Tham khảo tài liệu 'vehicular technologies increasing connectivity part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Hybrid Evolutionary Algorithm-based Schemes for Subcarrier Bit and Power Allocation in Multiuser OFDM Systems 201 Fig. 11. Performance comparison to demonstrate the tracking capability in terms of required transmit power at mobile speed 1km h the largest channel power difference among users 30dB and target BER 10-2 In the next simulation to demonstrate the tracking capacity with the scheme Adaptive III the frame duration is switched to 5 ms which is employed in WIMAX standard and a carrier frequency of GHz in the PCS Personal Communication Services band is adopted. The channel duration for the simulation is 1 second. The algorithm is performed with 200 generations for the solution of the first frame while being performed with 30 generation for those of the rest of the frames to provide the solutions. As displayed in Figs. 12-13 the performances are very close to those of Scheme V with the full number of generations and the full size of population per each frame operation. Fig. 12. Performance comparison to demonstrate the tracking capability in terms of required transmit power at mobile speed 1km h the largest channel power difference among users 15dB and target BER 10-2. Frame duration 5 ms carrier frequency GHz 202 Vehicular Technologies Increasing Connectivity Fig. 13. Performance comparison to demonstrate the tracking capability in terms of required transmit power at mobile speed 1km h the largest channel power difference among users 30dB and target BER 10-2. Frame duration 5 ms carrier frequency GHz 6. Conclusion This paper proposes a hybrid evolutionary algorithm-based scheme to solve the subcarrier bit and power allocation problem. The hybrid evolutionary algorithm is an evolutionary algorithm-based approach coupled with a local refinement strategy. It is presented to improve the performance and offers the faster convergence rate. Simulation results show that the proposed hybrid evolutionary algorithm-based scheme with the integer .
