Transceivers

A one-bit wireless transceiver is a power- and cost-efficient system architecture for terahertz (THz) multiple-input multiple-output (MIMO) communication systems using a few gigahertz bandwidths and more. Understanding the channel capacity has been limited because of the lack of explicit mutual information expressions when using one-bit transceivers. In this paper, we derive a lower bound of the capacity of the THz line-of-sight (LOS) MIMO channel constructed by uniform circular arrays (UCAs) at both ends. The proposed strategy harnesses a discrete Fourier transform-based analog precoder and combiner in conjunction with a novel waterfilling policy under the one-bit transceiver constraint. Using simulation, we verify that the proposed waterfilling solution provides a substantial gain in spectral efficiency compared to the uniform allocation policy.