Impact of HPA Nonlinearity on the Performance of Power Domain OFDM-NOMA System

Abstract Non-orthogonal multiple access (NOMA) is expected to be used in beyond fifth-generation (B5G) and sixth-generation (6G) mobile networks support ultra-massive connectivity. Since the two preceding generations orthogonal frequency division multiplexing (OFDM), NOMA combined with OFDM. Unfortunately, OFDM signal suffers from a high peak average power ratio (PAPR) that limits its performance as it passes through nonlinear amplifier (HPA). In literature, few works have studied effect of distortion on OFDM-NOMA. Furthermore, HPA models previous describe impact OFDM-NOMA downlink (DL) were impractical or inaccurate. contrast, this work uses well-known soft limiter (SL) model input back-off (IBO) practical controlling parameter. Also, instead investigating DL only, investigated both uplink (UL). particular, during work, system presence UL terms users’ achievable data rate, sum rate capacity, fairness, bit error (BER) each user. Results showed that, DL, NU most affected by distortion, while, UL, caused NU’s more severe than other users.