Research On Satellite Adaptive Transmission Control Based On Rateless Codes

There are a great number of differences between satellite communication andterrestrial communication. The most important differences are long round trip time andhige channel BER, which need a transmission control protocol different from terrestrialsystems. At the moment, the technology of adaptive data transmission control is moremature in the terrestrial communication, while there is a lack of study in satelliteenvironment. Combining rateless codes and HARQ to design a practical adaptive protocolfor satellite communication has great significance for the improving of spectral efficiencyand system throughput. This paper focuses on the designing of an adaptive datatransmission protocol, and an adaptive algorithm has been proposed to solve the rateadaptation problem. In addition, we analyze the difficulty of buffer management andproposed an effective scheme.Firstly, we study the theory of rateless codes and HARQ, and combine them togetherfor adaptive data transmission. Secondly, we analyze the features of satellitecommunication. According to this analysis, we propose a practical adaptive protocol forsatellite communication from the aspects of frame length designation, subframeencapsulation, way of repeat way of feedback. Thirdly, based on proposed protocol, wedesign an adaptive algorithm, which has been proved effective by simulation, andoptimize the ping-pong switch probem of the size of new package. Finally, we analyze thedifficulty of buffer management as the use rateless codes and selective repeat HARQ, anddesign a corresponding scheme for the transmitter and the receiver according to theirmajor problems.The protocol proposed is designed for satellite communication. With the controlscheme of the size of new package, it can improve the spectral efficiency and systemthroughput. Beside, the buffer management scheme can efficiently reduce the buffercapacity needed and buffer access rate.