Closed-Form Capacity Bounds for Downlink and Uplink Decoupling

Downlink (DL) and uplink (UL) decoupling (DUDe)
is a new architectural paradigm where DL and UL are not
constrained to be associated to the same base station (BS). Thus,
a user having access to multiple BSs within a dense cellular
network can receive the DL traffic from one BS and send its
UL traffic through another. Building upon this architectural
paradigm, the present paper provides tight analytical bounds
in closed form for the UL ergodic capacity that depend solely
on the density of the infrastructure. The devised bounds account
for the backbone network congestion and the synchronization of
the acknowledgments of the decoupled channels. The proposed
bounds are compared against extensive numerical simulations
demonstrating the tractability and accuracy of the expressions.
Index Terms—Downlink uplink decoupling; ergodic capacity;
bound; network density; acknowledgment synchronization.