Reconfigurable Antenna and Dynamic Spectrum Access Algorithm: Integration in a Cognitive Radio Platform for Reliable Communications

Abstract

Wireless communications provide many advantages for industrial applications; however, some problems regarding the reliability of the link must be dealt (e.g. wideband interferers or multipath fading). Cognitive Radio and Dynamic Spectrum Access are two of the technologies that enable the implementation of reliable communications. In order to ensure the reliability of the communication link, it is necessary to carry out a complete change of the transmission band, and not only small in-band changes. Therefore it has to be ensured that the new chosen band is uncorrelated with respect to the previous one, in terms of coherence bandwidth and RF interference. When performing a change in the transmission band the update of some parameters in the digital domain of the cognitive-radio is not enough, but it also requires the adjustment of the analog part, where the antenna element plays an important role. On this basis, this paper presents the integration of a frequency reconfigurable antenna and a Dynamic Spectrum Access algorithm in an FPGA-based cognitive-radio platform for reliable communications. The reconfigurable antenna and the DSA algorithm, together with a commercial adjustable RF front-end, make the system capable of performing both in-band and dual-band channel change in the Industrial, Scientific and Medical (ISM) bands of 868 MHz and 2.45 GHz.