FBMC vs UFMC vs GFDM: Comparing 5G Waveforms

This page compares FBMC vs UFMC vs GFDM waveforms used in 5G and mentions the difference between them. These techniques have been designed and implemented to overcome limitations of 5G technology, one of which is spectral re-growth.

Figure-1 depicts the comparison between LTE and 5G waveforms. As shown, 5G waveforms i.e., FBMC, UFMC, and GFDM are sharper than the LTE power spectrum waveform.

Table-1 mentions the PAPR of LTE (20MHz Bandwidth signal) and 5G waveforms e.g., FBMC, UFMC, and GFDM with respect to different PN sequences. These results have been obtained using Rohde & Schwarz 5G Vector Signal Generator and 5G Vector Signal analyzer/spectrum analyzer. The results are very useful for power amplifier characterization.

Let’s understand these waveforms:

FBMC - Filter Bank Multi Carrier

• The figure-2 depicts the FBMC Transmitter block diagram.
• FBMC is short for Filter Bank Multicarrier.
• Non-adjacent subcarriers are separated perfectly.
• No CP (Cyclic Prefix) is needed, hence there is an improvement in spectral efficiency.
• Filtering is applied in the frequency domain.
• The non-orthogonal multicarrier modulation technique OQAM is used here.
• The ISI problem due to overlapping of time symbols is solved due to OQAM modulation.
• For 64-QAM, the FBMC waveform performs better than OFDM.

UFMC - Universal Filtered Multicarrier

• UFMC is short for Universal Filtered Multicarrier.
• UFMC is complex, similar to OFDM, and uses the same OFDM processing chain. Unlike OFDM, filters are used in UFMC after IDFT modules.
• Figure-3 depicts the transmitter and receiver part of UFMC.

GFDM - Generalized Frequency Division Multiplexing used in 5G technology

• GFDM is short for Generalized Frequency Division Multiplexing.
• It uses a multi-dimensional block structure with CP (Cyclic Prefix).
• Circular signal structure (in time & frequency)
• Pulse-shaped sub-carriers
• Overlapping sub-carriers
• OQAM is used in GFDM