Filter Optimization for Carrier Frequency and Timing Offsets in Universal Filtered Multi-Carrier System
01 July 2015
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. The FIR-filter, used in UFMC to filter a group of subcarriers, is a key design parameter to gain more robustness in a relaxed synchronization condition e.g. time-frequency misalignment. While previous work shows very significant SIR improvement for UFMC by optimizing the FIR-filter, if only carrier frequency offset is taken into account. In this paper, we optimize the FIR-filter design by taking both carrier frequency and timing offset into account. From the simulation results, up to 3.6 dB and 15.7 dB SIR improvement can be achieved against UFMC with Dolph-Chebyshev filter (side-lobe attenuation of 40 dB) and classical CP-OFDM system respectively, if the carrier frequency and timing offsets are uniformly distributed in the interval +- 5%
