Apparatus and method for simultaneous estimation of transfer characteristics of multiple linear transmission paths
AssigneeNippon Telegraph and Telephone Corporation
InventorsSatoru Emura, Masato Miyoshi
Life of this patent
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Abstract
N correlated signals are processed by N pre-filters whose transfer characteristics have different zero points, then the processed signals are input into an N-input M-output linear FIR system, and its transfer characteristics are estimated from its response outputs and the processed signals from the pre-filters.
Claims21
A transfer characteristic measuring apparatus for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said apparatus comprising:
- N pre-filters having transfer characteristics of different zeros, for processing N-channel signals input thereinto and for outputting preprocessed signals, respectively;
- N actuators for inputting said preprocessed signals from said N pre-filters to said N input points of said linear FIR system, respectively;
- M sensors for detecting response signals from said linear FIR system at said M output points;
- and
- a transfer characteristic estimation part for calculating the transfer characteristics of said N×M transmission paths from said preprocessed signals output from said N pre-filters and said response signals detected by said M sensors;
- wherein said transfer characteristic estimation part includes:
- M N-input single-output adaptive filters supplied with said preprocessed signals from said N pre-filters, for outputting replica signals that are estimated versions of said response signals from said linear FIR system;
- and M subtractors supplied with said M replica signals and said M response signals from said linear FIR system, for detecting their differences and generating error signals corresponding thereto and for applying said M error signals to said M adaptive filters corresponding to said M subtractors, respectively, and wherein said M adaptive filters include means for adaptively updating filter coefficients representative of their transfer characteristics so that said error signals are minimized to thereby obtain said updated filter coefficients as impulse responses indicative of the transfer characteristics of said linear FIR system.
A transfer characteristic measuring apparatus for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said apparatus comprising:
- N pre-filters having transfer characteristics of different zeros, for processing N-channel signals input thereinto and for outputting preprocessed signals, respectively;
- N actuators for inputting said preprocessed signals from said N pre-filters to said N input points of said linear FIR system, respectively;
- M sensors for detecting response signals from said linear FIR system at said M output points;
- and
- a transfer characteristic estimation part for calculating the transfer characteristics of said N×M transmission paths from said preprocessed signals output from said N pre-filters and said response signals detected by said M sensors;
- wherein said transfer characteristic estimation part includes:
- multi-input/output waveform storage means supplied with said M response signals from said linear FIR system and said N preprocessed signals from said N pre-filters, for storing them over a predetermined number of points in time;
- and multi-input/output signal analysis means for obtaining said transfer characteristics of said linear FIR system by solving simultaneous equations which are obtained by setting that vectors using said stored response signals as elements are equal to the products of a matrix composed of said preprocessed signals and a vector composed of the transfer characteristics of said linear FIR system.
A transfer characteristic measuring method for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said method comprising the steps of:
- (a) processing N-channel input signals by N pre-filters having transfer functions of different zeros to thereby generate N-channel preprocessed signals;
- (b) inputting said N-channel preprocessed signals by N actuators to said N input points of said linear FIR system, respectively;
- (c) detecting response signals from said linear FIR system by M sensors at said M output points;
- and
- (d) estimating the transfer characteristics of said N×M transmission paths from said N-channel preprocessed signals and said response signals detected by said M sensors at said M output points;
- wherein said step (d) includes a step of:
- inputting said N-channel preprocessed signals to M N-input single-output adaptive filters, respectively;
- generating replica signals that are estimated versions of said M response signals from said linear FIR system;
- detecting differences between said M replica signals and said M response signals from said linear FIR system and generating error signals corresponding to said detected differences, respectively;
- and adaptively updating filter coefficients representative of their transfer characteristics so that said error signals are minimized.
A transfer characteristic measuring method for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said method comprising the steps of:
- (a) processing N-channel input signals by N pre-filters having transfer functions of different zeros to thereby generate N-channel preprocessed signals;
- (b) inputting said N-channel preprocessed signals by N actuators to said N input points of said linear FIR system, respectively;
- (c) detection response signals from said linear FIR system by M sensors at said M output points;
- and
- (d) estimating the transfer characteristics of said N×M transmission paths from said N-channel preprocessed signals and said response signals detected by said M sensors at said M output points;
- wherein said step (d) includes a step of:
- storing said response signals from said linear FIR system and said N-channel preprocessed signals over a predetermined number of points in time;
- and obtaining said transfer characteristics of said linear FIR system by solving simultaneous linear equations which are obtained by setting that vectors using said stored response signals as elements are equal to the products of a matrix composed of said preprocessed signals and a vector composed of said transfer characteristics of said linear FIR system.
A recording medium on which there are recorded, as a program for execution by a computer, a procedure for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said program comprising the steps of:
- (a) processing N-channel input signals by N pre-filters having transfer characteristics of different zero points to thereby generate N-channel preprocessed signals;
- (b) inputting said N-channel preprocessed signals by N actuators to said N input points of said linear FIR system respectively;
- (c) detecting response signals from said linear FIR system by M sensors at said M output points;
- and
- (d) estimating the transfer characteristics of said N×M transmission paths from said N-channel preprocessed signals and said response signals detected by said M sensors at said M output points;
- wherein said step (d) includes a step of:
- inputting said N-channel preprocessed signals to M N-input single-output adaptive filters, respectively;
- generating replica signals that are estimated versions of said M response signals from said linear FIR system;
- detecting differences between said M replica signals and said M response signals from said linear FIR system and generating error signals corresponding to said detected differences, respectively;
- and adaptively updating filter coefficients representative of their transfer characteristics so that said error signals are minimized.
A recording medium on which there are recorded, as a program for execution by a computer, a procedure for simultaneously measuring transfer characteristics of N×M transmission paths of a linear FIR system defined between its N input points and M output points, said N and M being an integer equal to or greater than 2 and an integer equal to or greater than 1, respectively, said program comprising the steps of:
- (a) processing N-channel input signals by N pre-filters having transfer characteristics of different zeros to thereby generate N-channel preprocessed signals;
- (b) inputting said N-channel preprocessed signals by N actuators to said N input points of said linear FIR system, respectively;
- (c) detecting response signals from said linear FIR system by M sensors at said M output points;
- and
- (d) estimating the transfer characteristics of said N×M transmission paths from said N-channel preprocessed signals and said response signals detected by said M sensors at said M output points;
- wherein said step (d) includes a step of:
- storing said response signals from said linear FIR system and said N-channel preprocessed signals over a predetermined number of points in time;
- and obtaining said transfer characteristics of said linear FIR system by solving simultaneous linear equations which are obtained by setting that vectors using said stored response signals as elements are equal to the products of a matrix composed of said preprocessed signals and a vector composed of said transfer characteristics of said linear FIR system.
Dependencies are inferred from the claim text.