A comparison of waveform candidates for 5G millimeter wave systems

Fifth generation wireless systems will heavily rely on available bandwidth in millimeter wave frequencies to achieve the very ambitious data rate targets that have been set forth. Besides overcoming challenging propagation conditions with reasonable implementation complexity and power consumption, careful system design is needed. In this paper we address a fundamental component, the waveform. We first characterize the requirements, and then explore possible multi-carrier and single carrier waveforms. Our analysis shows that design tradeoffs for millimeter wave are different from lower frequency bands, and that DFT-spread waveforms may represent a balanced solution between spectral efficiency and robustness to implementation impairments. Furthermore, we propose a newly introduced waveform, GI-DFT-s-OFDM, as a suitable candidate.