Research On Resource Optimization Allocation Algorithms Based On OFDMA Systems

With the explosive growth of high-speed wireless data business and seamless coverage requirements, the demand for wireless communication system performance is increased, so the urgent need to improve the system efficiency of wireless networks. With the limited bandwidth, how to guarantee quality of service and serve for all users within the wireless network is the biggest problem about radio resource allocation, since Orthogonal frequency division multiplexing (OFDM) can convert the frequency selective channel to multiple flat fading channels, eliminate inter-symbol interference in broadband channels, allocation radio resources flexible and support multiple users access dynamically. At the same time can improve the spectrum efficiency of system, These advantages make it become one of the key technology in the mobile communication standard.In a downlink OFDM-based orthogonal frequency division multiple access (OFDMA) system, a proper resource allocation scheme can efficiently allocate subcarriers to users, adapt data rate in each subcarrier and control transmit power to achieve high system performance. So, this paper respectively from two aspects of power rate of optimization and optimization of wireless resource allocation problem in the OFDMA system are studied.In the power optimization allocation algorithm, a proper number of contiguous subcarriers are grouped into chunks and spectrum is allocated chunk by chunk.And considering multiple BER requirements, the main aim of resource allocation is minimize the transmit power. After we analysis the optimal wireless resource allocation algorithm, an improved algorithm is proposed to reduce the complexity of the allocation of the system On the basis of the guarantee system performance.In the rate optimization allocation algorithm, we impose a set of proportional fairness constraints to assure that each user can achieve a required data rate. In the subcarriers allocation, we introduction an artificial fish swarm algorithm of intelligence optimization, the power allocation which has strong global strong global searching ability and easy to implement, we give a fitness function to ensure the fairness among all users, which can balance the fairness and the total system capacity.At last, the simulation results show that the presented methods had got a better performance.