水声网络按序递归与限制反馈的在线喷泉码算法与分析

Algorithm and Analysis of Sequential Recursive Online Fountain Code with Limited Feedback in Underwater Acoustic Networks

水声网络具有低带宽、长时延、高误码率等特征,这使得数据的可靠传输面临着巨大挑战.在线喷泉码具有低开销、在线反馈和通过给定瞬时解码状态获得最优编码策略等优点,因此,针对水声网络的特点,分析在线喷泉码的编解码和反馈问题,提出了按序递归与限制反馈的在线喷泉码(Sequential Recursive Online Fountain Code with Limited Feedback,SROFC-LF).基于随机图理论对SROFC-LF需要的编码包数量进行理论分析,理论分析和实验仿真一致.实验表明:无论开销和反馈包数量,SROFC-LF比大部分在线喷泉码均表现出更好性能,适合水声网络.

Underwater acoustic networks(UANs)have low bandwidth,long delay,high bit error rate and other fea⁃tures.All these features bring about significant challenges to the reliable transmission for UANs.Online fountain code(OFC)has the advantages such as low overhead,online feedback,and obtaining the optimal coding strategy through a given instantaneous decoding state.Therefore,according to the characteristics of UANs,the problems of codec and feedback of the OFC are analyzed.The sequential recursive online fountain code with limited feedback(SROFC-LF)is proposed.The number of coding packets required by the SROFC-LF is theoretically analyzed based on the random graph theory,and the theoretical analysis is consistent with the experimental simulation results.The experimental results show that regardless of the overhead and the number of feedback packets,the SROFC-LF shows better performance than most OFCs,which is suit⁃able for UANs.