DigitalSignal

class DSP.DigitalSignal

Bases: numpy.ndarray

Signal with noise and Fourier components

A signal is defined as a complex quantity:

S = I + i Q

which corresponds to Euler’s formula:

    ix
S  e    = S cos(x) + i S sin(x)
 0         0            0

The Fourier components in the imaginary part of the array Q are delayed by a quarter cycle with respect to I.

Note that this corresponds to what is known as the inverse transform. If x is w t, then the forward transform is defined as converting from time space (t) to frequency space (w). In this case we use frequencies w to create a signal in time t.

This subclass of numpy.ndarray has an attribute info which is a dict with properties of the signal

Methods Summary

spectrum()

Returns the spectrum of the signal, positive frequencies only if the signal is only real values.

Methods Documentation

spectrum()

Returns the spectrum of the signal, positive frequencies only if the signal is only real values.