标题： 通过合作的频谱租赁以增强物理层安全性 显示英文标题

标题： Spectrum Leasing via Cooperation for Enhanced Physical-Layer Secrecy

摘要： 通过合作的频谱租赁指的是主用户将一部分频谱资源租给次用户，以换取合作的可能性。 在存在窃听者的情况下，本文提出了一种该概念的新应用，其中次用户的合作旨在通过向窃听者而不是主接收器引入更多干扰来提高主网络的保密性。 为了以积极的方式产生干扰，本研究探讨了次发送端具有多天线的波束成形器的最优设计，该设计在满足次网络所需速率的前提下最大化主网络的保密速率。 此外，我们根据窃听者的操作情况研究了两种场景：i) 窃听者将次传输产生的干扰视为加性噪声（单用户解码）和 ii) 窃听者尝试解码并去除次信号（联合解码）。 数值结果证实，对于广泛范围的所需次速率约束，所提出的频谱租赁策略相比没有频谱租赁的情况提高了主网络的保密速率。 显示英文摘要

摘要： Spectrum leasing via cooperation refers to the possibility of primary users leasing a portion of the spectral resources to secondary users in exchange for cooperation. In the presence of an eavesdropper, this correspondence proposes a novel application of this concept in which the secondary cooperation aims at improving secrecy of the primary network by creating more interference to the eavesdropper than to the primary receiver. To generate the interference in a positive way, this work studies an optimal design of a beamformer at the secondary transmitter with multiple antennas that maximizes a secrecy rate of the primary network while satisfying a required rate for the secondary network. Moreover, we investigate two scenarios depending upon the operation of the eavesdropper: i) the eavesdropper treats the interference by the secondary transmission as an additive noise (single-user decoding) and ii) the eavesdropper tries to decode and remove the secondary signal (joint decoding). Numerical results confirm that, for a wide range of required secondary rate constraints, the proposed spectrum-leasing strategy increases the secrecy rate of the primary network compared to the case of no spectrum leasing.