Application of Rough Sets and Grey Clustering in Frequency of Wireless Railway Systems
Frequency planning of wireless system is the ubiquitous and urgent key problem due to limited frequency spectrum. This paper presents a frequency planning method according to the characteristics of GSM-R. Rough Sets (RS) theory and Grey Clustering (GC) theory are applied in frequency planning and the factors that affect on frequency planning and their proper thresholds are discussed. Then, the optimal plan is given by means of the GC assessment. Moreover, we compare different frequency planning methods by simulations. Finally, the derivation and simulation results show that the frequency planning based on RS and GC theory is more precise than other algorithms.