  We propose a tunable location-dependent base station (BS) cooperation scheme
by partitioning the plane into three regions: the cell centers, cell edges and
cell corners. The area fraction of each region is tuned by the cooperation
level $\gamma$ ranging from 0 to 1. Depending on the region a user resides in,
he/she receives no cooperation, two-BS cooperation or three-BS cooperation.
Here, we use a Poisson point process (PPP) to model BS locations and study a
non-coherent joint transmission scheme, $\textit{i.e.}$, selected BSs jointly
serve one user in the absence of channel state information (CSI). For the
proposed scheme, we examine its performance as a function of the cooperation
level using tools from stochastic geometry. We derive an analytical expression
for the signal-to-interference ratio (SIR) distribution and its approximation
based on the asymptotic SIR gain, along with the characterization of the
normalized spectral efficiency per BS. Our result suggests that the proposed
scheme with a moderate cooperation level can improve the SIR performance while
maintaining the normalized spectral efficiency.
