We use cookies to improve your experience with our site.

基于物理层测量的认知无线电网络吞吐量优化

Throughput Optimization in Cognitive Radio Networks Ensembling Physical Layer Measurement

  • 摘要: 当前无线网络的研究主要集中于两个方面, 一是更高效的频谱使用(以认知无线电网络研究为代表), 二是集中于多跳网络的研究(以无线网状网为代表)。在这些研究中, 如何高效的进行频谱分配以避免相互干扰是其中的关键。本文中, 我们主要研究通过在认知无线电网络中通过频谱分配进行吞吐量优化。之前的工作主要基于冲突图或者SINR模型来刻画干扰, 但前者忽略了累积干扰效应从而导致在优化中无法达到最优, 而后者则往往忽略了SINR模型的精确性严重依赖于对接收信号强度(RSS)测量的精确性。因此两者都不足以刻画干扰与吞吐量之间的复杂关系。有鉴于此, 我们提出了一种基于物理层高效测量的认知无线电网络吞吐量优化方法。我们的方法考虑到认知无线电网络物理层的特性, 如频谱多样性, 非连续OFDM等。一种高效的RSS测量方法被提出来解决SINR模型不精确的问题。同时在上层基于SINR的吞吐量优化问题被建模成MINLP问题。针对这个问题我们提出了一种(1-ε)近似算法。同时一个高效的分布式算法也被提出。所有算法的有效性及性能都在基于真实数据的模拟试验中被验证。

     

    Abstract: Wireless networks are developed under the fashion of wider spectrum utilization (e.g., cognitive radio) and multi-hop communication (e.g., wireless mesh networks). In these paradigms, how to effectively allocate the spectrum to different transmission links with minimized mutual interference becomes the key concern. In this paper, we study the throughput optimization via spectrum allocation in cognitive radio networks (CRNs). The previous studies incorporate either the conflict graph or SINR model to characterize the interference relationship. However, the former model neglects the accumulative interference effect and leads to unwanted interference and sub-optimal results, while the work based on the latter model neglects its heavy reliance on the accuracy of estimated RSS (receiving signal strength) among all potential links. Both are inadequate to characterize the complex relationship between interference and throughput. To this end, by considering the feature of CRs, like spectrum diversity and non-continuous OFDM, we propose a measurement-assisted SINR-based cross-layer throughput optimization solution. Our work concerns features in different layers: in the physical layer, we present an efficient RSS estimation algorithm to improve the accuracy of the SINR model; in the upper layer, a flow level SINR-based throughput optimization problem for WMNs is modelled as a mixed integer non-linear programming problem which is proved to be NP-hard. To solve this problem, a centralized (1 - ε)-optimal algorithm and an efficient distributed algorithm are provided. To evaluate the algorithm performance, the real-world traces are used to illustrate the effectiveness of our scheme.

     

/

返回文章
返回