Patent ID: 7433907
Filing Date: 2008-10-07
Classification: G10L,H03H

Abstract:
1. A signal analyzing method of a complex exponential modulation filter bank, which makes K times sampling of an input signal with sampling frequency fs by K times (K is a divisor of number of bands M and a positive integer greater than or equal to 1), and divides it into M complex band signals with equal bandwidth and sampling frequency fsK/M to be outputted, comprising: assuming that a filter coefficient of a linear phase non-recursive type prototype filter is set to h(n) (N is a filter order, 0≦n≦N), and values of first and last filter coefficients are set to zero, and an input signal at sampling time n is set to x(n), a step of calculating a first intermediate signal w a step of calculating a second intermediate signal w a step of calculating a third intermediate signal W a step of calculating a complex band output signal X(k, mM/K) at sampling time mM/K in k-th band (0≦k≦M/K−1) from the third intermediate signal by (formula 4) (* is a conjugate complex number, and A is a phase for signal analysis) when k is an even number (k=2l), and by (formula 5) when k is an odd number (k=2l+1)