Improper Gaussian Signaling for Multiple-Access Channels in Underlay Cognitive Radio
Improper Gaussian Signaling for Multiple-Access Channels in Underlay Cognitive Radio
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DOI：
10.1109/tcomm.2018.2880765
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发表时间：
2017-11
影响因子：
8.3
通讯作者：
C. Lameiro;I. Santamaría;P. Schreier
中科院分区：
文献类型：
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作者：
C. Lameiro;I. Santamaría;P. Schreier
本文考虑了一个未授权的多址接入信道（MAC），与一个授权的点对点用户共存，以下的认知无线电范式。我们假设，每个收发器，除了辅基站有一个天线，主用户（PU）的保护，由最小速率约束。与传统的高斯信号的假设相反，我们允许次用户发送与其复共轭相关的不适当的高斯信号。当辅基站执行迫零，我们表明，不正确的信令是最佳的，如果干扰信道增益的总和（在一个等效的规范模型）是高于一定的阈值。此外，我们推导出一个有效的算法来计算达到这种情况下的速率区域边界的传输参数。所提出的算法利用了单用户表示的辅助MAC沿着与新的结果上的最优性不适当的信令在单用户的情况下，当PU被损坏的不适当的噪声。
This paper considers an unlicensed multiple-access channel (MAC) that coexists with a licensed point-to-point user, following the underlay cognitive radio paradigm. We assume that every transceiver except the secondary base station has one antenna and that the primary user (PU) is protected by a minimum rate constraint. In contrast to the conventional assumption of proper Gaussian signaling, we allow the secondary users to transmit improper Gaussian signals, which are correlated with their complex conjugate. When the secondary base station performs zero-forcing, we show that improper signaling is optimal if the sum of the interference channel gains (in an equivalent canonical model) is above a certain threshold. Additionally, we derive an efficient algorithm to compute the transmission parameters that attain the rate region boundary for this scenario. The proposed algorithm exploits a single-user representation of the secondary MAC along with new results on the optimality of improper signaling in the single-user case when the PU is corrupted by an improper noise.