Secure Communications in Fading Cognitive Radio Networks with Finite-Alphabet Signaling

目的：建立频谱共享认知无线电网络安全通信的新方法和新算法，以最大限度地提高安全威胁下次级用户的保密吞吐量，保证主用户的服务质量，并保证信息的保密性。智慧的优点是：1)提出一个统一的网络模型来描述由多个主用户、次级用户和丢弃者组成的衰落认知无线电网络，这些网络都通过无线衰落信道连接；2)将次级用户的保密通信描述为有限字母(而不是高斯)信令和信道统计约束下的交互信息或吞吐量的直接最大化；3)提出了一种解决非凹凸优化问题的新方法。更广泛的影响包括：1)该项目将通过使用有限字母信令和信道统计来优化线性预编码器，以最大化实际可达到的数据速率或吞吐量，从而弥合网络信息理论和实际网络实施之间的差距；2)它将建立一种变换的方法，有效地解决认知无线电网络中困难的非凹、非凸和不确定的多项式时间(NP)硬优化问题。该方法可以很好地应用于其他无线网络环境，如协作中继网络、蜂窝网络、无线传感器和网络；3)研究将及时整合到与行业合作伙伴的合作以及本科生和研究生，特别是未被代表的少数族裔学生的教育中，从而通过技术创新提高对社会的影响。

Objective:The objective of this program is to establish transformative methodology and novelalgorithms for secure communications in spectrum sharing cognitive radio networks tosimultaneously maximize the secrecy throughput of secondary users under securitythreats, ensure the quality of service for primary users, and keep information secret toeavesdroppers.Intellectual merit:The intellectual merit is: 1) to propose a unified network model to describe the fadingcognitive radio network that has multiple primary users, secondary users andeavesdroppers, all connected by wireless fading channels; 2) to formulate the securecommunication of secondary users into direct maximization of mutual information orthroughput with finite-alphabet (rather than Gaussian) signaling and channel statisticsconstraints; 3) to present a novel approach to solving the neither concave nor convexoptimization problem.Broader impacts:The broader impacts include: 1) this project will bridge the gap between networkinformation theory and practical network implementation by employing finite-alphabetsignaling and channel statistics to optimize linear precoders which maximize thepractically achievable data rates or throughput; 2) it will establish a transformativemethodology that effectively tackles difficult non-concave, non-convex, and nondeterministicpolynomial-time (NP) hard optimization problems in cognitive radio networks. This methodology can be well applicable to other wireless network settingssuch as cooperative relay networks, cellular networks, and wireless sensor and meshnetworks; 3) The research will be timely integrated to collaborations with industrialpartners and education of undergraduate and graduate students, particularly, underrepresentedminority students, thus enhancing the impact to the society via technology innovation.