  Performance of multicell systems is inevitably limited by interference and
available resources. Although intercell interference can be mitigated by Base
Station (BS) Coordination, the demand on inter-BS information exchange and
computational complexity grows rapidly with the number of cells, subcarriers,
and users. On the other hand, some of the existing coordination beamforming
methods need computation of pseudo-inverse or generalized eigenvector of a
matrix, which are practically difficult to implement in a real system. To
handle these issues, we propose a novel linear beamforming across a set of
coordinated cells only with limiting backhaul signalling. Resource allocation
(i.e. precoding and power control) is formulated as an optimization problem
with objective function of signal-to-interference-plus-noise ratios (SINRs) in
order to maximize the instantaneous weighted sum-rate subject to power
constraints. Although the primal problem is nonconvex and difficult to be
optimally solved, an iterative algorithm is presented based on the
Karush-Kuhn-Tucker (KKT) condition. To have a practical solution with low
computational complexity and signalling overhead, we present CB-REFIM
(coordination beamforming-reference based interference management) and show the
recently proposed REFIM algorithm can be interpreted as a special case of
CB-REFIM. We evaluate CB-REFIM through extensive simulation and observe that
the proposed strategies achieve close-to-optimal performance.
