Coordinated Scheduling in Downlink Multi-Cell OFDMA Networks

In this paper, we propose a coordinated scheduling scheme in downlink multi-cell Orthogonal Frequency Division Multiplexing Access (OFDMA) networks. Firstly, a novel decision tree algorithm is introduced to categorize users according to certain attribute parameters to improve system performance. To suppress inter-cluster interference, a filter is used at the receive. To mitigate intra-cluster interference and enhance system performance, we jointly form precoding matrix (using Block Diagonalization precoding) and distribute power for coordinative users. Considering the fact that there is a constraint on number of coordinative users simultaneously served on one resource slot and there may be a large number of users needing coordinative transmission, it is necessary to allocate proper resource slots to them, seeking a tradeoff between coordinative user sum rate and system total capacity. Thus, a performance-based slot distribution is utilized. What needs to be pointed out is that our power control is a per BS power constraint. Simulation results show that our proposed scheme can significantly improve the performance of multi-cell networks.