Slepian pulses for multicarrier OQAM

OFDM/OQAM is spectrally efficient multicarrier (MC) system, robust to mobile channel (time and frequency) variability thanks to pulse shaping. In this contribution, pulse shaping with discrete non-orthogonal pulse based on Discrete Prolate Spheroidal Sequence (DPSS), is proposed. DPSS, being the most concentrated pulse out of all sequences of the same length, is the natural choice for pulse shaping. The novelty of the analysis lies in the discovery of quasi-orthogonality property of DPSS to its time and frequency shifts. DPSS pulse analysis shows that this property is valid in the case of short pulse of the single MC symbol length. MC/OQAM system performance with DPSS and other pulses types is analyzed by simulation confirming the quasi-orthogonality of DPSS. The advantage of using the most concentrated pulse is shown in terms of interference that two MC/OQAM systems in adjacent frequency bands cause one to another. Simulations also show that DPSS permits smaller frequency separation between systems that are allocated adjacent frequency bands.