Improving Throughput of Faster-than-Nyquist Signaling over Multiple-Access Channels

This work considers using faster-than-Nyquist (FTN) transmission in symbol-synchronous and symbol-asynchrounous multiple-access channels (MAC) when multi-user demodulation and decoding are used at the receiver. We derive a sum capacity expression for the FTN-MAC in the presence of user asynchronism and present numerical capacity results. This work demonstrates that the channel capacity can be improved by introducing the FTN signaling in the multiple-access channels with or without asynchronism among transmitters of various users.