Spectrally Efficient CPM Waveforms for Narrowband Tactical Communications in Frequency Hopped Networks

A family of spectrally efficient waveforms for serial concatenated continuous phase modulation in frequency hopping systems is presented, for the challenging case where there are multiple hops per interleaver duration. The proposed waveforms are designed for narrowband tactical communication systems and are shown to meet stringent spectral emission masks of -40 dBc at the band edges for terrestrial communications below 100 MHz whilst maintaining data rates up to 64 kbit/sec in a standard 25 kHz bandwidth. In addition, a design approach is outlined enabling near-constant envelope waveforms for a variety of user defined information rates. This ensures efficient use of energy by the transmitter power amplifier, and achieves good performance and spectral efficiency for both tactical data and low latency voice communications. Furthermore, simulation results based on channel measurements in the tactical VHF band allow for the evaluation of the overall system performance in typical multipath environments