On the Degrees of Freedom Achievable Through Interference Alignment in a MIMO Interference Channel
On the Degrees of Freedom Achievable Through Interference Alignment in a MIMO Interference Channel
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DOI：
10.1109/tsp.2011.2173683
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发表时间：
2011-04
影响因子：
5.4
通讯作者：
Meisam Razaviyayn;G. Lyubeznik;Z. Luo
中科院分区：
文献类型：
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作者：
Meisam Razaviyayn;G. Lyubeznik;Z. Luo
考虑一个k用户平坦衰落MIMO干扰信道，其中第k个发射机（或接收机）配备了Mk（分别为Nk）天线。如果在时间或频率上使用指数（以K为单位）的通用信道扩展数，Cadambe和Jafar[1]表明，可以通过干涉对准最大化可实现的总自由度（DoF），即使Mk和Nk有界，也会导致总DoF随a线性增长。在这项工作中，我们考虑不允许通道扩展的情况，并建立了任何自由度元组（d1）必须满足的一般条件。d2……dK)通过线性干涉对准实现。对于所有k都具有Mk = M, Nk = N, dk = d的对称系统，该条件意味着可实现的总自由度不能随k线性增长，实际上不大于k (M + N)/(k + 1)。我们还表明，当每个收发器的天线数量可以被d整除时，这个界限是紧的，d是每个用户的数据流数量。
Consider a K-user flat fading MIMO interference channel where the kth transmitter (or receiver) is equipped with Mk (respectively Nk) antennas. If an exponential (in K) number of generic channel extensions are used either across time or frequency, Cadambe and Jafar [1] showed that the total achievable degrees of freedom (DoF) can be maximized via interference alignment, resulting in a total DoF that grows linearly with A even if Mk and Nk are bounded. In this work we consider the case where no channel extension is allowed, and establish a general condition that must be satisfied by any degrees of freedom tuple (d1. d2....dK) achievable through linear interference alignment. For a symmetric system with Mk = M, Nk = N, dk = d for all k, this condition implies that the total achievable DoF cannot grow linearly with K, and is in fact no more than K(M + N)/(K + 1). We also show that this bound is tight when the number of antennas at each transceiver is divisible by d, the number of data streams per user.