  One of the main open problems for next generation wireless networks, is to
find the new OFDM-based waveform to be used in 5G. The new modulation scheme
must primarily be able to achieve higher spectral efficiency than its
predecessor. The main 3GPP's candidate is a new version of OFDM, called
Filtered Orthogonal Frequency-Division Multiplexing (f-OFDM), which is similar
to OFDM but with additional filtering in order to reduce Out-Of-Band (OOB)
emissions and to obtain a better spectral-localization. Another option is
windowed-OFDM (w-OFDM), which is basically a classical OFDM scheme where each
symbol is windowed and overlapped in the time domain. In this paper we compare
classic OFDM signals using Cyclic Prefix (CP-OFDM) with f-OFDM and w-OFDM, each
one with multiple parametric options and numerologies. A multirate transmitter
simultaneously operating with multiple numerologies is considered, where the
transmitted sub-bands must be up-sampled and interpolated in order to generate
the composite numerical signal fed to the Digital to Analog Converter (DAC).
Finally, we discuss advantages and disadvantages of the various schemes.
