Multi-band small-scale fading mitigation at UWB localization receivers in dense multipath channels

Abstract

Despite the intrinsic temporal resolution of Impulse Radio — Ultra Wideband (IR-UWB) signals, specific low-power and low-complexity integrated receiver architectures devoted to long-range localization are still structurally subject to severe intra-channel interference caused by dense colliding multipath components (MPCs). In order to restore the MPC tracking potential of such receivers and hence ultimately, to improve MPC-aided localization, we propose to opportunistically combine channel estimations performed in multiple sub-bands, which were initially intended for multiple access. First, we develop two simplified 2-path models interpreting the local interference phenomena in terms of both dynamics and patterns frequency, while illustrating the expected benefits from combined multiband channel estimations. Then, we evaluate the capability to capture the energy of the various MPCs independently through realistic simulations based on IEEE 802.15.4a channel models. Finally, we use the proposed method to feed an MPC-based mobile tracking algorithm, specifically designed for generalized non-visibility situations (i.e., with respect to anchors). Other simulations then show that our proposal overcomes conventional pre-filtering methods in terms of final localization performances.