  In this paper, we develop novel two-tier interference management strategies
that enable macrocell users (MUEs) to improve their performance, with the help
of open-access femtocells. To this end, we propose a rate-splitting technique
using which the MUEs optimize their uplink transmissions by dividing their
signals into two types: a coarse message that is intended for direct
transmission to the macrocell base station and a fine message that is decoded
by a neighboring femtocell and subsequently relayed over a heterogeneous
(wireless/wired) backhaul. For deploying the proposed technique, we formulate a
non-cooperative game between the MUEs in which each MUE can decide on its
relaying femtocell while maximizing a utility function that captures both the
achieved throughput and the expected backhaul delay. Simulation results show
that the proposed approach yields up to 125% rate improvement and up to 2 times
delay reduction with wired backhaul and, 150% rate improvement and up to 10
times delay reduction with wireless backhaul, relative to classical
interference management approaches, with no cross-tier cooperation.
