Abstract:

Spectrum allocation is an important issue in cognitive radio, but the spectrum difference is rarely discussed in traditional spectrum allocation algorithms. A new spectrum allocation algorithm is proposed, which is based on Immune-Clonal-Selection (ICS) and takes account of the spectrum difference. A reliability matrix is introduced to model the time difference of spectrum. The algorithm shows a rise in total network bandwidth by using the Difference-Constraint Satisfaction Operator when two cognitive users have interference using the same spectrum. The DifferenceConstraint Satisfaction Operator can allocate spectrum in higher credibility to cognitive users. The algorithm also shows an improvement in fairness by using the Fairness-Constraint Satisfaction Operator to deal with the interference. The Fairness-Constraint Satisfaction Operator can allocate spectrum to cognitive users with more intensive conflicts. Simulation results show that, compared with the traditional ICS algorithm and color-sensitive graph coloring (CSGC) algorithm and Genetic algorithm (GA), DICS can achieve higher total network bandwidth, higher credibility and better fairness.

Key words: cognitive radio;spectrum allocation;immune-clonal-selection;differences;fairness