Erasure Coding for Decentralized Coded Caching

THIS PAPER IS ELIGIBLE FOR THE STUDENT PAPER AWARD. Coded caching can significantly decrease the communication load in peak hours of the network. The gain of caching is maximized in a centralized setting, where the cache content of users are opportunistically designed. In the absence of a centralized placement, users' caches are filled with randomly selected packets of the files. This yields to a loss in the caching gain, especially for small cache size. A novel placement scheme is introduced in this work which is based on (within file) precoding of the files at the server, followed by random cache placement. It is shown that the proposed technique improves the caching gain compared to the uncoded placement. Surprisingly, the performance of the proposed decentralized placement matches with that of the centralized placement for small cache size.