Advances in Equalization and Diversity for Portable Wireless Systems

Falconer, D.D.; Abdulrahman, M.; Lo, N.W.K.; Petersen, Brent R.; Sheikh, A.U.H.

doi:10.1006/dspr.1993.1021

Cited by 46 publications

(7 citation statements)

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“…According to a basic premise of the vertical architecture, we optimize the number of transmitters used. The diagonal capacity in bit/s per available dimension, when using transmitters with optimally chosen when there are transmitters available, is bit/s/Hz/dim large (13) Letting , we take the limit as goes to infinity and rewrite (13) as an integral to express the capacity in terms of maximization over the set . Partition the interval [0, 1] into equal subintervals each of size .…”

Section: Capacity Perormance For Large Numbers Of Antennasmentioning

confidence: 99%

Simplified processing for high spectral efficiency wireless communication employing multi-element arrays

Foschini¹,

Golden²,

Valenzuela³

et al. 1999

IEEE J. Select. Areas Commun.

988

590

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Abstract-We investigate robust wireless communication in high-scattering propagation environments using multi-element antenna arrays (MEA's) at both transmit and receive sites. A simplified, but highly spectrally efficient space-time communication processing method is presented. The user's bit stream is mapped to a vector of independently modulated equal bit-rate signal components that are simultaneously transmitted in the same band. A detection algorithm similar to multiuser detection is employed to detect the signal components in white Gaussian noise (WGN). For a large number of antennas, a more efficient architecture can offer no more than about 40% more capacity than the simple architecture presented. A testbed that is now being completed operates at 1.9 GHz with up to 16 quadrature amplitude modulation (QAM) transmitters and 16 receive antennas. Under ideal operation at 18 dB signal-to-noise ratio (SNR), using 12 transmit antennas and 16 receive antennas (even with uncoded communication), the theoretical spectral efficiency is 36 bit/s/Hz, whereas the Shannon capacity is 71.1 bit/s/Hz. The 36 bits per vector symbol, which corresponds to over 200 billion constellation points, assumes a 5% block error rate (BLER) for 100 vector symbol bursts.

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Section: Capacity Perormance For Large Numbers Of Antennasmentioning

confidence: 99%

Simplified processing for high spectral efficiency wireless communication employing multi-element arrays

Foschini¹,

Golden²,

Valenzuela³

et al. 1999

IEEE J. Select. Areas Commun.

988

590

View full text Add to dashboard Cite

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“…A number of papers have been published which illustrate the effectiveness of the DFE in combatting such interference. As examples of this work, we cite the papers by Falconer et al [452], Abdulrahman et al [438], and Duel Hallen [451].…”

Section: E Equalization Of Interference In Multiuser Communication Smentioning

confidence: 99%

Fading Channels: InformationTheoretic and Communications Aspects

2009

Information Theory

250

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Abstract-In this paper we review the most peculiar and interesting information-theoretic and communications features of fading channels. We first describe the statistical models of fading channels which are frequently used in the analysis and design of communication systems. Next, we focus on the information theory of fading channels, by emphasizing capacity as the most important performance measure. Both single-user and multiuser transmission are examined. Further, we describe how the structure of fading channels impacts code design, and finally overview equalization of fading multipath channels.

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“…Insufficient a priori information about the channel and, especially in the case of wireless channels, the time-varying nature of the channel response, necessitate adaptive equalization. Linear transversal equalizers and decision feedback equalizers (DFE's) have been used for many decades in conjunction with deterministic or statistical least-squares (LS) algorithms, like the least-meansquare (LMS) algorithm [1], [3], the Kalman filter [4], [5], and the recursive least-squares (RLS) algorithm [6], [7], to adjust the equalizer coefficients. Parameter estimators can either be employed to directly adapt the equalizer taps or to estimate the impulse response of an FIR channel model, which in turn is used to compute an optimal equalizer, usually in the sense of MMSE.…”

Section: Introductionmentioning

confidence: 99%

Set-membership adaptive equalization and an updator-shared implementation for multiple channel communications systems

Gollamudi

Kapoor

Nagaraj

et al. 1998

IEEE Trans. Signal Process.

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Abstract-This paper considers the problems of channel estimation and adaptive equalization in the novel framework of set-membership parameter estimation. Channel estimation using a class of set-membership identification algorithms known as optimal bounding ellipsoid (OBE) algorithms and their extension to track time-varying channels are described. Simulation results show that the OBE channel estimators outperform the leastmean-square (LMS) algorithm and perform comparably with the RLS and the Kalman filter. The concept of set-membership equalization is introduced along with the notion of a feasible equalizer. Necessary and sufficient conditions are derived for the existence of feasible equalizers in the case of linear equalization for a linear FIR additive noise channel. An adaptive OBE algorithm is shown to provide a set of estimated feasible equalizers. The selective update feature of the OBE algorithms is exploited to devise an updator-shared scheme in a multiple channel environment, referred to as updator-shared parallel adaptive equalization (U-SHAPE). U-SHAPE is shown to reduce hardware complexity significantly. Procedures to compute the minimum number of updating processors required for a specified quality of service are presented.

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Advances in Equalization and Diversity for Portable Wireless Systems

Cited by 46 publications

References 0 publications

Simplified processing for high spectral efficiency wireless communication employing multi-element arrays

Simplified processing for high spectral efficiency wireless communication employing multi-element arrays

Fading Channels: InformationTheoretic and Communications Aspects

Set-membership adaptive equalization and an updator-shared implementation for multiple channel communications systems

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