Abstract Orthogonal frequency division multiplexing (OFDM), a technique that uses frequency division multiplexing to allow parallel transmission of data over multiple subchannels, is widely used in various wireless systems. Its effectiveness even extends to HF links, where it has demonstrated superior performance compared to single-carrier schemes. In addition, OFDM’s robustness to multipath fading and its ability to efficiently utilize the available bandwidth make it a preferred choice for modern communication systems, but also for scenarios with complex communication links, such as HF range communications. The objective of this experimental research is to analyze and improve the performance of the OFDM technique adapted to HF communication channels. This study is motivated by the lack of a protocol to regulate HF communications using OFDM. The analysis and optimization method starts by considering the fundamental bandwidths of HF channels (ranging from 3 to 24 kHz). For this purpose, OFDM-specific modifications have been analyzed, including changes in the FFT size (representing the number of subcarriers), adjustment of the number and amplitude of pilots, analysis of the impact of packet length modification (pre-OFDM), and evaluation of guard intervals. In essence, our goal is to implement an OFDM technique commonly used in modern data communications in the context of traditional HF communications systems.
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