Waveform Optimization in UWB Antenna Systems Based on Prolate Spheroidal Wave Signal Spaces

Antenna waveform distortion evaluation in ultrawideband (UWB) communications has become an important concern due to the possible degradation in system performance. Fidelity is the typical measure to take into account distortion for single waveforms. In this paper, a new method designed for computing approximately the optimum waveform in a two- antenna system, exploiting an important mathematical concept, the orthogonality, is proposed. The method is based on a matrix decomposition obtained using prolate-spheroidal wave signal spaces and an evaluation of its eigenvalues. It is showed that this method allows to improve distortion. Finally, this algorithm is applied in three real links using computed transfer functions when two typical radiating structures are used for building a radio link, showing a good improvement in fidelity values.