Artificial Noise Aided Secure Communications for Cooperative NOMA Networks
Artificial Noise Aided Secure Communications for Cooperative NOMA Networks
复制标题
人工噪声辅助 NOMA 合作网络的安全通信
DOI：
10.1109/tccn.2021.3130979
复制
发表时间：
2022
影响因子：
8.6
通讯作者：
O. Dobre
中科院分区：
文献类型：
--
作者：
Zhanghua Cao;Xiaodong Ji;Jue Wang;Wei Wang;K. Cumanan;Z. Ding;O. Dobre
非正交多址(NOMA)被认为是未来无线网络中提高频谱效率和提供大规模连接的一种很有前途的多址技术。然而，应仔细解决NOMA继承的安全问题，以进一步发挥其在启用NOMA的无线网络中的潜在优势。因此，我们考虑协作NOMA网络，其中信源使用NOMA同时与多天线近用户和远用户通信。在与近用户直接通信的同时，信源使用多个全双工(FD)解码和转发(DF)中继器来在被动窃听者存在的情况下与远用户建立通信。为了解决这种协作NOMA网络中的窃听问题，我们提出了一种新的两阶段基于FD的人工噪声(AN)方案，并采用了不同的中继选择技术。在第一阶段，所选的FD中继器在接收来自信源的叠加信号时发出一个干扰窃听者的信号。在第二阶段，在广播所得到的混合信号之前，所选择的中继器对发往远端用户的消息和AN两者执行异或(XOR)操作。通过利用零空间波束形成、自干扰抵消技术和DF-XOR协作协议，该方案可以在近用户和远用户以及选择的中继处有效地消除AN。然而，通过降低窃听者的解码能力，无法在用于AN目的的窃听者处抑制AN。我们从安全-可靠性权衡(SRT)的角度对该方案的性能进行了评估。对于具有最大-最小和部分中继选择技术的AN辅助方案，我们从理论上推导了中断概率和截获概率的精确和渐近闭合表达式。给出了数值结果，验证了推导的正确性。此外，仿真结果还表明，增加近用户的天线数目和增加中继器的数目可以改善近用户和远用户的SRT。
Non-orthogonal multiple access (NOMA) has been envisioned as a promising multiple access technique to improve spectral efficiency and provide massive connectivity in future wireless networks. However, the inherited security issues with NOMA should be carefully addressed to further exploit its potential benefits in NOMA enabled wireless networks. As such, we consider a cooperative NOMA network, where a source uses the NOMA to simultaneously communicate with a multi-antenna near-user and a far-user. While directly communicating with the near-user, the source employs multiple full-duplex (FD) decode-and forward (DF) relays to establish communication with the far-user in the presence of a passive eavesdropper. To address the eavesdropping in this cooperative NOMA network, we propose a new two-phase FD-based artificial noise (AN) scheme with different relay selection techniques. In the first phase, the selected FD relay emits AN to confuse the eavesdropper while receiving the superimposed signal from the source. In the second phase, the selected relay performs exclusive OR (XOR) operation on both the message intended to the far-user and the AN before broadcasting the resulting mixed signal. By utilizing null-space beamforming, self-interference cancellation techniques and DF-XOR cooperative protocol, the AN in the proposed scheme can be efficiently eliminated at the near-user and far-user as well as at the selected relay. However, the AN cannot be suppressed at the eavesdropper which serves the purpose of AN through degrading the decoding capability of the eavesdropper. We evaluate the performance of the proposed scheme in terms of security-reliability trade-off (SRT). For the AN-aided scheme with max-min and partial relay selection techniques, we theoretically derive the exact and asymptotic closed-form expressions of the outage probability and intercept probability. Numerical results have been provided to validate the derivations. In addition, the results reveal that the SRT of the near-user and far-user can be improved by increasing the number of antennas at the near-user and the number of relays.