Enhanced inter-cell carrier aggregation with spread spectrum technique for next generation mobile systems

In next generation mobile communication systems, the cell size reduction is unavoidable due to the transmission power limitation at user equipments (UEs). The small cell size accelerates traffic non-uniformity between cells, and this situation brings non-uniform transmission performance between cells across the system. The inter-cell carrier aggregation (CA) technique, which aggregates multiple component carriers (CCs) provided by both serving and its adjacent cells, has been proposed to overcome non-uniform traffic problem, and this scheme provides some capability of mitigating the non-uniform transmission performance. However, the mitigation of the non-uniform transmission performance is limited even when introducing the inter-cell CA. In this paper, an enhanced inter-cell CA scheme using variable spreading factor spread spectrum transmission is proposed to further mitigate non-uniform transmission performance between cells, and also improve user throughput performance. The computer simulation results demonstrate the effectiveness of the proposed scheme under non-uniform traffic environments.