标题： 网络简化用于安全AF中继 显示英文标题

标题： Network Simplification for Secure AF Relaying

摘要： 我们考虑一类高斯分层网络，其中源节点通过L个中间中继层与目标节点通信，每层有N个节点，在存在一个窃听者的情况下，该窃听者可以窃听最后一层节点的传输。 对于此类网络，我们提出一个问题：如果每层仅使用可用中继节点的一小部分，可以保持最大安全可实现速率的多少比例？ 特别是，我们提供了当每层使用所有N个中继时的最优安全AF与仅在每层使用k个中继（1 <= k < N）时的加法和乘法差距的上界。 我们证明，随着源功率的增加，加法差距最多以N/k和L的比值的对数增长，而相应的乘法差距最多以N/k和L的比值的二次方增长。据我们所知，这项工作首次在存在窃听者的情况下，对分层放大转发中继网络中网络简化的性能进行了表征。 显示英文摘要

摘要： We consider a class of Gaussian layered networks where a source communicates with a destination through L intermediate relay layers with N nodes in each layer in the presence of a single eavesdropper which can overhear the transmissions of the nodes in the last layer. For such networks we address the question: what fraction of maximum secure achievable rate can be maintained if only a fraction of available relay nodes are used in each layer? In particular, we provide upper bounds on additive and multiplicative gaps between the optimal secure AF when all N relays in each layer are used and when only k, 1 <= k < N, relays are used in each layer. We show that asymptotically (in source power), the additive gap increases at most logarithmically with ratio N/k and L, and the corresponding multiplicative gap increases at most quadratically with ratio N/k and L. To the best of our knowledge, this work offers the first characterization of the performance of network simplification in layered amplify-and-forward relay networks in the presence of an eavesdropper.