基于网络编码与空时编码的协作MAC协议

Cooperative MAC protocol based on network coding and space-time coding

针对无线ad hoc网络中协作造成的中继效率低以及不同QoS需求难以满足等问题,提出了一种联合网络编码和空时编码的协作MAC协议(NSTCMAC)。NSTCMAC将网络编码与空时编码技术相结合,设计出区分业务类型的协作MAC协议传输机制,以满足不同业务类型的QoS需求;进一步通过马尔科夫链模型分析了区分业务类型的协作机制及性能。仿真结果表明,相比传统的DCF、COOPMAC以及CD-MAC协议,NSTCMAC协议能更好地保证不同的QoS需求,并能有效地解决协作造成的中继效率低的问题。

Aiming at the problems in wireless ad hoc networks, such as relays＇ low efficiency caused by cooperation and difficult to meet the different Qos requirements, a cooperative MAC protocol was proposed based on the combination of network coding and space-time coding（NSTCMAC）. Based on NSTCMAC protocol with the combination of Network coding and space-time coding techniques, a kind of cooperative MAC transmission mechanism that could distinguish the type of DATA packet was designed in order to meet the QoS requirements of different types of transmission. Further more, cooperative transmission mechanism and its performance were analyzed through Markov chain model. When transmitting the non-real-time（NR） packets, network coding was adopted to improve the efficiency of relay nodes; when transmitting the real-time（R） packets, randomized distributed space-time coding（R-DSTC） was used to enhance the reli-ability of transmission. Simulation results show that NSTCMAC protocol can meet different QoS requirements better, and solve the problem of relays＇ low efficiency more effectively, when compared with legacy DCF, COOPMAC and CD-MAC protocol.