关键词: 链路自适应, 跨层, 无线局域网, 服务质量

Abstract: To overcome the defect that IEEE 802.11 Wireless Local Area Network (WLAN) does not provide link adaptation scheme, a joint Medium Access Control (MAC) layer and physical (PHY) layer cross layer link adaptation scheme (CLLA) is proposed. The proposed CLLA scheme, which takes channel interference into consideration and distinguishes collision lose and interference lose, provides mathematical description of PHY layer and MAC layer respectively. CLLA also deduces the relationship of two layers in term of throughput. CLLA selects rate adaptively to improve throughput. Simulation results and comparisons with existed schemes prove that the proposed CLLA scheme not only adapts interference and channel variation, but also improves system throughput obviously.

Key words: link adaptation, cross layer, wireless local area networks, Quality of Service (QoS)