From OFDM to FBMC: Principles and Comparisons

This chapter describes the filter bank multi-carrier (FBMC) scheme with a prototype filter as used by the PHYDYAS project. It reviews the classical schemes of filtered orthogonal frequency division multiplexing (OFDM) and compares with the FBMC in terms of the out-of-band (OOB) performance achieved and its implementation complexity. Nowadays, practical communication systems are implemented on digital signal processor or field programmable gate array chipsets in a digital form. So it makes sense to discuss discrete-time implementation of the filter bank. The classical sidelobe-suppression methods for OFDM signals, time windowing and active interference cancelation (AIC), are also reviewed. The performance of these filtered OFDM approaches, measured by the OOB power radiation and implementation complexity, is described, together with those of the FBMC scheme. The key idea of AIC is the insertion of several cancelation subcarriers at the edges of OFDM spectrum.