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1、Adaptive Antenna System in IEEE 802文章来源 毕业论文网 全部作者： 赵力强 第1作者单位： 西安电子科技大学综合业务网国家重点实验室 论文摘要： Directional distributed coordination function (D-DCF), a modified medium access control protocol of IEEE 802.11, is proposed in this paper to support smart adaptive array antennas over
2、 WLAN. D-DCF based on hybrid virtual carrier sense (HVCS) mechanism can coexist with DCF. A smart antenna has omni-directional and directional mode in operation. In D-DCF, before sending any data-frames, the sender and receiver node transmit a pilot sequence by means of omni-directional request-to-s
3、end/clear-to-send (ORTS/OCTS) handshake mechanism. Based on the pilot, the directional beam can be formed by the smart antenna. Then the node can transmit its data-frame in directional mode. The other nodes save the transmission time between the sender and receiver in omni-directional mode in their
4、network allocation vectors. When the sender and receiver communicate in directional mode, the other nodes can contend channel to send their data-frames. Hence, D-DCF supports space division multiple access (SDMA). 关键词： WLAN, Smart Adaptive Array Antennas, MAC, SDMA, TDD (浏览全文) 发表日期： 2006年09月04日 同行评议： （暂时没有） 综合评价： （暂时没有） 修改稿：
