蜂窝系统使用免费频段的方法研究

摘要

蜂窝系统使用免费频段是解决蜂窝系统频谱资源紧张的途径之一.首先阐述IEEE 802.11的MAC机制,针对蜂窝系统利用载波监听传统机制去竞争无线局域网频段存在的无法充分利用频谱资源的缺陷,提出一种基于最大化比例公平准则的自适应概率可调的动态频谱接入方法,该方法可以步进地调整蜂窝的接入概率,从而使系统工作在最大化比例公平的理想点附近,仿真结果表明该方法比传统机制在公平性和吞吐量指标上都有提升.%Cellular system sharing the unlicensed spectrum is one of the approaches to release the load of the crowded cellular band. First, we express the MAC mechanism of IEEE 802. 11. For the limitation of cellular system that it cannot fully utilise the spectrum resource when employing traditional carrier sensing mechanism to rival WLAN band, we propose an adaptive probability access (APA) method which can adjust the channel accessing probability based on maximised proportional fairness rule. This method can adjust the cellular accessing probability step by step to ensure that the whole system works at the maximum proportional fairness. Simulation results show that the proposed APA method has benefit on both the proportional fairness and total throughput than traditional mechanism.