6,159 research outputs found
Finite automata for caching in matrix product algorithms
A diagram is introduced for visualizing matrix product states which makes
transparent a connection between matrix product factorizations of states and
operators, and complex weighted finite state automata. It is then shown how one
can proceed in the opposite direction: writing an automaton that ``generates''
an operator gives one an immediate matrix product factorization of it. Matrix
product factorizations have the advantage of reducing the cost of computing
expectation values by facilitating caching of intermediate calculations. Thus
our connection to complex weighted finite state automata yields insight into
what allows for efficient caching in matrix product algorithms. Finally, these
techniques are generalized to the case of multiple dimensions.Comment: 18 pages, 19 figures, LaTeX; numerous improvements have been made to
the manuscript in response to referee feedbac
Optimal Error Correcting Delivery Scheme for Coded Caching with Symmetric Batch Prefetching
Coded caching is used to reduce network congestion during peak hours. A
single server is connected to a set of users through a bottleneck link, which
generally is assumed to be error-free. During non-peak hours, all the users
have full access to the files and they fill their local cache with portions of
the files available. During delivery phase, each user requests a file and the
server delivers coded transmissions to meet the demands taking into
consideration their cache contents. In this paper we assume that the shared
link is error prone. A new delivery scheme is required to meet the demands of
each user even after receiving finite number of transmissions in error. We
characterize the minimum average rate and minimum peak rate for this problem.
We find closed form expressions of these rates for a particular caching scheme
namely \textit{symmetric batch prefetching}. We also propose an optimal error
correcting delivery scheme for coded caching problem with symmetric batch
prefetching.Comment: 9 pages and 4 figure
Optimizing MDS Codes for Caching at the Edge
In this paper we investigate the problem of optimal MDS-encoded cache
placement at the wireless edge to minimize the backhaul rate in heterogeneous
networks. We derive the backhaul rate performance of any caching scheme based
on file splitting and MDS encoding and we formulate the optimal caching scheme
as a convex optimization problem. We then thoroughly investigate the
performance of this optimal scheme for an important heterogeneous network
scenario. We compare it to several other caching strategies and we analyze the
influence of the system parameters, such as the popularity and size of the
library files and the capabilities of the small-cell base stations, on the
overall performance of our optimal caching strategy. Our results show that the
careful placement of MDS-encoded content in caches at the wireless edge leads
to a significant decrease of the load of the network backhaul and hence to a
considerable performance enhancement of the network.Comment: to appear in Globecom 201
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