## 4 Conclusions  
This work developed a comprehensive analytical toolbox for the statistical characterization of nonlinear distortions of eDAC-generated signal constellations to be transmitted over communication links. The emerging rigorous all-analytic statistical model for the UNIP! BIP ThWgt! BiWgt eDACs pertains to the propagation of electronic mismatch random variations in current-steering eDAC. The all-analytic toolbox, derived and explored here, consists of closed-form expressions for the second-order statistics (means, variances, STD) of all relevant quantities in the current-steering eDACs building blocks impacting communication transmitters. A key insight emerging from our eDAC statistical modeling is that conventional INL! DNL constellation metrics, routinely used in the electronic devices and circuits community, are ineffective characterizations in the context of communication links performance. Unfortunately, the INL! DNL metrics of an eDAC in a communication transmitter are not amenable to being translated into the statistical performance of transmission links, for which communication engineers resort to other metrics, e.g., SER, BER and constellation error vector magnitude (EVM). To rectify this disconnect between the modeling methodologies used in the respective devices and circuits [4; 5; 6] vs. communication [15; 16; 17; 18; 19] domains, this paper introduced modified variants of the INL! DNL, namely the IEV! DEV constellation metrics, from which statistical transmission performance metrics are readily inferred, relevant to communication engineers in their designs of wireless, wireline or optical channels, especially with Rx-s using coherent detection (for which BIP eDACs are needed). In Part I of this paper, we have established the IEV! DEV as straightforward predictors of EVM. Nevertheless, INL! DNL withstand as useful metrics for experimental characterization of individual eDAC specimens, whereas IEV! DEV are best suited for modeling communication links performance on an aggregate basis, across statistical ensembles of eDACs, inevitably affected by random current mismatch variations. Our upcoming Part II, building upon the current Part I foundations, is going to explore the impact of the various eDAC metrics (INL! DNL! IF! DEV) onto the SER! BER characteristics of data transmission links. Our all-analytic model of the second-order statistics of electronic mismatch, impairing the eDAC driver in the (wireless/wireline/optical) Tx, will be propagated all the way to the Tx output and then via the linear AWG channel, to the Rx. In particular, we shall treat MZM-based coherent optical interconnects, using the BIP BiWgt eDAC topology for the I! Q tributaries of QAM transmitters. Figure 12: Verification of Theorem 5 in Section 3.8, for the ensemble of 1500 UNIP eDACs, indicating excellent fit between the empirical standard deviation vector of the new DEV metric, and its analytically derived (as in (376) of Theorem 5) theoretical expected standard deviation vector. The analytic STD is the orange curve which is slightly higher than the blue curve, which in turn is the graph of the empirical STD of the array of 1500 eDACs, i.e., the Root-Average-Mean-Square (RAMS) of the 1500 realizations of each of the 8 samples of the IEV vector, evaluated for each of the Monte Carlo simulated 1500 eDACs. Space limitations also precluded us from addressing the extension of the current statistical all-analytic modeling toolbox from the UNIP | BIP ThWgt| BiWgt eDAC topologies, extensively modeled here, to linear segmented (Seg) DACs. We note here that optical DACs such as our MP-oDACs [14; 20; 21] may be interpreted as a form of DAC segmentation in the optical domain. The analytic modeling of the Seg-eDAC |MP-oDAC topologies is deferred to upcoming publications. It is our hope that the analytical toolbox developed here may serve as a common-modeling-language bridging between the devices and circuits and the wireless/optical communication tech-communities. Conceptualization, M.N. ; methodology, M.N. ; software, M.N.