An $M$-ary Amplitude DCSK Modulation with Two-Ring Constellation

The $M$-ary differential chaos shift keying (M-DCSK) scheme based on amplitude phase shift keying (APSK) is proposed to improve bit error rate (BER) performance. This approach, called $M$-ary amplitude DCSK (M-ADCSK), overcomes the high peak-to-average power ratio (PAPR) problem, commonly seen in traditional M-DCSK. It is called $M$-ary amplitude DCSK (M-ADCSK). It utilizes a two-ring constellation and incorporates amplitude as a variable parameter. The transmission process involves sending a reference signal followed by a modulated signal with phase and amplitude information obtained through Hilbert transform and amplitude comparator. The BER performance of the proposed scheme is analyzed and validated through simulations over multipath Rayleigh fading channels, demonstrating its superiority compared to traditional M-DCSK modulation.