Improving OFDM Maximum Transmission Rate Uplink Based on the Cognitive One-Way Af-Relay Networks via Genetic Algorithm

In wireless communication systems the demand for spectrum resources are increasing rapidly due to increasing spectrum utilization that causes scarceness of the spectrum frequency bands, the Cognitive Radio Network is considered the best solution for this problem, and its cooperated network if it merges with Relay technology. The resource allocation for an OFDM (orthogonal frequency-division multiplexing) with N subcarrier-based-cognitive AF (amplify and forward) for relay network and relay selection is proposed in this paper, the Objective Function is to Maximization the sum transmission rate over the sub-carriers of the secondary user under the Interference constraints from the secondary users (SUs) to the primary users (PUs) and the power constraints for both (the secondary users and relays). The subcarrier allocation and power allocation for the secondary network with relay selection were solved by using a Genetic algorithm.