Robust DWMMSE Framework for Energy-Efficient Relay-Assisted Carrier Aggregation (RACA) in ...

Extended Reality (XR) applications demanding high data rates pose significant challenges for uplink transmissions from user equipment (UE) with limited power and antenna resources. Recently, relay-assisted carrier aggregation (RACA) systems have been proposed to enhance data rates by transmitting data across two frequency bands. This paper addresses the practical issues of power-constrained XR devices and imperfect channel state information (CSI) in RACA systems. We propose a robust Dinkelbach’s-transformed weighted minimum mean square error (DWMMSE) framework to maximize energy efficiency (EE) and minimize mean square error (MSE) under Gaussian CSI errors. The framework adapts to content-intensive, power-constrained, and reliability-critical XR scenarios through specific alternating optimization settings. Simulation results demonstrate that DWMMSE achieves superior EE with a 92% reduction in complexity compared to baseline methods. Moreover, it delivers lower MSE and bit error rate (BER) than non-robust schemes.

Robust DWMMSE Framework for Energy-Efficient Relay-Assisted Carrier Aggregation (RACA) in Power-Constrained XR Systems

Chi-Wei Chen, National Taiwan University