Research On Adaptive Resource Optimization Allocation Algorithms Based On OFDMA Systems

With the continuous development and progress of science and technology,there is a growing demand for high-speed communications services,but the limited spectrum resources and poor wireless communication environment will affect the user's communication experience.Therefore,in order to meet the needs of cellular users for faster and more reliable data services,there is an urgent need for a suitable resource allocation approach to rational use of resources to get better system performance.Orthogonal Frequency Division Multiple Access technology has been increasingly deployed in a variety of emerging and evolved cellular systems,application of this technology can effectively reduce the inter-symbol interference,dynamic allocation of resources,and improve the overall system performance.Currently,the allocation of resources in the downlink of the OFDMA system mainly includes subcarrier-based and based on subcarrier block.When the number of subcarriers is large,the algorithm of allocating each subcarrier will be very complicated.In this paper,we propose an adaptive power optimization scheme based on subcarrier block and a rate optimization scheme based on artificial fish swarm algorithm for a large number of subcarriers to achieve optimal allocation.In the power optimization,carrier aggregation is carried out according to the correlation between adjacent subcarriers to form some subcarrier blocks,and a resource allocation scheme based on the combined subcarrier block,power and bit is proposed to maximize the system throughput under the constraint of the total transmit power.And then,taking into account the digital nature of the symbol bits in practice,we proposed the digitization process of the bits.The simulation verifies the throughput comparison between this algorithm and the fixed power distribution algorithm,the results show that when the number of users is increasing,the performance of the two algorithms on the theoretical results are almost the same,however,after adding the digital process,the dynamic power allocation algorithm proposed in this paper is much larger than the fixed power allocation.At the same time,the way of partition allocation greatly reduces the complexity of the distribution process,saving the running time.In the rate optimization,the user's rate fairness is added to the objective function.First,the initial rate ratio value is set for each user.In addition,the fitness function is used to measure the relationship between user fairness and system throughput.The optimal power allocation is realized by using the parallel processing ability and the global fast searching ability of the artificial fish swarm algorithm.In the simulation experiment,compared with the Shen algorithm and Max-Min algorithm,the results show that under the condition that the total power of the system is constant,user fairness obtained is about 0.98-0.99,close to the maximum value of 1,the system capacity of about 0.17?0.49bit/s/Hz upgrade compared to the Shen algorithm and the Max-Min algorithm.Therefore,the algorithm can obtain the maximum system transmission rate and ensure the fairness of the users.