Improved rate for a multi-server coded caching.

Multi-server coded caching, which can further reduce the amount of transmission by means of the collaboration among these servers in the wireless network during the peak traffic times, can be seen everywhere in our life. This amount is called rate. The three servers setting (two data servers and one parity check server)is widely used in practice, e.g. redundant array of independent disks-4. Luo et al. in 2016 proposed the first coded caching scheme for this setting. In this paper, we obtain a smaller rate by modifying Luo's scheme for some parameters. In addition, our method can be more generalized to further reduce the rate.