On the effect of ISI in the error performance of precoded FBMC/OQAM systems

Chang, Bruno S.; Rocha, Carlos A. F. da; Ruyet, Didier Le; Roviras, Daniel

doi:10.1109/apcc.2012.6388232

Cited by 5 publications

(2 citation statements)

References 13 publications

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“…The proposed system is limited by the assumption of perfect equalization at the receiver whereas, imperfect equalization can lead to residual ISI and ICI terms. The authors then analyzed the effect of interference from imperfect equalization in [33]. The results suggest that multi-tap equalization is required to reduce the effect of interference in FBMC system for highly frequency selective channels.…”

Section: Introductionmentioning

confidence: 99%

Spectrum Efficient MIMO-FBMC System Using Filter Output Truncation

Zafar

Zhang

Xiao

et al. 2018

IEEE Trans. Veh. Technol.

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Abstract-Due to the use of an appropriately designed pulse shaping prototype filter, filter bank multicarrier (FBMC) system can achieve low out of band (OoB) emissions and is also robust to the channel and synchronization errors. However, it comes at a cost of long filter tails which may reduce the spectral efficiency significantly when the block size is small. Filter output truncation (FOT) can reduce the overhead by discarding the filter tails but may also significantly destroy the orthogonality of FBMC system, by introducing inter carrier interference (ICI) and inter symbol interference (ISI) terms in the received signal. As a result, the signal to interference ratio (SIR) is degraded. In addition, the presence of intrinsic interference terms in FBMC also proves to be an obstacle in combining multiple input multiple output (MIMO) with FBMC. In this paper, we present a theoretical analysis on the effect of FOT in an MIMO-FBMC system. First, we derive the matrix model of MIMO-FBMC system which is subsequently used to analyze the impact of finite filter length and FOT on the system performance. The analysis reveals that FOT can avoid the overhead in time domain but also introduces extra interference in the received symbols. To combat the interference terms, we then propose a compensation algorithm that considers odd and even overlapping factors as two separate cases, where the signals are interfered by the truncation in different ways. The general form of the compensation algorithm can compensate all the symbols in a MIMO-FBMC block and can improve the SIR values of each symbol for better detection at the receiver. It is also shown that the proposed algorithm requires no overhead and can still achieve a comparable BER performance to the case with no filter truncation.

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Section: Introductionmentioning

confidence: 99%

Spectrum Efficient MIMO-FBMC System Using Filter Output Truncation

Zafar

Zhang

Xiao

et al. 2018

IEEE Trans. Veh. Technol.

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“…It was shown that significant gain can be achieved at a cost of slightly higher complexity. The authors in [18] have analyzed the effect of multi-tap subcarrier equalization on error performance of precoded MIMO-FBMC systems transmitting through highly frequency selective channel. Their results suggest that subcarrier equalizers with more than three taps do not bring any noticeable improvement in the system performance.…”

Section: Introductionmentioning

confidence: 99%

FBMC System: An Insight into Doubly Dispersive Channel Impact

Zhang

Xiao

Zafar

et al. 2016

IEEE Trans. Veh. Technol.

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Abstract-It has been claimed that the filter bank multicarrier (FBMC) systems suffer from negligible performance loss caused by moderate dispersive channels in the absence of guard time protection between symbols. However, a theoretical and systematic explanation/analysis for the statement is missing in the literature to date. In this paper, based on one-tap minimum mean square error (MMSE) and zero-forcing (ZF) channel equalizations, the impact of doubly dispersive channel on the performance of FBMC systems is analyzed in terms of mean square error (MSE) of received symbols. Based on this analytical framework, we prove that the circular convolution property between symbols and the corresponding channel coefficients in the frequency domain holds loosely with a set of inaccuracies. To facilitate analysis, we first model the FBMC system in a vector/matrix form and derive the estimated symbols as a sum of desired signal, noise, inter-symbol interference (ISI), inter-carrier interference (ICI), inter-block interference (IBI) and estimation bias in the MMSE equalizer. Those terms are derived one-by-one and expressed as a function of channel parameters. The numerical results reveal that in harsh channel conditions, e.g., with large Doppler spread or channel delay spread, the FBMC system performance may be severely deteriorated and error floor will occur.

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