论文标题
具有有限精度CSIT的蜂窝网络：多细胞锡的GDOF最优性和多细胞合作的极端收益
Cellular Networks With Finite Precision CSIT: GDoF Optimality of Multi-Cell TIN and Extremal Gains of Multi-Cell Cooperation
论文作者
论文摘要
我们研究了发射机（CSIT）处的有限精确通道状态信息下细胞网络的普遍自由度（GDOF）。我们考虑在没有多细胞合作下由干扰广播频道（IBC）建模的下行链路设置，以及在完整的多细胞合作下超载的多输入单输出广播渠道（MISO-BC）。我们专注于三个感兴趣的制度：MC-TIN制度，其中基于将细胞间干扰视为噪声（MC-TIN）的方案被证明是IBC最佳的GDOF； MC-CTIN政权，MC-TIN可以实现的GDOF地区是凸面，而无需分时分配； MC-SLS制度扩展了先前识别的制度，其中简单的分层叠加（SLS）方案对于3型Transmitter-3使用Miso-BC是最佳的，以超载的蜂窝型网络与发射机更多的用户。我们首先表明，当CSIT仅限于有限的精度时，MC-TIN对IBC的最优性扩展到整个MC-CTIN制度。相反的证明依赖于对齐图像边界的新应用。然后，我们将IBC Converse证明扩展到通过启用完整的发射机合作获得的对应物超载Miso-BC。反过来，这被用来表明SLS方案的多细胞变体在完整的多细胞合作下，在MC-SLS制度中是最佳的，尽管仅适用于2细胞网络。 GDOF区域的压倒性组合复杂性以将此结果扩展到较大的网络的方式。另外，我们呼吁Chan等人最近引入的极端网络分析，并研究了三种感兴趣的制度中多单元合作对MC-TIN的GDOF增益。我们表明，这种极端GDOF的增益在MC-TIN和MC-CTIN机制中的小常数界定，但与MC-SLS机制中的细胞数量对数缩放。
We study the generalized degrees-of-freedom (GDoF) of cellular networks under finite precision channel state information at the transmitters (CSIT). We consider downlink settings modeled by the interfering broadcast channel (IBC) under no multi-cell cooperation, and the overloaded multiple-input-single-output broadcast channel (MISO-BC) under full multi-cell cooperation. We focus on three regimes of interest: the mc-TIN regime, where a scheme based on treating inter-cell interference as noise (mc-TIN) was shown to be GDoF optimal for the IBC; the mc-CTIN regime, where the GDoF region achievable by mc-TIN is convex without the need for time-sharing; and the mc-SLS regime which extends a previously identified regime, where a simple layered superposition (SLS) scheme is optimal for the 3-transmitter-3-user MISO-BC, to overloaded cellular-type networks with more users than transmitters. We first show that the optimality of mc-TIN for the IBC extends to the entire mc-CTIN regime when CSIT is limited to finite precision. The converse proof of this result relies on a new application of aligned images bounds. We then extend the IBC converse proof to the counterpart overloaded MISO-BC, obtained by enabling full transmitter cooperation. This, in turn, is utilized to show that a multi-cell variant of the SLS scheme is optimal in the mc-SLS regime under full multi-cell cooperation, albeit only for 2-cell networks. The overwhelming combinatorial complexity of the GDoF region stands in the way of extending this result to larger networks. Alternatively, we appeal to extremal network analysis, recently introduced by Chan et al., and study the GDoF gain of multi-cell cooperation over mc-TIN in the three regimes of interest. We show that this extremal GDoF gain is bounded by small constants in the mc-TIN and mc-CTIN regimes, yet scales logarithmically with the number of cells in the mc-SLS regime.
