DFT-s-OFDM(DFT spread OFDM)
You would know of SC-OFDM because this is the waveform that we use in current LTE. If you are familiar with SC-FDMA, you can easily understand DFT-s-OFDM. High level view of DFT-s-OFDM waveform generation is illustrated as follows. You would notice that this is almost same as high level SC-OFDM process.