DFT-Spread Spectrally Efficient Non-Orthogonal FDMA

Single carrier frequency division multiple access (SC-FDMA) has been comprehensively investigated and standardized in 4th generation (4G) and 5th generation (5G) mobile systems. Its significant advantage is low peak-to-average power ratio (PAPR), which makes it suitable for uplink channel communications. However, over a long time period, SC-FDMA has not made breakthrough especially in data rate enhancement, which may not catch up with the next generation evolution in communications. This work proposes to use a non-orthogonal waveform in SC-FDMA to promote a new concept, termed single carrier spectrally efficient frequency division multiple access (SC-SEFDMA). This non-orthogonal single carrier access technique maintains essentially similar complexity as SC-FDMA but advantageously can either achieve higher data rate for the same amount of power consumption or the same data rate with less power consumption.