qpsk-demod 0.1.0

A library for QPSK demodulation

qpsk_demod

Perform Quadrature Phase Shift Keying (QPSK) demodulation on the received signal.

Parameters:
r (array-like): The received modulated signal.
fc (float): Carrier frequency.
of (int): Oversampling factor, determining the number of samples per symbol.

Returns:
tuple:
    a_hat (numpy.ndarray): The estimated binary data stream.
    x (numpy.ndarray): The demodulated in-phase component.
    y (numpy.ndarray): The demodulated quadrature component.

This function performs the following steps:
1. Demodulates the in-phase (I) and quadrature (Q) components from the received signal.
2. Applies a low-pass filter to extract the baseband signal.
3. Downsamples the filtered signals to the symbol rate.
4. Estimates the binary data stream by thresholding the demodulated signals.

Example:
>>>import qpsk_demod as qd
>>> r = np.array([0.5, -0.5, 1.0, -1.0, 0.5, -0.5, -1.0, 1.0])
>>> fc = 100
>>> of = 4
>>> a_hat, x, y = qd.qpsk_demod(r, fc, of)

Installation

pip install qpsk-demod