Enhanced Frequency Diversity Exploitation in Carrier Aggregation for LTE-Advanced Systems

LTE-Advanced systems have adopted the concept of Carrier Aggregation (CA) to meet the data rate requirements of IMT-Advanced systems. The CA approach opens up several new implementation challenges as well as opportunities for further performance improvement. Existing works on CA focus on implementation issues, but exploitation of CA-specific features for performance improvement has not been addressed yet. In this paper, we fill this gap and investigate the enhanced frequency diversity exploitation in CA based systems. New interleaving schemes for both downlink OFDMA and uplink SC-FDMA of LTE-Advanced systems are proposed to capture CA-specific enhanced frequency diversity with simple implementation. The proposed schemes also provide full backward compatibility with the LTE system. Performance evaluation via simulation in a simplified LTE system environment corroborates that the proposed approach provides performance advantages in both downlink and uplink.