Carrier aggregation for LTE-advanced: functionality and performance aspects

TLDR

Carrier aggregation is a key LTE‑Advanced feature that enables users to access up to 100 MHz of bandwidth, either contiguous or composed of multiple non‑contiguous chunks, to satisfy IMT‑Advanced requirements. The paper aims to summarize supported CA scenarios and demonstrate its use as an enabler for frequency‑domain interference management in LTE‑Advanced. It describes the CA architecture, defining primary and secondary cells, their activation/deactivation procedures, and cross‑cell scheduling for improved control‑channel optimization. Interference management via CA is expected to yield significant gains in heterogeneous networks with uncoordinated home base stations.

Abstract

Carrier aggregation (CA) is one of the key features for LTE-Advanced. By means of CA, users gain access to a total bandwidth of up to 100 MHz in order to meet the IMT-Advanced requirements. The system bandwidth may be contiguous, or composed of several non-contiguous bandwidth chunks, which are aggregated. This paper presents a summary of the supported CA scenarios as well as an overview of the CA functionality for LTE-Advanced with special emphasis on the basic concept, control mechanisms, and performance aspects. The discussion includes definitions of the new terms primary cell (PCell) and secondary cell (SCell), mechanisms for activation and deactivation of CCs, and the new cross-CC scheduling functionality for improved control channel optimizations. We also demonstrate how CA can be used as an enabler for simple yet effective frequency domain interference management schemes. In particular, interference management is anticipated to provide significant gains in heterogeneous networks, envisioning intrinsically uncoordinated deployments of home base stations.