A system incorporates time-hopped impulse radio (TH-IR) and transmitted-reference impulse radio (TR-IR) transceivers in the same wireless network. A transmitter modulates a sequence of bits in a wireless communications network by generating a reference waveform and a data waveform of a waveform pair for each current bit. The phase of the reference waveform depends on a previous modulated bit, and a difference in phase between the reference waveform and the data waveform pair depend on the current bit. A symbol period for the current bit is partitioned into multiple time intervals, and the reference waveform and the data waveform are encoded in a selected one of the time intervals that depends on the current bit.