基于rank自适应的3D MIMO有限反馈传输方案

大规模多输入多输出 (multiple-input multiple-output,MIMO) 技术能够提高频谱效率和能量效率,被认为是下一代无线通信的关键技术。随着有源天线技术的发展,基站配置二维天线阵列可在三维(three-dimensional,3D)空间控制波束,这使得3D MIMO技术成为一个新的研究热点。在单用户MIMO下,本文提出了两种基于秩(rank)自适应的3D MIMO有限反馈方案。方案I在水平维采用rank自适应,垂直维支持rank 1传输;方案II在垂直维采用rank自适应,水平维支持rank 1传输。在三维城市宏小区和三维城市微小区场景下,采用系统级仿真验证了两种方案的性能。相较于水平维和垂直维都仅支持rank 1的传输方案,两种方案都取得了性能增益,同时方案I优于方案II。

Limited feedback schemes based rank adaptation for 3D MIMO

Massive multiple-input multiple-output (MIMO) is a potential technology to improve spectrum efficiency and energy efficiency, and deemed to be a key technology for the next generation of wireless communication. As the active antenna system (AAS) technology develops, the base station equipped with two dimensional (2D) antenna array can control the beams in the three-dimensional (3D) space,which makes 3D MIMO become a research hotspot. In the downlink single-user MIMO (SU-MIMO) system, two limited feedback schemes based on rank adaptation for 3D MIMO are proposed. Scheme I adopts rank adaptation in the horizontal domain and supports rank 1 in the vertical domain. On the contrary, scheme II adopts rank adaptation in the vertical domain and supports rank 1 in the horizontal domain. System-level simulations are conducted to test the performance of the two schemes under the 3D-urban macro (3D-UMa) and 3D-urban micro (3D-UMi) scenarios. Simulation results reveal that, compared with the scheme which only supports rank 1 in both horizontal and vertical domains, the two schemes achieve performance gain. Also, scheme I outperforms scheme II.