Pilot-symbol-aided channel estimation for OFDM in wireless systems

Li, Ye

doi:10.1109/25.875230

Cited by 505 publications

(21 citation statements)

References 21 publications

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“…That is why in this paper, we investigate on MMSE to derive an "optimum" interpolator. This kind of interpolation has already been used in wireless communications for fading channels (Li, 2000) to deal with fast varying fading process and somehow in optical communication (Ip & Kahn, 2007). In that work a soft-decision phase-estimation stage followed by hard-decision estimation of the carrier phase and the transmitted symbols are used.…”

Section: Phase Noise Interpolation By Wiener Filters Using Mmse and Lmentioning

confidence: 99%

Phase Noise Jitter Synchronization for Coherent Optical OFDM via Pilot-Data-Aided and Wiener Filter

Temga¹,

Liu²,

Hamidine³

et al. 2014

CIS

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We investigate a carrier phase jitter synchronization technique for square M-ary quadrature amplitude modulation (M-QAM) coherent optical orthogonal frequency division multiplexing (CO-OFDM) signal employing a unique pilot's system design, Feed forward maximum likelihood phase estimator as well as Wiener filter-type Minimum Mean square error (MMSE) interpolator. The wiener filter relies upon Kolmogorov type to interpolate the estimated phase noise with M taps.A 20 Gb/s CO-OFDM via 4-QAM, 16-QAM, 64-QAM then 256-QAM modulation is applied as simulation model in Optisystem. System efficiency is evaluated throughout phase root mean square error (RMSE) calculated in degree. A comparative investigation of four different modulation techniques found that 4-QAM performs with good RMSE versus the rest of square M-QAM. A free-noise receiver, a pilot aided feed forward maximum likelihood (PA-FF-ML) receiver and a PA-FF-ML with MMSE (PA-FF-ML-MMSE) are compared. PA-FF-ML-MMSE exhibited superior performance rather than receiver using just PA-FF-ML.

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Section: Phase Noise Interpolation By Wiener Filters Using Mmse and Lmentioning

confidence: 99%

Phase Noise Jitter Synchronization for Coherent Optical OFDM via Pilot-Data-Aided and Wiener Filter

Temga¹,

Liu²,

Hamidine³

et al. 2014

CIS

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“…The quality of each user's channel can be indicated by the signal-to-noise ratio (SNR) function; as shown in [16], in a FDD system (such as ours, which is a TDMA-FDD one) using pilot symbols that are inserted in the downlink with a certain time-frequency pattern, the mobile terminals can effectively estimate their SNR function and send it to the BS, which can then make its scheduling decisions based on all the collected cross-layer information from the terminals. This process, however, introduces both errors and delays in the estimates.…”

Section: New Base Station Scheduling Ideasmentioning

confidence: 99%

Performance Evaluation of the Enhanced MI-MAC Protocol for Multimedia Integration over Wireless Cellular Networks

Drivas

Koutsakis

Paterakis

2008

Wireless Pers Commun

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In recent work (Koutsakis et al., IEEE Trans Veh Technol 54(5):1863-1874, 2005, we have introduced multimedia integration multiple access control protocol (MI-MAC). The protocol was shown to achieve superior performance in comparison to other protocols of the literature when integrating various types of multimedia traffic over wireless cellular networks. In this work we enhance the scheduling scheme of MI-MAC by adding three important parameters into its study. These are: (a) the handling of handoff traffic, (b) per user varying channel conditions in the uplink and downlink channels and (c) video sources' contention for channel resources. These parameters are added in order to evaluate the protocol under a significantly more realistic wireless cellular network scenario. New scheduling ideas are proposed in order to efficiently incorporate the new parameters into the scheme. The evaluation, conducted by comparing the enhanced MI-MAC with another efficient protocol of the literature and with an "ideal" MAC protocol, focuses on the efficient transmission of MPEG-4 video traffic and shows that our scheme achieves excellent performance results.

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“…Offset quadrature amplitude modulation (OQAM) can also be combined with OFDM to make the system have lower spectral sidelobes by using the pulse shaping filters, which is a candidate technology for 5G communication [10,11]. In OFDM systems, channel estimation is an important module for coherent detection and frequency-domain equalization, and the accuracy of channel estimation directly affects the recovery quality of the final received OFDM signals [12,13]. However, channel estimation 2 of 20 is a challenging technology in wireless systems due to the noise effect and time variance of wireless channels [14,15].…”

Section: Introductionmentioning

confidence: 99%

“…However, these two methods suffer from high computational complexity and are not preferred in practice. Due to reliability and simplicity, the pilot-based channel estimation is more attractive in practical applications [12]. Pilot-based channel estimation method estimates the channel impulse response (CIR) or channel frequency response (CFR) by multiplexing the known pilot sequences into OFDM symbols.…”

Section: Introductionmentioning

confidence: 99%

A Novel Noise Suppression Channel Estimation Method Based on Adaptive Weighted Averaging for OFDM Systems

2019

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Orthogonal frequency division multiplexing (OFDM) systems have inherent symmetric properties, such as coding and decoding, constellation mapping and demapping, inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT) operations corresponding to multi-carrier modulation and demodulation, and channel estimation is a necessary module to resist channel fading in the OFDM system. However, the noise in the channel will significantly affect the accuracy of channel estimation, which further affects the recovery quality of the final received signals. Therefore, this paper proposes an efficient noise suppression channel estimation method for OFDM systems based on adaptive weighted averaging. The basic idea of the proposed method is averaging the last few channel coefficients obtained from coarse estimation to suppress the noise effect, while the average frame number is adaptively adjusted by combining Doppler spread and signal-to-noise ratio (SNR) information. Meanwhile, to better combat the negative effect brought by Doppler spread and inter-carrier interference (ICI), the proposed method introduces a weighting factor to correct the weighted value of each frame in the averaging process. Simulation results show that the proposed channel estimation method is effective and provides better performance compared with other conventional channel estimation methods.

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Pilot-symbol-aided channel estimation for OFDM in wireless systems

Cited by 505 publications

References 21 publications

Phase Noise Jitter Synchronization for Coherent Optical OFDM via Pilot-Data-Aided and Wiener Filter

Phase Noise Jitter Synchronization for Coherent Optical OFDM via Pilot-Data-Aided and Wiener Filter

Performance Evaluation of the Enhanced MI-MAC Protocol for Multimedia Integration over Wireless Cellular Networks

A Novel Noise Suppression Channel Estimation Method Based on Adaptive Weighted Averaging for OFDM Systems

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