Based On Energy-efficiency Resource Allocation In LTE-A Downlink OFDMA System

In modern society, more people require to have an access to the high-speed radio wireless communication systems. LTE-Advanced, based on OFDMA systems and derived from LTE(Long Term Evolution), appears to work very efficiently in both system capacity and spectrum efficiency. However, due to the high bit-rates service, the energy consumption in wireless communication systems is increasing in large scale. Therefore, it’s urgent to promote energy conservation and make efforts to improve the energy efficiency(EE for short) of the system in wireless communication. This paper mainly focuses on how to improve efficiency by allocating wireless resource, firstly, OFDMA system model and classical algorithms for resource allocation are introduced, then the article studies the problem of EE in OFDMA systems and relative algorithms, and finally a more efficient algorithm which is to improve LTE-A downlink system’s EE is proposed, and it is proved to work well.First of all, we introduce the basic principles of OFDMA system, and then introduce the solutions of traditional resource allocation in OFDMA system, which aims at spectrum efficiency. The main contents concentrated in two directions, rate maximization and power minimization. The research of traditional resource allocation solution in OFDMA system is the theoretical basis of this article.Then, for the energy-efficient OFDMA system, this paper completed three processes, including model building, research idea analysis, algorithm and simulation. First, we define the concept of EE and establish the resource allocation model, second, we analyze the parameter characteristics and design algorithms according to the established objective function. Thirdly, we propose a solution named Max-Min Resource Allocation Method and divide it into two steps: sub-carriers allocation and power allocation. The simulation results prove its efficiency in improvement of EE.Finally, we make an analysis of the EE in a special OFDMA system: LTE-A downlink system, whose basic unit to allocate resource is RB. We first make an analysis and model for LTE-A OFDMA system based on EE, and we propose a solution to solve the EE problem in it, finally, we make simulations to test and verify the effectiveness of the proposed solution.