基于非理想CSIT的LTE/LTE-A无线通信系统的鲁棒干扰管理技术研究

Full frequency reuse networking is utilized in LTE/LTE-A systems. As the base stations use the same frequency, the users in a cell suffer the co-channel interference from its neighboring cells, which affects the system performance severely. Therefore, it is urgent to study the interference management in LTE/LTE-A systems. Current studies show that timely and accurate channel state information at transmitter (CSIT) plays a significant role in the beamforming design and interference management. Unfortunately, CSIT, in practical systems, is always imprefect due to some factors such as CSIT delay, channel estimation error, quantization error, RF calibration error and so on. The interference management based on the imperfect CSIT is therefore very important for real applications. In this study, according to the channel characteristic of the wireless communication systems, we will analyze the performance of beamforming and the multiuser channel capacity in LTE/LTE-A systems on the basis of the imperfect CSIT, especially focus on the robust coordinated multipoint (CoMP) transmission technique. We will model the imperfect CSIT, design multicell dynamic clustering algorithms and then propose pragmatic robust CoMP transmission schemes for bouned and statistical CSIT error model repectively by utilizing optimization theory, Game theory and some other latest mathematical theory and methods.

LTE/LTE-A系统实行全频率复用的组网方式，由于基站采用同频传输，相邻小区往往会产生相互间干扰，严重影响系统性能。因此，LTE/LTE-A系统的干扰管理技术是一个亟待研究的课题。现有研究表明，及时而准确的发送端信道状态信息（CSIT）对LTE/LTE-系统的波束成形传输和干扰管理技术是非常重要的。然而，在实际系统中，由于存在CSIT延时、信道估计误差、量化误差和射频校准误差等，CSIT总是非理想的。所以，基于非理想CSIT的相关干扰管理技术显得非常重要。我们将根据实际无线通信系统的信道特性，分析非理想CSIT条件下LTE/LTE-A波束成形系统的性能和多用户信道容量，并着重针对干扰管理技术中的CoMP技术开展深入研究，对信道非理想因素进行建模；设计多小区动态分簇算法；进而通过优化理论、博弈论和其他新的数学理论和变换方法，分别针对有界误差和统计误差模型，提出可实现的鲁棒CoMP传输方案。

本课题对基于非理想CSIT的LTE/LTE-A无线通信系统的干扰管理技术进行了研究，主要包括波束成形系统的性能分析、导频干扰消除、无线信道的容量分析、干扰抑制以及CoMP传输方案等。通过研究，我们获得了多项符合课题目标的创新成果，主要包括信道状态信息的误差建模方法、导频干扰消除方案、非理想CSIT和干扰场景下的波束成形系统的性能分析结论、基于非理想CSI的干扰抑制方案、基于有界误差和统计误差的鲁棒性CoMP传输方案、面向分簇场景的鲁棒性波束成形算法等。在课题研究中，课题组成员在IEEE Trans. Wireless Comm.、IEEE Trans. Comm.、IEEE Comm. Letters、IEEE Wireless Comm. Letters、 IET Comm.、电子学报、通信学报等国内外权威刊物以及IEEE ICC、IEEE Globecom、IEEE VTC等知名会议上发表论文共44篇，申请并公开发明专利8项，其中授权6项，培养博士生6名，硕士生7名。