论文标题
k-user miso广播频道与交替的CSIT的k-user Miso广播频道
On Sum Secure Degrees of Freedom for K-User MISO Broadcast Channel With Alternating CSIT
论文作者
论文摘要
在本文中，研究了带有机密消息（BCCM）的$ K $ - 用户多输入/单输出（MISO）广播频道的总和自由度（SDOF）和发射器（CSIT）的交替频道状态信息。在Miso BCCM中，A $ K $ -Antenna发射机（TX）向$ K $ single-Antenna接收器（RXS）通信，因此RX $ K $的消息与$ j <k $的RX $ J $保持了秘密。对于此模型，我们考虑了RXS的CSI从$ 2 $到$ k $即时在发射器中瞬间知道，而RX $ 1 $的CSI在发射机（i）的一半时间内就以剩余时间为单位延迟在发射机（i）瞬间（i）中知道。我们将此CSIT的可用性称为\ emph {交替} csit。交替的CIST已被证明可以从SDOF方面提供协同的收益，因此是一种可行的策略，可以通过简单地依靠CSI反馈策略来确保安全沟通。我们的主要贡献是该模型的SUM SDOF的表征为$ SDOF _ {\ rm sum} =（2K-1）/2 $。有趣的是，这种$ sdof _ {\ rm sum} $是通过一种相当简单的可实现的，在该可实现的情况下，TX使用人工噪声来防止以RX $ 1 $为$的意外接收器的消息解码。首先为简单起见，详细讨论了$ k = 3 $的证明，此后，我们介绍了任何数量的RXS的结果。
In this paper, the sum secure degrees of freedom (SDoF) of the $K$-user Multiple Input/Single Output (MISO) Broadcast Channel with Confidential Messages (BCCM) and alternating Channel State Information at the Transmitter (CSIT) is investigated. In the MISO BCCM, a $K$-antenna transmitter (TX) communicates toward $K$ single-antenna receivers (RXs), so that message for RX $k$ is kept secret from RX $j$ with $j<k$. For this model, we consider the scenario in which the CSI of the RXs from $2$ to $K$ is instantaneously known at the transmitter while CSI of RX $1$ is known at the transmitter (i) instantaneously for half of the time and (ii) with a unit delay for the remainder of the time. We refer to this CSIT availability as \emph{alternating} CSIT. Alternating CIST has been shown to provide synergistic gains in terms of SDoF and is thus of a viable strategy to ensure secure communication by simply relying on the CSI feedback strategy. Our main contribution is the characterization of sum SDoF for this model as $SDoF_{\rm sum}= (2K-1)/2$. Interestingly, this $SDoF_{\rm sum}$ is attained by a rather simple achievability in which the TX uses artificial noise to prevent the decoding of the message of the unintended receivers at RX $1$. For simplicity first, the proof for the case $K=3$ is discussed in detail and after that, we have presented the results for any number of RXs.
