Table 2 Simulation parameters

Transmission bandwidth

W =40 MHz

Delay spread

τ =0.8 μs

Channel length

N =64

Number of nonzero coefficients

K =2 and 6

Distribution of nonzero coefficient

random Gaussian $\mathcal{C}\mathcal{N}\left(0,1\right)$

Threshold parameter for VSS-NLMS

$C=\left\{\begin{array}{c}\hfill 6.0\times {10}^{-6},\mathrm{\text{for}}\mathrm{\text{SNR}}=5\mathrm{dB}\hfill \\ \hfill 3.0\times {10}^{-6},\mathrm{\text{for}}\mathrm{\text{SNR}}=10\mathrm{dB}\hfill \\ \hfill 2.0\times {10}^{-6},\mathrm{\text{for}}\mathrm{\text{SNR}}=20\mathrm{dB}\hfill \end{array}\right.$

Received SNR E _s /N₀

0 ~ 40 dB

Step size

μ = 0.5 and μ_max = 2

Regularization parameter

$\rho =0.0015{\sigma }_n^2$

Modulation schemes

8 PSK, 16 PSK, 16 QAM, and 64 QAM