Résumé : Massive antenna technologies provide a good power focusing gain for emerging communication systems. They can easily be integrated into an orthogonal frequency-division multiplexing (OFDM) system. However, OFDM is known to be prone to carrier frequency offset (CFO) due to the loss of the orthogonality among OFDM subcarriers. In this Letter, the authors investigate the impact of residual CFO (RCFO) on the downlink performance of massive multiple-input single-output (MISO) OFDM systems using matched-filter (MF) and maximum-ratio-transmission (MRT) precoders. Particularly, the exact mean-square-error (MSE) expressions of the equalised received signal of both MF and MRT systems are derived. Numerical simulations with Rayleigh fading channels are carried out to validate the analysis. The results show that the RCFO causes a MSE plateau compared to the ideal case of no CFO.