  This letter focuses on integrating rate-splitting multiple-access (RSMA) with
time-division-duplex Cell-free Massive MIMO (multiple-input multiple-output)
for massive machine-type communications. Due to the large number of devices,
their sporadic access behaviour and limited coherence interval, we assume a
random access strategy with all active devices utilizing the same pilot for
uplink channel estimation. This gives rise to a highly pilot-contaminated
scenario, which inevitably deteriorates channel estimates. Motivated by the
robustness of RSMA towards imperfect channel state information, we propose a
novel RSMA-assisted downlink transmission framework for cell-free massive MIMO.
On the basis of the downlink achievable spectral efficiency of the common and
private streams, we devise a heuristic common precoder design and propose a
novel max-min power control method for the proposed RSMA-assisted scheme.
Numerical results show that RSMA effectively mitigates the effect of pilot
contamination in the downlink and achieves a significant performance gain over
a conventional cell-free massive MIMO network.
