  In this paper, the digital self-interference (SI) cancellation in a single
radio frequency (RF) chain massive multi-input multi-output (MIMO) full-duplex
(FD) orthogonal frequency division multiplexing (OFDM) system with phase noise
is studied. To compensate the phase noise, which introduces SI channel
estimation error and thus degrades the SI cancellation performance, a weighted
linear SI channel estimator is derived to minimize the residual SI power in
each OFDM symbol. The digital SI cancellation ability of the proposed method,
which is defined as the ratio of the SI power before and after the SI
cancellation, is analyzed. Simulation results show that the proposed optimal
linear SI channel estimator significantly outperforms the conventional least
square (LS) estimator in terms of the SI cancellation ability for the cases
with strong SI and low oscillator quality.
