Interference mitigation with rate splitting in multi-cell wireless networks

Cell-edge users inevitably experience strong interference from adjacent cells, and consequently suffer from performance degradation. Currently, Han-Kobayashi (HK) rate splitting scheme is viewed as the best strategy to cancel the interference and improve the performance. As a special superposition coding scheme, the HK rate splitting scheme has been shown to potentially achieve the channel capacity. However, the way from theory to practice is not straightforward. Current investigations adapting the HK rate splitting scheme to practical applications only deal with the strongest interference and treat the other interferences as noise. In general, more than one strong interferer usually exists, which is targeted in this work. By applying a multi-layer rate splitting scheme for more than one strong interferer, a new ordered detection is proposed and a power allocation algorithm is derived associated with the detection order. Simulation results show that the multi-layer rate splitting scheme mitigates the interference from two different interferers and provides more than twice the gain in terms of average throughput compared with a reference scheme with a fixed frequency reuse factor of 3 in a realistic wireless network.