TD-LTE-A系统中波束赋形权值PMI量化仿真研究

Simulation Research on PMI-Quantization of Beamforming for TD-LTE-A

为了降低TD-LTE-A系统下行链路波束赋形技术实现难度,本文在基于有效功率最大化准则,通过构建PMI码本对波束赋形权值进行量化,并且根据TDD系统的上下行互易性选取最优权值补偿信号的衰落与失真,进而搭建基于Matlab的评估平台对PMI量化方案和SVD分解算法下的功率、权值相关性进行对比分析。仿真结果表明,权值PMI量化可以正确实现波束赋形,由于量化误差的存在,PMI量化方案相对于SVD分解算法有一定的性能损失,但随着码本数的增加和搜索方案的优化,PMI量化方案性能接近于SVD分解算法。仿真结果为实际场景中的算法选择提供了重要的参考依据。

In order to reduce the difficulty of downlink beamforming in TD-LTE-A system, a PMI-quantized dual-stream beamforming method is proposed by using the idea of maximizes effective power of transmitted signals. Beamforming weights are quantified by constructing codebooks based on PMI. And searching schemes are designed for selecting the optimal weights to compensate for the fading and distortion of the signal according to the reciprocal channel estimation information of TDD. And then a simulation platform based on matlab is built for researching the correlation of power and weight. Simulation results show that weight PMI-quantization can be realized in beamforming. Due to the existence of quantization error, the PMI-quantization scheme has some performance loss compared with the SVD algorithm. However, with the increase of the amount of codebooks and searching schemes, the performance of PMI is close to the SVD algorithm. The simulation results provide important reference for the implementation of beamforming in real scene.