Patent ID: 11922966
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 2:
3. A signal separation method that is executed by a signal separation device for acquiring a source signal from a mixed signal observed by a plurality of sensors,
the signal separation device including a database that stores feature information of a clean signal, said feature information being a power spectrum for each discrete time of the clean signal, said power spectrum being obtained by converting a signal for each discrete time of the clean signal to be stored in the database into a time-frequency representation and calculating a square of the time-frequency representation, the method comprising:
a separation matrix calculation step of repeatedly performing, until a termination condition is met, processes of, based on a separated signal obtained by multiplication of a mixed signal converted into a time-frequency representation by a separation matrix and on the feature information stored in the database, calculating a parameter to be used for an objective function representing a negative log likelihood for optimizing the separation matrix, and calculating a separation matrix for minimizing the objective function using the parameter, said termination condition being at least of one of a first condition that a number of repetition of the processes reaches a predetermined value, and a second condition that the separation matrix converges; and
an output step of outputting a separated signal calculated using the optimized separation matrix obtained by a separation matrix calculator.