Index Modulation-Based Non-Orthogonal Multiple Access With Constant Envelop

This paper proposes a new downlink Non-Orthogonal Multiple Access (NOMA) system called IM-NOMA-CE. This system combines NOMA with index modulation (IM) and constant envelope (CE) modulation techniques, providing richer frequency diversity and strong robustness while enhancing the efficiency of power amplifiers. The simulations indicate that at a bit error rate (BER) of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> dB, the BER performance of IM-NOMA-CE is approximately 3 dB better than that of IM-NOMA and about 12 dB better than NOMA. Benefiting from its constant envelope characteristic, IM-NOMA-CE exhibits a 0 dB peak-to-average power ratio (PAPR). At a complementary cumulative distribution function (CCDF) of 0.1, the PAPR performance of IM-NOMA-CE is approximately 8.7 dB better than that of IM-NOMA.