Signal separation

Computer apparatus for separating a plurality of source signals from a composite signal expressed as a series of values of signal amplitude, the source signals having periodicities similar or equal to p, the computer apparatus being programmed to:

• (a) express the composite signal as a matrix X having rows each of which is a respective segment of signal amplitude values and corresponding to a length of time associated with a signal cyclet;
• (b) decompose the matrix X by decorrelation and normalisation to obtain decomposition results;
• and
• (c) perform independent component analysis (ICA) of the decomposition results to obtain at least one of estimated separated signal modulation envelopes and estimated separated signal cyclets.

Computer apparatus arranged to separate for separating a plurality of source signals from a composite signal expressed as a series of values of signal amplitude, the source signals having periodicities similar or equal to p, characterised in that and the computer apparatus being programmed to:

• (a) partition the composite signal into a plurality of partition matrices X having rows each of which is a respective segment of signal amplitude values and corresponds to a length of time associated with a signal cyclet;
• (b) perform a singular value decomposition (SVD) of at least one of the matrices X to obtain two singular vector matrices U, V and a singular value matrix λ;
• (c) estimate a true period p of the source signals from an average of data within rows of the partition matrices X;
• and
• (d) perform an independent component analysis of one of the singular vector matrices U, V generated by SVD from the matrix X partitioned in accordance with the estimated period p and so to obtain an independent component matrix UR2T, R1TV and an associated component matrix R2λV, UλR1, one component matrix UR2T, UλR1 containing estimated separated signal modulation envelopes and the other R2λV, R1TV contains containing estimated separated cyclets.

A computer-readable medium embodying instructions for execution by computer apparatus, the instructions relating to separation of a plurality of source signals from a composite signal expressed as a series of values of signal amplitude, the source signals having periodicities similar or equal to p, and the computer-readable medium incorporating program code for controlling a computer apparatus to:

• (a) express the composite signal as a matrix X having rows each of which is a respective segment of signal amplitude values and corresponds to a length of time associated with a signal cyclet;
• (b) decompose the matrix X by decorrelation and normalisation to obtain decomposition results;
• and
• (c) perform ICA of the decomposition results to obtain at least one of estimated separated signal modulation envelopes and estimated separated signal cyclets.

A computer-readable medium embodying instructions for execution by a computer apparatus, the instructions relating to separation of a plurality of source signals from a composite signal expressed as a series of values of signal amplitude, the source signals having periodicities similar or equal to p, the computer-readable medium incorporating program code for controlling computer apparatus to:

• (a) partition the composite signal into sections to provide respective rows of a partition matrix X;
• (b) performing a singular value decomposition of the matrix X to obtain two singular vector matrices U, V and a singular value matrix λ;
• and
• (c) performing an independent component analysis of one of the singular vector matrices U, V to obtain an independent component matrix UR2T, R1TV and an associated component matrix R2λV, UλR1, characterised in that one matrix UR2T, UλR1 containing estimated separated signal modulation envelopes and the other matrix R2λV, R1TV containing estimated separated cyclets.