analog_frontend#

Compensation of analog_frontend impairments

DSP-based compensation functions to overcome analog impairments prior to the ADC in the receiver.

qampy.core.analog_frontend.comp_IQ_inbalance(signal)#

Compensate for imbalance between I and Q from an optical hybrid. Takes I as the real part and orthogonalize Q with respect to it.

qampy.core.analog_frontend.comp_rf_delay(signal, delay, sampling_rate=50000000000.0)#

Adds a delay of X picoseconds to the signal in frequency domain. Can be used to compensate for impairments such as RF cables of different length between the optical hybrid and ADC.

Parameters:

  • signal (array_like) – Real-valued input signal

  • delay (float) – Delay in s

  • sampling_rate (scalar, optional) – ADC sampling rate

Returns:

sig_out – Signal after compensating for delay

Return type:

array_like

qampy.core.analog_frontend.orthonormalize_signal(E, os=1)#

Orthogonalizing signal using the Gram-Schmidt process _[1].

Parameters:

  • E (array_like) – input signal

  • os (int, optional) – oversampling ratio of the signal

Returns:

E_out – orthonormalized signal

Return type:

array_like

References