Achieving linear scaling with interference alignment
Achieving linear scaling with interference alignment
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DOI：
10.1109/isit.2009.5205265
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
Ayfer Özgür;David Tse
中科院分区：
文献类型：
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作者：
Ayfer Özgür;David Tse
最近的研究结果表明，在信道系数随时间或频率变化的K用户干扰信道中，干扰对齐可以达到K/2个自由度。对于固定用户数K，自由度数表征了高信噪比极限下性能的渐近行为，但它不能回答在任何固定信噪比下性能如何随K变化的问题。特别是，随着更多的用户进入系统，目前还不清楚是否可以保持每个用户的恒定费率。本文研究了文献[5]中提出的干扰对齐方案在固定信噪比下的性能。我们假设用户之间的信道系数的形式为rEjθ，其中r在通信持续时间内是固定的，并且θ是快衰落阶段。我们证明了对于任意的SNR和K，[5]的干扰对准方案所获得的合计速率是c1Klog(1+c2SNR)的下界，其中c1和c2是与SNR和K无关的正常数。这一结果为所考虑的随机相位信道模型建立了干扰对准方案的线性标度。
Recent results have shown that interference alignment can achieve K/2 degrees of freedom in a K-user interference channel with time or frequency varying channel coefficients. For fixed number of users K, the number of degrees of freedom characterizes the asymptotic behavior of the performance in the high SNR limit but it does not answer the question of how the performance scales with K for any fixed SNR. In particular, it is unclear if a constant rate per user can be maintained as more users enter into the system. In this paper, we investigate the performance of the interference alignment scheme proposed in [5] for fixed SNR. We assume that the channel coefficients between the users are of the form r ejθ where r is fixed over the duration of communication and θ is a fast fading phase. We show that for any value of the SNR and K, the aggregate rate achieved by the interference alignment scheme of [5] is lower bounded by c1K log(1 + c2 SNR) where c1 and c2 are positive constants independent of both SNR and K. This result establishes the linear scaling of the interference alignment scheme for the considered random phase channel model.