Research On Marine OFDM Intelligent Receiving Method Based On ResNet

At present,with the development of wireless communication,OFDM technology is used in different scenarios as an important technology in wireless communication.The application of OFDM technology to wireless communication systems in complex marine scenarios enables marine wireless communication systems to have higher transmission rates and better communication quality.Existing physical layer receivers usually use progressive serial processing of modules such as carrier and symbol synchronization,channel estimation,equalization,demodulation,etc.The error of the preprocessing module may affect the optimization of the subsequent processing module,resulting in the accumulation of errors,so the receiver model with the best overall performance cannot be obtained.In order to realize the joint optimization of the receiver,this thesis attempts to use a deep neural network to replace the various modules of the OFDM receiver.The research contents of this thesis as follows:(1)Aiming at the defects of the existing methods of OFDM technology and the difficulty of feature extraction of OFDM information bit stream in the complex marine environment,and the problem that the bit error rate cannot be further reduced,an intelligent receiving method for OFDM in ocean based on deep learing is studied.A ResNet is used to replace the channel estimation,equalization,demodulation and decoding at the receiver of marine OFDM to realize the overall optimization of the receiver.And the channel attention module is introduced into the ResNet model to build a deep neural network,extract signal features,and finally restore the information bit stream.The performance of the OFDM system affected by the pilot frequency,carrier frequency offset and other factors under the model is analyzed.The experimental results show that the model can effectively extract the characteristics of the OFDM signal in the complex marine scene and achieve a lower bit error rate.(2)Aiming at the high PAPR in OFDM system,which destroys the orthogonality between subcarriers and worsens the transmission performance,an OFDM intelligent receiving method based on neural network to suppress PAPR is studied.A multilayer neural network is used between the serial to parallel conversion and IFFT at the transmitter of OFDM system to suppress PAPR,and combined with the proposed OFDM intelligent receiving model to suppress PAPR when the bit error rate of OFDM system increases within a controllable range.The experimental results show that the model has a significant effect in suppressing PAPR,and the increase of bit error rate is controllable.