复杂环境下的可调协作检测机理研究

Cooperative communication has significant value of application, one of its core support technology is cooperative detection. However, the performance of cooperative detection would be influenced by complex environment (non-Gaussian noise and frequency selective channel), it's the problem that must be considered. In order to improve the detction performance more effectively, the project intends to investigate the mechanism of adjustable cooperative detection systematically. First, for complex enviroment, the mechanism of relay node selection, that use steady mean square error of equalization detector as the performance index, is proposed to realise adjustment of node numbers participated in cooperation detection. Second, to further consider the effects of channel difference, for the relay node in decode-and-forward mode, adjustable observation window length (AOWL) equalization detector based on H∞ criterion is proposed to further improve the detection performance. At last, on the basis of the above investigation, for the receiving node, the mechanism of multi-branch equalization detection based on H∞ criterion is proposed to combine effectively the signals from multiple nodes. And then to to further consider the effects of channel difference, the the mechanism of multi-branch AOWL equalization detection is proposed. The project is to estabilish the mechanism system of adjustable cooperative detection in complex enviromment that fully exploit the potential advantages of cooperative detection, and it would provide a valuable reference for realization of cooperative detection.

协作通信蕴藏着巨大的潜在应用价值，协作检测是其核心支撑技术之一。而复杂环境(噪声具非高斯性且信道为频率选择性信道)会影响协作检测的性能，是必须要考虑的问题。为更大程度提高检测性能，本项目拟对复杂环境下的可调协作检测机理进行系统性的研究。首先针对复杂环境，提出以均衡检测器输出稳态均方误差作为性能指标的中继节点选择机制，实现参与节点数可调；而后进一步考虑信道不同影响，对工作于解码转发(DF)模式的中继节点，提出基于H∞标准的观察窗口长度可调的均衡检测器，以期进一步提高检测性能；在以上研究基础上，在接收节点端，提出基于H∞标准的多分支均衡检测机制，以期有效合并处理来自于多个节点的信号；进一步考虑信道不同，提出各分支观察窗口长度可调的多分支均衡检测机制。本项目充分挖掘协作检测的潜在优势，可建立起复杂环境下的可调协作检测机理体系，为协作检测实现提供一种有价值的参考方案。

本项目针对复杂环境对协作检测的影响，为更大程度提高检测性能，围绕可调协作检测技术展开了研究。项目达到了预期目标，初步建立了复杂环境下的可调协作检测机理体系。已发表(或录用)学术论文11篇，其中SCI收录3篇，EI收录6篇；申请受理发明专利3项；3篇SCI检索期刊文章已投在审中；此外还有2篇论文正在整理中。主要研究成果如下：.(1) 多分支联合合并处理方法设计.针对多节点信号的处理问题，提出了一种多分支联合合并检测器，该检测器能联合处理接收到的多个节点信号；并且定量分析了该检测器的理论上限。.(2) 检测器结构可调方法. 首先，定量分析了检测器的最优观察窗口长度，证明了最优观察窗口长度的存在；针对信道不同问题，提出了一种各分支观察窗口长度可调的多分支联合合并检测器，该检测器能根据具体的信道调整相应分支的观察窗口长度；针对观察窗口长度调整的收敛问题，研究了抽头长度自适应步长参数对窗口长度调整的影响，提出了一种自适应步长参数可变的可调观察窗口长度滤波算法，提高了观察窗口长度的收敛速度。.(3) 可调节点选择机制. 针对节点数对协作检测性能的影响，提出了一种可调中继节点选择机制，该机制能动态选出参与协作的节点数，使得系统能以最少的节点取得逼近于最优节点数的性能。.(4) 非高斯噪声抑制方法.针对非高斯噪声的影响，提出了一种基于H∞标准的多分支联合合并检测器，其对非高斯噪声具有一定的抑制能力。