Page 15 - Buletin_January_2023

Satellite communications

The increasing number of applications of nanosatel-
lites, e.g., in the Cubesat form factor, requires new
types of radio links delivering high-throughput and
high-reliability communications currently not availa-
ble for nanosatellites. Research in the area of satellite
communications focuses on baseband/physical layer,
as well as data-link-layer algorithms and protocols
which can be used for the development of cheap
communication modules implemented using the
Software Defined Radio (SDR) technique. In particu-
lar, energy-efficient modulation types are investigat-
ed, since their application is crucial when limited
power is available onboard the nanosatellites. Due to
the tight radio link budget, advanced synchronization and channel coding schemes are considered as
well. The selected solutions are implemented using the Software Defined Radio technique, based on
off-the-shelf SDR platforms and general-purpose processors, as well as dedicated hardware including
FPGA chips and integrated transceivers.

Cognitive radio systems

Research in the area of cognitive radio technologies includes theoretical studies and experimental trials
on the acquisition of context information related to the radio environment, machine learning methods
for the improvement of the quality of this information, as well as the principles of signal transmission
in radio communication networks using it. In particular, the research focuses on autonomous and co-
operative sensing and spectrum sharing policies based on either centralized or distributed coordina-
tion of dynamic spectrum access. Radio Environment Maps (REMs) are being investigated for their use
in cognitive radio systems for the reduction of interference between systems utilizing a range of the
radio frequency band. Moreover, physical-layer algorithms are being investigated that increase the
spectral efficiency of systems with frequency-neighboring signal spectra.