A time-domain estimation method of rapidly time-varying channels for OFDM-based LTE-R systems

Choi, Jin-Kyu; Nguyen, Van Duc; Nguyen, Hai Nam; Duong, Van Vinh; Nguyen, Tien Hoa; Cho, Hanbyeog; Choi, Heon‐Jin; Park, Seong-Gyoon

doi:10.1016/j.dcan.2018.01.002

Cited by 15 publications

(5 citation statements)

References 18 publications

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“…The key difference between ParEst and such work is that ParEst is based on the recent discovery of constant frequency sinusoid approximation of the CSI, which enables dramatic reduction of run-time computation complexity. CSI-related issues in high-speed scenarios have been investigated in [21][22][23], while in this paper, the mobility is assumed to be at a low or modest level.…”

Section: Related Workmentioning

confidence: 99%

ParEst: joint estimation of the OFDM channel state information in MIMO systems

Zhang

2020

J Wireless Com Network

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OFDM channel state information (CSI) is needed for determining key parameters in MIMO transmissions. In this paper, a novel CSI estimation method, ParEst, is proposed, which estimates the CSI from multiple transmitting antennas simultaneously. ParEst is based on a recent discovery that the CSI can be approximated very well by the linear combination of complex-based sinusoids on constant frequencies. ParEst finds the CSI of all antennas jointly by solving an optimization problem and achieves higher accuracy than existing heuristic methods. As the base sinusoids are on constant frequencies, ParEst pre-computes most key steps and reduces the run-time computation complexity to just a modest number of vector dot products equivalent to a few FFT calculations. ParEst can be applied to MIMO links in networks such as LTE, 5G, or Wi-Fi.

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Section: Related Workmentioning

confidence: 99%

ParEst: joint estimation of the OFDM channel state information in MIMO systems

Zhang

2020

J Wireless Com Network

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“…[14][15][16] It enables the receiver to effectively eliminate ICI, but the complexity for the compensation operation is relatively high. 17 Another approach is to preprocess the data symbols at the transmitter, which includes time-domain windowing [17][18][19][20][21][22] and self-cancelation. [23][24][25][26][27][28][29][30][31][32] The time-domain windowing schemes are based on a priori statistical information of the channel and design the windowing parameters according to minimum mean square error (MMSE) criterion to mitigate the effects of ICI.…”

Section: Related Work and Motivationmentioning

confidence: 99%

Rateless coded Orthogonal Frequency Division Multiplexing system design based on intercarrier interference self‐cancelation

Zhang

Yang

Hua

et al. 2020

Int J Communication

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Summary In this paper, we consider a rateless coded Orthogonal Frequency Division Multiplexing (OFDM) system under a quasistatic fading channel. During each transmission round, transmitter keeps transmitting to the receiver using Raptor code until the receiver feeds back an acknowledgement (ACK). On the other hand, frequency offset between the transmitter and receiver ruins the orthogonality of OFDM subcarriers and cause intercarrier interference (ICI). We resort to ICI self‐cancelation precoding to combat ICI, wherein the data symbol vectors are multiplied with some precoding matrix before transmission. To improve the system robustness, we jointly optimize the precoding matrix and the degree profile of Raptor code, with only statistical channel state information (CSI) being assumed at the transmitter. The optimization problem is formulated based on the extrinsic information transfer (EXIT) analysis of the decoding process at the receiver. The advantage of the proposed design is that the instant CSI is not required at the transmitter, which reduces the system overhead. Simulation results verify that the proposed scheme with the optimized precoding matrix and degree profile can effectively combat ICI and achieve good performance both in bit error ratio (BER) and average transmission rate.

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“…Nevertheless, the unique properties of the UWA channel, such as the slow propagation speed of the acoustic wave, the narrow bandwidth, and the time-varying multipath effect, that hinders the enhancement of the communication quality [3]. OFDM has been successfully applied in broadband wireless communication over time-varying radio channels [4]. Therefore, it is obviously appropriate to continue using OFDM for UWA systems to combat the multipath effect as well as improve the transmission rate [5].…”

Section: Introductionmentioning

confidence: 99%

“…We focus on pilot-based channel estimation methods, similar to those of the UWA-OFDM studies that appear for example in [18]. Continuing with the problem of timefrequency doubly-selective channel estimation, the solution of insert pilots in both time and frequency domains is applied [4]. In the many literature, pilots will first be used for CFO correction, and then offset-corrected signals will be used for channel estimation [19].…”

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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A time-domain estimation method of rapidly time-varying channels for OFDM-based LTE-R systems

Cited by 15 publications

References 18 publications

ParEst: joint estimation of the OFDM channel state information in MIMO systems

ParEst: joint estimation of the OFDM channel state information in MIMO systems

Rateless coded Orthogonal Frequency Division Multiplexing system design based on intercarrier interference self‐cancelation

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

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