MUSIC Based Multipath Delay Estimation Method in the Fractional Domain for OFDM-LFM

Abstract

This letter proposes a high-resolution multipath time delay estimation (TDE) method for orthogonal frequency division multiplexing linear frequency modulation (OFDM-LFM) signals. Leveraging the expression of OFDM-LFM signals in the fractional domain, where the compressed subcarriers conform to a linear uniform arrangement, the algorithm combines with the multiple signal classification (MUSIC) algorithm for TDE. Simulation results show that regardless of the presence of Doppler effect, OFDM-LFM results in less relative root mean square error (RRMSE) compared to orthogonal frequency division multiplexing (OFDM). Furthermore, the superiority of OFDM-LFM signals is particularly evident at lower signal-to-noise ratios (SNRs). So the proposed algorithm offers promising implications for TDE in mobile scenarios.