Cooperative Jamming for Secure Communications in MIMO Relay Networks
Cooperative Jamming for Secure Communications in MIMO Relay Networks
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DOI：
10.1109/tsp.2011.2161295
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发表时间：
2011-10-01
影响因子：
5.4
通讯作者：
Swindlehurst, A. Lee
中科院分区：
文献类型：
--
作者：
Huang, Jing;Swindlehurst, A. Lee
在传统的中继系统中，窃听者会阻碍安全通信。提出了两跳中继网络中的协作干扰策略，窃听者可以窃听中继信道的两个跳。在这些方法中，中继网络中通常不活动的节点可以被用作合作干扰源来迷惑窃听者。线性预编码方案进行了调查的两种情况下，通过解码和转发（DF）中继传输单个或多个数据流，假设全球信道状态信息（CSI）是可用的。对于单数据流传输的情况，我们推导了封闭形式的干扰波束形成器和相应的最优功率分配。提出了一种基于广义奇异值分解（GSVD）的多数据流安全中继方案。通过几何规划的最优功率分配GSVD中继方案。在此基础上，提出了一种基于GSVD的协同干扰方案，与无干扰方案相比，该方案在保密率方面有明显的提高。此外，本文还研究了窃听者具有未知CSI的情况。仿真结果表明，中继网络中的非活动节点参与协作干扰后，保密率得到了显著提高。
Secure communications can be impeded by eavesdroppers in conventional relay systems. This paper proposes cooperative jamming strategies for two-hop relay networks where the eavesdropper can wiretap the relay channels in both hops. In these approaches, the normally inactive nodes in the relay network can be used as cooperative jamming sources to confuse the eavesdropper. Linear precoding schemes are investigated for two scenarios where single or multiple data streams are transmitted via a decode-and-forward (DF) relay, under the assumption that global channel state information (CSI) is available. For the case of single data stream transmission, we derive closed-form jamming beamformers and the corresponding optimal power allocation. Generalized singular value decomposition (GSVD)-based secure relaying schemes are proposed for the transmission of multiple data streams. The optimal power allocation is found for the GSVD relaying scheme via geometric programming. Based on this result, a GSVD-based cooperative jamming scheme is proposed that shows significant improvement in terms of secrecy rate compared to the approach without jamming. Furthermore, the case involving an eavesdropper with unknown CSI is also investigated in this paper. Simulation results show that the secrecy rate is dramatically increased when inactive nodes in the relay network participate in cooperative jamming.