A Rate-Distortion Approach to Caching

作者：Timo Roy^*; Bidokhti Shirin Saeedi; Wigger Michele; Geiger Bernhard C

来源：IEEE Transactions on Information Theory, 2018, 64(3): 1957-1976.

DOI：10.1109/TIT.2017.2768058

• Coded caching
• rate-distortion
• common information

In this paper, we consider a lossy single-user caching problem with correlated sources. We first describe the fundamental interplay between the source correlations, the capacity of the user's cache, the user's reconstruction distortion requirements, and the final delivery-phase (compression) rate. We then illustrate this interplay using a multivariate Gaussian source example and a binary symmetric source example. To fully explore the effect of the user's distortion requirements, we formulate the caching problem using f-separable distortion functions recently introduce by Shkel and Verdu. The class of f-separable distortion functions includes separable distortion functions as a special case, and our analysis covers both the expected- and excess-distortion settings in detail. We also determine what "common information" should be placed in the cache, and what information should be transmitted during the delivery phase. To this end, two new common-information measures are introduced for caching, and their relationship to the common-information measures of Wyner, Gacs, and Korner is discussed in detail.

• 出版日期2018-3
• 单位TELECOM ParisTech