  This paper proposes a novel scheme for mitigating strong interferences, which
is applicable to various wireless scenarios, including full-duplex wireless
communications and uncoordinated heterogenous networks. As strong interferences
can saturate the receiver's analog-to-digital converters (ADC), they need to be
mitigated both before and after the ADCs, i.e., via hybrid processing. The key
idea of the proposed scheme, namely the Hybrid Interference Mitigation using
Analog Prewhitening (HIMAP), is to insert an M-input M-output analog phase
shifter network (PSN) between the receive antennas and the ADCs to spatially
prewhiten the interferences, which requires no signal information but only an
estimate of the covariance matrix. After interference mitigation by the PSN
prewhitener, the preamble can be synchronized, the signal channel response can
be estimated, and thus a minimum mean squared error (MMSE) beamformer can be
applied in the digital domain to further mitigate the residual interferences.
The simulation results verify that the HIMAP scheme can suppress interferences
80dB stronger than the signal by using off-the-shelf phase shifters (PS) of
6-bit resolution.
