基于贝叶斯滤波及平滑理论的动态协作中继单跳信道估计研究

在协作中继网络各节点处获取单跳链路的信道信息可优化中继信号处理操作，从而提升系统全局性能。目前绝大多数协作中继信道估计研究均假设信道服从准静态衰落，然而信源、中继和信宿间易发生相对移动，致使信道发生动态变化，导致现有的准静态单跳信道估计不再适用。本项目将结合动态单跳信道的时间相关特性，基于有限参数基扩展模型设计切合协作中继系统自身拓扑架构的动态单跳信道信息初始捕获算法，进而融合中继节点的辅助功能，运用贝叶斯滤波和平滑理论实现在线信道跟踪和离线信道平滑等。所设计的算法无需节点间信道信息反馈链路，可以有效的节省频谱资源。在此基础上，分析动态单跳信道初始捕获、跟踪及平滑误差的统计特性，设计鲁棒性的训练序列，寻求最优训练功率分配方案，最终形成动态协作中继单跳信道的完整估计体系，为未来协作中继系统应用提供重要的理论依据和技术支撑。

The cooperative relay networks can utilize the individual channel state information to optimize the relaying operation and thus enhance the system performance. Most existing works assume the cooperative relay system experiences the static channel fading. However, due to the motion of the source, relay or destination, the cooperative relay network is more susceptible to time-varying fading as compared to the conventional point-to-point communication systems, which makes the existing static individual channel estimation methods no longer valid. In this project, we will embrace the time correlations of the dynamic individual channels, and utilize the basis expansion model to construct initial individual channel acquisition algorithm, where the topology structures of the cooperative relay networks are fully taken into consideration. We will then apply Bayesian filtering theory to construct proper filters to track the individual channel dynamic variations online. Moreover, we will resort to Bayesian smoothing theory to design corresponding smoothers for the individual channel tracking results in an offline manner. Hence, the dynamic individual channel estimation is implemented at destination without the aid of channel information feedback links. Furthermore, we will analyze the individual channel estimation errors during the initial acquisition, the tracking and the smoothing, based on which we will design robust training sequences and calculate the optimal training power allocation. The proposed project targets at developing the dynamic individual channel tracking-smoothing system for the relay network, which can serve as the theoretical foundation and technical support for the future cooperative relay networks.