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This paper provides an overview of the state-of-the-art radio propagation and channel models for wireless multiple-input multiple-output (MIMO) systems. We distinguish between physical models and analytical models and discuss popular examples from both model types. Physical models focus on the double-directional propagation mechanisms between the location(More)
Abstracr-We propose two related iterative algorithms for computing the capacity of discrete memoryless channels. The celebrated Blahnt-Arimoto algorithm is a special case of our framework. The formulation of these algorithms is based on the natural gradient and proximal point methods. We also provide interpretations in terms of notions from information(More)
Interleave-division multiple access (IDMA) has recently been proposed as an alternative to CDMA. IDMA employs user-specific in-terleavers combined with low-rate channel coding for user separation. It can outperform coded CDMA when iterative receivers are used, and it allows the design of multiuser detectors with moderate complexity. In this paper, we extend(More)
—We propose decision-directed channel predictors for orthogonal frequency-division multiplexing (OFDM) communications over time-varying channels. Channel prediction is capable of yielding up-to-date channel state information even without regular transmission of pilot symbols. It is thus potentially useful for delay-free equalization, antenna combining,(More)
—This paper considers pulse shaping multicarrier (MC) systems that transmit over doubly dispersive fading channels. We provide exact and approximate expressions for the intersymbol and intercarrier interference occuring in such systems. This analysis reveals that the time and frequency concentration of the transmit and receive pulse is of paramount(More)
The fading process in high speed vehicular traffic telematic applications at 5 GHz is expected to fulfill the wide-sense stationarity uncorrelated scattering (WSSUS) assumption for very short time-intervals only. In order to test this assumption we apply the concept of a local time– and frequency–variant scattering function, which we estimate from(More)
This paper considers practically relevant aspects and advantages of pulse-shaping orthogonal/biorthogonal frequency division multiplexing (OFDM/BFDM) systems. We analyze the intersymbol/intercarrier interference (ISI/ICI) in such systems when they operate over time-varying channels. Two methods for an ISI/ICI-minimizing pulse design are proposed, and(More)
We extend the approximate transfer function calculus of " undersnreadll linear time-varvine fLTV1 svstems introduced by W. Kozek. Our extensiog is' based o " n a new, generalized definition of underspread LTV svstems that does not assume finite support of the systems " ' spreading function. We establish explicit bounds on various error quantities associated(More)