Faster than Nyquist Waveform for Beyond 5G Systems - Evaluation and Implementation Aspects

With the exponential growth of cellular traffic in recent times, larger bandwidth and higher spectral efficiency (SE) have become indispensable for higher data rate applications. Discrete Fourier transform spreading orthogonal frequency division multiplexing (DFT-s-OFDM) waveform is being considered as one of the potential candidates for the next generation communications, because of its low peak to average power ratio (PAPR), which is more suitable for large bandwidth systems that are limited by inefficient power amplifiers. However, DFT-s-OFDM suffers from low SE, thus affecting the system throughput. Recently, faster than Nyquist (FTN) signaling combined with DFT-s-OFDM is being studied for its improved spectral efficiency with less PAPR. In this paper, we analyze the performance benefits of applying FTN signaling on DFT-s-OFDM waveform with 5G new radio uplink system. We show that the FTN combined with DFT-s-OFDM has 2% ∼ 75% more throughput than that of of DFT-s-OFDM for the same signal to noise ratio (SNR), using fading channel model. We further show through link adaptation method that the SE of DFT-s-OFDM waveform improves significantly when combined with FTN signaling. We also discuss about the implementation aspects and the performance trade-off with FTN integration into beyond 5G systems.