comnum.adc#

comnum.adc(x, bits, *, fs=1.0, full_scale=None, loading=None, enob=None, jitter_s=0.0, bandwidth_hz=None, rng=None)#

An analogue-to-digital converter on the in-phase and quadrature components: the front-end bandwidth (Gaussian, 3 dB at bandwidth_hz), the sampling-clock jitter (first order), the noise of the effective number of bits, then a uniform mid-rise quantiser of bits bits with clipping at the full scale.

Parameters:

  • x (array_like) – the analogue signal (complex).

  • bits (int) – resolution N.

  • fs (float) – sampling rate (Hz).

  • full_scale (float, optional) – the full scale A of each dimension (the levels span ±(A - Δ/2), Δ = 2A/2^N).

  • loading (float, optional) – without full_scale, A is loading times the RMS value of one dimension of x; by default the loading that minimises the error of a Gaussian input (optimal_loading).

  • enob (float, optional) – effective number of bits (≤ N).

  • jitter_s (float) – RMS clock jitter (s).

  • bandwidth_hz (float, optional) – 3 dB bandwidth of the front end (Hz).

  • rng (Rng, optional) – the generator, needed with enob or jitter_s.

Returns:

the digital samples (complex128).

Return type:

numpy.ndarray

Raises:

ValueError – for an invalid parameter or input (the message names it).

Examples

>>> import comnum, numpy as np
>>> comnum.adc(np.array([0.3 - 0.01j]), 3, full_scale=1.0).tolist()
[(0.375-0.125j)]
On this page
Show Source