Faster-than-Nyquist Single-Carrier MIMO Signaling

Faster-Than-Nyquist (FTN) signaling is created when a digital communications signal has an occupied bandwidth less than the symbol rate. It has been previously demonstrated that FTN signals can achieve bit error rates near that of full-bandwidth signaling for BPSK and 4-QPSK modulation. Iterative frequency domain equalization allows for low cost receivers. This paper presents FTN signaling for Multiple-Input/Multiple-Output (MIMO) signals where a Single-Carrier (SC) MIMO signal is converted to the frequency domain and its occupied bandwidth is reduced by removing some of the frequency components before conversion back to the time domain. A previously proposed Single-Input/Single-Output FTN iterative receiver algorithm is extended for FTN SC-MIMO signals. Singular Value Decompositions (SVD) are proactively performed on the channel transfer matrices to reduce the computation cost of the iterative receiver. It is demonstrated that the Bit Error Rate (BER) performance of this MIMO FTN scheme is near that of full bandwidth MIMO signals with a low cost receiver algorithm. The signalling is robust to the selection of the frequency components that are nulled.