Companding Transform Assisted Constant Envelope OFDM

Constant envelope orthogonal frequency division multiplexing (CE-OFDM) has been extensively studied due to its ability to achieve low peak-to-average power ratio (PAPR) waveforms. However, CE-OFDM may encounter the phase ambiguity problem when the modulation index is relatively large. To mitigate this issue, we incorporate companding technique into CE-OFDM successfully enhance the overall system performance. Moreover, companding scheme requires a balanced consideration between the degree of signal compression and phase ambiguity problem. Therefore, this paper derives the optimal parameter selection by analysing the signal-to-interference-plus-noise ratio (SINR) of the scheme. Simulation results demonstrate that the proposed approach enhances the performance of CE-OFDM effectively by reducing the phase ambiguity as well as minimizing the interference caused by the companding technique.