5G NR

Figure 3.21 Comparison of OFDM and FBMC signals in the frequency domain [38].

3.2.3.3 Universal Filtered Multicarrier

Universal filtered multicarrier (UFMC) is a generalization of OFDM and FBMC. The ultimate goal of UFMC is to combine the advantages of OFDM and FBMC while avoiding their main drawbacks. By filtering groups of adjacent subcarriers, the side-lobe levels (compare to OFDM) and the prototype filter length (compare to FBMC) can be simultaneously and significantly reduced. The kth OFDM signal over the ith physical resource block (i.e., 12 adjacent subcarriers in NR) can be expressed as follows [38]:

$x_{k,i}(m)=\sum _{n\in S_i}{s}_{k,n}{e}^{j\left(2\pi /N_{\mathrm{sub}}\right)kn}$