Permutation Polynomial Interleaved DFT-s-OFDM

• Published in: IEEE open journal of the Communications Society Vol. 4; pp. 1551 - 1566
• Main Authors: Berggren, Fredrik, Popovic, Branislav M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Channels; Discrete Fourier transform spread orthogonal division multiplexing (DFT-s-OFDM); Discrete Fourier transforms; Doppler effect; Fourier transforms; Frequency division multiplexing; Frequency domain analysis; interleaver; Mathematical analysis; Modulation; Orthogonal Frequency Division Multiplexing; Peak to average power ratio; permutation polynomial; Permutations; Polynomials; Symbols; Time-frequency analysis
• ISSN: 2644-125X; 2644-125X
• DOI: 10.1109/OJCOMS.2023.3293330

We propose frequency-domain interleaver for discrete Fourier transform spread orthogonal division multiplexing (DFT-s-OFDM) based on a linear- or quadratic permutation polynomial (LPP/QPP). Interleaving the Fourier coefficients (i.e., the DFT precoder output) implies that the modulation symbols become transmitted over both time- and frequency domain, which is beneficial over time-frequency selective channels. Despite that the single-carrier property is lost due to the interleaving, the peak-to-average-power ratio (PAPR) can be improved. The results show that a QPP can suppress the error floor of the bit/block error rate (BER/BLER) which occurs on channels with large Doppler spread and simultaneously reduce the PAPR. An LPP primarily decreases the PAPR, especially for BPSK, where the gain is several dB. We derive criteria of how to analytically determine the QPPs and the LPPs.