In the article we summed several years of research and development in the area of broadband communications via high altitude platforms (HAPs) with the emphasys on the role of HAPs in the provision of global wireless connectivity. In the paper we evaluated the suitability of several advanced communication technologies for their use on HAPS, including cognitive radio and dynamic spectrum access, and provided challenges and directions for future research work. The article is one in the series of invited articles published upon a centenial year of publication of prestigeous journal "Proceedings of the IEEE" in the broader field of electrical engineering (first quartile, 3/247) with an impact factor significantly above average.
COBISS.SI-ID: 25035303
In the paper we discussed resource allocation issues in the context of a virtual multiuser MIMO uplink. We presented a new scheduling algorithm which efficiently mitigates the co-channel interference arising from the spatial correlation of users sharing common resources. The user selection criterion is based on an adaptive, utility-based scheduling metric designed for the purpose. Its main advantage is in the periodic adaptation of priority weights according to the application characteristics described with its utility curves and according to momentary quality of service parameters. The results show a better performance than the existing utility based scheduling metrics.
COBISS.SI-ID: 24911655
In this paper, we presented closed-form bit error rate expression for orthogonal frequency division multiplexing modulation technique with a pilot-assisted channel estimation in a nonlinear and frequency-selective fading channel. We discussed how, and to what extent, the nonlinear degradation affects the bit error rate performance with the channel estimation based on a time/frequency division-multiplexed pilot. The analysis was based on a Gaussian approximation of the nonlinear noise due to both HPA amplitude limitation and signal quantization. We also evaluated the estimator’s mean square error with both TDM and FDM pilots.
COBISS.SI-ID: 24581927