A New Design of Interleaved DFT-s-OFDM against Power Amplifier Non-Linearity

The non-linearity of power amplifiers (PAs) is a major challenge in satellite communications and high-frequency bands. Traditionally, discrete fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) uses localized subcarrier mapping, which induces a high peak-to-average power ratio (PAPR) and obstructs the efficient operation of the PA. In this paper, we propose an interleaved mapping based DFT-s-OFDM with data length extension to reduce PAPR. To overcome the unrealistic constraints in interleaved mapping, where the occupied subcarriers must be a divisor of the total, we introduce a trans-formation method based on time-domain waveform invariance. Furthermore, we provide its equivalent frequency-domain matrix representation. The constructed waveform reduces PAPR and simultaneously mitigates inter-carrier interference (ICI) caused by non-linearity, effectively achieving resistance to PA non-linearity. Simulations show that our method achieves a gain of up to 1.6 dB in PAPR and 2.4 dB in block error rate (BLER) compared to localized mapping.