Showing papers by "Chong Han published in 2015"
TL;DR: A unified multi-ray channel model in the Terahertz Band is developed based on ray tracing techniques, which incorporates the propagation models for the line-of-sight, reflected, scattered, and diffracted paths to lay out the foundation for reliable and efficient ultra-high-speed wireless communications in the (0.06-10) THz Band.
Abstract: Terahertz (0.06–10 THz) Band communication is envisioned as a key technology for satisfying the increasing demand for ultra-high-speed wireless links. In this paper, first, a unified multi-ray channel model in the THz Band is developed based on ray tracing techniques, which incorporates the propagation models for the line-of-sight, reflected, scattered, and diffracted paths. The developed theoretical model is validated with the experimental measurements (0.06–1 THz) from the literature. Then, using the developed propagation models, an in-depth analysis on the THz channel characteristics is carried out. In particular, the distance-varying and frequency-selective nature of the Terahertz channel is analyzed. Moreover, the coherence bandwidth and the significance of the delay spread are studied. Furthermore, the wideband channel capacity using flat and water-filling power allocation strategies is characterized. Additionally, the temporal broadening effects of the Terahertz channel are studied. Finally, distance-adaptive and multi-carrier transmissions are suggested to best benefit from the unique relationship between distance and bandwidth. The provided analysis lays out the foundation for reliable and efficient ultra-high-speed wireless communications in the (0.06–10) THz Band.
376 citations
21 Sep 2015
TL;DR: Results show that the LSR algorithm is desired with the uniform sampling at 1/20 of the Nyquist rate for the directional transmission, while the ML-based algorithm is suitable in the multipath propagation with a half-reduced searching space.
Abstract: Terahertz (0.06-10 THz) band communication is envisioned as a key technology to satisfy the increasing demand for ultra-broadband wireless communication. Due to the very broad bandwidth and high frequency-selectivity, the synchronization faces major challenges, such as the ultra-high sampling rate demand, the stringent timing requirement for demodulation, and the THz band communication peculiarities. To address these challenges, in this paper, two algorithms for timing acquisition are proposed. First, a low-sampling-rate (LSR) synchronization algorithm is developed, by extending the theory of sampling signals with finite rate of innovation in the communication context and exploiting the annihilating filter method. Moreover, a maximum likelihood (ML)-based approach for timing acquisition is developed, which is a two-step procedure and uses the weighted average template construction to exploit the ML criterion. Extensive simulations are carried out, and the results show that the LSR algorithm is desired with the uniform sampling at 1/20 of the Nyquist rate for the directional transmission, while the ML-based algorithm is suitable in the multipath propagation with a half-reduced searching space.
5 citations