Universal Filtered Multi-Carrier with Leakage-Based Filter Optimization

Universal Filtered Multi-Carrier (UFMC) is a novel modulation technique which can be seen as a generalization of filtered OFDM and filter bank based multi-carrier (FBMCFMT). Being a candidate waveform technology for 5G wireless systems it combines the simplicity of OFDM with the advantages of FBMC. While previous work on UFMC was based on Dolph-Chebyshev-filters, in this paper we now optimize the FIR filter design, using two different optimization criteria. The first criterion is the maximization of the signal over out-of-band leakage ratio. The second criterion uses signal over in-band distortion plus out-of-band leakage ratio. We compare UFMC based on filters with those two optimization approaches against UFMC with Dolph-Chebyshev filters and against OFDM in a setting with non-perfect frequency alignment. The performance gains of the optimized filters are demonstrated in link level simulations. Both of the proposed approaches show significant performance gains over OFDM in terms of average SIR: Almost 10 dB and 7 dB SIR improvement can be achieved by using the first and second criterion, respectively.