Oblique Projection-Based Robust Linear Receiver for Spatial Multiplexing Systems with Unknown Cochannel Interference

In this paper, we propose an oblique projection-based robust linear receiver for spatial multiplexing systems in multi-cell environments. In our receiver design, we first obtain an oblique projection operator by using the received data, and then use such operator to extract the desired signal subspace and cancel the interference-plus-noise subspace from the received signals. After suppressing the unknown cochannel interference (CCI) included in the interference-plus-noise subspace, we further use zero-forcing (ZF) receiver to suppress the coantenna interference (CAI) and detect the desired transmitted symbols in the desired signal subspace. Finally, simulation results show that the proposed linear receiver obtains significant performance improvement over ZF receiver without considering the unknown CCI in the practical environments.