基于OFDMA的无线资源分配算法研究

发布时间：2018-09-17 17:11

【摘要】：无线通信业务随着用户对高速率数据业务越来越高的需求而飞速发展,频谱资源和能源作为不可再生资源受到越来越多的关注。正交频分多址(Orthogonal Freqency-Division Multiple Acess,OFDMA)作为一种先进的多址技术,能够提高系统频谱利用率,得益于OFDM(正交频分复用)技术子载波间的正交性以及良好的抗多径干扰能力。这些特性使得OFDMA系统的资源分配更灵活高效。本文基于频谱效率和能源效率对OFDMA系统资源分配问题进行了深入研究,具体工作如下:首先,研究了典型的Shen算法和传统比例公平资源分配算法,分析了两种算法在子载波分配时对用户在子载波上的不同衰落情况利用不充分的问题,提出了一种基于速率差的子载波均衡分配算法。该算法在为比例速率最小用户进行子载波分配时,进行用户间速率的均衡,确定最终子载波分配方案。仿真结果表明该算法能够在不增加算法复杂度的情况下有效提高系统吞吐量。其次,针对以往资源分配问题往往只是关注频谱利用率而忽略能源效率的问题,提出了一种基于能效的二分法功率分配算法。该算法中,首先采用均衡子载波分配算法为用户进行子载波分配,然后利用二分法求得能效优化问题的近似解。仿真结果表明该算法能够在保证系统吞吐量没有损失的情况下,提高了系统能效。最后,针对异构网络中双层毫微微蜂窝网络系统中不能最大限度利用宏基站用户所能承受干扰上限的问题,提出了基于能效的最大化功率利用率的功率分配算法。该算法在宏基站用户最大干扰限制内,使毫微微蜂窝用户对宏基站用户的干扰最大化,从而使毫微微蜂窝用户分得更多有效功率,提高功率利用率,进而提高毫微微蜂窝用户能效。仿真结果表明该算法在保证吞吐量的前提下,能够有效提高毫微微蜂窝用户能效。
[Abstract]:With the rapid development of wireless communication services, spectrum resources and energy as non-renewable resources have attracted more and more attention. Orthogonal Frequency Division multiple access (Orthogonal Freqency-Division Multiple Acess,OFDMA), as an advanced multiple access technology, can improve the spectral efficiency of the system, thanks to the orthogonal frequency division multiplexing (OFDM) subcarrier orthogonality and good anti-multipath interference. These features make the resource allocation of OFDMA system more flexible and efficient. In this paper, based on spectrum efficiency and energy efficiency, the resource allocation problem of OFDMA system is deeply studied. The specific work is as follows: firstly, the typical Shen algorithm and the traditional proportional fair resource allocation algorithm are studied. In this paper, the problem of inadequate utilization of two subcarrier allocation algorithms for different fading cases of users on subcarriers is analyzed, and a subcarrier equalization allocation algorithm based on rate difference is proposed. The algorithm equalizes the rate between users and determines the final subcarrier allocation scheme when sub-carriers are allocated to the least proportional rate users. Simulation results show that the proposed algorithm can effectively improve the system throughput without increasing the complexity of the algorithm. Secondly, a dichotomy power allocation algorithm based on energy efficiency is proposed to solve the problem of resource allocation, which only focuses on spectrum efficiency and neglects energy efficiency. In this algorithm, the equalization subcarrier allocation algorithm is first used to allocate subcarriers for the user, and then the approximate solution of the energy efficiency optimization problem is obtained by using the dichotomy. Simulation results show that the proposed algorithm can improve system energy efficiency without loss of system throughput. Finally, a power allocation algorithm based on energy efficiency is proposed to solve the problem that the interference upper limit can not be maximized by the users of the macro base station in the two-layer femtosecellular networks in heterogeneous networks. The algorithm maximizes the interference of the femto cell users to the users of the macro base station within the maximum interference limit of the users of the macro base station, so that the femto cellular users can get more effective power and improve the power efficiency. In turn, it improves the energy efficiency of femtosecellular users. Simulation results show that the proposed algorithm can effectively improve the energy efficiency of femto cellular users on the premise of ensuring throughput.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.5

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