This letter presents a new scheme to solve the issue of high redundant energy in Unique Word Orthogonal Frequency Division Multiplexing (UW-OFDM). The proposed scheme, called Low-Redundant Energy UW-OFDM (LRE-UW-OFDM), is suitable for time-varied harsh channels such as the Underwater Acoustic (UWA) channel were inserting the UW data in the time domain leads to huge redundant energy and a dramatic deterioration in Bit Error Rate (BER) performance. The insertion of UW in the proposed LRE-UW-OFDM is done in frequency domain to be any desired sequences in time domain with constant redundant subcarriers energy regardless of the size and the location of data subcarriers. The proposed scheme is evaluated over a long-delay UWA channel demonstrating its outperformance against conventional schemes in terms of BER and mean symbol energy.

中文翻译：

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为水声通信启用独特的字 OFDM


这封信提出了一种新方案来解决独特字正交频分复用（UW-OFDM）中的高冗余能量问题。所提出的方案称为低冗余能量UW-OFDM（LRE-UW-OFDM），适用于时变恶劣信道，例如水下声学（UWA）信道，在时域中插入UW数据会导致巨大的冗余能源和误码率 (BER) 性能急剧恶化。所提出的LRE-UW-OFDM中的UW插入是在频域中完成的，以成为具有恒定冗余子载波能量的时域中的任何所需序列，而不管数据子载波的大小和位置。该方案在长延迟 UWA 信道上进行了评估，证明其在 BER 和平均符号能量方面优于传统方案。