Original Investigation of Terahertz Band Communication Channel Characteristics for Ultra-Short-Range Applications in Nigerian Urban Environments

Terahertz band frequencies between 100 GHz and 10 THz offer multi-terabit per second data rate potential for ultra-short-range wireless links, making them a candidate technology for device-level communication in future 6G systems, wireless chip-to-chip interconnects, and kiosk download applications. The channel characteristics of the terahertz band in Nigerian urban environments, including the effects of tropical humidity, dust, and building material composition on propagation, have not been experimentally characterized or theoretically analyzed. This doctoral study conducts an original experimental and theoretical investigation of terahertz band communication channel characteristics for ultra-short-range applications in Nigerian urban environments. Experimental channel measurements were conducted at 300 GHz and 1 THz using a time-domain spectroscopy system in representative Nigerian urban environments in Lagos and Kano, capturing path loss, atmospheric absorption, and multipath characteristics. An original theoretical channel model is derived incorporating measured atmospheric absorption coefficients for tropical humidity conditions, building material surface scattering characteristics, and multipath cluster statistics. Molecular absorption databases for water vapor at Nigerian tropical atmospheric conditions are extended with measurement-derived coefficients at previously unmeasured frequencies. The developed theoretical model is validated against measurement data with root mean square error below 1.8 dB across the measured frequency range. Capacity analysis using the derived channel model identifies specific terahertz absorption windows where achievable rates exceed 100 Gbps within 1-meter links in Nigerian urban atmospheric conditions. Keywords: terahertz communication, channel characterization, 6G, tropical propagation, ultra-wideband.