Design and implementation study of FPGA-based underwater acoustic MFSK-OFDM communication algorithm

The application of underwater acoustic communication (UWAC) technology in the field of marine resource development and utilization is increasingly in demand, and UWA MFSK-OFDM technology has attracted much attention because of its superior anti-interference. However, in the multitasking and high real-time requirements, FPGA has a greater parallelism advantage over the traditional DSP. In this paper, we first analyze the principle and characteristics of the UWA MFSKOFDM communication algorithm, and propose a UWA MFSK-OFDM algorithm suitable for real-time implementation on FPGA, which is based on the band-pass sampling theorem to finish the frame synchronization and demodulation of MFSKOFDM, and greatly reduces the computational complexity of the system, and secondly, we propose a scheme to reduce the computational complexity of the system, which is based on the frame synchronization and demodulation based on conventional Nyquist sampling theorem. Second, according to the proposed UWA MFSK-OFDM algorithm structure, relying on the advantages of FPGA in parallel computing, the UWA MFSK-OFDM communication system is realized in real-time through reasonable resource allocation and task scheduling. Finally, the pool experimental results show that the proposed algorithm improves the communication efficiency while maintaining the stability and real-time performance of the system, and the uncoded BER is 10⁻³ when the signal-to-noise ratio is around 8 dB, and the BER after decoding of the Turbo code with 1/2 code rate is 0. In addition, the consumption of FPGA hardware resources is greatly reduced compared with the conventional scheme.