Generalized frequency division multiplexing: Unified multicarrier framework

Generalized frequency division multiplexing (GFDM) was proposed as a contender waveform for 5G. The focus was on fulfilling new requirements such as low out-of-band (OOB) emissions to increase the spectral efficiency and allow asynchronous multiple access. Afterwards, it started evolving as a flexible waveform. In this chapter, we review GFDM beyond its conventional purpose. First, we highlight the role of GFDM in the description and implementation of multicarrier systems. Then, we reproduce GFDM in a unified time-frequency representation. This allows better understanding of the GFDM structure and enables a comprehensive derivation of most of the results presented in the literature. Based on that, we introduce GFDM modem implementation in a more flexible practical architecture. This structure provides additional degrees of freedom for the processing of conventional and new waveforms. Finally, for practical exploitation of GFDM, we introduce the integration of GFDM modem as a precoding technique on top of the OFDM system. Our goal is to provide the readers with a comprehensive handbook that facilitates the understanding of not only GFDM but also multicarrier systems in general.