New Placement Delivery Array Construction for Coded Caching with Flexible Memory Size

Coded caching is an emerging technique to alleviate the network pressure in data transmissions. In such a scheme, each file in the data center or library is usually divided into a number of packets to pursue a low broadcasting rate based on the designed placements at each user's cache. However, the implementation complexity of this scheme increases as the number of packets increases. Therefore, it is crucial to design a scheme with a small subpacketization, while maintaining a relatively low transmission rate. In this paper, a placement delivery array (PDA) scheme that works with flexible memory sizes is proposed, and then it is generalized to fit more scenarios. It is shown that the subpacketization level can be decreased while maintaining the same number of users, memory ratio and transmission rate.