1,030 research outputs found
Multi-Antenna Coded Caching
In this paper we consider a single-cell downlink scenario where a
multiple-antenna base station delivers contents to multiple cache-enabled user
terminals. Based on the multicasting opportunities provided by the so-called
Coded Caching technique, we investigate three delivery approaches. Our baseline
scheme employs the coded caching technique on top of max-min fair multicasting.
The second one consists of a joint design of Zero-Forcing (ZF) and coded
caching, where the coded chunks are formed in the signal domain (complex
field). The third scheme is similar to the second one with the difference that
the coded chunks are formed in the data domain (finite field). We derive
closed-form rate expressions where our results suggest that the latter two
schemes surpass the first one in terms of Degrees of Freedom (DoF). However, at
the intermediate SNR regime forming coded chunks in the signal domain results
in power loss, and will deteriorate throughput of the second scheme. The main
message of our paper is that the schemes performing well in terms of DoF may
not be directly appropriate for intermediate SNR regimes, and modified schemes
should be employed.Comment: 7 pages, 2 figure
Multi-Antenna Coded Caching for Multi-Access Networks with Cyclic Wrap-Around
This work explores a multiple transmit antenna setting in a multi-access
coded caching (MACC) network where each user accesses more than one cache. A
MACC network has users and caches, and each user has access to
consecutive caches in a cyclic wrap-around manner. There are antennas at
the server, and each cache has a normalized size of . The cyclic
wrap-around MACC network with a single antenna at the server has been a
well-investigated topic, and several coded caching schemes and improved lower
bounds on the performance are known for the same. However, this MACC network
has not yet been studied under multi-antenna settings in the coded caching
literature. We study the multi-antenna MACC problem and propose a solution for
the same by constructing a pair of arrays called caching and delivery arrays.
We present three constructions of caching and delivery arrays for different
scenarios and obtain corresponding multi-antenna MACC schemes for the same. Two
schemes resulting from the above constructions achieve optimal performance
under uncoded placement and one-shot delivery. The optimality is shown by
matching the performance of the multi-antenna MACC scheme to that of an optimal
multi-antenna scheme for a dedicated cache network having an identical number
of users, and each user has a normalized cache size of . Further, as a
special case, one of the proposed schemes subsumes an existing optimal MACC
scheme for the single-antenna setting.Comment: 11 pages (double column), 3 Figure
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