Robustness of Modified FBMC-SS Against Partial-Band Noise-Like Interference

Abstract

As spectrum has grown more congested, there has been a greater emphasis on interference-robust low-signal-to-noise ratio (SNR) waveforms capable of operating under interference from other users and under hostile jamming. Traditional robust waveforms have limitations of only being robust against certain types of partial-band interference. A modification on the existing scheme of filterbank multicarrier spread-spectrum (FBMC-SS) is proposed that pseudo-randomly maps spread data chips to different time and frequency locations within a packet. The intended effect of this is to allow the decoder to consider and notch noise-like interference independent of its location in time and frequency. Additionally, the effects of this interference on joint frequency, time, and phase estimation are considered. The Cramér- Rao variance bounds (CRVBs) are derived for joint estimation of these values for arbitrary locations of pilots that are and are not under interference. These CRVBs are considered for different pilot mapping schemes and different interference and jamming scenarios, finding that a pseudorandom uniform pilot mapping scheme is optimal for resistance to interference and jamming.