Research Of OFDM Underwater Acoustic Communication Based On ZoomFFT

The outline of the "14th Five-Year Plan" points out: develop marine equipment and other strategic emerging industries,develop marine economy,and build a maritime power.Underwater acoustic communication is one of the key technologies for the development of marine equipment.Orthogonal Frequency Division Multiplexing(OFDM)has broad application prospects in Underwater Acoustic Communication(UWA).Fast Fourier Transform is used as the main method of OFDM technology due to its low complexity and easy implementation.However,the effective information of underwater acoustic signals is usually concentrated in a narrow frequency band.Therefore,using the FFT algorithm as an underwater acoustic OFDM signal demodulation algorithm will cause the problem of too low spectral resolution of the frequency band where the actual effective information is located,which will cause the actual demodulation to be affected.The frequency spectrum leakage caused by the fence effect causes the communication system to suffer from the degradation of the Signal to Interference plus Noise Ratio(SINR),which causes the acoustics of the underwater OFDM communication system to suffer many limitations,such as narrowband interference.As a result,the performance improvement of the underwater acoustic OFDM system is limited.This paper studies the application of the Zoom Fast Fourier Transformation(ZoomFFT)algorithm in the underwater acoustic OFDM system for the problem of the barrier effect of the modulation and demodulation algorithm of the underwater acoustic communication physical layer.This article first studies the principle and implementation of the ZoomFFT algorithm in detail.This article compares the similarities and differences between the performance of the ZoomFFT algorithm and the performance of the FFT algorithm in detail.Next,this article explores the effects of the ZoomFFT algorithm and the FFT algorithm on the communication signal in detail.After completing the research on the principle of ZoomFFT algorithm.This article begins to study how to use ZoomFFT to inversely transform and modulate the transmitted signal under the OFDM communication system,and how to use the ZoomFFT algorithm to process the received signal.And analyzed in detail the impact on the entire communication system after adding the ZoomFFT algorithm.Finally,this paper designs an underwater acoustic OFDM communication system based on ZoomFFT based on the previous research on ZoomFFT.Finally,this article uses the measured channel data of Wuyuan Bay in Xiamen and Songhua Lake in Jilin as parameter values to substitute into the underwater acoustic channel model to establish a simulation channel model,and test the performance of the communication system by means of simulation experiments.The performance index of the communication system is obtained.Then,the performance of the communication system proposed in this paper is tested under the real channel environment,and the experimental results are in line with expectations.The underwater acoustic OFDM communication system based on ZoomFFT proposed in this paper realizes the OFDM communication system by using the ZoomFFT algorithm instead of the FFT algorithm.The introduction of ZoomFFT eliminates the problems of narrow-band interference caused by spectrum distortion and fence effect in underwater acoustic communication.Further improve the performance of the underwater acoustic OFDM communication system.With the further exploration of the ocean by mankind,there is an increasing demand for high-performance OFDM communication technology.The underwater acoustic OFDM communication system based on ZoomFFT will provide a way of thinking to meet people's pursuit of higher performance communication systems.