{'fraction_non_alphanumeric': 0.028771384136858476, 'fraction_numerical': 0.006220839813374806, 'mean_word_length': 5.467336683417085, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Timing Acquisition for Pulse-based Wireless Systems in the Terahertz Band

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.