  In this letter, we investigate the downlink performance of massive
multiple-input multiple-output (MIMO) systems where the base station is
equipped with one-bit analogto-digital/digital-to-analog converters (ADC/DACs).
Considering training-based transmission, we assume the base station (BS)
employs the linear minimum mean-squared-error (LMMSE) channel estimator and
treats the channel estimate as the true channel to precode the data symbols. We
derive an expression for the downlink achievable rate for matched-filter (MF)
precoding. A detailed analysis of the resulting power efficiency is pursued
using our expression of the achievable rate. Numerical results are presented to
verify our analysis. In particular it is shown that, compared with conventional
massive MIMO systems, the performance loss in one-bit massive MIMO systems can
be compensated for by deploying approximately 2.5 times more antennas at the
BS.
