论文标题
高速缓存的误会系统的多安特纳纳放置阵列
Multiple-antenna Placement Delivery Array for Cache-aided MISO Systems
论文作者
论文摘要
我们考虑使用缓存的多输入单输出(MISO)广播频道,该频道由具有$ l $ antennas和$ k $ single-antenna用户的服务器组成,其中服务器包含相等长度的$ n $文件,每个用户都配备了$ M $文件的本地cache。每个用户从库请求任意文件。目的是设计基于未编码的放置和一声线性输送的编码缓存方案,以实现具有低子包装的最大总和自由度(sum-dof)。在文献中显示,在未编码的放置和单发线性传递的约束下,最佳总和为$ L+\ frac {km} {n} $。但是,以前针对此设置的计划在$ k $中产生了指数的子包装订单,或者在系统参数$ l $,$ k $,$ m $和$ n $中所需的特定条件。在本文中,我们提出了一种新的组合结构,称为多 - 安特纳放置递送阵列(MAPDA)。基于MAPDA和拉丁广场,第一个提出的方案实现了最佳的总和$ l+\ frac {km} {n} {n} $,当$ k $的子包装$ \ frac {km} {km} {n} {n}+l = k $时。随后,对于一般情况,我们提出了一种转换方法,用于从任何$ g $的PDA(一类PDA)构建MAPDA(阵列中的每个整数都会发生$ G $ times),以用于原始的共享链接编码的缓存问题。当原始PDA对应于Maddah-Ali和Niesen编码的缓存方案时,MAPDA组合结构下的结果方案可以实现最佳的总和DOF $ l+\ frac {km} {n} {n} {N} $,并减少了子包装,而对现有方案而言减少了。这项工作可以扩展到与Naderializadeh等人提出的高速缓存干扰通道相对应的多个独立的单触角发射机(服务器)。以及配备多个天线的发射机的情况。
We consider the cache-aided multiple-input single-output (MISO) broadcast channel, which consists of a server with $L$ antennas and $K$ single-antenna users, where the server contains $N$ files of equal length and each user is equipped with a local cache of size $M$ files. Each user requests an arbitrary file from library. The objective is to design a coded caching scheme based on uncoded placement and one-shot linear delivery, to achieve the maximum sum Degree-of-Freedom (sum-DoF) with low subpacketization. It was shown in the literature that under the constraint of uncoded placement and one-shot linear delivery, the optimal sum-DoF is $L+\frac{KM}{N}$. However, previously proposed schemes for this setting incurred either an exponential subpacketization order in $K$, or required specific conditions in the system parameters $L$, $K$, $M$ and $N$. In this paper, we propose a new combinatorial structure called multiple-antenna placement delivery array (MAPDA). Based on MAPDA and Latin square, the first proposed scheme achieves the optimal sum-DoF $L+\frac{KM}{N}$ with the subpacketization of $K$ when $\frac{KM}{N}+L=K$. Subsequently, for the general case we propose a transformation approach to construct an MAPDA from any $g$-regular PDA (a class of PDA where each integer in the array occurs $g$ times) for the original shared-link coded caching problem. When the original PDA corresponds to the Maddah-Ali and Niesen coded caching scheme, the resulting scheme under the combinatorial structure of MAPDA can achieve the optimal sum-DoF $L+\frac{KM}{N}$ with reduced subpacketization with respect to the existing schemes. The work can be extended to the multiple independent single-antenna transmitters (servers) corresponding to the cache-aided interference channel proposed by Naderializadeh et al. and the scenario of transmitters equipped with multiple antennas.