Table 1.

The ${\sigma }_{\left|\widehat{N}\left(f\right)\right|}$ for clean signal $s\left(k\right)$ and noisy signal $x\left(k\right)$ with PLn ($SNR=5\mathrm{dB}$).

		mitdb/100	mitdb/105	mitdb/108	mitdb/203	mitdb/223	mitdb/228
IMF 1	$s\left(k\right)$	1.16 × 10−4	7.90 × 10−5	6.97 × 10−5	8.37 × 10−5	1.27 × 10−4	7.84 × 10−5
	$x\left(k\right)$	2.56 × 10−3	4.54 × 10−3	2.78 × 10−3	4.40 × 10−3	6.39 × 10−3	2.60 × 10−3
IMF 2	$s\left(k\right)$	5.18 × 10−5	3.91 × 10−5	2.93 × 10−5	4.23 × 10−5	5.065 × 10−5	3.24 × 10−5
	$x\left(k\right)$	6.58 × 10−4	1.22 × 10−3	6.52 × 10−4	1.13 × 10−3	1.61 × 10−3	6.81 × 10−4
IMF 3	$s\left(k\right)$	2.66 × 10−5	3.05 × 10−5	1.70 × 10−5	2.37 × 10−5	2.98 × 10−5	1.57 × 10−5
	$x\left(k\right)$	2.08 × 10−4	3.51 × 10−4	2.06 × 10−4	3.31 × 10−4	4.85 × 10−4	2.02 × 10−4
IMF 4	$s\left(k\right)$	1.43 × 10−5	1.36 × 10−5	9.01 × 10−6	1.25 × 10−5	2.51 × 10−5	7.02 × 10−6
	$x\left(k\right)$	8.93 × 10−5	1.01 × 10−4	6.09 × 10−5	1.05 × 10−4	1.65 × 10−4	5.63 × 10−5
IMF 5	$s\left(k\right)$	6.58 × 10−6	6.85 × 10−6	5.22 × 10−6	7.67 × 10−6	1.12 × 10−5	3.80 × 10−6
	$x\left(k\right)$	3.28 × 10−5	4.26 × 10−5	2.40 × 10−5	3.59 × 10−5	6.25 × 10−5	2.61 × 10−5