A First Encounter with Faster-than-Nyquist Signaling on the MIMO Channel

In this paper we investigate MIMO systems where faster-than-Nyquist (FTN) signaling is used as modulation. On the AWGN channel, the main characteristic of FTN is the so called Mazo limit; it is possible to signal considerably faster than conventional without loss in minimum Euclidean distance. We show that MIMO-FTN systems inherit this property from the AWGN-FTN systems. Moreover, not only does it exist a Mazo limit in MIMO, but it occurs at exactly the same signaling rate as for the AWGN channel. We also discuss information rates of MIMO-FTN systems.