无线传感器网络中协作干扰噪声策略研究

摘要

针对 WSNs中节点间通信易受窃听的问题，提出了两种提高节点间可达安全速率的协作干扰噪声策略：零空间策略和最优噪声策略。零空间策略利用协作干扰节点到目的节点信道的零空间发送噪声，因而噪声只会干扰窃听节点而不影响目的节点。最优噪声策略利用协作干扰节点到目的节点和窃听节点的信道状态信息，通过优化噪声输入协方差矩阵最大化节点间的可达安全速率。然而，可达安全速率的最大化是一个很难直接求解的非凸优化问题，为解决此问题，本文设计了最优可达安全速率计算的一维搜索算法。仿真结果表明，提出的两种协作干扰噪声策略都可以显著提高 WSNs中节点间的可达安全速率。%Aiming at the problem that wireless communication between nodes is susceptible to be wire-tapped in WSNs,zero space strategy and optimal noise strategy have been put forward to maximize the a-chievable secrecy rate of the system.Zero space strategy uses the channel state information of the intended link to transmit noise,which only interferes in the wiretap node.The optimal noise strategy makes use of the channel state information about the interned node and wiretap node to maximize the achievable secrecy rate by optimizing input noise covariance matrix.However,the calculating of maximizing the achievable secrecy rate is a non-convex optimization problem,which is difficult to be solved directly.To handle this problem,one-dimensional algorithm is proposed to calculate the optimal achievable secrecy rate.The sim-ulation results show that both zero space strategy and optimal noise strategy can significantly improve the achievable secrecy rate between nodes in WSNs.