A comparative analysis of the performance of SL-SIC (Symbol Level - Serial Interference Cancellation) and CWL-SIC (Codeword Level-SIC) decoders of PD-NOMA (Power Doman - Non-Orthogonal Multiple Access) baseband signals in a system with two users is presented. Real signal code constructs (SCC) from the 3GPP LTE (Long Term Evolution of 3rd Generation Partnership Project) communication standard are used. The performance of CWL-SIC achievable in practice in real systems for all possible designs of a group PD-NOMA signal consisting of different pair combinations of noise-immune SCCs has been obtained. With the help of mathematical modeling, weighting power coefficients are obtained that provide the maximum average performance of the group signal for two user channels. The high efficiency of the CWL-SIC and the expediency of its use in real systems, especially in conditions of low signal-to-noise ratio, are shown.