Binary multilevel convolutional codes (CCs) with unequal error protection (UEP) capabilities are studied. These codes belong to the class of generalized concatenated (GC) codes. Binary CCs are used as outer codes. Binary linear block codes of short length, and selected subcodes in their two-way subcode partition chain, are used as inner codes. Multistage decodings are presented that use Viterbi decoders operating on trellises with similar structure to that of the constituent binary CCs. Simulation results of example binary two-level CC's are also reported.
Robert H. Morelos-Zaragoza and Hideki Imai. "Binary Multilevel Convolutional Codes with Unequal Error Protection Capabilities" Faculty Publications (1998): 850-853. doi:10.1109/26.701299