Performance analysis and transmission design of pliable index coding with restricted message requirements

Pliable index coding studies flexible communication networks where each receiver just needs to receive any message that it does not already have. The aim is to find the optimal broadcast rate that can satisfy all the receivers' requirements. In this work, we consider a more practical but restricted scenario where each receiver wants any message it does not have from a particular subset of messages. We first adapt coding schemes from pliable index coding to this new restricted pliable index coding setting. We show that the adapted scheme is optimal under certain conditions. We also construct a new coding scheme for the restricted setting, which can outperform the adapted scheme. In addition, we simplify the computational complexity when constructing coding schemes for pliable index coding from exponential to linear, in which such reduced complexity is also applicable to restricted pliable index coding. Finally, we derive lower bounds on the rate of restricted pliable index coding. Then, we show that the lower bound we found for restricted pliable index coding is much tighter compared to the pliable index coding lower bound in many cases.