We propose and study a variant of pliable index coding (PICOD) where receivers have preferences for their unknown messages and give each unknown message a preference ranking. We call this the preferential pliable index-coding (PPICOD) problem and study the Pareto trade-off between the code length and overall satisfaction metric among all receivers. We derive theoretical characteristics of the PPICOD problem in terms of interactions between achievable code length and satisfaction metric. We also conceptually characterise two methods for computation of the Pareto boundary of the set of all achievable code length-satisfaction pairs. As for a coding scheme, we extend the Greedy Cover Algorithm for PICOD by Brahma and Fragouli, 2015, to balance the number of satisfied receivers and average satisfaction metric in each iteration. We present numerical results which show the efficacy of our proposed algorithm in approaching the Pareto boundary, found via brute-force computation.

翻译：我们提出并研究了一种可塑索引编码（PICOD）的变体，其中接收者对其未知消息具有偏好，并为每个未知消息赋予偏好排序。我们将此问题称为优先可塑索引编码（PPICOD）问题，并研究所有接收者间码长与整体满意度指标之间的帕累托权衡。我们推导了PPICOD问题在可达码长与满意度指标交互方面的理论特性，并从概念上刻画了两种计算所有可达码长-满意度对帕累托边界的方法。在编码方案方面，我们将Brahma与Fragouli于2015年提出的PICOD贪婪覆盖算法进行扩展，以在每个迭代中平衡满意接收者数量与平均满意度指标。数值结果表明，我们提出的算法在逼近通过暴力搜索获得的帕累托边界方面具有有效性。