On the time-frequency localisation of 5G candidate waveforms

Among the requirements of the 5th generation (5G) radio access technology (RAT) is that the associated waveform be well-localised in time and frequency. Localisation characteristics of waveforms are important when considering multiplexing and duplexing of transmissions. This paper proposes a measure of time-frequency localisation (TFL) for sets of orthogonal waveforms, based on Heisenberg´s well-known Uncertainty Principle, allowing for the containment of OFDM and FBMC multicarrier signals over the entire bandwidth to be determined. A theoretical bound on TFL for sets of orthogonal waveforms sharper than the general uncertainty principle is provided. Several multicarrier waveforms generated using well-defined filters are shown by simulation to approach the derived bound as the number of subcarriers increases.