Experimental Studies on Direction Finding Via Blind Beamforming

Blind beamforming algorithms have the ability to recover the desired signals from array outputs without any prior knowledge of the array geometry. After blind separation of the signals, the DOAs can be estimated for each source individually. In this paper, the performance of the multistage constant modulus (CM) array, one of the most striking blind beamforming algorithms, for the source DOA estimation was analyzed via water tank experiments, and was compared to that of other DOA estimation algorithms including the 'non-blind' and the 'blind' algorithms. Results of water tank experiments showed that the multistage CM array can not only blindly recover the independent signal, but also correctly estimate the DOAs. The angle separating ability of the CM array was beyond the Rayleigh resolution limit.