Abstract
We consider the problem of cache-aided interference management in a network consisting of KT single-antenna transmitters and KR single-antenna receivers, where each node is equipped with a cache memory. Transmitters communicate with receivers over two heterogenous parallel subchannels: the P-subchannel for which transmitters have perfect instantaneous knowledge of the channel state, and the N-subchannel for which the transmitters have no knowledge of the instantaneous channel state. Under the assumptions of uncoded placement and separable one-shot linear delivery over the two subchannels, we characterize the optimal degrees-of-freedom (DoF) to within a constant multiplicative factor of 2. We extend the result to a decentralized setting in which no coordination is required for content placement at the receivers. In this case, we characterize the optimal one-shot linear DoF to within a factor of 3.
| Original language | English |
|---|---|
| Article number | 8936332 |
| Pages (from-to) | 1881-1896 |
| Number of pages | 16 |
| Journal | IEEE Transactions on Communications |
| Volume | 68 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Mar 2020 |
| Externally published | Yes |
Funding
Manuscript received June 21, 2019; revised November 6, 2019; accepted December 11, 2019. Date of publication December 18, 2019; date of current version March 18, 2020. This work was partially supported by the U.K. EPSRC under Grants EP/N015312/1 and EP/R511547/1. The associate editor coordinating the review of this article and approving it for publication was N. B. Mehta. (Corresponding author: Bruno Clerckx.) E. Piovano was with the Communications and Signal Processing Group, Department of Electrical and Electronic Engineering, Imperial College London, London SW7 2AZ, U.K. He is now with Amazon, 10117 Berlin, Germany (e-mail: [email protected]).
Keywords
- Coded caching
- hybrid CSIT
- linear degrees-of-freedom
- parallel channels
- wireless caching