ask fsk psk

import matplotlib.pyplot as plt

import numpy as np

import sys

from scipy import signal

type='fsk'

freq=10

Fs = 150.0;  # sampling rate

Ts = 1.0/Fs; # sampling interval

t = np.arange(0,2,Ts)

if (type=='fsk'):

    bit_arr = np.array([5,5,-5,5,-5])

    samples_per_bit = 2*Fs/bit_arr.size 

    dd = np.repeat(bit_arr, samples_per_bit)

    y= np.sin(2 * np.pi * (freq + dd) * t)

elif (type=='psk'):

    bit_arr = np.array([180,180,0,180,0])

    samples_per_bit = 2*Fs/bit_arr.size 

    dd = np.repeat(bit_arr, samples_per_bit)

    y= np.sin(2 * np.pi * (freq) * t+(np.pi*dd/180))

else:

    bit_arr = np.array([1, 0, 1, 1, 0])

    samples_per_bit = 2*Fs/bit_arr.size 

    dd = np.repeat(bit_arr, samples_per_bit)

    y= dd*np.sin(2 * np.pi * freq * t)

plt.plot(t,y)

plt.show()