Co-existence of UF-OFDM and CP-OFDM

Universal Filtered Orthogonal Frequency Division Multiple Access (UF-OFDM) has two major advantages 1- a relatively simple transceiver structure (comparable complexity to Cyclic Prefix OFDM (CP-OFDM) 2- much better spectral properties. Hence, it is considered as a promising 5G waveform candidate. During the early deployment of the 5G system, many frequency bands will still be occupied by the 4G system, using the legacy CP-OFDM waveform. Since both waveforms (CP-OFDM and UF-OFDM) are not designed to be orthogonal to each other, inter-carrier interference (ICI) arises if both waveforms are used on the same carrier, which is expected in a soft migration stage. The main focus in this work lies on using the uplink shared channel (PUSCH) with both 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 CP-OFDM signal to reduce the ICI on the CPOFDM receiver and 2- windowing (or filtering) at the UF-OFDM receiver to suppress the power spectral leakage from the CPOFDM signal.