TD-HSDPA系统中改进的CQI预测方法

摘要

By analyzing the AMC procedure in TD-HSDPA system, an improved CQI prediction method which considers the accuracy of SNR-CQI mapping and the impact of feedback delays jointly is proposed in this paper. And then the algorithm is verified based on TD-HSDPA downlink link level simulation. In this approach, NodeB derives the predicted CQI value using the history CQI values reported by UE to reduce the impact of feedback delay. Additionally, UE adjusts the CQI mapping table in the light of the ACK/NACK to make a more accurate selection of CQI. Simulation results show that the proposed scheme can bring a certain throughput gain, especially for medium and high vehicular speed.%针对TD-HSDPA系统中自适应调制编码的实现过程,综合考虑信噪比与信道质量指示映射的准确性和反馈时延对系统性能的影响,提出了一种能补偿其带来的AMC性能下降的CQI预测方法,并通过MATLAB搭建了TD-HSDPA仿真链路对其进行了仿真验证.该方法在基站端利用上报的CQI历史值进行预测,同时根据接收数据的准确性,在UE端对SNR与CQI的映射表进行调整.仿真结果表明,该方案在中高速移动环境下能带来较大的吞吐量增益.