The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Xavier Mestre - One of the best experts on this subject based on the ideXlab platform.
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Single-Tap Precoders and Decoders for Multiuser MIMO FBMC-OQAM Under Strong Channel Frequency Selectivity
IEEE Transactions on Signal Processing, 2017Co-Authors: François Rottenberg, Xavier Mestre, François Horlin, Jérôme LouveauxAbstract:The design of linear precoders or decoders for multiuser multiple-input multiple-output filterbank multicarrier (FBMC) modulations in the case of a strong channel Frequency Selectivity is presented. The users and the base station (BS) communicate using space division multiple access. The low complexity proposed solution is based on a single tap per-subcarrier precoding/decoding matrix at the BS in the downlink/uplink. As opposed to classical approaches that assume flat channel Frequency Selectivity at the subcarrier level, the BS does not make this assumption and takes into account the distortion caused by channel Frequency Selectivity. The expression of the FBMC asymptotic mean squared error (MSE) in the case of strong channel Selectivity derived in earlier works is developed and extended. The linear precoders and decoders are found by optimizing the MSE formula under two design criteria, namely zero forcing or minimum MSE. Finally, simulation results demonstrate the performance of the optimized design. As long as the number of BS antennas is larger than the number of users, it is shown that those extra degrees of freedom can be used to compensate for the channel Frequency Selectivity.
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uplink fbmc oqam based multiple access channel distortion analysis under strong Frequency Selectivity
IEEE Transactions on Signal Processing, 2016Co-Authors: David Gregoratti, Xavier MestreAbstract:This paper computes the distortion power at the receiver side of an FBMC/OQAM-based OFDMA uplink channel under strong Frequency Selectivity and/or user timing errors. More precisely, it provides a distortion expression that is valid for a wide class of prototype pulses (not necessarily perfect-reconstruction ones) when the number of subcarriers is sufficiently large. This result is a valuable instrument for analyzing how users interfere to one another and to justify, formally, the common choice of placing an empty guard band between adjacent users. Interestingly, the number of out-band subcarriers contaminated by each user only depends on the prototype pulses and not on the channel nor on the equalizer. To conclude, the distortion analysis presented in this paper, together with some simulation results for a realistic scenario, also provide convincing evidence that FBMC/OQAM-based OFDMA is superior to classic circular-prefix OFDMA in the case of asynchronous users.
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parallelized structures for mimo fbmc under strong channel Frequency Selectivity
IEEE Transactions on Signal Processing, 2016Co-Authors: Xavier Mestre, David GregorattiAbstract:A novel architecture for MIMO transmission and reception of filterbank multicarrier (FBMC) modulated signals under strong Frequency Selectivity is presented. The proposed system seeks to approximate an ideal Frequency-selective precoder and linear receiver by Taylor expansion, exploiting the structure of the analysis and synthesis filterbanks. The resulting architecture is implemented by linearly combining conventional MIMO linear transceivers, which are applied to sequential derivatives of the original filterbank. The classical per-subcarrier precoding/linear receiver configuration is obtained as a special case of this architecture, when only one stage is fixed at both transmitter and receiver. An asymptotic expression for the resulting intersymbol/intercarrier (ISI/ICI) distortion is derived assuming that the number of subcarriers grows large. This expression can in practice be used in order to determine the number of parallel stages that need to be implemented in the proposed architecture. Performance evaluation studies confirm the substantial advantage of the proposed scheme in practical Frequency-selective MIMO scenarios.
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a parallel processing approach to filterbank multicarrier mimo transmission under strong Frequency Selectivity
International Conference on Acoustics Speech and Signal Processing, 2014Co-Authors: Xavier Mestre, David GregorattiAbstract:The problem of MIMO transmission using filterbank multicarrier (FBMC) modulations in strong Frequency selective channels is considered. A novel architecture for the implementation of MIMO precoders and linear receivers is derived, which consists of multiple parallel stages that are combined at the per-subcarrier level. Each of these stages is constructed like a classical FBMC modulator/demodulator, using the successive derivatives of the prototype pulse instead of the original one. The performance of the proposed architecture is theoretically characterized in terms of the residual distortion power at the output of the receiver, assuming an asymptotically large number of subcarriers. Results demonstrate the effectiveness of the proposed architecture in MIMO channels with severe Frequency Selectivity.
David Gregoratti - One of the best experts on this subject based on the ideXlab platform.
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uplink fbmc oqam based multiple access channel distortion analysis under strong Frequency Selectivity
IEEE Transactions on Signal Processing, 2016Co-Authors: David Gregoratti, Xavier MestreAbstract:This paper computes the distortion power at the receiver side of an FBMC/OQAM-based OFDMA uplink channel under strong Frequency Selectivity and/or user timing errors. More precisely, it provides a distortion expression that is valid for a wide class of prototype pulses (not necessarily perfect-reconstruction ones) when the number of subcarriers is sufficiently large. This result is a valuable instrument for analyzing how users interfere to one another and to justify, formally, the common choice of placing an empty guard band between adjacent users. Interestingly, the number of out-band subcarriers contaminated by each user only depends on the prototype pulses and not on the channel nor on the equalizer. To conclude, the distortion analysis presented in this paper, together with some simulation results for a realistic scenario, also provide convincing evidence that FBMC/OQAM-based OFDMA is superior to classic circular-prefix OFDMA in the case of asynchronous users.
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parallelized structures for mimo fbmc under strong channel Frequency Selectivity
IEEE Transactions on Signal Processing, 2016Co-Authors: Xavier Mestre, David GregorattiAbstract:A novel architecture for MIMO transmission and reception of filterbank multicarrier (FBMC) modulated signals under strong Frequency Selectivity is presented. The proposed system seeks to approximate an ideal Frequency-selective precoder and linear receiver by Taylor expansion, exploiting the structure of the analysis and synthesis filterbanks. The resulting architecture is implemented by linearly combining conventional MIMO linear transceivers, which are applied to sequential derivatives of the original filterbank. The classical per-subcarrier precoding/linear receiver configuration is obtained as a special case of this architecture, when only one stage is fixed at both transmitter and receiver. An asymptotic expression for the resulting intersymbol/intercarrier (ISI/ICI) distortion is derived assuming that the number of subcarriers grows large. This expression can in practice be used in order to determine the number of parallel stages that need to be implemented in the proposed architecture. Performance evaluation studies confirm the substantial advantage of the proposed scheme in practical Frequency-selective MIMO scenarios.
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a parallel processing approach to filterbank multicarrier mimo transmission under strong Frequency Selectivity
International Conference on Acoustics Speech and Signal Processing, 2014Co-Authors: Xavier Mestre, David GregorattiAbstract:The problem of MIMO transmission using filterbank multicarrier (FBMC) modulations in strong Frequency selective channels is considered. A novel architecture for the implementation of MIMO precoders and linear receivers is derived, which consists of multiple parallel stages that are combined at the per-subcarrier level. Each of these stages is constructed like a classical FBMC modulator/demodulator, using the successive derivatives of the prototype pulse instead of the original one. The performance of the proposed architecture is theoretically characterized in terms of the residual distortion power at the output of the receiver, assuming an asymptotically large number of subcarriers. Results demonstrate the effectiveness of the proposed architecture in MIMO channels with severe Frequency Selectivity.
Jérôme Louveaux - One of the best experts on this subject based on the ideXlab platform.
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Single-Tap Precoders and Decoders for Multiuser MIMO FBMC-OQAM Under Strong Channel Frequency Selectivity
IEEE Transactions on Signal Processing, 2017Co-Authors: François Rottenberg, Xavier Mestre, François Horlin, Jérôme LouveauxAbstract:The design of linear precoders or decoders for multiuser multiple-input multiple-output filterbank multicarrier (FBMC) modulations in the case of a strong channel Frequency Selectivity is presented. The users and the base station (BS) communicate using space division multiple access. The low complexity proposed solution is based on a single tap per-subcarrier precoding/decoding matrix at the BS in the downlink/uplink. As opposed to classical approaches that assume flat channel Frequency Selectivity at the subcarrier level, the BS does not make this assumption and takes into account the distortion caused by channel Frequency Selectivity. The expression of the FBMC asymptotic mean squared error (MSE) in the case of strong channel Selectivity derived in earlier works is developed and extended. The linear precoders and decoders are found by optimizing the MSE formula under two design criteria, namely zero forcing or minimum MSE. Finally, simulation results demonstrate the performance of the optimized design. As long as the number of BS antennas is larger than the number of users, it is shown that those extra degrees of freedom can be used to compensate for the channel Frequency Selectivity.
Pim Van Dijk - One of the best experts on this subject based on the ideXlab platform.
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Frequency Selectivity of the human cochlea suppression tuning of spontaneous otoacoustic emissions
Hearing Research, 2016Co-Authors: Geoffrey A Manley, Pim Van DijkAbstract:Frequency Selectivity is a key functional property of the inner ear and since hearing research began, the Frequency resolution of the human ear has been a central question. In contrast to animal studies, which permit invasive recording of neural activity, human studies must rely on indirect methods to determine hearing Selectivity. Psychophysical studies, which used masking of a tone by other sounds, indicate a modest Frequency Selectivity in humans. By contrast, estimates using the phase delays of stimulus-Frequency otoacoustic emissions (SFOAE) predict a remarkably high Selectivity, unique among mammals. An alternative measure of cochlear Frequency Selectivity are suppression tuning curves of spontaneous otoacoustic emissions (SOAE). Several animal studies show that these measures are in excellent agreement with neural Frequency Selectivity. Here we contribute a large data set from normal-hearing young humans on suppression tuning curves (STC) of spontaneous otoacoustic emissions (SOAE). The Frequency selectivities of human STC measured near threshold levels agree with the earlier, much lower, psychophysical estimates. They differ, however, from the typical patterns seen in animal auditory nerve data in that the Selectivity is remarkably independent of Frequency. In addition, SOAE are suppressed by higher-level tones in narrow Frequency bands clearly above the main suppression frequencies. These narrow suppression bands suggest interactions between the suppressor tone and a cochlear standing wave corresponding to the SOAE Frequency being suppressed. The data show that the relationship between pre-neural mechanical processing in the cochlea and neural coding at the hair-cell/auditory nerve synapse needs to be reconsidered.
François Rottenberg - One of the best experts on this subject based on the ideXlab platform.
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Single-Tap Precoders and Decoders for Multiuser MIMO FBMC-OQAM Under Strong Channel Frequency Selectivity
IEEE Transactions on Signal Processing, 2017Co-Authors: François Rottenberg, Xavier Mestre, François Horlin, Jérôme LouveauxAbstract:The design of linear precoders or decoders for multiuser multiple-input multiple-output filterbank multicarrier (FBMC) modulations in the case of a strong channel Frequency Selectivity is presented. The users and the base station (BS) communicate using space division multiple access. The low complexity proposed solution is based on a single tap per-subcarrier precoding/decoding matrix at the BS in the downlink/uplink. As opposed to classical approaches that assume flat channel Frequency Selectivity at the subcarrier level, the BS does not make this assumption and takes into account the distortion caused by channel Frequency Selectivity. The expression of the FBMC asymptotic mean squared error (MSE) in the case of strong channel Selectivity derived in earlier works is developed and extended. The linear precoders and decoders are found by optimizing the MSE formula under two design criteria, namely zero forcing or minimum MSE. Finally, simulation results demonstrate the performance of the optimized design. As long as the number of BS antennas is larger than the number of users, it is shown that those extra degrees of freedom can be used to compensate for the channel Frequency Selectivity.
