Analysis of Indoor THz Communication Systems With Finite-Bit DACs and ADCs

Terahertz (THz) communication is foreseen to be a key technology for the 6G wireless communications. In this paper, performance of downlink systems with low-resolution digital-to-analog converters (DACs) at Access Point (AP) and/or finite-bit analog-to-digital (ADCs) user sides are investigated. Array-of-subarrays architecture assumed AP, where each RF chain uniquely activates disjoint subset antennas, which connected an exclusive phase shifter. Hybrid precodings including maximum ratio transmission (MRT) and zero-forcing (ZF) precoding considered. The best beamsteering direction shifters in large subarray antenna regime first proved line-of-sight (LOS) path. Subsequently, closed-form expression lower-bound achievable rate derived, same both MRT ZF independent transmit power. Moreover, numerical results show that loss caused by uncertainties can negligible moderate resolution DACs ADCs achieve close infinite-resolution one. Numerical validating analysis provided as well. Overall, impact on indoor THz characterized.