On the AWGN MAC With Imperfect Feedback
On the AWGN MAC With Imperfect Feedback
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关于不完美反馈的 AWGN MAC
DOI：
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发表时间：
2009
影响因子：
2.5
通讯作者：
Michèle A. Wigger
中科院分区：
文献类型：
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作者：
A. Lapidoth;Michèle A. Wigger
针对带噪声反馈的两用户加性白色高斯多址信道，推导了新的可达速率域。这些区域表现出以下两个属性。不管（有限）高斯反馈噪声方差，该区域包括位于无反馈容量区域之外的速率点，并且当反馈噪声方差趋于零时，该区域收敛到完美反馈容量区域。新的可实现区域也适用于部分反馈设置，其中一个发射机具有噪声反馈链路，而另一个发射机根本没有反馈。同样，不管反馈链路上的（有限）噪声方差如何，这些区域包括位于无反馈容量区域之外的速率点。此外，在完全部分反馈的情况下，即，在仅有的反馈链路是无噪声的情况下，对于某些信道参数，新区域包括位于Cover-Leung区域之外的速率点。这在否定中回答了货车德Meulen提出的关于覆盖梁区域是否等于具有完美部分反馈的高斯多址信道的容量区域的问题。最后，我们提出了新的可实现的区域，也为接收器是认知的反馈链路上的噪声序列的实现的设置。
New achievable rate regions are derived for the two-user additive white Gaussian multiple-access channel with noisy feedback. The regions exhibit the following two properties. Irrespective of the (finite) Gaussian feedback-noise variances, the regions include rate points that lie outside the no-feedback capacity region, and when the feedback-noise variances tend to zero the regions converge to the perfect-feedback capacity region. The new achievable regions also apply to the partial-feedback setting where one of the transmitters has a noisy feedback link and the other transmitter has no feedback at all. Again, irrespective of the (finite) noise variance on the feedback link, the regions include rate points that lie outside the no-feedback capacity region. Moreover, in the case of perfect partial feedback, i.e., where the only feedback link is noise-free, for certain channel parameters the new regions include rate points that lie outside the Cover-Leung region. This answers in the negative the question posed by van der Meulen as to whether the Cover-Leung region equals the capacity region of the Gaussian multiple-access channel with perfect partial feedback. Finally, we propose new achievable regions also for a setting where the receiver is cognizant of the realizations of the noise sequences on the feedback links.