Cross-correlation quasi-gradient Doppler estimation for underwater acoustic OFDM mobile communications

Li, Bin; Tong, Feng; Li, Jianghui; Zheng, Siyuan

doi:10.1016/j.apacoust.2022.108640

Cited by 9 publications

(4 citation statements)

References 43 publications

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“…The classic cross-correlation estimation schemes realize extremely high-precision Doppler estimation in complex underwater multipath channel with calculating crossambiguity function (CAF) between transmitted and received packets [15,16]. However, as the maximum CAF magnitude calculation is accomplished utilizing enormous searches in a two-dimensional grid of Doppler factors and delays, tremendous amounts of searching grids cause intensive computational complexity.…”

Section: Of 11mentioning

confidence: 99%

R&D of an Innovative OFDM Communication Payload for Small-Size AUV

Tong

Gao

et al. 2023

JMSE

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With its superiorities of low cost, high flexibility and deployment convenience, small-size autonomous underwater vehicles (AUVs) have been extensively applied to perform a variety of undersea missions. While underwater acoustic (UWA) communication provides a practical way to establish a wireless link, it still poses a significant challenge due to the strict limitations of a small-size AUV platform in terms of load capacity, energy supply and cost. Orthogonal frequency division multiplexing (OFDM) has drawn extensive attention due to its high data rate capability and relative robustness to multipath, the performance of which is unfortunately sensitive to the widespread Doppler effect. While efficient Doppler compensation is significantly crucial for UWA OFDM mobile communication, most of the conventional approaches are conducted using software resampling, thus rendering a huge burden on memory and calculation capability as well as a considerable processing delay. In this paper, from the perspective of hardware completion an UWA OFDM communication payload based on STM32F407 processor is designed and implemented to facilitate agile Doppler compensation with low computational overhead. In particular, after estimating Doppler by calculating the time compression or extension of the preamble signal, Doppler compensation is performed by directly adjusting the direct digital frequency synthesizer (DDS)-driven sampling rate of the analog-to-digital converter (ADC). As the Doppler is compensated parallel to the ADC acquisition, processing delay and memory requirement can be avoided. Finally, hardware-in-loop (HIP) simulation is performed to demonstrate the effectiveness and superiority of the proposed system. The results show that the designed system has the potential to achieve an effective communication rate of 3.19 kbps with the admissible implementation overhead. Future work will entail the integration and performance evaluation of the proposed UWA OFDM communication payload on a practical small-size AUV platform.

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Section: Of 11mentioning

confidence: 99%

R&D of an Innovative OFDM Communication Payload for Small-Size AUV

Tong

Gao

et al. 2023

JMSE

Self Cite

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“…The transmit packet is composed of a synchronization sequence, protection interval, training symbols, and data symbols. To estimate the Doppler shift, the correlation detection between an LFM preamble and an LFM postamble around each data frame is performed to obtain the variation of the time difference between the first and last correlation peaks, which can be transformed into the Doppler factor [18,31].…”

Section: Sea Experimentsmentioning

confidence: 99%

A Low-Complexity Underwater Acoustic Coherent Communication System for Small AUV

et al. 2022

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While underwater acoustic (UWA) communication offers a practical way to establish a wireless link with underwater vehicles, designing a UWA communication system onboard a small autonomous underwater vehicle (AUV) still poses significant challenges. As the adoption of the low-complexity, robust noncoherent communication technology is limited by low bandwidth efficiency and a low data rate, coherent UWA communication requires Doppler mitigation and channel equalization measures to achieve a relatively high data rate in a moving state. Due to the strict constraints of a small-scale AUV in terms of resources and energy consumption, it is not appropriate to use high-complexity Doppler/multipath compensation technology from the prospect of system implementation. In this paper, an efficient and low-complexity UWA differential binary phase-shift keying (DBPSK) system onboard a small AUV is proposed by simplifying the Doppler and multipath compensation. Specifically, for Doppler, the delay of the adjacent DBPSK symbols is calculated according to the Doppler estimate to facilitate delay-tuning Doppler correction. For multipath, low-complexity LMS channel equalization is incorporated with error correction coding to enable multipath mitigation. With a simple structure and low computational complexity, the proposed scheme facilitates the practical hardware implementation and system integration in the small AUV platform. The numerical simulations are conducted to assess the validity of the proposed scheme under different channel conditions and the effectiveness of the proposed scheme is further verified by two UWA communication field tests, which are performed at a practical shallow water sea and lake, respectively.

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“…When the UWA communication system with a high data rate is equipped on a mobile underwater node, Doppler estimation and compensation are essential before demodulation at the receiver [2,3]. For the traditional Doppler method, a set of correlators are adopted to compute the correlation between various Doppler replicas of the transmitted signal and 2 of 21 the received signal.…”

Section: Introductionmentioning

confidence: 99%

Doppler and Channel Estimation Using Superimposed Linear Frequency Modulation Preamble Signal for Underwater Acoustic Communication

Lv,

Sun,

Chen

et al. 2024

JMSE

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Due to the relative motion between transmitters and receivers and the multipath characteristic of wideband underwater acoustic channels, Doppler and channel estimations are of great significance for an underwater acoustic (UWA) communication system. In this paper, a preamble signal based on superimposed linear frequency modulation (LFM) signals is first designed. Based on the designed preamble signal, a real-time Doppler factor estimation algorithm is proposed. The relative correlation peak shift of two LFM signals in the designed preamble signal is utilized to estimate the Doppler factor. Moreover, an enhanced channel estimation algorithm, the correlation-peak-search-based improved orthogonal matching pursuit (CPS-IOMP) algorithm, is also proposed. In the CPS-IOMP algorithm, the excellent autocorrelation characteristic of the designed preamble signal is used to estimate the channel sparsity and multipath delays, which are utilized to construct the simplified dictionary matrix. The simulation and sea trial data analysis results validated the designed preamble, the proposed Doppler estimation algorithm, and the channel estimation algorithm. The performance of the proposed Doppler factor estimation is better than that of the block estimation algorithm. Compared with the original OMP algorithm with known channel sparsity, the proposed CPS-IOMP algorithm achieves a similar estimation accuracy with a smaller computational complexity, as well as requiring no prior knowledge about the channel sparsity.

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Cross-correlation quasi-gradient Doppler estimation for underwater acoustic OFDM mobile communications

Cited by 9 publications

References 43 publications

R&D of an Innovative OFDM Communication Payload for Small-Size AUV

R&D of an Innovative OFDM Communication Payload for Small-Size AUV

A Low-Complexity Underwater Acoustic Coherent Communication System for Small AUV

Doppler and Channel Estimation Using Superimposed Linear Frequency Modulation Preamble Signal for Underwater Acoustic Communication

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