TD-LTE Carrier Aggregation performance with PUCCH format 1bcs and PUCCH format 3

Downlink Carrier Aggregation is a promising LTE-Advanced technology which is introduced in 3GPP LTE Release 10. Meanwhile, it introduces some challenges since more uplink control information needs to be fed backed from UE to eNB to enable the carrier aggregation. In this paper, we firstly introduce the CA feature in LTE-Advanced, and present the PUCCH format 1b with channel selection and PUCCH format 3 mechanisms. Secondly, different solutions in 3GPP to deal with the ambiguity issue within ACK/NACK/DTX are analyzed. Lastly, system simulation is performed to investigate the performance difference between these solutions.