A Scalable Dual LFM Waveform for Unambiguous Localization in Distributed Antenna Arrays

Distributed antenna arrays, comprising a set of transceivers wirelessly-coordinated at the level of the RF wavelength, require high-accuracy localization to form beams in arbitrary directions. The phase relationship between the transmitted signals are corrected based on the beamsteering phase and the direction of interest, thus any error in the distance measurement will lead to degraded beamforming gain. Previously, it was shown that a spectrally-sparse two-tone waveform can achieve near-optimal localization accuracy between nodes, but results in ambiguous range measurements that must be accounted for. In this work, we present a novel waveform combining spectral sparsity for high-accuracy localization, modulation for range disambiguation, and time-frequency duplexing to enable scalability for accurate ranging between multiple nodes simultaneously.