Application of a Probabilistic Model to High Frequency Spectrum Occupancy

Spectrum occupancy measurements and statistical models for spectrum occupancy data have been subject of interest since many years and are important as the spectrum becomes more and more crowded. Even with the unexpected growth of mobile communications, High Frequency (HF) radio links have advantages that make them unique in some application areas, justifying the development of spectrum occupancy models for the HF domain. In this paper a bidimensional Markov model for spectrum occupancy in HF is presented. The model takes into account both the time dimension and the frequency dimension one. The model is validated using real HF data acquired in the western part of Romania, using a Universal Software Radio Peripheral and a HF antenna. The spectrum occupancy values have been computed off-line for a set of frequency bands according to ITU frequency allocation. The results confirm the validity of the bidimensional Markov model as a useful tool to capture the statistical properties of spectrum occupancy in HF domain.