Self-Interference Cancellation for Full-Duplex Massive MIMO OFDM With Single RF Chain

In this letter, the digital self-intereference (SI) canellation 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 compsenate 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 anlyzed. Simulation results show that the proposed optimal linear SI channel estimator significantly outperforms the conventional least square (LS) etimator in terms of the SI cancellation ability for the cases with strong SI and low oscillator quality.