TD-LTE系统中动态下行波束赋形算法性能分析

Performance Analysis of Downlink Beamforming Algorithms in TDLTE System

根据加权粒度的差别,介绍了per-RB-MRT算法和full-BW-EBB算法的原理,并对这两种算法的特点以及性能差异进行了理论分析。构建了符合3GPP规范定义的TD-LTE系统上下行仿真平台,对这两种算法在有信道估计误差(包括信道估计精准度和信道信息时延)的情况下的其性能进行了理论分析和仿真研究。仿真结果表明,per-RB-MRT算法在上行信道估计值和下行信道实际值契合较好的情况下能够趋于最佳理论性能,而full-BW-EBB算法由于利用了相对稳定的信道空间相关特性,因而能够在较差的信道环境中保持较高的性能鲁棒性。这些仿真结果对于实际场景中的算法选择提供了重要的参考依据。

Principles of two beamforming algorithms, i.e., per - RB - MRT and full - BW - EBB, are intro- duced. To provide performance reference for practical applications, a complete uplink-downlink simulation plat-form is built according to 3GPP - LTE specifications. The performance of two algorithms under imperfect channel estimation and channel information delay is studied. It is shown that performance of the per - RB - MRT algo- rithm approaches the optimal theoretical benchmark when the uplink channel estimation is accurate and uplink/ downlink channel matches well. The full - BW - EBB algorithm, on the other side, provides robust performance under imperfect channel estimation and uplink/downlink mismatch. The theoretical discussion and simulation results provide valuable reference for algorithm design in TD - LTE systems.