Providing fair service in LTE-A heterogeneous networks through coordinated scheduling

We consider an LTE-A heterogeneous network involving a set of low-power remote radio heads (RRHs) connected to the macro BS through optical fibers. RRHs share the same cell ID with the macro BS such that coordinated multi-point (CoMP) operations can be performed in a finer granularity without triggering frequent handover operations. We first formulate an optimization problem for coordinated scheduling from multiple transmission points to a set of users demanding fair service. Since the problem incurs high complexity, we transform the formulation into an iterative scheduling problem for each scheduling time slot. To solve the non-linear binary integer problem, we propose an algorithm that relaxes the discrete variables into continuous variables while imposing proper penalty and smooth functions for minimizing the chance of the solution falling into local optimum. Simulation results show that the proposed algorithm can effectively solve the target problem with noticeable performance gain compared to related approaches.