  In this paper, the potential benefits of applying the Rate-Splitting Multiple
Access (RSMA) in multi-cell dense networks are explored. Using tools of
stochastic geometry, the sum-rate of RSMA-enhanced multi-cell dense networks is
evaluated mathematically based on a Moment Generating Function (MGF) based
framework to prove that RSMA is a general and powerful strategy for
multi-antenna downlink systems. Further elaboration of the systematic
performance metrics is undertaken by developing analytical expressions for area
spectral efficiency and sum-rate in the RSMA-enhanced multi-cell dense
networks. Based on the tractable expressions, we then offer an optimization
framework for energy efficiency in terms of the number of antennas.
Additionally, simulation results are shown to verify the accuracy of our
analytical results and provide some insightful insights into system design.
Analytically, it has been shown that: 1) the sum-rate of RSMA-enhanced
multi-cell dense networks is significantly influenced by the power splitting
ratio, and there is a unique value that maximizes the sum-rate; 2) the
RSMA-enhanced multi-cell dense networks transmission scheme has superior
sum-rate performance compared with Non-Orthogonal Multiple Access (NOMA) and
Space-Division Multiple Access (SDMA) in a wide range of power splitting ratio;
3) By increasing the number of antennas and BS density in an RSMA-enhanced
multi-cell dense network, the area spectral efficiency can be substantially
enhanced; 4) As for energy efficiency, there exists an optimal antenna number
for maximizing this performance metric.
