B. Muquet

Motorola

15Publications

11H-index

1,377Citations

Publications 15

Newest*
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Estimated H-index: 11

Estimated H-index: 25

Estimated H-index: 44

Zero padding (ZP) of multicarrier transmissions has been proposed as an appealing alternative to the traditional cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM) to ensure symbol recovery regardless of the channel zero locations. In this paper, both systems are studied to delineate their relative merits in wireless systems where channel knowledge is not available at the transmitter. Two novel equalizers are developed for ZP-OFDM to tradeoff performance with implementation com...

Estimated H-index: 11

Estimated H-index: 19

Estimated H-index: 44

This paper proposes a new blind channel estimation method for orthogonal frequency division multiplexing (OFDM) systems. The algorithm makes use of the redundancy introduced by the cyclic prefix to identify the channel based on a subspace approach. Thus, the proposed method does not require any modification of the transmitter and applies to most existing OFDM systems. Semi-blind procedures taking advantage of training data are also proposed. These can be training symbols or pilot tones, the latt...

Estimated H-index: 52

Estimated H-index: 11

Estimated H-index: 112

Space time coding has by now been well documented as an attractive means of achieving high data rate transmissions with diversity and coding gains, provided that the underlying propagation channels can be accounted for. We rely on redundant linear precoding to develop a (semi-)blind channel estimation algorithm for space time (ST) orthogonal frequency division multiplexing (OFDM) transmissions with Alamouti's (see IEEE J. Select. Areas Commun., vol.16, p.1451-58, Oct. 1998) block code applied on...

Published on Jan 1, 2002

Estimated H-index: 11

Estimated H-index: 44

Estimated H-index: 19

We provide a geometrical interpretation of the it- erative decoding of bit interleaved coded modulation (BICM) (2) as an algorithm performing successive projections of probabili- ties densities onto well defined density spaces with respect to the Kullback distance. This enables to derive a convergence result.

Published on Jan 1, 2000

Estimated H-index: 11

Estimated H-index: 19

Estimated H-index: 3

We extend the turbo demodulation procedure proposed by Li and Ritcey (see IEEE Journal on Selected Areas in Communications, vol.17, no.4, p.715-24, 1999) and by Magniez, Muquet, Duhamel, Buzenac and de Courville (see Proc. Int. Symp. on Turbo Codes and Related Topics, Brest, France, p.169-72, 2000) to OFDM systems with cyclic prefix (CP-OFDM) or zero-padding (ZP-OFDM). The extensions account for the noise color introduced by linear equalization. Resorting to realistic simulations, we also show t...

Subspace-based estimation of frequency-selective channels for space-time block precoded transmissions*
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Published on Jan 1, 2000

Estimated H-index: 11

Estimated H-index: 52

Estimated H-index: 112

Space time coding has been by now well documented as an attractive means of achieving high data rate transmissions with high quality of service, provided that the underlying channels can be accounted for. We propose in this paper a (semi-) blind channel estimation algorithm that is suitable for space time (ST) block precoded transmissions over frequency-selective channels. We show that multi-channel identifiability is guaranteed up to only one scalar ambiguity regardless of channel zero location...

OFDM with trailing zeros versus OFDM with cyclic prefix: links, comparisons and application to the HiperLAN/2 system*
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Published on Jan 1, 2000

Estimated H-index: 11

Estimated H-index: 19

Estimated H-index: 112

This paper proposes a simple equalizer for a multicarrier block transmission scheme which pads zeros (as opposed to a cyclic prefix) in each transmitted block. In the absence of high-power amplifier induced nonlinear effects, it is shown that the resulting scheme is simply the dual of the classical cyclic prefix OFDM transceiver. Comparison between the two systems that takes into account nonlinear distortions introduced by the clipper is also performed in the practical context of the wireless br...

Published on Jan 1, 2000

Estimated H-index: 3

Estimated H-index: 11

Estimated H-index: 19

Turbo-equalization has been proposed as a powerful means for recovering unknown symbols sent through frequency selective channels. Most algorithms proposed so far were designed in the framework of a binary symbol alphabet, and then extended to modulations with a larger number of states. Moreover symbol interleaving was mainly considered. This paper improves existing algorithms in that our algorithm (i) exhibits better performance when used with large constellations, and (ii) can be used in conju...

Estimated H-index: 11

Estimated H-index: 2

Estimated H-index: 44

Published on Jan 1, 2000

Estimated H-index: 11

Estimated H-index: 19

Estimated H-index: 44

The widespread application of OFDM for local area mobile wireless broadband systems is strongly motivated by the simple equalization it affords. OFDM's bottleneck of channel-dependent performance was only previously addressed by replacing the cyclic prefix (CP) with trailing zeros (TZ). Such zero-padded OFDM transmissions enable FIR channel-irrespective symbol recovery which results in significant BER gains. The price paid is increased receiver complexity compared to the classical CP-OFDM. To re...

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