Fluid Antenna System 

Fluid antenna system (FAS) refers to any software-controllable fluidic conductive structure, movable mechanical antenna structure, or reconfigurable radio-frequency (RF)-pixels that can change its shape and position to reconfigure the gain, radiation pattern, operating frequency, and other characteristics. Thus, FAS embraces all forms of movable and non-movable flexible-position antennas. Of particular interest in the physical layer design is the position flexibility FAS can offer. By near-continuously switching the antenna’s position within a predefined area to a position where the channel has desirable conditions, FAS can obtain spatial diversity and in multiuser communications, make interference disappear by exploiting opportunities in fading.