Energy-efficient localization with OFDM transmission in multipath channels

In this paper, we investigate the green characteristic of orthogonal frequency-division multiplexing (OFDM) transmissions in terms of range estimation and localization in multipath channels, relative to the pseudo-random noise (PN) transmissions. Based on the analysis of the fundamental bounds in gentle multipath channels, we observe that the required transmit energy for OFDM is proved to be much more efficient than that of PN to acquire a fixed ranging and positioning accuracy. Furthermore, the localization performance and the optimal network topology for attaining the best accuracy are presented. Numerical results, for both gentle multipath channels and nonseparable multipath channels, show a consistency with the proposed theory.