Compensation of IQ imbalance in OFDM systems

Tubbax, J.; Côme, B.; Perre, Liesbet Van der; Deneire, Luc; Donnay, S.; Engels, M.

doi:10.1109/icc.2003.1204086

Cited by 96 publications

(38 citation statements)

References 1 publication

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“…However, when there is imbalance, we have (5) which is same as and (6) represent the corresponding baseband signal components. Substituting and in (6) and grouping the terms carefully, we get (7) where and . Substituting (4) in (6) and using the relations and , we obtain (8) Then, is transmitted through the channel and the received passband signal is (9) which has the baseband equivalent signal (10) where is the channel impulse response (CIR) and is additive white Gaussian noise (AWGN) with two-sided power spectral density of .…”

Section: A General I/q Imbalance Modelmentioning

confidence: 99%

Digital Compensation of Frequency-Dependent Joint Tx/Rx I/Q Imbalance in OFDM Systems Under High Mobility

Narasimhan

Wang

Narayanan

et al. 2009

IEEE J. Sel. Top. Signal Process.

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Abstract-Direct conversion orthogonal frequency division multiplexing (OFDM) systems suffer from transmit and receive analog processing impairments such as in-phase/quadrature (I/Q) imbalance causing inter-carrier interference (ICI) among sub-carriers. Another source of performance-limiting ICI in OFDM systems is Doppler spread due to mobility. However, the nature of ICI due to each of them is quite different. Unlike previous work which considered these two impairments separately, we develop a unified mathematical framework to characterize, estimate, and jointly mitigate ICI due to I/Q imbalance and high mobility. Based on our general model, we derive a closed-form expression for the degradation in signal-to-interference-plus-noise ratio (SINR) due to the impairments. Moreover, we exploit the special ICI structure to design efficient OFDM channel estimation and digital baseband compensation schemes for joint transmit/receive frequency-independent (FI) and frequency-dependent (FD) I/Q imbalances under highmobility conditions. Index Terms-Channel estimation, in-phase/quadrature (I/Q) imbalance, inter-carrier interference (ICI), minimum mean square error (MMSE) equalization, mobility, orthogonal frequency division multiplexing (OFDM), signal-to-interference-plus-noise ratio (SINR).

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Section: A General I/q Imbalance Modelmentioning

confidence: 99%

Digital Compensation of Frequency-Dependent Joint Tx/Rx I/Q Imbalance in OFDM Systems Under High Mobility

Narasimhan

Wang

Narayanan

et al. 2009

IEEE J. Sel. Top. Signal Process.

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“…CHANNEL ESTIMATION SCHEME In order to perform the equalization step in (10), we need to estimate the G k,l 's in (6). To do this, we first ignore the ICI due to mobility and estimate only the G k,k 's.…”

Section: Compensation Schemesmentioning

confidence: 99%

Digital baseband compensation of joint TX/RX frequency-dependent I/Q imbalance in mobile MIMO-OFDM transceivers

Narasimhan

Narayanan

Al-Dhahir

et al. 2009

2009 43rd Annual Conference on Information Sciences and Systems

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Abstract-Direct-conversion Orthogonal Frequency Division Multiplexing (OFDM) systems suffer from transmit and receive analog processing impairments such as Inphase/Quadrature (I/Q) imbalance causing Inter-Carrier Interference (ICI) between the sub-carriers. Another source of performance-limiting ICI, but with a different nature, in OFDM systems is Doppler spread due to mobility. Unlike previous work which considered these two problems separately, we develop a generalized analytical framework to characterize, estimate and jointly mitigate ICI due to both I/Q imbalance and high mobility. Based on our general model, we exploit the special ICI structure to design efficient channel and I/Q imbalance parameter estimation and digital baseband compensation schemes for joint transmit/receive frequency-independent and frequencydependent I/Q imbalance under high-mobility conditions. Moreover, we extend the model, compensation and channel estimation methods to the Multiple Input Multiple Output (MIMO) case, Spatial Multiplexing (SM) in particular.

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“…To reduce the ICI power due to timing jitter, applied the matrix in previous work to show that both fractional oversampling and integer oversampling can be used is explained in [7]. When a front-end component doesn't respect the orthogonality between the I and Q branch or the power balance I/Q imbalance occurs which is very well explained in [8].If the receiver having the imperfections in the analog local oscillator (LO) of the receiver may mean that the amplitudes of the local I and Q carriers are not equal and/or the phase difference is not of exactly 90 degrees causes I/Q imbalance. Amplitude and phase imbalance causes due to the mismatches of amplitude and phase shift, respectively.…”

Section: Introductionmentioning

confidence: 99%

A Review Paper on Analysis Of I/Q Imbalance and Impact of Timing Jitter and In OFDM Transmission Systems for ICI Reduction

Gawande¹

2017

IJRASET

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in the past years tremendous progress has been made on the ofdm (orthogonal frequency division multiplexing) communication model and its applications, although all this progress, still impairments like timing jitter and i/q imbalance have huge impact on the system performance . As orthogonal frequency division multiplexing (ofdm) is the high data rate systems has the problem of inter carrier interference (ici) and due to timing jitter and i/q imbalance system leads the performance as high bit error rate. Analyzing the interaction between timing jitter and i/q imbalance a new algorithm is propose which leads the extra ici terms in their interaction. Indication of analysis is that the inter carrier interference (ici) has equal real and imaginary components and is independent of received subcarrier index .due to the relative contribution on timing jitter and i/q imbalance its parameters values influences the inter carrier interference (ici), whereas i/q imbalance dominating when timing jitter is relatively small and timing jitter taking over for larger jitter values. Observation shows the negligible interaction for extra ici in all cases. Analytical results will compare with simulation results for minimum ber. Key words: -ofdm (orthogonal frequency division multiplexing),i/q imbalance, timing jitter, ici(inter carrier interference).

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Compensation of IQ imbalance in OFDM systems

Cited by 96 publications

References 1 publication

Digital Compensation of Frequency-Dependent Joint Tx/Rx I/Q Imbalance in OFDM Systems Under High Mobility

Digital Compensation of Frequency-Dependent Joint Tx/Rx I/Q Imbalance in OFDM Systems Under High Mobility

Digital baseband compensation of joint TX/RX frequency-dependent I/Q imbalance in mobile MIMO-OFDM transceivers

A Review Paper on Analysis Of I/Q Imbalance and Impact of Timing Jitter and In OFDM Transmission Systems for ICI Reduction

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