Centralized coded caching schemes have been widely studied in wireless networks. Placement delivery array (PDA) can be used to generate a coded caching scheme with low subpacketization when all the requested files are different. However, all existing schemes based on PDA design treat the request of each user as an independent file, without leveraging the multicast opportunities when one file is requested by several users. In this letter, for any existing scheme based on PDA design, after its coded multicast messages generation, we proposed an approach to remove the redundant multicast messages.

中文翻译：

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一种减少随机需求的放置交付阵列方案冗余的方法

集中式编码缓存方案已在无线网络中得到广泛研究。当所有请求的文件都不同时，放置传送阵列 (PDA) 可用于生成具有低子包化的编码缓存方案。然而，所有基于PDA设计的现有方案都将每个用户的请求视为一个独立的文件，当多个用户请求一个文件时没有利用多播机会。在这封信中，对于任何基于 PDA 设计的现有方案，在其编码组播消息生成后，我们提出了一种去除冗余组播消息的方法。