Research on the Attenuation Characteristics of AE Signals of Marble and Granite Stone

Table 5

The frequency band range of reconstructed signal by wavelet packet decomposition.

Layer	S (i, 0)	S (i, 1)	S (i, 2)	…	S (i, j − 1)	S (i, j)
1	0–750	–	–	–	–	750–1500
2	0–375	375–750	750–1125	–	–	1125–1500
3	0–187.5	187.5–375	375–562.5	…	1125–1312.5	1312.5–1500
4	0–93.75	93.75–187.5	187.5–281.25	…	1312.5–1406.25	1406.25–1500
5	0–46.875	46.875–93.75	93.75–140.625	…	1406.25–1453.125	1453.125–1500
6	0–23.4375	23.4375–46.875	46.875–70.3125	…	1453.125–1476.5625	1476.5625–1500
7	0–11.71875	11.71875–23.4375	23.4375–35.15625	…	1476.5625–1488.28125	1488.28125–1500

S (i, j) represents the reconstruction signal of the j-th wavelet packet decomposition coefficient in the i-th layer, i = 1,2,3,4; j = 0,1,2, … 2ⁱ-1.