Faster-than-Nyquist (FTN) signaling

as a non-orthogonal signaling format

has been attracting a lot of attention recently. FTN signaling has a symbol rate that is higher than the Nyquist rate

which causes intersymbol interference inevitably. However

this signaling method has been proved to bring higher channel capacity. Therefore

FTN signaling has become a new bandwidth-efficient modulation method which offers a promising solution to the communication scenario with scarce bandwidth. Furthermore

faster-than-Nyquist signaling has also become a hot topic in the research of satellite communication and backhauling technique in 5G communication standard. This paper provides a summary of FTN signaling in terms of its concept and theory

capacity

implementation

detection

as well as performance and applications

respectively. Some discussions of current research difficulties are also given in the paper.