Research And Implementation Of Single Carrier Underwater Acoustic Communication Based On TMS320C6655

Along with the development of the marine industry,underwater sensor network technology with wide coverage and flexible real-time features has increasingly become an emerging technology in resource exploration,environmental monitoring,and territorial defense.As an important part of the underwater acoustic(UWA)communication network,the UWA Modem is responsible for data transmission and exchange between various communication nodes,which has an irreplaceable role.Therefore,the development of efficient and robust UWA communication Modem has strong necessity and good application prospects.The paper is based on the single-carrier UWA communication algorithm.The design and simulation of a single-carrier UWA communication scheme for complex shallow multi-channels in shallow seas is carried out for the problem of severe multi-path expansion of shallow seawater acoustic channels.The reasonable single-carrier communication algorithm is designed and embedded in the TMS320C6655 processing platform,which lays a foundation for realizing a single-carrier UWA communication system with high reliability.Firstly,the characteristics of shallow seawater acoustic channel are analyzed.The physical characteristics of the UWA channel: multi-path expansion,limited bandwidth and time-varying,have a great impact on the transmission of signals.The main difficulty faced by current single-carrier UWA communication is inter-symbol interference.Time-domain equalization can effectively suppress inter-symbol interference caused by multiple channels and reduce the bit error rate,which has certain research significance.For the adaptive channel equalization in time domain equalization,the paper analyzes two commonly used equalizer structures: linear equalizer and decision feedback equalizer,and two adaptive algorithms: LMS and RLS.As another time domain equalization technology,passive time reversal mirror has two kinds of compressed sensing channel estimation methods: MP algorithm and OMP algorithm.Compare their channel equalization performance through computer simulation.Aiming at the shortcomings of adaptive equalization and passive time reversal mirrors,a scheme of cascading them is proposed.According to the asymmetry of the underwater acoustic channel impulse response function,a bidirectional decision feedback equalizer is proposed.Finally,the communication scheme adopted in the paper,the bidirectional decision feedback equalization based on passive time-reversal mirror,is simulated to prove the effectiveness and reliability of the algorithm.For the implementation part of the communication algorithm,the performance and platform of TMS320C6655 are briefly introduced firstly.Then the implementation process of C language program is designed.According to the actual application,fast synchronization and filtering are realized by ping-pong operation,linear convolution based on FFT algorithm and overlap addition.Then through the joint test to verify the correctness of the algorithm implementation.Finally,the communication scheme is verified by using the field test data.Forward,reverse,and bidirectional decision feedback equalization are used in the MATLAB environment to compare the equalization effects.The TMS320C6655 is used to equalize the signal of a single array element to verify the correctness of the embedded development of the communication algorithm and lay a foundation for the development of subsequent UWA communication Modem.