衰落认知多址接入窃听信道的线性预编码
Linear Precoding for Fading Cognitive Multiple Access Wiretap Channel with Finite-Alphabet Inputs
摘要：
研究了衰落认知多址接入窃听信道（CMAC-WT），在该信道中，两个次用户发射机（ST）向一个次用户接收机（SR）发送安全消息，同时在多个主用户接收机（PR）处受到干扰门限的约束.我们设计的线性预编码器，以最大化的平均保密和率多输入多输出（MIMO）衰落CMAC-WT有限字母表输入和统计信道状态信息（CSI）在ST。对于这个非确定性的多项式时间（NP）困难问题，我们利用平均保密和率的精确近似来降低计算复杂度，然后通过将凹凸过程嵌入到外部近似框架中，提出了一个两层算法.该算法的思想是将近似的平均保密和率转化为凸函数的差，然后生成一系列简单的松弛集来逼近非凸可行集。随后，我们最大化的近似平均保密率和松弛集序列通过使用凹凸过程。数值结果表明，我们提出的预编码算法是优于传统的高斯预编码方法在中等和高信噪比（SNR）的制度。
英文摘要：
We investigate the fading cognitive multiple access wiretap channel (CMAC-WT), in which two secondary-user transmitters (STs) send secure messages to a secondary-user receiver (SR) in the presence of an eavesdropper (ED) and subject to interference threshold constraints at multiple primary-user receivers (PRs). We design linear precoders to maximize the average secrecy sum rate for multiple-input multiple-output (MIMO) fading CMAC-WT under finite-alphabet inputs and statistical channel state information (CSI) at STs. For this non-deterministic polynomial time (NP)-hard problem, we utilize an accurate approximation of the average secrecy sum rate to reduce the computational complexity, and then present a two-layer algorithm by embedding the convex-concave procedure into an outer approximation framework. The idea behind this algorithm is to reformulate the approximated average secrecy sum rate as a difference of convex functions, and then generate a sequence of simpler relaxed sets to approach the non-convex feasible set. Subsequently, we maximize the approximated average secrecy sum rate over the sequence of relaxed sets by using the convex-concave procedure. Numerical results indicate that our proposed precoding algorithm is superior to the conventional Gaussian precoding method in the medium and high signal-to-noise ratio (SNR) regimes.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
