Introduction to QAM-FBMC: From Waveform Optimization to System Design

The asynchronous heterogeneous network scenario is becoming one of the key features for 5G mobile communications. Compared to CP-OFDM, which is 4G waveform, superior spectrum confinement as well as higher spectral efficiency has been taken into consideration for 5G waveform design. In this article, we introduce a new waveform called QAM-FBMC that provides superior spectrum confinement and higher spectral efficiency simultaneously against CP-OFDM. The article explains fundamental trade-offs in waveform design and shows how they can be optimized for QAM-FBMC. We also introduce the transmission and reception procedures for QAM-FBMC including its similarities and differences compared to well-known waveforms such as CP-OFDM and OQAM-FBMC. Performance evaluation results show where the spectral efficiency gain of QAM-FBMC over CP-OFDM comes from.