Multi-user resource allocation for Downlink Control Channel in LTE systems

The Physical Downlink Control Channel (PDCCH) is used to signal dynamic resource assignment information in the Long Term Evolution (LTE) system. In the presence of numerous active users, the system performance is likely to be hindered by shortage of control channel resource. In this paper, several simple algorithms are brought forward for making efficient PDCCH resource allocation. We first propose a minimum aggregation level algorithm (Min-AL) to maximize the total number of scheduled users by exploiting multi-user diversity gain, followed by algorithms with the purpose of improving the blocking performance of cell-edge area through co-channel interference avoidance (CCI-A) and priority boosting (PB). Simulation results have shown that the Min-AL algorithm achieves the best system performance at the expense of cell-edge performance, while both CCI-A and PB algorithms are effective in reaching a compromise between system and cell-edge performance.