面向无人机中继通信平台的混合网络编码算法

A hybrid network coding algorithm for the Unmanned Aerial Vehicle (UAV) mobile relay platform is proposed to solve the low throughput of existing remote relay communication systems. The algorithm considers the network coding strategy and the state of the air-ground channel and selects the coding mode according to the real-time signal-to-noise ratio (SNR) of the users. Firstly, the SNR and bit error rate (BER) between remote users and UAV relay platform is obtained according to the cyclic reciprocating UAV flight trajectory and line-of-sight channel conditions. Then, the users SNR constraint and UAV position constraint are introduced to solve the optimal communication mode conversion time according to the SNR and BER between UAV and the users. Finally, the UAV relay platform adopts three timeslot network coding modes and two timeslot direct transmission modes to receive and send data packets before and after the switching time to effectively improve the overall throughput rate of the relay communication system. Experimental results show that when the distance between users is 1 600 m, the flight radius of UAV is 600 m and the flight speed of UAV is 10 m/s, the hybrid network coding algorithm improves the total throughput rate of the system by 28.42% and reduces the throughput change rate by 17.8%, compared with the traditional three-slot mobile relay communication algorithm. These results reflect that the proposed algorithm has the higher communication efficiency and system stability and it has good application prospect.