Design And Development Of Sign In System Base On Acoustic Near Communication

With the growing popularity of smartphones,it has become a must-have tool.System development based on smart phones has become a hot research direction.With the development of smart phones,short-distance field communication between mobile phones is increasingly diversified.This paper is to study the acoustic near-field communication between smart phones and develop a signing system based on acoustic near-field communication.The vast majority of smart phones have speakers and microphones,which can easily send and receive sound waves.This provides a hardware basis for the study of acoustic near-field communication between smartphones.First of all,this paper designs a multi-pair acoustic wave near-field communication system based on smart phones and elaborates its technical principle.Secondly,based on the double-sliding window method,a variable-step-length double-sliding window method is proposed for detecting arrival of acoustic signals.In terms of multi-user detection,a multi-user detector based on genetic algorithm least square support vector machine is proposed.Finally,this paper developed a sign-in system based on acoustic near-field communication and described the implementation process of various parts of the sign-in system in detail.The main research contents of this paper are acoustic near-field communication system between the smartphones and the sign-in system base on acoustic near fiels communication system.The content of this article is as follows:Firstly,in the detection of the arrival time of the acoustic wave signal,this paper proposes a double-sliding window method with variable step size based on the double sliding window method.The variable step size double sliding window method can reduce the time complexity of the signal detection algorithm under the premise of keeping the detection accuracy as far as possible.Secondly,int the target user identification,this paper proposes a multi-user detector based on genetic algorithm least squares support vector machine.The symbol represented by the signal of the target user is either +1 or-1.The multi-user detection demodulates the signal of the target user from the received signals that interfere with each other.This algorithm regards the multi-user detection process as a two-class problem.The algorithm uses the algorithm to divide the received signal symbols into “+1” class and “-1” class to demodulate the target user's signal.Thirdly,this paper applies the designed sonic near-field communication system to the sign-in scene.This paper has developed a check-in system based on acoustic near-field communication.This paper describes in detail the work flow of the sound wave near-field sign-in system and elaborates the software framework design of the client,server and database.Fourthly,test the sound wave near-field sign-in system software in different scenarios and illustrate the test results.