Coexistence of UF-OFDM and CP-OFDM

Universal Filtered Orthogonal Frequency Division Multiplexing (UF-OFDM) is considered as a promising 5G waveform candidate. It requires a relatively simple transceiver structure, while achieving much better spectral properties compared to CP-OFDM. During the early deployment of 5G systems, many frequency bands will still be occupied by 4G systems, using the legacy CP-OFDM waveform. The main focus in this work lies on using the uplink shared channel (PUSCH) with both waveforms on the same carrier. We analyze the impact of inter-carrier interference (ICI) leakage on the performance of both receivers for neighboring allocations using the different waveforms. We also propose two techniques to mitigate the effect of ICI between both waveforms, namely: 1-delaying the transmitted UF-OFDM signal relative to the transmitted CPOFDM signal to reduce the ICI on the CP-OFDM receiver and 2-windowing at the UF-OFDM receiver to suppress the power spectral leakage from the CP-OFDM signal.