Some Variant of Known Coded Caching Schemes With Good Performance
Minquan Cheng, Jing Jiang, Xiaohu Tang, Qifa Yan · IEEE Transactions on Communications · 2019
In coded caching system, we prefer to design a scheme with the rate R and the packet number F of each file split as small as possible since the efficiency of transmission in the peak traffic times increases with the decreasing of R and the realizing complexity increases with the increasing of F. Up to now, almost all of the previously known schemes can be realized by the combinatorial structure which is called placement delivery array (PDA). In this paper, we also study the schemes by means of PDAs. We first show that given the minimum rate, the scheme proposed by Maddah-Ali and Niesen (MN scheme) has the minimum packet number which is too large in practice. From the view point of combinatorial design, two variant MN schemes, which can significantly reduce the packet number by increasing some rate, are obtained. Especially one of these schemes has better performance than the scheme generated by the well known grouping method.