Robust Iterative Interference Alignment for Cellular Networks With Limited Feedback
Robust Iterative Interference Alignment for Cellular Networks With Limited Feedback
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DOI：
10.1109/twc.2014.2361335
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发表时间：
2013-08
影响因子：
10.4
通讯作者：
J. Schreck;G. Wunder;P. Jung
中科院分区：
文献类型：
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作者：
J. Schreck;G. Wunder;P. Jung
从理论上讲，协调多点传输(CoMP)有望在频谱效率方面获得巨大收益。然而，工业现场试验显示，吞吐量增长相当令人失望，其中主要限制因素是适当地共享信道状态信息。最近的许多论文都是在CoMP的背景下考虑这种所谓的有限反馈问题，通常采取如下假设，即无限信噪比机制、没有用户选择和理想的链路自适应，使得分析过于乐观。在本文中，我们通过引入一种改进的性能评估指标来更真实地评估有限反馈问题，该度量更好地捕捉了吞吐量的下降。我们找到了相关的标度律(上下界)，并表明它们不同于现有的标度律。此外，我们还提出了一种稳健的迭代干扰对齐算法和相应的反馈策略，实现了所得到的标度律。其主要思想是，不是发送完整的信道矩阵，而是每个用户固定接收滤波器并反馈有效信道的量化版本。最后，我们通过对所提出的系统的模拟来强调我们的发现。
In theory, coordinated multipoint transmission (CoMP) promises vast gains in spectral efficiency. However, industrial field trials show rather disappointing throughput gains, whereby the major limiting factor is proper sharing of channel state information. Many recent papers have considered this so-called limited feedback problem in the context of CoMP, usually taking the following assumptions, namely, infinite SNR regime, no user selection, and ideal link adaptation, rendering the analysis too optimistic. In this paper, we make a step forward toward a more realistic assessment of the limited feedback problem by introducing an improved metric for the performance evaluation, which better captures the throughput degradation. We find the relevant scaling laws (lower and upper bounds) and show that they are different from existing ones. Moreover, we provide a robust iterative interference alignment algorithm and corresponding feedback strategies achieving the obtained scaling laws. The main idea is that, instead of sending the complete channel matrix, each user fixes a receive filter and feeds back a quantized version of the effective channel. Finally, we underline our findings with simulations for the proposed system.