Collaborative spatial-frequency filter based on oblique projection

Interference suppression is a main problem to be solved in both radar and wireless communication systems. To minimize the impact of interference, a number of signal processing techniques, such as adaptive beamforming and frequency filtering, have been developed. However, the performance of these conventional methods degrades a lot when the target and interferences have similar parameters. In this paper, a collaborative spatial-frequency filer (CSFF) is proposed. Such CSFF is constructed with oblique projection operators to suppress the interferences and extract the target signals while keeping its amplitude and phase unchanged. Theoretical analysis and simulation results demonstrate that the CSFF performs better than spatial filtering. Moreover, there is no requirement to increase the number of antenna elements, which increases the application scope of CSFF.