def sync_angle(*, snr, preamble_duration=9.3e-6, bandwidth=1.2e6, **kwargs):
    """
    Computes the angle of de-synchronisation.
    :param snr: an SNR of the received signal
    :param preamble_duration: the duration of PHY-preamble in seconds
    :param bandwidth: the bandwidth of the signal in herzs
    :param kwargs:
    :return: the angle of de-synchronisation
    """
    return (snr * preamble_duration * bandwidth) ** -0.5