Genetic Algorithm and Simulated Annealing for Dynamic OVSF Code Allocation in WCDMA Networks

Orthogonal variable spreading factor (OVSF) codes are used to provide variable data rates for supporting different bandwidth requirements in wideband code division multiple access (WCDMA) systems. Unlike existent studies such as assign OVSF codes using conventional (CCA) or dynamic (DCA) code allocation algorithms, in this paper, genetic algorithm (GA) and simulated annealing (SA) algorithms were applied which population size is adaptively constructed according to existing traffic density in the OVSF code-tree. The simulation results show that the GA and SA provide reduced code blocking probability and improved spectral efficiency in the system when compared to the CCA and DCA schemes. Finally, the more system performance results the more computational load.