一种数据包合并跨层优化编码方案

摘要

In a conventional layered system,data packets are firstly encoded by packet-level error detection code in the data link layer. Then a data packet corresponding to an information block is encoded by symbol-level error correction code in the physical layer. Finally,the data packets are transmitted in channels. In order to improve the transmission efficiency of system,this paper proposes a cross-layer optimization scheme of the physical layer and data link layer coding based on data packets merge. Namely multiple packets of da-ta link layer merge and correspond to an information block of the physical layer,and then transmit after error correction coding. Furthermore,through theoretical deduction,the optimal number of merging packets and the best length of each packet are computed analytically when the transmission efficiency of system is maximal. Simulation results verify the accuracy of theoretical analysis,and show that the proposed scheme significantly improves the transmission efficiency of system compared with traditional scheme.%在传统分层系统中，信息数据包首先在数据链路层进行数据包级的检错码编码，然后一个数据包对应一个信息分组在物理层进行符号级的纠错码编码，最后送入信道中传输。为提高系统的传输效率，提出了一种基于数据包合并的物理层与数据链路层编码的跨层优化方案，即数据链路层的多个数据包合并对应物理层的一个信息分组，然后进行纠错编码后再传输。通过理论推导得出了使系统传输效率最大的最优合并数据包个数和数据包长度表达式。通过仿真验证了理论推导的正确性，并与传统方案进行了比较，结果表明，该方案能有效提高系统的传输效率。