Inter Numerology Interference Minimization Using Windowing and Precoding Techniques for 5G NOMA Based OFDM Numerologies

Fifth generation radio technologies are expected to serve versatile use cases with constraints on the parameters like data rate, delay and the number of connected devices. To achieve such a flexibility third generation partnership project (3GPP) has proposed Orthogonal Frequency Division Multiplexing (OFDM) based mixed numerologies scheme wherein different subcarrier spacing (SCS) are assigned to different users depending on the service to be offered. But mixed numerology scheme suffers from a severe problem called Inter Numerology Interference (INI) which needs to be addressed. This work proposes the two effective techniques of mitigating the INI that need to be employed at transmitter and receiver, namely windowing and precoding. The performance of these two techniques is demonstrated in terms of Error Vector Magnitude (EVM) versus subcarrier indices. The proposed work is carried out under Non-Orthogonal Multiple Access (NOMA) scenario which makes use of the spectral resources efficiently.