ADAPTIVE BLIND SIGNAL SEPARATION METHOD AND DEVICE THEREFOR

• Main Authors: OISHI KUNIO, SAITO SHINYA, FURUKAWA TOSHIHIRO
• Format: Patent
• Language: English; Japanese
• Published: 19.09.2019
• Subjects: ACOUSTICS; MUSICAL INSTRUMENTS; PHYSICS; SPEECH ANALYSIS OR SYNTHESIS; SPEECH OR AUDIO CODING OR DECODING; SPEECH OR VOICE PROCESSING; SPEECH RECOGNITION

To provide an adaptive blind signal separation method and a device therefor that estimate an unknown signal source signal with high accuracy without increasing the amount of calculation.SOLUTION: After short-time discrete Fourier transform of an observation signal multiplied by a window function, a mutual spectrum density matrix of the observation signal is determined at each epoch time, and an indirect/direct type least-squares evaluation amount obtained by restricting an evaluation section from the mutual spectrum density matrix of the observation signal, and then weighting with an oblivious coefficient is derived. A constraint condition is added to this evaluation amount such that a matrix condition number used for a mixed matrix and a diagonal matrix is minimized, and the least-squares type simultaneous diagonalization problem is efficiently solved even in a case where the observation signal number is restricted. Then, the evaluation section is restricted, and a correlation matrix between a power ratio of separation signals in frequency bins different from each other weighed with the oblivious coefficient is used for solving a permutation problem to estimate a permutation matrix, so that signal separation performance is improved adaptively.SELECTED DRAWING: Figure 1 【課題】演算量を増加させることなく、未知信号源信号を高い精度で推定する適応ブラインド信号分離方法とその装置を提供する。【解決手段】窓関数を乗算した観測信号の短時間離散フーリエ変換後、観測信号の相互スペクトル密度行列をエポック時刻毎に求め、観測信号の相互スペクトル密度行列から評価区間を制限した上、忘却係数で重み付けしたインダイレクト・ダイレクト型最小２乗評価量を導出する。この評価量に、混合行列及び対角行列に用いられる行列の条件数ができる限り小さくなるように制約条件を加え、観測信号数が制限されている場合においても最小２乗型同時対角化問題を能率的に解法する。次いで、評価区間を制限し、忘却係数で重み付けされた、相異なる周波数ビンにおける分離信号の電力比間の相関行列をパーミュテーション問題の解法に用いることによってパーミュテーション行列を推定し、適応的に信号分離性能を向上させる。【選択図】図１