Advanced Pulse Sequence Design in Time-Modulated Arrays for Cognitive Radio

This work deals with the synthesis of time-modulated arrays (TMAs) for cognitive radio systems, in which the harmonic radiations arising from the periodic modulation of the elements in the time-domain are exploited as independent channels for multi-point-to-point communications. The descriptors of advanced time-modulating sequences using sum-of-weighted cosine waveforms are optimized through the particle swarm optimization with the aim of maximizing the overall signal-to-interference-plus-noise ratio on receiving and increasing the antenna directivity. Representative numerical results are presented and discussed in comparison with the ones obtained from classical TMA implementations, based on rectangular pulse sequences in order to highlight the achievable performance improvements.