Multi-antenna coded content delivery with caching: a low-complexity solution
File(s)
Accepted version
Author(s)
Zhao, Junlin
Mohammadi Amiri, Mohammadi
Gunduz, Deniz
Type
Journal Article
Abstract
We study downlink beamforming in a single-cell
network with a multi-antenna base station serving cache-enabled
users. Assuming a library of files with a common rate, we formulate the minimum transmit power with proactive caching and
coded delivery as a non-convex optimization problem. While this
multiple multicast problem can be efficiently solved by successive
convex approximation (SCA), the complexity of the problem
grows exponentially with the number of subfiles delivered to
each user in each time slot, which itself grows exponentially with
the number of users. We introduce a low-complexity alternative
through time-sharing that limits the number of subfiles received
by a user in each time slot. We then consider the joint design of
beamforming and content delivery with sparsity constraints to
limit the number of subfiles received by a user in each time slot.
Numerical simulations show that the low-complexity scheme has
only a small performance gap to that obtained by solving the joint
problem with sparsity constraints, and outperforms state-of-theart results at all signal-to-noise ratio (SNR) and rate values with
a sufficient number of transmit antennas. A lower bound on
the achievable degrees-of-freedom (DoF) of the low-complexity
scheme is derived to characterize its performance in the high
SNR regime.
network with a multi-antenna base station serving cache-enabled
users. Assuming a library of files with a common rate, we formulate the minimum transmit power with proactive caching and
coded delivery as a non-convex optimization problem. While this
multiple multicast problem can be efficiently solved by successive
convex approximation (SCA), the complexity of the problem
grows exponentially with the number of subfiles delivered to
each user in each time slot, which itself grows exponentially with
the number of users. We introduce a low-complexity alternative
through time-sharing that limits the number of subfiles received
by a user in each time slot. We then consider the joint design of
beamforming and content delivery with sparsity constraints to
limit the number of subfiles received by a user in each time slot.
Numerical simulations show that the low-complexity scheme has
only a small performance gap to that obtained by solving the joint
problem with sparsity constraints, and outperforms state-of-theart results at all signal-to-noise ratio (SNR) and rate values with
a sufficient number of transmit antennas. A lower bound on
the achievable degrees-of-freedom (DoF) of the low-complexity
scheme is derived to characterize its performance in the high
SNR regime.
Date Issued
2020-08-03
Date Acceptance
2020-07-11
Citation
IEEE Transactions on Wireless Communications, 2020, 19 (11), pp.7484-7497
ISSN
1536-1276
Publisher
Institute of Electrical and Electronics Engineers
Start Page
7484
End Page
7497
Journal / Book Title
IEEE Transactions on Wireless Communications
Volume
19
Issue
11
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Commission of the European Communities
Commission of the European Communities
Identifier
https://ieeexplore.ieee.org/document/9154573
Grant Number
677854
675891
Subjects
Networking & Telecommunications
0805 Distributed Computing
0906 Electrical and Electronic Engineering
1005 Communications Technologies
Publication Status
Published
Date Publish Online
2020-08-03