Robust chance-constrained distributed beamforming for multicell interference networks

Abstract

We propose a robust coordinated game theoretic
approach that distributively minimizes the aggregate downlink
transmit power in a multicell interference network in the presence
of imperfect channel state information (CSI). The optimization
is constrained to satisfying the signal-to-interferenceplus-
noise-ratio (SINR) requirements at individual user terminals
within certain predefined SINR outage probabilities. This
problem is numerically intractable due to the cross-link coupling
effect among a cluster of base stations (BSs) as well as the
robust constraints that involve the second order statistical CSI
estimation error. By employing cumulative distribution function
of standard normal distribution, Lemma 2 and semidefinite
relaxation technique, we first convert the original problem to
a linear matrix inequality form. Then, we introduce an iterative
subgradient algorithm that decomposes the multicell-wise general
problem into a set of parallel subproblems at individual BSs to
find the global optimality. We show that the proposed design coordinates
intercell interference among the BSs with a light inter-
BS communication overhead. Simulation results demonstrate the
advantages of the proposed chance-constrained distributed design
in terms of power efficiency and achievable robustness trade-off.