Uplink Power Allocation for RSMA-aided User-centric Cell-free Massive MIMO Systems

This paper tackles the problem of maximizing the minimum spectral efficiency (SE) via allocation of the uplink optimal transmission power in a rate splitting multiple access (RSMA)-aided user-centric (UC) cell-free (CF) massive MIMO (mMIMO) system. It is shown that the optimization problem is non-convex. The problem is then transformed into a second-order cone programming problem which is solved iteratively by leveraging the bisection method. Numerical results demonstrate the effectiveness of the RSMA technique to improve the 95%-likely SE gain by up to 332% compared to a UC CF mMIMO system with no power control.