Magnus Lundberg Nordenvaad

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—We derive eigenvalue beamformers to resolve an unknown signal of interest whose spatial signature lies in a known subspace, but whose orientation in that subspace is otherwise unknown. The unknown orientation may be fixed, in which case the signal covariance is rank-1, or it may be random, in which case the signal covariance is multirank. We present a(More)
Several naturally occurring hybrids in Potentilla (Rosaceae) have been reported, but no molecular evidence has so far been available to test these hypotheses of hybridization. We have compared a nuclear and a chloroplast gene tree to identify topological incongruences that may indicate hybridization events in the genus. Furthermore, the monophyly and(More)
We consider using the conjugate gradient (CG) algorithm to equalize a time-varying channel in an orthogonal frequency division mul-tiplexing (OFDM) system. Preconditioning technique to accelerate the convergence of the CG algorithm is discussed, where we show that when the Doppler spread becomes higher, the commonly used diagonal preconditioner, despite its(More)
— This paper addresses canonical correlation analysis of two-channel data, when channel covariances are estimated from a limited number of samples, and are not necessarily full-rank. We show that empirical canonical correlations measure the cosines of the principal angles between the row spaces of the data matrices for the two channels. When the number of(More)
—We consider an orthogonal frequency-division multi-plexing (OFDM) transmission scheme over wideband underwater acoustic channels, where the propagation paths can experience distinct Doppler effects (manifested in signal scales) and time of arrivals (manifested in lags). We capture such an effect in this paper with a multi-scale multi-lag (MSML) model, and(More)
— Constrained minimization problems considered here arise in the design of multi-dimensional subspace beam-formers for radar, sonar, seismology, and wireless communications , and in the design of precoders and equalizers for digital communications. The problem is to minimize a quadratic form, under a set of linear or quadratic constraints. We derive the(More)
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