1. An apparatus comprising: a receiver component configured to receive a transmission signal, wherein the received transmission signal reflects an encoded and modulated initial source signal, amplified via a source transmitter, and transmitted over one or more channels of a wireless communications network; a first signal processing component configured to process the received transmission signal to generate a replica transmission signal that estimates the encoded and modulated initial source signal; and a second signal processing component configured to determine an optimal parametric function for modeling the source transmitter, wherein the determination of the optimal parametric function comprises an iterative non-linear curve-fitting process, and wherein the optimal parametric function reflects one or more parameters of the source transmitter.