Optimal link adaption to the scattering function of wide sense stationary uncorrelated scattering (WSSUS) mobile communication channels is still an unsolved problem despite its importance for next-generation system design. In multicarrier transmission such link adaption is performed by pulse shaping which in turn is equivalent to precoding with respect to the second order channel statistics. In...

The performance of Orthogonal Frequency Division Multiple Access (OFDMA) system degrades significantly in doubly dispersive channels. This is due to the fact that exponential sub-carriers do not match the singular functions of this type of channels. To solve this problem, we develop a system whose sub-carriers are chirp functions. This is equivalent to exploiting Fractional Fourier Transform (F...

Optimal link adaption to the scattering function of wide sense stationary uncorrelated scattering (WSSUS) mobile communication channels is still an unsolved problem despite its importance for next-generation system design. In multicarrier transmission such link adaption is performed by pulse shaping which in turn is equivalent to precoding with respect to the second order channel statistics. In...

In this paper, we investigate three different concepts for robust link-level performance under doubly-dispersive wireless channels, namely, i) channel estimation, ii) cyclic prefix (CP)-free transmission, and iii) waveform design. We employ a unique word-based where decouple the related errors into estimation error (CEE) Doppler (DE). Then, show that trade-off between CEE DE emerges in frame de...

We present several novel tools for the statistical characterization of fading dispersive channels that do not satisfy the usual WSSUS assumption. A local scattering function, describing the timeand frequency-dependentaverage scatterer power, is introduced. Furthermore, a novel channel correlation function is presented that quantifies the scatterer correlation. Based on the channel correlation f...

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We study the problem of modulation and coding for doubly dispersive, i.e., time and frequency selective fading channels. Using the recent result that under-spread linear systems are approximately diagonalized by biorthogonal Weyl-Heisenberg bases, we arrive at a canonical formulation of modulation and code design. For coherent reception with maximum likelihood decoding, we derive the code desig...