| 摘要 |
A microphone array method and system for increasing speech recognition performance in an environment such as an indoor environment where an echo occurs, and a speech recognition method and system using the same are provided. The microphone array system includes an input unit which receives sound signals using a plurality of microphones, a frequency splitter which splits each sound signal received through the input unit into a plurality of narrowband signals, an average spatial covariance matrix estimator which uses spatial smoothing, by which spatial covariance matrixes for a plurality of virtual sub-arrays, which are configured in the plurality of microphones comprised in the input unit, are obtained with respect to each frequency component of the sound signal processed by the frequency splitter and then an average spatial covariance matrix is calculated, to obtain a spatial covariance matrix for each frequency component of the sound signal, a signal source location detector which detects an incidence angle of the sound signal based on the average spatial covariance matrix calculated using the spatial smoothing, a signal distortion compensator which calculates a weight for each of frequency components of the sound signal based on the incidence angle of the sound signal and multiplies the weight by each frequency component, thereby compensating for distortion of each frequency component, and a signal restoring unit which restores a sound signal using distortion compensated frequency. The signal source location detector splits each sound signal received from the input unit into the frequency components, into which the frequency splitter splits the sound signal, and performs a multiple signal classification (MUSIC) algorithm only with respect to frequency components selected according to a predetermined reference from among the split frequency components, thereby determining the incidence angle of the sound signal.
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