import sk_dsp_comm.fir_design_helper as fir_h
import numpy as np
import matplotlib.pyplot as plt
from sk_dsp_comm import sigsys as ss
fs_bank = 1000
b_lpf_chan = fir_h.fir_remez_lpf(80,110,0.1,70,fs_bank)
w = np.random.randn(100000)
w_bank,fax, fax_des = ss.fft_filt_bank(w,b_lpf_chan + 0j,n_fft2=512,n_bands2=2,bs=200,fs = fs_bank)
for k in range(5):
    P_w,f_w = ss.psd(w_bank[k,:],2**10,fs_bank)
    plt.plot(f_w,10*np.log10(P_w))
plt.title(r'Filter Bank Characterization using White Noise with $\sigma_w^2 = 1$')
plt.ylabel(r'Gain (dB)')
plt.xlabel(r'Frequency (Hz)')
plt.grid()
plt.show()