Subspace-Based Propagation Delay Estimation Robust to Frequency Offset for Two-Way Ranging

This letter proposes a subspace-based propagation delay estimation algorithm immune to sampling frequency offset and carrier frequency offset. The proposed algorithm is able to achieve a highly accurate propagation delay estimation by combining subspace-based fractional delay estimation with a symmetric double sided two-way ranging protocol. Not only Cramer-Rao lower bound (CRLB) was derived but also the performance of the proposed algorithm was analyzed and verified through Monte-Carlo simulations in additive white Gaussian noise (AWGN) and a two-path channel.