On Outage Performance of Terahertz Wireless Communication Systems

Abstract

To expedite research progress on terahertz (THz) communications, we analyze the outage performance of THz communication systems by a compound channel model in this paper. Different from existing models, the compound channel model incorporates the effects of spreading loss, molecular absorption loss, shadowing, and multi-path fading via a composite distribution. By using this model, we maintain an equilibrium of the outage performance analysis between mathematical tractability and the fidelity of realistic THz channels. Specifically, by utilizing the compound channel model, outage performance analysis can get rid of sophisticated case-specific channel modeling relying on field measurement and the ray-tracing assessment. To facilitate the application of the proposed channel model, we also design a maximum likelihood estimation (MLE) based channel parameter estimation approach for the compound channel model. The analytical results of outage performance by using the compound channel model are given in closed form and verified by numerical results.Index Terms-Outage performance analysis, terahertz communications, compound/composite channel model, channel parameter estimation, gaseous molecular absorption. I. INTRODUCTIONN OVEL wireless communication applications pose everincreasing requirements and challenges to the post fifth generation (post-5G) and sixth generation (6G) network design [1], among which the terabit-per-second (Tbps) wireless transmission is demanding and almost impossible by existing communication technologies. As foreseen in [2], both enhancing spectral efficiency (SE) and extending the available spectrum could be feasible solutions to the coming wireless capacity crisis with a set of preconditions. Different from non-orthogonal multiple access (NOMA) and index modulation (IM) that aim to enhance SE within a limited spectrum [3]-[6], terahertz (THz) communication technology focuses on expending the available spectrum to the frequency range between 0.1 THz and 10 THz [7]. In this way, a series of unprecedented wireless communication applications in the automotive industry, indoor

Coexisting Terahertz and RF Finite Wireless Networks: Coverage and Rate Analysis

“…Furthermore, since THz communication is very sensitive to the availability of LoS paths, the Rayleigh fading assumption is invalid and the small scale fading follows a Nakagami-m distribution instead. Nakagami-m fading has been used widely in the literature to model the small-scale fading of THz communications [26], [33], [36]. We use different path loss exponents and Nakagami-m parameters for THz LoS and NLoS transmissions (α L and m L for LoS links and α N and m N for NLoS links).…”

Pre-6G Graduate Education of Communications Engineering

“…Moreover, the research routine based on numerical simulations by computers might not work well for the latest research of 6G communications (Raghavan and Li, 2019). This is because many physical phenomena related to 6G wireless technologies have not been fully understood and can hardly be modeled in an accurate manner, for example, the molecular absorption effect of terahertz radios, the non-Gaussian noise, and a variety of hardware impairments (Park et al, 2012;Guo et al, 2020;Ye et al, 2021). To consider real-world issues and propel practically feasible communications technologies forward, greater efforts need to be made on practical designs and hands-on experiments in the pre-6G era.…”

Deriving Upper Bound on Channel Capacity of LEO Satellite Communication Link at sub-THz Frequencies

“…brightness temperature of the sky and the ground, antenna physical temperature, receiver circuit temperature and molecular absorption. With the assumption as considered in various articles [14]- [17] that the overall noise can be approximated as Gaussian due to contribution from many asynchronous sources, we can approximate the THz satellite link channel capacity using Shannon-Hartley theorem. Thus, the channel capacity of the wideband satellite link for a signal arriving at an elevation angle θ 0 at the ground station receiver can be expressed as [11], [18]…”