A redundancy system for a co-channel telecommunication system and related methods. Implementations of the redundancy system may include at least a first modulator and a second modulator having a symbol mapper coupled to a parallel bit signal. The symbol mapper may be configured to route each of a plurality of parallel bits received through the parallel bit signal to a plurality of significant bit signals. In a first implementation, a plurality of significant bit signal multiplexers may be used to switch the plurality of parallel bit signals to allow the first and second modulators to operate in either a redundant or operating mode. In a second implementation, a premapped symbol (PMSI) encoder and a PMSI decoder may be used to transmit the plurality of significant bit signals across an interface bus as a real dual-data rate (DDR) signal and an imaginary DDR signal.