Algorithm 1 Spectrum sensing algorithm with multi-resolution singular spectral entropy
Input: Network parameters, decision threshold ($P_f$) and sampled data $y[\mathrm{n}]$
Output: The state of the channel perceived by the spectrum sensing algorithm ($Cs$)
1:	Initialization, parameter setting: $\gamma ,m,L,J$
2:	for all$y[\mathrm{n}]\in R$do
3:	calculate wavelet packet coefficients: $S_{J,i}$, i = 1, 2, …, 2J
4:	for all $i\le 2^J$ do
5:	calculate the singular spectral entropy: $h_i$
6:	end for
7:	for all $2\le i\le 2^J$ do
8:	$d_i=h_i-h_{i-1}$
9:	end for
10:	$D={\displaystyle \sum _{i=2}^{2^J}{d}_i}$
11:	if $D\ge \gamma$ then
12:	return: $Cs\leftarrow H_1$
13:	Else
14:	return: $Cs\leftarrow H_0$
15:	end if
16:	end for