Advanced CPM receiver for the NATO tactical narrowband waveform

The NATO tactical narrowband waveform (NBWF) is considered in this paper with particular attention to the characteristics and the performance of the NC3A functional reference software. We describe the relevant parts of the software focusing on the signaling scheme which is based on the serial concatenation of a convolutional code with a continuous phase modulation (CPM) through an interleaver. The proposed CPM receiver exploits an advanced soft-input soft-output detection algorithm which relies on a simplified CPM representation. It does not need to explicitly estimate the channel phase, and iteratively exchanges soft information with the outer decoder. The receiver performance will be assessed through computer simulations with reference to two modes: one robust mode that offers high range of coverage and a spectrally efficient one offering a higher throughput for a shorter coverage.