改进相位迭代的低精度混合预编码方法

Improved Iterative Phase Based Hybrid Precoding with Low-Resolution Phase Shifter

针对毫米波大规模天线(Massive-MIMO)系统中,低精度移相器的模拟预编码算法复杂度高的问题,该文提出一种改进的迭代相位混合预编码算法。该算法将模拟预编码优化矩阵分解为列向量逐个求解,并采用2阶秩矩阵近似得到次优的优化函数,然后将优化函数转化为求和形式并迭代收敛求得最优相位,以此降低计算复杂度。同时,为了最大化硬件效率,还设计出移相器相位分辨率为1 bit的模拟预编码方案。理论分析和仿真结果表明,所提算法计算复杂度较低,且其频谱效率更优。

In the millimeter-wave massive multiple-input multiple-output(Massive-MIMO)system,the analog precoding algorithm with low-resolution phase shifter has a high algorithm complexity.To cope with the computational complexity problem,an improved iterative phase hybrid precoding algorithm is proposed.It decomposes the analog precoding optimization matrix into column vectors one by one,and uses the second-order rank matrix to obtain the suboptimal optimization function approximately.Then,the optimization function is transformed into a summation form and the optimal phase is obtained by iterative convergence.Meanwhile,in order to maximize hardware efficiency,an analog beamforming scheme with 1 bit resolution phaser is designed.Theoretical analysis and simulation results show that the proposed algorithm has lower computational complexity and improving spectral efficiency.