Carrier aggregation for LTE-advanced: design challenges of terminals

Carrier aggregation is a key feature of 3GPP LTE that addresses the support of higher data rates and utilization of fragmented spectrum holdings. In this article, the relevant design challenges of terminals are discussed. The transmitter architectures are reviewed, and the minimum amount of power amplifier back-offs is evaluated. In addition, several receiver architectures are compared from the perspective of design tradeoff. The radio impairments affecting the receiver performance are analyzed and the simulation results are provided. The corresponding silicon implementation is presented together with the measurement results.