Variable Range Resampling for Computationally Efficient Doppler Compensation in Underwater Acoustic Communication

Yoshizawa, Shingo; Saito, Takashi; Mabuchi, Yusaku; Tsukui, Tomoya; Sawada, Shin–ichi

doi:10.1109/oceanskobe.2018.8559418

Cited by 7 publications

(8 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Resampling is proven to be an effective method to alleviate the Doppler effect 3,4,24 . This is a very demanding task, especially when high precision is required, and need to reduce complexity of resampling with keeping the same communication performance 25 . Discrete signal resampling (sampling rate conversion) can usually be achieved through digital‐to‐analog conversion or interpolation, after that residual Doppler frequency offset compensation is also required.…”

Section: Related Workmentioning

confidence: 99%

Doppler estimation based on linear interpolation for underwater acoustic communication

Wang

et al. 2022

Trans Emerging Tel Tech

View full text Add to dashboard Cite

In this article, we develop a Doppler estimation approach based on linear interpolation for underwater acoustic (UWA) OFDM system. Linear interpolation is used to achieve the resampling of the received signal. By interpolating the sampled signal with different compensation factors at the receiving end, the repeating structure of the CP-OFDM symbol is used to maximize the correlation value at the fixed window to obtain the estimated value of the Doppler factor. The fixed window is determined based on the length of the cyclic prefix and the maximum path delay. In addition, we deduced the expression of the received discrete sequence to perform correlation operations after interpolation, which is the theoretical basis of our proposed algorithm. Moreover, in order to reduce the number of iterations, which means computational complexity in this algorithm, we recommend using the dichotomy to quickly find the maximum correlation value. Simulation proves that the proposed algorithm perform better than other CP-OFDM-based time-domain autocorrelation algorithms.

show abstract

Section: Related Workmentioning

confidence: 99%

Doppler estimation based on linear interpolation for underwater acoustic communication

Wang

et al. 2022

Trans Emerging Tel Tech

View full text Add to dashboard Cite

show abstract

“…1 [5], July 24, 2019 DRAFT [19], [28]. This channel representation is often implicitly used for designing UWA receivers [2], [6], [8], [29]. The time-variant delay line described by the impulse response δ(τ − τ d (t)), where δ(τ ) is the Dirac delta function, is associated with the fastest channel variations caused by the varying distance between the transmitter and the receiver.…”

Section: Channel Modelmentioning

confidence: 99%

“…Modems with multicarrier modulation, such as Orthogonal Frequency Division Multiplexing (OFDM) [2]- [5], exhibit good performance and relatively low complexity channel estimation and equalization, as most of the signal processing is performed in the frequency domain. However, OFDM signals are sensitive to Doppler distortions in the channel, thus requiring complicated Doppler estimators [6]. OFDM signals also have a high peak to average power ratio (PAPR), which places severe demands on the power amplifier at the transmitter.…”

Section: Introductionmentioning

confidence: 99%

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Zakharov

Henson

Diamant

et al. 2019

IEEE J. Oceanic Eng.

View full text Add to dashboard Cite

In underwater acoustic (UWA) communications, the propagated signal undergoes severe Doppler and multipath distortions. The Doppler estimation/compensation and channel estimation/equalization techniques required to deal with these distortions contribute significantly to the overall complexity of UWA modems. In this paper, we propose a data packet structure for high data rate transmission in time-varying UWA channels with the channel dynamic modelled by velocity and acceleration between the transmitter and receiver. The data packet consists of superimposed data and periodic pilot sequences. The superposition allows achievement of a high spectral efficiency for data transmission. The repeated pilot symbols allow the use of a low-complexity multi-branch autocorrelation method for coarse estimation of Doppler parameters related to the velocity and acceleration. To refine these estimates, we further propose a lowcomplexity fine Doppler estimator based on dichotomous iterations. We also present a low complexity frequency domain channel estimator exploiting the channel sparsity. The proposed modem design has been evaluated using simulation and practical sea trials. The experiments demonstrate high detection performance of the proposed design, in particular in comparison with a more traditional design that ignores the acceleration between the transmitter and receiver.

show abstract

“…Instead, we use the PCF proposed in [17] to estimate the Doppler frequency. As introduced in [18], Doppler compensation in OFDM-based UWA communication systems can be achieved though two-step of signal processing, namely resampling and residual CFO compensation. The novelty of our proposed method lies in the second step, where we estimate the residual CFO using nonuniform FFT and mitigate the ICI that was not fully handled in step 1.…”

Section: Introduction *mentioning

confidence: 99%

Proposal for a Doppler Shift Compensation Method Using Non-Uniform FFT with Pilot Carrier Frequency for OFDM-Based Underwater Acoustic Communication Systems

2023

JST: SSAD

View full text Add to dashboard Cite

In this paper, we propose a method that uses the non-uniform Fast Fourier Transform (FFT) to compensate for Doppler frequency shifts in orthogonal frequency division multiplexing (OFDM) based underwater acoustic (UWA) communication systems. To estimate the Doppler frequency shift, the paper proposes using a pilot carrier frequency (PCF) that is identified by transmitting with greater power in the frequency domain compared to other subcarriers. This identifier helps estimate both the Doppler frequency shift and the channel. The paper proposes estimating and compensating for the Doppler frequency shift in two steps: Step 1 performs coarse frequency synchronization, where the Doppler frequency shift is determined by using PCF signal. The Doppler shift correction is obtained by re-sampling the received signal, and then interpolating re-sampled signal. However, the Doppler shift compensation in the step 1 cannot correct the phase distortion of the measured PCF signal. Therefore, performing step 2, known as fine frequency synchronization, is necessary. In this step, the correction for the phase distortion is determined based on the phase difference between the two consecutive OFDM signals in one frame. The remaining Doppler frequency shift is adjusted based on the phase deviation, using the non-uniform FFT. By using the non-uniform FFT, the complexity of the ICI compensation is significantly reduced, and the quality of Doppler shift compensation is improved. The experience results show that the transmitted text will be decoded correctly by using the proposed technique

show abstract

Variable Range Resampling for Computationally Efficient Doppler Compensation in Underwater Acoustic Communication

Cited by 7 publications

References 7 publications

Doppler estimation based on linear interpolation for underwater acoustic communication

Doppler estimation based on linear interpolation for underwater acoustic communication

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Proposal for a Doppler Shift Compensation Method Using Non-Uniform FFT with Pilot Carrier Frequency for OFDM-Based Underwater Acoustic Communication Systems

Contact Info

Product

Resources

About