Modeling and Analysis of Coverage in Wideband Sub-Thz Multi-Carrier Systems with Beam-Squint

This paper studies the effect of beam-squint on the coverage performance in wideband sub-Terahertz (sub-THz) multi-carrier systems from a system-level analysis perspective. Beam-squint, a frequency-dependent beam misalignment, intensifies in wideband systems, reducing beamforming accuracy and overall network performance. To address this issue, we use tools from stochastic geometry and provide an analytical framework to investigate the coverage probability performance of sub-THz networks under the effect of beam-squint. Our framework integrates important system parameters, such as the spatial deployment of base stations (BSs), system transmission bandwidth, transmit and receive antenna array sizes, channel propagation conditions, and blockage impacts. Using numerical and Monte Carlo simulations, we validate our framework's accuracy and highlight the critical impact of beam-squint in constraining the performance of wideband sub-THz networks. The findings reveal that in wideband multi-carrier systems, coverage performance declines as subcarrier frequencies diverge further from the center frequency due to the beam-squint effect. Additionally, the results highlight that although larger antenna arrays improve the coverage performance, their benefits diminish at higher subcarrier frequencies. This is due to reduced beamwidth, which makes the communication link more susceptible to beam-squint effects, ultimately degrading system performance. These insights are valuable for optimizing sub- THz network parameters to mitigate beam-squint's adverse effects and enhance overall network performance.