The Design And Implementation Of Combined Spread Spectrum Multi-carrier Underwater Acoustic Communication System

As the development of marine oil and gas resources increases,the problems of platform oil spills,blowout accidents,and aging materials not only cause huge economic losses and casualties to the country,but also cause huge pollution to the local environment.Therefore,real-time monitoring and forecasting of offshore oil platforms,timely handling of risk factors,and improving the reliability of the platform have certain engineering application value.In this paper,based on the characteristics of underwater acoustic channels,combined with multi-carrier communication technology,combined spread spectrum technology and chaotic communication technology,a high-speed underwater communication system research and design is carried out.In this paper,in response to the needs of a large variety of offshore oil platform monitoring data and the high-speed and reliable transmission of data,spread spectrum technology is used to deal with the multipath delay of underwater acoustic channels,noise interference and other factors to ensure the reliability of data transmission.The multi-carrier technology constructs a combined spread spectrum multi-carrier system,to a certain extent,solves the problem of low transmission rate and bandwidth utilization of the spread spectrum system.In addition,the use of chaotic sequences to construct spread-spectrum sequences is intended to improve the system's anti-jamming,anti-aliasing,and anti-noise performance,and to ensure the reliability and transmission rate of the underwater acoustic communication system.By modeling and simulating the underwater acoustic channel environment,the reliability of the communication system was further verified.In this paper,the core of data demodulation is the realization of correlation operations.The overlap-preservation method is used to achieve real-time correlation operations of chaotic spreading sequences and sampling sequences,and a frequency division correlation operation mode is proposed to solve the problem of super-long chaotic original sequences and infinite length sequences after sampling Related calculation problems are converted into related operations of short sequences and infinitely long sequences through frequency division and superposition.And through the frequency domain transform method and hardware acceleration algorithm,further reduce the amount of related operations and operation time,to solve the problem of real-time related operations of the combined spread spectrum system.Finally,the underwater acoustic communication system platform was built according to the communication system plan.Through the pool experiment,it was verified that the short-distance bit error rate of the plan is 0,and the communication rate can reach 1073bit/s.Compared with the traditional spread spectrum communication system,on the premise of ensuring the reliability of data transmission,the system's transmission efficiency and bandwidth utilization rate are improved.