UAV Image Transmission Adaptive Decoding Based On Gray Code Algorithm And Implementation

In recent years,with the applications of UAV(UAV)in military and civil become widely available,the image transmission system in UAV has attracted more attention.Aiming at the characteristics of UAV image transmission,such as susceptibility of interference,limited load,the channel coding of UAV image transmission has become a hot topic.The traditional channel coding between the UAV and the ground receiver usually uses Turbo code,LDPC code,et al.The decoding of Turbo code and LDPC code is complex,lack of real-time,and high cost of hardware.In addition,the LDPC code is easy to cause the wrong floor at high signal to noise ratio.Gray code has tow computational complexity,less operation time,simple hardware implementation and its power consunption is relatively lower.So,in this paper,a decoding algorithm of adaptive transmission UAV images based on Gray code is proposed.Moreover,the implement of the proposed algorithm is also achieved.Firstly,an adaptive decoding algorithm based on gray code have been proposed to solved the problem of traditional channel coding and decoding,such as high complexity,poor real-time performance,high cost of hardware aults.This proposed algorithm meets the reliable and real-time communication requirements of UAV image transmissioa Gray code has a short length,concentrated energy,low decoding complexity,fast calculation speed and good reliability.The hard decision decoding gray code has less accuracy,but running fester.The soft decision decoding has higher accuracy,but it needs more operation time.According to this characteristic,based on the parity bit with the hard decision and soft decision combination of gray code,we design a adaptive decoding algorithm based on Gray code,and hybrid automatic repeat request(Hybrid Automatic Repeat request,HARQ)adaptive decoding mechanism into gray code,in order to improve the decoding accuracy of gray code adaptive decoding algorithm.Secondly,by considering the demand of the reliability,real-time,stability,and hardware implementation requires hardware design function module contains characteristics of image information acquisition,compression,encoding,modulation image information,wireless transmission of information.An unmanned aerial vehicle(UAV)image transmission system is design with MSP430F149 MCU as control unit and SI4432 module as transmitter and receiver based on Gray code adaptive decoding algorithm This system meets the demand of function in UAV image transmission.In this system,transmitter can collect image information,compress,coding,modulate image information,wireless transmission informatioa In addition,the receiver needs to demodulate,decode,decompress and restore the image information.MSP430F149 is used for decoding data according to adaptive gray code while SI4432 is used for data transmitting and receiving.Moreover,PC is used for issuing image data.Finally,the simulation results show that the decoding algorithm can improve the reliability and real-time performance of unmanned aerial vehicle(UAV)image transmission,and it is a feasible scheme.The hardware realization can effectively resist all kinds of signal interference and reduce the cost.It is an effective way to realize high quality UAV image transmission.