To meet long term evolution-advanced (LTE-A) requirements of wider bandwidth and maintain backwards compatibility with LTE release 8 (Rel-8) simultaneously, carrier aggregation has been agreed by the third generation partnership project (3GPP).High cubic metric (CM) values and peak-to-average power ratio (PAPR) of aggregated component carriers (CCs) exists as an unpleasant issue for both uplink and downlink (DL) transmission. For DL transmission, to use distinct cell ID per DL CC to generate DL reference signal (RS) sequence can mitigate this problem but will cause some other issues on the corresponding uplink carrier. This article proposes two approaches to solve the problem of high CM/PAPR by introducing new variables to change the cell-specific DL RS sequence. In both methods, same cell identifier (cell ID) is allocated to all DL CCs. Simulation results show the performance improvements and prove the effectivity of our proposed approaches.