On the Impact of Hardware Impairments on Performance of Terahertz Communication Systems Utilizing Hybrid Beamforming Techniques

Terahertz (THz) communication is widely recognized as a key technology for next-generation wireless communication. However, high propagation losses and inter-symbol interference, due to the frequency-selective nature of the channel, pose significant challenges in THz links. To address these challenges, integrating massive multiple-input-multiple-output (MIMO) with orthogonal frequency division multiplexing (OFDM) is commonly employed. The beam squint effect, along with hardware impairments such as nonlinearity of power amplifiers (PAs) and in-phase/quadrature (I/Q) imbalance caused by quadrature modulators, further affects the performance of THz massive MIMO systems. This paper investigates the effects of various hardware impairments on the performance of THz hybrid beamformed systems. A novel aspect of this study is the exploration of the joint effects of hardware impairments and limited resolution True Time Delay (TTD), an area previously unexplored in the literature. With perfect knowledge of the Power Amplifier Compensation Matrix (PACM), we demonstrate effective compensation of nonlinear distortions within the THz system. Additionally, we implement an adaptive algorithm at the receiver to mitigate I/Q imbalance. Our findings highlight the importance of addressing both individual and combined hardware impairments in the design and optimization of THz hybrid beamformed systems, thereby enhancing the robustness and efficiency of communication technologies at terahertz frequencies.