%0 Journal Article
%T 一种不等差错保护的多用户随机接入方法<br>A random multi-user access method with unequal protection
%A 孙景云
%A 刘荣科
%A 胡应梦
%J 北京航空航天大学学报
%D 2017
%R 10.13700/j.bh.1001-5965.2016.0938
%X 摘要 针对在随机接入中由于碰撞导致吞吐率低、信道拥塞时不能满足高优先级数据有效传输的问题，提出一种具有不等差错保护性能的多用户随机接入方法。该方法将数据包复制多份，根据选定的度分布在不同时隙中传输，将随机接入过程映射到二分图上；接收端利用连续干扰消除（SIC）技术，将碰撞的数据包恢复出来。在高链路负载下，从每帧中选取若干时隙，只允许高优先级用户接入，以提高对高优先级数据包的译码概率。使用“与或树”理论对提出的方法进行了理论分析，并进行了实验仿真验证。仿真结果表明：提出的多用户随机接入方法与传统ALOHA协议相比，在低链路负载下有效避免由于碰撞引起的吞吐率下降；与IRSA协议相比，高链路负载下有效提高高优先级用户的吞吐率。<br>Abstract：The throughput performance degrades under high traffic loads when massive bursty users have access to the satellite. To solve this problem, a random multi-user access method with unequal protection was proposed. Several copies of a packet were created and sent during different time slots according to a selected degree distribution. The random access procedure could be described by a bipartite graph. By using successive interference cancellation (SIC), collided packets can be recovered instead of abandoned. In addition, a portion of time slots in each frame were selected exclusively for high-priority users to improve the decoding probability of high-priority data packet. An analysis using standard "and-or trees" theory was introduced. Further, the proposed method was verified with experimental simulations. The simulation results show that the proposed random multi-user access method, compared with traditional ALOHA protocol, effectively avoids the throughput degradation caused by impact under low traffic loads. Compared with IRSA protocol, it enhances high-priority users' throughput under high traffic loads.
%K 随机接入
%K 不等差错保护
%K 时隙ALOHA
%K 连续干扰消除(SIC)
%K IRSA&lt
%K br&gt
%K random access
%K unequal protection
%K slotted ALOHA
%K successive interference cancellation (SIC)
%K IRSA
%U http://bhxb.buaa.edu.cn/CN/abstract/abstract14339.shtml