Research And Design Of Sound Communication System And Encryption Algorithm

The promotion and application of near field communication technology greatly facilitates people's life and work.In today's society where intelligent devices are widely used,more and more users hope to experience more diversified near field communication technology.In addition to paying attention to the efficiency of communication and the stability of the connection,users are paying more and more attention to the security of communication when experiencing a communication technology.With the change of users' concerns and the need of users for more diversified experiences,the emergence of new communication technologies has gained a market.Compared with the existing near flied communication technologies,acoustic communication technology has its own unique advantages.The implementation of acoustic wave communication technology does not require specific hardware devices,and the connection speed at work is fast,and It also does not depend on the network and has great privacy when communicating.In recent years,acoustic wave communication technology has been applied in different fields,such as mobile payment,streamlined data transmission,access control identification and so on.Using acoustic wave to transmit data in the air medium is still a new technology,which is still in the initial stage of development.In order to improve the security and reliability of the data transmitted in the acoustic wave communication technology,it is necessary to study the encryption algorithm and modulation technology used in the acoustic communication technology in detail.The work of this paper is as follows:(1)Some phenomena that occur when acoustic waves are transmitted in air media are studied.The basic framework of both analog and digital communication systems is studied,and several very classic digital communication technologies are briefly introduced.(2)A feasible acoustic wave near field wireless communication framework is designed.The ECC algorithm is used to encrypt the data,the signal is modulated by OFDM modulation,and the convolutional code is used for error correction.(3)The study compares the performance of various encryption algorithms,and uses the ECC algorithm to encrypt and decrypt data.After combing the relevant theoretical knowledge in the ECC algorithm,the C++ function code block corresponding to each step of ECC encryption and decryption is complied.(4)The OFDM system was simulated in MATLAB,and several important technical points were studied,such as adding guard interval/cyclic prefix,windowing and synchronization.(5)For the Android smartphone platform,the JAVA programming language is used in the Android Studio software to call the locally compiled dynamic library through the JNI function interface to write an APP that can perform acoustic wave communication.During the experimental test,the noise generated by the system during communication is insignificant and does not cause interference to the human ear.The results of the test show that the system can work normally,and the safety and reliability at work can be guaranteed.