EDA-BASED RELAY ASSIGNMENT SCHEME FOR MULTIUSER COGNITIVE RADIO SYSTEMS

摘要

In this paper, we present an EDA-based interference aware multiple relay assignment scheme for cognitive radio systems that employ cooperative transmission techniques. In relay-assisted cognitive radio systems with given numbers of relays and destination nodes, we consider the problem of optimally assigning the relays to the destination nodes. We use the sum capacity of the cognitive radio system as the objective function to maximize under the constraint of acceptable levels of interference to the primary users (PU). The computational complexity of optimal relay assignment using exhaustive search algorithm (ESA) grows exponentially with the number of relays and receivers. We consider Estimation of Distribution Algorithm (EDA) for the relay assignment problem. EDA is a probabilistic evolutionary algorithm and updates its population at each iteration on the basis of the probability distribution learned from the population of superior candidate solutions chosen at the previous iterations. The proposed EDA for relay assignment has low computational complexity and its effectiveness is verified through simulation results.