A radio apparatus and system may include a means for modulating and/or demodulating an optical signal for respective transmission and/or reception of the optical signal using an optical channel connected to a remote radio unit. There may also be provided a means for performing, based on one or more pre-trained computational models, one or more operations on a digital signal corresponding to the optical signal for mitigating one or more non-linearities introduced by the optical modulating and/or demodulating means and the optical channel. The one or more pre-trained computational models may be pre-trained based on feedback data indicative of said one or more non-linearities.