Design And Implementation Of Near Field Communication System For Smart Phone

With the popularity of smart phones and the booming development of mobile Internet,the demand for point to point near field communications based on smart phones in the absence of wireless networks is also growing.At present,point-to-point short distance wireless communication technology including Bluetooth,Wi-Fi,ZigBee(802.11),infrared(IrDA),near field communication(NFC),but to be applied to the mobile phone,you will need to increase the intelligent mobile phone hardware module,the intelligent mobile phone configuration is not a condition,it is difficult to promote therefore,to achieve a mobile phone all common technology of short range wireless communication.In this paper,the synchronization algorithm and related technology of OFDM are studied and analyzed.The PARK algorithm is improved,and the mobile phone acoustic near field communication system using the improved algorithm is designed.Using this system,a APP with simple transceiver function is developed on the Android platform.The main work includes the following aspects:1.the modulation and demodulation principle of OFDM is studied and analyzed,and the protection interval,IFFT oversampling,channel estima tion,and synchronization method are analyzed.2.analysis and comparison of three commonly used synchronization algorithms based on training sequences.And aiming at the shortcomings of PARK algorithm,proposed an improved synchronization algorithm,reduce the probability value of the timing metric complexity and timing errors,compared with the Park algorithm,the timing is close to the performance of the improved algorithm,but the computational complexity is significantly reduced.Detailed functional design of near field communication OFDM system synchronization algorithm based on improved 3.to use the mobile phone,including channel analysis,noise analysis,and based on these analysis,choose appropriate system parameters,and then the design of the s ystem from the sending end and receiving end.4.the key technology of OFDM system for mobile phone near field communication is implemented on Android platform,and a APP with transceiver function is developed,which verifies the effectiveness of the synch ronization algorithm designed in this paper.The design of the mobile phone OFDM acoustic near-field communication system based on a good solution to the realization of near field communication dependence on specific hardware of traditional intelligent mob ile phone,mobile phone has just made a loudspeaker and a microphone can realize the short distance wireless communication,the use of fast reaction speed,simple and quick connection,has been used to a cloud assistant application software,and obtained t he promotion.