Technique combining multiple component carriers to increase bandwidth and throughput.
Description
Carrier Aggregation (CA) is a key feature of LTE-Advanced that allows combining multiple component carriers (CCs) to increase the transmission bandwidth and thereby achieve higher data rates.
Each component carrier can have bandwidth of 1.4, 3, 5, 10, 15, or 20 MHz, and up to 5 carriers can be aggregated (up to 100 MHz total in Rel-10). The aggregated carriers can be in the same band (intra-band) or different bands (inter-band), and contiguous or non-contiguous.
CA enables flexible spectrum utilization, allowing operators to combine fragmented spectrum holdings for maximum efficiency.
Purpose & Motivation
Carrier Aggregation was introduced to:
- Achieve IMT-Advanced peak data rate requirements (1 Gbps DL, 500 Mbps UL) - Enable flexible use of fragmented operator spectrum - Provide backward compatibility with Rel-8 UEs on individual carriers - Support heterogeneous network deployments with different carriers
Key Features
- ✓Up to 5 component carriers (Rel-10)
- ✓Intra-band and inter-band aggregation
- ✓Contiguous and non-contiguous
- ✓Primary Cell (PCell) and Secondary Cells (SCells)
- ✓Cross-carrier scheduling
- ✓Independent HARQ per carrier