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.
Based on FFT algorithm.
- 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