Performance evaluation of the UFMC scheme under various transmission impairments

Abstract

The next generation mobile network (fifth generation or 5G) considers the novel multi-carrier (MC) technique dubbed as Universal Filtered Multi-Carrier (UFMC) for implementation. It maintains the advantages of Orthogonal Frequency Division Multiplexing (OFDM) from the fourth generation while avoiding its drawbacks; mainly, the requirements for a strict synchronization between transmitter and receiver. This convenience, however, increases computational complexity as UFMC employs filters to achieve this effect. While the performance of OFDM and UFMC against frequency synchronization error is investigated thoroughly, their performance to delay spread (aka multipath) and timing error has little attention. This paper contains the results of a simulation of UFMC against these communication impediments using MATLAB/Simulink™. In both schemes, the bit error rate is measured when the same number of bits modulated, transmitted, equalized, and demodulated. It is shown that UFMC outshines OFDM under both time and frequency synchronization errors and lags in performance under delay spread when delay spread is below a certain value. This is expected as OFDM preserves orthogonality due to the use of a cyclic prefix (CP). Also investigated in this study is the effect of increasing the filter length of UFMC in its performance. An increase in performance is evident for increasing lengths, but this convenience requires an increase in the number of sub-bands which complicates the system.