Interference alignment: From degrees-of-freedom to constant-gap capacity approximations
Interference alignment: From degrees-of-freedom to constant-gap capacity approximations
复制标题
干涉对准：从自由度到恒定间隙容量近似
DOI：
10.1109/isit.2012.6283727
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
M. Maddah
中科院分区：
文献类型：
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作者：
Urs Niesen;M. Maddah
干涉对齐是具有多个干扰链接的通信方案的关键技术。在几种这样的情况下，使用干扰对准来表征通道的自由度。但是，这些自由度的容量近似通常太弱，无法准确预测有限的信噪比下的通道容量的行为。本文的目的是通过表明可以使用干扰对齐方式来表征在恒定间隙内的能力来显着增强这些结果。我们专注于实时不变的频率 - 静电板X通道，为此，只有自fruperedom。我们提出了一种新的通信计划，并表明它达到了高斯X通道在恒定间隙内的能力。为了帮助这一过程，我们开发了一种新颖的确定性渠道模型，承认可以将其转化为高斯通道的更广泛的可实现方案。对于这种确定性模型，我们找到了一个大约最佳的通信方案。然后，我们将此方案转换为确定性通道的原始高斯X通道，并表明它可以在恒定间隙内实现能力。这是需要干扰对齐的完全连接网络的第一个常数结果。
Interference alignment is a key technique for communication scenarios with multiple interfering links. In several such scenarios, interference alignment was used to characterize the degrees-of-freedom of the channel. However, these degrees-of-freedom capacity approximations are often too weak to make accurate predictions about the behavior of channel capacity at finite signal-to-noise ratios. The aim of this paper is to significantly strengthen these results by showing that interference alignment can be used to characterize capacity to within a constant gap. We focus on real time-invariant frequency-flat X-channels, for which only the degrees-of-freedom are known. We propose a new communication scheme and show that it achieves the capacity of the Gaussian X-channel to within a constant gap. To aid in this process, we develop a novel deterministic channel model, admitting a wider range of achievable schemes that can be translated to the Gaussian channel. For this deterministic model, we find an approximately optimal communication scheme. We then translate this scheme for the deterministic channel to the original Gaussian X-channel and show that it achieves capacity to within a constant gap. This is the first constant-gap result for a fully-connected network requiring interference alignment.