The demodulation of digital signals in a wireless system can be achieved either as coherent, in which the frequency and phase of the carrier have been previously recovered, or as non-coherent.

In free-space optical communication scenarios, atmospheric turbulence distorts the complex wavefront of signal-carrying light beams, leading to bit errors and even communication interruptions. Note ...

Light detection and ranging (lidar) was first conceptualized in the 1930s, at about the same time as radio detection and ranging (radar). However, it took the arrival of lasers in the 1960s before the ...