Root-raised-cosine filter
In signal processing, a root-raised-cosine filter (RRC), sometimes known as square-root-raised-cosine filter (SRRC), is frequently used as the transmit and receive pulse shaping filter in a digital communication system to perform matched filtering. This helps in constraining the occupied bandwidth of the waveform without introducing intersymbol interference (ISI).
Source: Wikipedia — Root-raised-cosine filter (CC BY-SA 4.0)