Temporal Autocorrelation of Small-Scale Fading Using Leaky Coaxial Cable in Confined Space

In this letter, a narrow-band measurement at 1.8 GHz was conducted in a tunnel-like environment in order to investigate the temporal variation of small-scale fading with leaky coaxial cable (LCX) propagation. Both the vertically and horizontally polarized LCXs were used to generate different small-scale fading behavior which determines the channel temporal variation. Temporal variation was determined by statistical analysis in terms of coherence time extracted from empirical temporal autocorrelation of received signal power. Results show that larger coherence time exists in co-polarization transmission which has higher K-factor than cross-polarization transmission. This was also illustrated by a positive correlation between coherence time and K-factor. By using Akaike information criterion, Rice and Weibull are the best distributions to fit the amplitude of small-scale fading for co-polarization and cross-polarization, respectively. In addition, the corresponding Nakagami-Rice and Weibull autocorrelation functions were parameterized to well model small-scale temporal autocorrelation of received signal power measured in co-polarization and cross-polarization, respectively.