Design and Implementation of OFDM Underwater Acoustic Communication Algorithm Based on OMAP-L138

Liu, Songzuo; Ma, Lu; Li, Hui; Chen, Tingting; Qiao, Gang

doi:10.1145/2671490.2674577

Cited by 6 publications

(2 citation statements)

References 12 publications

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“…Therefore, using training sequences will certainly not be effective. Instead, some studies use cyclic prefix (CP) as a preamble to handle with the problem of Inter-symbol interference (ISI), and to do synchronization of the UWA-OFDM system [21]- [23].…”

Section: Introductionmentioning

confidence: 99%

Low Complexity Non-Uniform FFT for Doppler Compensation in OFDM-Based Underwater Acoustic Communication Systems

et al. 2022

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The Doppler effect critically degrades the performance of orthogonal frequency division multiplexing (OFDM) systems in general. This problem is significantly worse for underwater acoustic (UWA) communication systems due to the distinct characteristics of the underwater channel, resulting in the loss of orthogonality among sub-carriers. In order to compensate Doppler shifts, including phase noise and multipath channels in realistic communication scenarios, the joint of channel estimation and ICI reduction is often performed. However, the accuracy depends on the channel estimation and the FFT size, while this leads to increased computational complexity at the receiver. To achieve this dual goal in the actual underwater communication environment, a novel pilot structure in the frequency domain has been applied to overcome the channel impulse response (CIR) variation in a block period. The coarse Doppler shift is firstly estimated by using the received pilot signal. Afterward, the study takes advantage of the flexibility provided by non-uniform fast Fourier transform (NFFT) in choosing the sampling points to construct a fast and stable Doppler frequency Compensation Matrix-based NFFT (DCMN) to fine compensate the Doppler phase shift. Finally, this study shows the improvement of the proposed method's performance by actual experimental measurements and simulations.

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Section: Introductionmentioning

confidence: 99%

Low Complexity Non-Uniform FFT for Doppler Compensation in OFDM-Based Underwater Acoustic Communication Systems

et al. 2022

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“…Both of the two methods have a common application limitation, which is not ideal for real time processing of the estimation algorithm. DE-Sync adopts a combined Doppler scale estimation scheme that involves two steps to enhance the accuracy of the Doppler scale factor acquired in real time [22,23,24]. In the first step, one linear frequency modulation (LFM) and two identical short orthogonal frequency-division multiplexing (OFDM) symbols preceded by a cyclic prefix (CP), are used as a preamble for initial Doppler scale estimation.…”

Section: Introductionmentioning

confidence: 99%

DE-Sync: A Doppler-Enhanced Time Synchronization for Mobile Underwater Sensor Networks

Zhou

Wang

Nie

et al. 2018

Sensors

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Time synchronization is the foundation of cooperative work among nodes of underwater sensor networks; it takes a critical role in the research and application of underwater sensor networks. Although numerous time synchronization protocols have been proposed for terrestrial wireless sensor networks, they cannot be directly applied to underwater sensor networks. This is because most of them typically assume that the propagation delay among sensor nodes is negligible, which is not the case in underwater sensor networks. Time synchronization is mainly affected by a long propagation delay among sensor nodes due to the low propagation speed of acoustic signals. Furthermore, sensor nodes in underwater tend to experience some degree of mobility due to wind or ocean current, or some other nodes are on self-propelled vehicles, such as autonomous underwater vehicles (AUVs). In this paper, we propose a Doppler-enhanced time synchronization scheme for mobile underwater sensor networks, called DE-Sync. Our new scheme considers the effect of the clock skew during the process of estimating the Doppler scale factor and directly substitutes the Doppler scale factor into linear regression to achieve the estimation of the clock skew and offset. Simulation results show that DE-Sync outperforms existing time synchronization protocols in both accuracy and energy efficiency.

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Adaptive OFDMA with partial CSI for downlink underwater acoustic communications

Zhang

Huang

Wan³

et al. 2016

J. Commun. Netw.

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Design and Implementation of OFDM Underwater Acoustic Communication Algorithm Based on OMAP-L138

Cited by 6 publications

References 12 publications

Low Complexity Non-Uniform FFT for Doppler Compensation in OFDM-Based Underwater Acoustic Communication Systems

Low Complexity Non-Uniform FFT for Doppler Compensation in OFDM-Based Underwater Acoustic Communication Systems

DE-Sync: A Doppler-Enhanced Time Synchronization for Mobile Underwater Sensor Networks

Adaptive OFDMA with partial CSI for downlink underwater acoustic communications

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