A method, apparatus, and system for modulating and demodulating signals compatible with multiple receiver types and designed for improved receiver performance. The invention includes the use of hybrid impulse radio (H-IR) ultra-wideband (UWB) with forward error correction coding, recursive modulation and other techniques designed to enable one transmitter to transmit a waveform capable of being demodulated concurrently by a coherent receiver, a differentially coherent receiver, and/or a non-coherent receiver.