Adaptive heterogeneous interference coordination algorithm in uplink LTE-Advanced systems

The performance of heterogeneous networks is seriously decreased due to the uplink co-channel interference (CCI), especially the interference to low-power nodes which are located within the coverage of macrocells. In this paper, we take into consideration the application of spatial interference coordination (IC) technique to mitigate the uplink CCI from macrocell users to the picocell. The lower bound of average signal to interference plus noise ratio (SINR) in uplink transmission is developed as an analytical expression for the user of picocells applied with spatial IC. Furthermore, to determine the suitable coordination set, we propose two adaptive IC algorithms, which are based on the metrics of instantaneous SINR and the lower bound of average SINR, respectively. It is observed from the simulation results that the throughput of picocells is greatly enhanced by the proposed algorithms.