Efficient frequency-domain realization of robust generalized, sidelobe cancellers

Robust Adaptive Beamforming Algorithm using Instantaneous Direction of Arrival with Enhanced Noise Suppression Capability

“…With the spatial probability P (k) we have a direct control over the maximum allowable DOA error. Unlike the previous RGSCs [2,3], we do not have to impose ad hoc constraints on the ABM filter coefficients, which indirectly affect the maximum target direction error. The speech presence probability P1 (k) in the k-th frequency bin, which is the second term in the right-…”

“…We can also impose norm-constraints on the AIC coefficients as the other RGSCs [2,3,4], but as long as the probability estimator works properly, these constraints are usually not necessary.…”

“…In order to avoid target signal cancellation, a number of methods have been proposed to make the whole system more robust to steering vector errors [2,3,4]. The robust GSC (RGSC) proposed in [2] uses an adaptive blocking matrix (ABM) with coefficient-constrained adaptive filters, which prevents the target signal from leaking into the adaptive interference canceller (AIC).…”

“…This adaptive beamformer is robust to DOA errors without significant degradation in the interference rejection capability. In [3], a similar RGSC has been implemented in frequency-domain, with a comparable performance at a lower computational cost.…”

“…Although these RGSCs [2,3] are good at rejecting directional interference signals (such as "jammer" signals), their noise suppression capability is not satisfactory under the conditions of practically isotropic ambient noise, therefore these algorithms are not quite suitable for noisy environments such as the automotive environment.…”