binary_antipodal_signaling.py

import numpy as np
import matplotlib.pyplot as plt

BIT_DURATION = 1
MODULATION_FREQ = 3 / BIT_DURATION
N_SAMPLES = 10000


def generate_random_sequence(length):
    return np.random.randint(0, 2, (length, ))


def to_bipolar(arr):
    """
    Binary Antipodal signaling.
    Note that arr is assumed to be a numpy array
    """
    return 2 * arr - 1


def main():
    length = int(input("Please enter the length of the signal: "))
    arr = generate_random_sequence(length)
    unipolar_arr = np.array(arr)
    bipolar = to_bipolar(unipolar_arr)
    time = np.linspace(0, unipolar_arr.size, N_SAMPLES)
    samples_per_bit = N_SAMPLES/unipolar_arr.size

    dd = np.repeat(unipolar_arr, samples_per_bit)
    bb = np.repeat(bipolar, samples_per_bit)

    _, ax = plt.subplots(2, 1, sharex=True, sharey=True, squeeze=True)
    ax[0].plot(time, dd)
    ax[1].plot(time, bb)
    ax[0].set_xlabel('Time')
    ax[0].set_ylabel('Baseband Signal')
    ax[1].set_ylabel('Antipodal Signal')
    label = "Random numbers generated: " + str(arr)
    plt.text(5, 4, label, ha='right')
    plt.show()


if __name__ == '__main__':
    main()