Python-振动信号加入噪声-代码实现

1. 原理

2.代码

def wgn(x, snr):
    ## x: input vibration signal shape (a,b); a:samples number; b samples length
    ## snr: noise intensity,like -8,4,2,0,2,4,8
    ### snr=0 means noise equal to vibration signal 
    ### snr>0 means vibration signal stronger than noise, →∞ means no noise
    ### snr<0 means noise stronger than vibration signal  →-∞ means no signal
    Ps = np.sum(abs(x)**2,axis=1)/len(x)
    Pn = Ps/(10**((snr/10)))
    row,columns=x.shape
    Pn = np.repeat(Pn.reshape(-1,1),columns, axis=1)

    noise = np.random.randn(row,columns) * np.sqrt(Pn)
    signal_add_noise = x + noise
    return signal_add_noise