Low Complexity Implementation of Universal Filtered Multi-Carrier Transmitter

Abstract

Universal Filtered Multi-Carrier (UFMC) is a promising multi-carrier modulation scheme. It can be considered as the combine of filtered OFDM and Filter Bank Multi-Carrier (FBMC) modulations. The difference among them is that filtered OFDM filters the entire band and FBMC filters the single subcarrier, while UFMC filters groups of subcarriers. It is evaluated their performance for the new conditions. While UFMC offers superior advantages, such as higher spectral efficiency, lower overhead, more robustness and less out-of-band (OOB) emission, the introduction of filters and the application of FFTs for the subband increase the implementation complexity of the transmitter. In terms of complexity, based on the analysis of UFMC transceiver structure, few low complexity implementation methods for UFMC systems are recently put forward. The low complexity solutions need to be found. In this paper, the computational complexity of different UFMC implementation methods based on lightweight structure which combines with the FIR filter and the poly-phase filter is evaluated. It is shown that the computational complexity of the UFMC transmitter can be reduced to be similar to OFDM, which is a promising solution for the advanced waveform. In addition, we analyze the effect of the filter on the power spectral density (PSD) of the proposed structure. Analysis shows that the system can be implemented with better performance by adjusting the filter parameters.