基于多用户OFDM和分布式天线的认知无线电中最优子载波分配方案

基于多用户OFDM和分布式天线的认知无线电中最优子载波分配方案

内容简介：分别在平坦衰落和频率选择性衰落的无线信道模型中建立了基于多用户正交频分复用技术(OFDM)和分布式天线的认知无线电系统中子载波分配模型.该模型不再用"干扰温度"限制认知用户来保护主用户,而是规定主用户在其所有子载波上的吞吐量之和需要高于一定的门限.然后,根据不同信道模型的特点提出了最优子载波分配方案,该方案利用分支定界法和隐枚举法最大化系统的吞吐量.最后,利用Pegging算法提出了效率与公平折中的子载波分配方案.仿真证明,在不同场景中所提出的子载波分配方案与现有方案相比在吞吐量和公平性方面均具有较大的优势.

Abstract：The subcarrier allocation problem in cognitive radio (CR) networks with multi-user orthogonal frequency-division multiplexing (OFDM) and distributed antenna is analyzed and modeled for the flat fading channel and the frequency selective channel, where the constraint on the secondary user (SU) to protect the primary user (PU) is that the total throughput of each PU must be above the given threshold instead of the "interference temperature". According to the features of different types of channels, the optimal subcarrier allocation schemes are proposed to pursue efficiency (or maximal throughput), using the branch and bound algorithm and the 0-1 implicit enumeration algorithm. Furthermore, considering the tradeoff between efficiency and fairness, the optimal subcarrier allocation schemes with fairness are proposed in different fading channels, using the pegging algorithm. Extensive simulation results illustrate the significant performance improvement of the proposed subcarrier allocation schemes compared with the existing ones in different scenarios.

作者：葛文栋, 纪红, 司鹏搏, 李曦,

关键词：认知无线电, 子载波分配, 多用户OFDM, 分布式天线, 分支定界法, 隐枚举法, Pegging算法,