171 / 2019-12-15 16:13:00

Hybrid Interference Mitigation Using Analog Prewhitening

interference mitigation; full-duplex wireless; phase shifter network

Strong interferences occur in several wireless scenarios, such as full-duplex wireless communications and heterogenous networks in unlicensed spectrum. Because strong interferences can cause excessive quantization noise in the receiver's analog-to-digital converters (ADC), mitigation of strong interferences via hybrid - both analog and digital - processing has been actively researched in recent years. In this paper, we propose to use an M-input M-output analog phase shifter
network (PSN) between the receiving antennas and the ADCs to prewhiten spatially the interferences (plus signal and noise). This scheme, referred to as the Hybrid Interference Mitigation using Analog Prewhitening (HIMAP), requires no knowledge about the interferences except the spatial covariance matrix. Before the ADCs, the HIMAP scheme suppresses the interferences by optimizing the coefficients of the PSN; after the ADCs, the HIMAP suppresses the residual interferences by employing
digital minimum mean squared error (MMSE) beamforming. The simulation results verify the effectiveness of the HIMAP scheme.