Double-layered coordinated resource allocation in multi-cell MIMO-OFDMA systems

In this paper, we aim to formulate the coordinated beam-forming problem for a multi-cell MIMO-OFDMA system by an optimization method. The formulation has been done for downlink channel, using double layer pre-coder and post-coder matrices in both transmitter and receiver. We have proposed an iterative algorithm to find the proper beam-forming matrices in such a way that minimizes the mean square error (MMSE) in internal layer and maximizes the total system throughput in external layer. Our proposed algorithm guarantees the MMSE at each user in each subcarrier and also maximizes the sum rate of multi-cell system. The simulation results show that the proposed method leads to a greater throughput in comparison with conventional algorithms and provides substantial performance gains compared to single-cell optimization.