Enhanced Uplink Carrier Aggregation for LTE-Advanced Femtocells

In this paper we investigate uplink carrier aggregation in the context of dense residential deployments of LTE-Advanced Femtocells. Previous work in the literature based on macro-cells suggested considering UE power limitations to infer which UEs should be allowed to employ multiple component carriers. However, due to the very small radius of femtocells, UEs are not expected to become power-limited at all. We propose a decentralized scheme with limited signalling requirements that incorporates power control information, not only to guide the UE-specific carrier selection procedure, but also to capitalize on the inherent power spectral density and path loss differences in order to minimize inter-cell interference. We present a series of system level simulation results which provide strong evidence that our scheme delivers substantial gains in terms of coverage compared to existing solutions without sacrificing the SINR.