Performance Comparison of Doppler Scale Estimation Methods for Underwater Acoustic OFDM

Abstract

Doppler scale estimation is one critical step needed by the resampling operation in acoustic communication receivers. In this paper, we compare different Doppler scale estimation methods using either cyclic-prefixed (CP) or zero-padded (ZP) orthogonal-frequency division-multiplexing (OFDM) waveforms. For a CP-OFDM preamble, a self-correlation method allows for blind Doppler scale estimation based on an embedded repetition structure while a cross-correlation method is available with the knowledge of the waveform. For each received ZP-OFDM block, the existence of null subcarriers allows for blind Doppler scale estimation. In addition, a pilot-aided method and a decision-aided method are applicable based on cross-correlation with templates constructed from symbols on pilot subcarriers only and from symbols on all subcarriers after data decoding, respectively. This paper carries out extensive comparisons among these methods using both simulated and real experimental data. Further, the applicabilities of these methods to distributed multiuser systems are investigated.

Pilot structure for Doppler scaling estimation in multicarrier communications

“…This point has been noted in some recent publications, [1]- [3], and active research works are still in progress to solve this challenging problem. The Doppler scaling problem has been found more damaging in communication systems that use multicarrier techniques [3].…”

Comparison of sparse recovery algorithms for channel estimation in underwater acoustic OFDM with data-driven sparsity learning

“…The Doppler scaleâ and the carrier frequency offset (CFO)ε are estimated as described in [2,37]. The signal after the Doppler compensation can be expressed as:z(t) =ỹ(t/(1 +â))e −j2πεt .…”

Analysis of Underwater OFDM Performance During a 2-Month Deployment in Chesapeake Bay

“…In recent years, in addition to the active investigation on single carrier transmissions such as the studies by Gomes et al (2008); Ling and Li (2012); Song et al (2010Song et al ( , 2008; Tao et al (2011Tao et al ( , 2010; Wan et al (2011);Xu et al (2013); and Zheng et al (2010), OFDM technique has been very actively pursued for underwater acoustic communications, due to its ability to handle long multipath channels Carrascosa & Stojanovic, 2010;Huang et al, 2011Huang et al, , 2013Kang et al, 2010;Kang & Iltis, 2008;Leus & van Walree, 2008;Li et al, 2009Li et al, , 2008Liu & Yang, 2013;Radosevic et al, 2013;Rojo & Stojanovic, 2010;Tao & Zheng, 2013;Tu et al, 2013;Wan et al, 2012;Wang et al, 2013;Xu et al, 2012;Zajic & Edelmann, 2013). In contrast with extensive research work, there is limited work on OFDM acoustic modem development.…”