Rate-Splitting Assisted Cell-Free Massive MIMO Systems with Channel Aging and Pilot Contamination

In this paper, the downlink spectral efficiency of rate-splitting (RS) assisted cell-free massive multiple-input-multiple-output (mMIMO) system is analyzed. Considering im-perfect CSI due to channel aging and pilot contamination, closed-form spectral efficiency expressions are derived for the common and private streams. By comparison, we show that rate-splitting multiple access (RSMA) is superior to conventional space division multiple access (SDMA). Numerical results show that the closed-form expressions are exact with the Monte Carlo simulations.