大规模MIMO系统中基于能效最大化的资源联合优化算法

针对信道条件未知的多小区大规模多输入多输出(MIMO)系统,提出一种对导频序列长度、导频符号功率以及数据符号功率进行联合优化的资源分配算法.采用最大比合并(MRC)接收,考虑电功率和导频污染的影响,并对最大传输功率进行约束从而建立起以能效(EE)最大化为目标的非凸函数模型.根据分数规划的性质,首先将分数形式转化成减式形式,进而分解成一系列凸函数之差(DC)的问题,最后采用交替优化算法联合调整3个变量从而达到能效最大化的目标.仿真结果表明,随着最大符号传输功率的增加,所提方案仍然能保持良好系统能效性能.

A joint optimization algorithm based on energy efficiency maximization for massive MIMO systems

For the massive multi-cell multi-input multiple-output (MIMO) communication uplink system with unknown channel status information,a resource allocation algorithm which jointly optimizes the pilot sequence length,pilot symbol power and data symbol power was proposed.With the maximum ratio combining (MRC) receiver,the influence of circuit power was considered,pilot contamination and the constraint of maximum transmission power,and a nonconvex function modeled with the goal of maximizing energy efficiency (EE) was established.Firstly,the fractional form was transformed into an equivalent subtractive form by using the properties of fractional programming and then decomposed into a series of DC problems,finally,by using an iterative optimization algorithm,the three variables were alternately adjusted with maximizing the energy efficiency.Simulation results show that with the increasing of the maximum symbol transmission power,the proposed scheme can still have the great EE performance for the massive MIMO systems.