Adaptive detection method of FTN signalling at constant Nyquist sampling rate

Abstract

Faster-than-Nyquist (FTN) signalling, as a candidate technology of fifth generation, can transmit more data with the same bandwidth. In the adaptive transmission system based on FTN signalling (FNS), the transmitter changes the packing ratios to adapt to the wireless channels. The scheme that combines the adaptive coding and modulation with the FNS has higher spectral efficiency. However, the symbol rate changing with the packing ratio challenges the receiver of adaptive transmission system based on FNS. Moreover, the decoding complexity based on viterbi algorithm (VA) is increasing exponentially when the packing ratios of FNS decrease. In this study, the authors proposed an adaptive detection method to detect FTN signal at constant sampling rate. The proposed method adopted an linear minimum mean square error (LMMSE) equaliser to solve the mismatch of the symbol rate and the sampling rate. Their simulation results show that the adaptive detection method of FNS can approach the optimal bit error rate performance of the coded FTN system. At the same time, the proposed method can avoid the complexity induced by the variable sampling rate in the adaptive transmission system based on FNS.