多输入多输出(MIMO,Multiple Input Multiple Output)技术可以通过实现空分复用有效地提高无线系统的性能.提出了一个对于站点(station)和无线接入点(AP,Access Point)都装配有多天线的无线局域网的介质访问控制层(MAC,Medium Access Contr01)协议.此协议利用跨层优化设计的方法解决了将MIMO技术用于WLAN(WirelessLocal Area Network)中存在的一些问题.例如,如何在传统的802.11协议中加入训练用的导频序列,以及如何实现数据的并行传输等等.随后,提出一个三维离散马尔可夫模型来分析此协议性能,并与理论值进行比较.最后的仿真结果说明此协议能有效的提高系统吞吐量.
Multiple input multiple output (MIMO), as an important technology to enhance the physical layer capability, can achieve this target via spatial reuse. An medium access control(MAC) protocol was proposed for uplink transmissions in WLAN, where both stations and access point(AP) were equipped with multiple antennas. This protocol solves those problems existing in utilizing MIMO under current 802.11 protocol, for example, how to deploy preamble (training sequence) used for channel estimation and how to enable sim- ultaneous data transmissions via a cross-layer approach. Furthermore, a 3-dimension discrete-time Markov model was developed to analyze the performance of the proposed WLAN scheme. The analytical results were verified by the simulations, and numerical results show that system throughput can be significantly improved by the proposed scheme compared to conventional schemes.