Redesigned Waveforms in the Maritime Medium Frequency Bands

Several studies have shown that the signals of marine radio beacons, which operate in the maritime medium frequency (MF) band, can be modified to enable range and position estimate. This technology called Ranging Mode (R-Mode) faces challenges in the resolution of ambiguities and suppression of multipath interference which are related to the small bandwidth of 500 to 1000 Hz per radio beacon. This paper shows that increasing the overall used bandwidth per station with the transmission in two separate MF channels or using the complete maritime MF band would increase the ability to estimate the ambiguities and identify signals reflected by the ionosphere. A matching pursuit algorithm is proposed to decompose the received signal into the ground-wave and sky-wave component.