摘要:
This invention achieves high-quality separation of mixed signals in situations where the relationship between the number of signal sources N and the number of sensors M is such that N>M. First, the values of the observed signal observed by M sensors are transformed into frequency domain values, and these frequency domain values are used to calculate the relative values of the observed values between the sensors at each frequency. These relative values are clustered into N clusters, and the representative value of each cluster is calculated. Then, using these representative values, a mask is produced to extract the values of the signals emitted by V (1≦V≦M) signal sources from the frequency-domain signal values, and this mask is used to extract the signal values emitted by V signal sources from these frequency-domain signal values. After that, if V=1 then the limited signal is output directly as a separated signal, while if V≧2 then the separated values are obtained from this limited signal by subjecting it to separation techniques such as ICA.
摘要:
Observed signals x1(t) to xj(t) from a plurality of sensors disposed in two dimensions are subject to a short-time Fourier transform, from which signals X1(ω1) to X1(ωN), . . . XJ(ω1) to XJ(ωN) are derived. Using the independent component analysis process, separation matrices W(ω1) to W(ωN) are produced. Their inverse matrices H(ω1) to H(ωN) are calculated, and for each ωn (n=1, . . . , N), using a pair of elements from each column of H(ωn), Hji(ωn) and Hj′i(ωn), an angle {circumflex over (θ)}i,jj′(ωn)=cos−1(arg(|Hji(ωn)/Hj′i(ωn))/(ωnc−1∥dj−dj′∥)) is calculated where arg(α) represents an argument of α, c the propagation velocity of a signal, and ∥dj−dj′∥ represents a spacing between sensors i and j′. Columns are permuted so that {circumflex over (θ)}i,jj′(ωn) obtained from each column of H(ω1) to H(ωN) assume an ascending order. For columns which cannot be permuted, the equation ∥qi−dj′∥/∥qi−dj∥=|Hji(ωn)/Hj′i(ωn)|=DRi,jj′(ωn) is solved for qi to calculate Ri,jj′(ωn)=∥DRi,jj′(ωn)·(dj−dj′)/(DR2i,jj′(ωn)−1)|. Columns of H(ωn) is permuted so that Ri,jj′(ωn) assume an ascending order. H(ωn) is used to solve the permutation problem of W(ω).
摘要:
A frequency domain transforming section transforms mixed signals observed by multiple sensors into mixed signals in the frequency domain, a complex vector generating section generates a complex vector by using the frequency-domain mixed signals, a normalizing section generates a normalized vector excluding frequency dependence of the complex vector, and a clustering section clusters the normalized vectors to generate clusters. Then, a separated signal generating section generates separated signals in the frequency domain by using information about the clusters and a time domain transforming section transforms the separated signals in the frequency domain into separated signals in the time domain.
摘要:
Signals from a plurality of sources are observed by a plurality of sensors disposed in two dimensions, and the observed signals are subject to a short-time Fourier transform, from which frequency domain signals are derived. Using the independent component analysis process on the frequency domain signals, separation matrices are produced, and an inverse matrix of each separation matrix is calculated. The direction of each source is calculated based on a ratio of a pair of elements in each column of the inverse matrix.
摘要:
A method and a device for signal separation. First, values of signals observed by M sensors are transformed into frequency domain values, and these frequency domain values are used to calculate relative values of the observed values between the sensors at each frequency. These relative values are clustered into N clusters, and the representative value of each cluster is calculated. Then, using these representative values, a mask is produced to extract the values of the signals emitted by V (1≦V≦M) signal sources from the frequency-domain signal values, and this mask is applied to the frequency-domain signal values. After that, if V=1 then the limited signal is output directly as a separated signal, while if V≧2 then the separated values are obtained by separating this limited signal with separation techniques such as ICA.
摘要:
A frequency domain transforming section 2 transforms mixed signals observed by multiple sensors into mixed signals in the frequency domain, a complex vector generating section 3 generates a complex vector by using the frequency-domain mixed signals, a normalizing section 4 generates a normalized vector excluding frequency dependence of the complex vector, and a clustering section 5 clusters the normalized vectors to generate clusters. Then, a separated signal generating section 6 generates separated signals in the frequency domain by using information about the clusters and a time domain transforming section 7 transforms the separated signals in the frequency domain into separated signals in the time domain.