描述了两跳MIMO(Multiple-input and Multiple-output)中继系统模型,概述了中继通用的转发策略以及系统性能分析常涉及到的信道模型和信源发射方案,详细介绍了两跳MIMO中继系统通信性能分析国内外的研究进展,通过一个具体的例子比较了不同发射策略系统的性能,最后探讨和展望了两跳MIMO中继系统下一步的研究方向。MIMO中继系统的性能分析为MIMO中继系统的工程应用提供了有价值的理论参考。
Based on the level set model and the reliability theory, a numerical approach of reliability-based topology optimization for compliant mechanisms with multiple inputs and outputs is presented. A multi-objective topology optimal model of compliant mechanisms considering uncertainties of the loads, material properties, and member geometries is developed. The reliability analysis and topology optimization are integrated in the optimal iterative process. The reliabilities of the compliant mechanisms are evaluated by using the first order reliability method. Meanwhile, the problem of structural topology optimization is solved by the level set method which is flexible in handling complex topological changes and concise in describing the boundary shape of the mechanism. Numerical examples show the importance of considering the stochastic nature of the compliant mechanisms in the topology optimization process.