可重构智能表面辅助大规模MIMO通信波束成形设计

可重构智能表面(reconfigurable intelligent surface, RIS)在无线通信系统中能够提高信道性能。为了降低传统波束成形方案中功率分配的复杂度，结合毫米波(millimeter wave, mmWave)特点建立信道模型，提出一种基于正交匹配追踪(orthogonal matching pursuit, OMP)和统一信道分解(uniform channel decomposition, UCD)的RIS辅助mmWave多输入多输出(multiple input multiple output, MIMO)系统混合波束成形设计方案。利用视距(line of sight, LoS)信道的到达角(angle of arrival, AoA)和离开角(angle of departure, AoD)设计了RIS的反射矩阵。该方法不需要复杂的功率分配，能够使得多个并行数据流具有相同的信道增益。仿真结果表明，该混合波束成形方案具有更好的误比特率(bit error rate, BER)性能及频谱效率。

Beamforming design of reconfigurable intelligent surface aided massive MIMO communication

Reconfigurable intelligent surface (RIS) is considered to improve the channel performance in wireless communication systems. To reduce the complexity of power allocation in the traditional beamforming scheme, in this paper, we establish the channel model according to the characteristics of millimeter wave (mmWave), propose an orthogonal matching pursuit (OMP) and uniform channel decomposition (UCD) based hybrid beamforming scheme for RIS assisted mmWave multiple input multiple output (MIMO) system. The reflection matrix of RIS is designed by using the angle of arrival (AoA) and angle of departure (AoD) of the line of sight (LoS) channel. This method does not need complex power allocation, and can make multiple parallel data streams have the same channel gain. The simulation results show that this hybrid beamforming scheme has better bit error rate (BER) performance and spectral efficiency.