This paper deals with synthesis of time-modulated linear arrays for adaptive nulling and beamforming where the intrinsic characteristics of this type of antenna arrays can be fully exploited, thanks to the capability of fast reconfiguration of its radiation pattern through the modification of the digital on-off signals controlling the element excitations. A strategy based on the particle swarm optimization is adopted to determine the optimal pulse sequences. A set of simulation experiments is finally proposed as a numerical validation.