Empirical analyses on maritime radio propagation

Empirical analyses, based on extensive measurements results, were performed to characterize maritime radio propagation in the GSM1800 frequency band. As the height of sea waves increases, it blocks more of the Fresnel zones below the line-of-sight path. It is of interest, therefore, to examine the overall statistics of the received signal in rough sea surface conditions. The overall statistics of the received signal was found to be properly represented by a mixture of the Rician and log-normal distributions with varying Rician factor and standard deviation. From our observations, a coherent reflection component is voluntarily imposed over incoherent components, resulting in a large value of Rician factor, especially under small sea wave height or calm sea conditions. Fading depth and intensity were also evaluated. The BER performance, corresponding to these sea surface profiles, were analyzed by computer simulation.