{'fraction_non_alphanumeric': 0.03125, 'fraction_numerical': 0.0, 'mean_word_length': 5.473404255319149, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A distortionless approach for PAPR reduction using SC-FDMA-IDMA in acoustic environment

This paper provides a simple strategy to reduce peak-to-average power-ratio (PAPR) of single-carrier frequency-division multiple-access interleave-division multiple-access (SC-FDMA-IDMA) scheme employed in underwater acoustic (UWA) communications. The attributes that are attractive for UWA communications are power and bandwidth. High-order modulations are used to make SC-FDMA-IDMA more bandwidth efficient. But as we move towards high-order modulations PAPR of localised SC-FDMA-IDMA signal becomes high. Presented technique aims to further reduce PAPR of SC-FDMA-IDMA signals. Transmitter structure of the presented technique employs random interleaver to differentiate users and power interleaver to generate multiple interleaved sequences for the same user. All power interleaved data sequences are compared and the sequence with minimum PAPR is selected for transmission. Performance has been analysed by PAPR simulations and BER (Bit Error Rate) results in acoustic environment. Analysis confirms the merits of our technique over other competing alternatives in terms of performance, complexity and spectral efficiency.