5G cellular communications promise to deliver the gigabit experience to mobile users, with a capacity increase of up to three orders of magnitude with respect to current LTE systems. There is widespread agreement that such an ambitious goal will be realized through a combination of innovative techniques involving different network layers. At the physical layer, the OFDM modulation format, along with its multiple-access strategy OFDMA, is not taken for granted, and several alternatives promising larger values of spectral efficiency are being considered. This paper provides a review of some modulation formats suited for 5G, enriched by a comparative analysis of their performance in a cellular environment, and by a discussion on their interactions with specific 5G ingredients. The interaction with a massive MIMO system is also discussed by employing real channel measurements from Lund University.
Modulation Formats and Waveforms for 5G Networks: Who Will Be the Heir of OFDM?: An overview of alternative modulation schemes for improved spectral efficiency / Banelli, Paolo; Buzzi, Stefano; Colavolpe, Giulio; Modenini, Andrea; Rusek, Fredrik; Ugolini, Alessandro. - In: IEEE SIGNAL PROCESSING MAGAZINE. - ISSN 1053-5888. - 31:6(2014), pp. 80-93. [10.1109/MSP.2014.2337391]