A new generalized sidelobe canceller with a compact array of microphones suitable for mobile terminals

Abstract

This paper proposes a new generalized sidelobe canceller with a compact array of microphones suitable for mobile terminals. The output of the fixed beamformer (FBF) is further processed by a newly introduced decorrelation unit which has an auxiliary input signal to improve poor interference suppression of FBF in low frequencies. The output of the decorrelation unit is used as the reference signal for the adaptive blocking matrix and the input for the multi-input canceller. Because low and high frequency components are cancelled or suppressed by the decorrelation unit and FBF, better output-signal quality is obtained. Output signal comparison confirms approximately 12 dB higher interference cancellation by the new beamformer.