TY - JOUR
T1 - Cache-Aided K-User Broadcast Channels With State Information at Receivers
AU - Reisizadeh, Hadi
AU - Maddah-Ali, Mohammad Ali
AU - Mohajer, Soheil
N1 - Publisher Copyright:
© 1963-2012 IEEE.
PY - 2024/4/1
Y1 - 2024/4/1
N2 - We study a K-user coded-caching broadcast problem in a joint source-channel coding framework. The transmitter observes a database of files that are being generated at a certain rate per channel use, and each user has a cache, which can store a fixed fraction of the generated symbols. In the delivery phase, the transmitter broadcasts a message so that the users can decode their desired files using the received signal and their cache content. The communication between the transmitter and the receivers happens over a (deterministic) time-varying erasure broadcast channel, and the channel state information is only available to the users. We characterize the maximum achievable source rate for the 2-user and the degraded K-user problems. We provide an upper bound for any caching strategy's achievable source rates. Finally, we present a linear programming formulation to show that the upper bound is not a sharp characterization. Closing the gap between the achievable rate and the optimum rate remains open.
AB - We study a K-user coded-caching broadcast problem in a joint source-channel coding framework. The transmitter observes a database of files that are being generated at a certain rate per channel use, and each user has a cache, which can store a fixed fraction of the generated symbols. In the delivery phase, the transmitter broadcasts a message so that the users can decode their desired files using the received signal and their cache content. The communication between the transmitter and the receivers happens over a (deterministic) time-varying erasure broadcast channel, and the channel state information is only available to the users. We characterize the maximum achievable source rate for the 2-user and the degraded K-user problems. We provide an upper bound for any caching strategy's achievable source rates. Finally, we present a linear programming formulation to show that the upper bound is not a sharp characterization. Closing the gap between the achievable rate and the optimum rate remains open.
KW - Coded caching
KW - broadcast channel
KW - joint source-channel coding
KW - wireless networks
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U2 - 10.1109/TIT.2023.3322897
DO - 10.1109/TIT.2023.3322897
M3 - Article
AN - SCOPUS:85174849515
SN - 0018-9448
VL - 70
SP - 2518
EP - 2537
JO - IEEE Transactions on Information Theory
JF - IEEE Transactions on Information Theory
IS - 4
ER -