Low complexity generic receiver for the NATO Narrow Band Waveform

The principal objective of the NATO Narrow Band Waveform (NBWF) is to achieve coalition interoperability within lower tactical levels. This paper describes a low-complexity generic receiver for the different modes of the NBWF. The NBWF burst consists of a continuous wave (CW) signal followed by a pseudo-random sequence and a data sequence modulated by continuous phase modulation (CPM). Joint coarse carrier frequency, phase and time synchronization is performed on the CW signal. Fine time synchronization is performed on the CW and CPM pseudo-random sequence signals. Fine carrier frequency and phase synchronization is performed on the full burst. The main idea is to transform the CPM signal with modulation index h < 1/2 into a CPM signal with modulation index h = 1/2 by exponentiation so that the signal can be demodulated with a generic linear demodulator based on Laurent's filters. Simulations are conducted to evaluate the performance of the different NBWF modes and the different algorithms. Simulation results confirm that the low complexity receiver achieves good performance and can be applied on all NBWF modes.