Downlink Reference-Signal for Carrier Aggregation with Reduced Cubic Metric in LTE-Advanced

Carrier aggregation (CA) has been considered to meet LTE-Advanced (LTE-A) requirements of wider bandwidth up to 100 MHz and maintain backwards compatibility with LTE Release 8 (Rel-8) simultaneously. High cubic metric (CM) values and Peak-to-Average Power Ratio (PAPR) of aggregated component carriers (CCs) have appeared to be a crucial issue needing to be solved for both uplink and downlink (DL) transmission. Distinct cell ID per DL CC can mitigate this problem but will cause some other issues on the corresponding uplink carrier. In this paper, we propose an approach by introducing a variable of component carrier ID to change the initialization method of cell-specific DL RS sequence generator to solve the high DL CM/ PAPR problem. Simulation results show the performance improvements and prove the effectivity of our proposed approach.