The FPGA Design And Implementation Of An Inductive Coupling Chain Communication System For Marine Use Based On OFDM

With the development of ocean monitoring technology,ocean inductive coupling chain communication technology gradually becomes a new ocean monitoring technology based on the traditional technology.Nowadays,with the expansion of deep-sea observation field,there shows an increasing need in the improvement of transmission distance and rate.Ocean inductive coupling chain achieves non-contact type anchor cable data communication based on the electromagnetic induction principle,and the key of the communication technology is the open sea data transmission channel.There exists a multipath delay effect in the process of electrical signal transmission in the infinite seawater space.Therefore,solution of the multipath interference,the induction coupling data transmission rate and reliability are the major factors.In this essay,firstly,the research group designs a multipath channel simulator based on the FPGA simulation according to the multipath channel mathematical model,and the hardware simulation of the channel model is realized.After that,according to the characteristics of the inductive coupling channel,the research group develops a set of communication transceiver system FPGA algorithm framework using orthogonal frequency division multiplexing(OFDM)technology,and according to the functional requirements and top-down design ideas,we use Verilog to realise the partitioning module functions.Then,we use the third party ModelSim simulation software to ensure the correctness of the key module design.During the process of simulation,we also use MATLAB software and QuartusⅡ software to exchange data,and the MATLAB provides test data and reads simulation results for processing and analysing.Secondly,the implemented modules are instantiated at top level to realise the OFDM transceiver system,and the system functions are verified by simulation tests.Finally,the projects of OFDM transceiver system and multi-path simulator are downloaded into the FPGA development board of Altera company,and the hardware system platform is built.On this basis,the system is tested under different CP lengths and maximum channel delay,and the relationship between CP length and maximum delay is verified.The suitable CP length is determined for the maximum delay of laboratory inductive coupling chain channel,and the bit error rate is analyzed at different SNR.This essay provides a laboratory test platform for researching multi-path delay effect of induction coupling chain and a new idea for improving transmission performance.