Cooperative OFDM-Based Virtual Clustering Scheme for Distributed Coordination in Cognitive Radio Networks
Cooperative OFDM-Based Virtual Clustering Scheme for Distributed Coordination in Cognitive Radio Networks
复制标题
DOI：
10.1109/tvt.2014.2360985
复制
发表时间：
2015-08
影响因子：
6.8
通讯作者：
H. Salameh;Mohammad F. El-Attar
中科院分区：
文献类型：
--
作者：
H. Salameh;Mohammad F. El-Attar
认知无线电网络通过动态频谱接入技术为无线用户提供了巨大的带宽。为了实现这种新的网络范例，需要有效的分布式协调方案来交换控制信息，而无需假设预先指定的公共控制信道（CCC）的可用性。在本文中，我们提出了一种分布式组基于载波侦听多址接入与冲突避免（CSMA/CA）的CR网络的频谱感知协调方案，这是所谓的虚拟分簇分布式协调（VCDC）。通过使用CSMA/CA接入机制，VCDC允许具有类似频谱机会的相邻CR用户异步地将自己组织成虚拟集群，并使用本地可用的CCC来协调它们的通信。VCDC不同于以前的基于簇的方案，因为它利用离散正交频分复用（D-OFDM）技术来减少邻居发现时间，并促进簇间通信和广播。三种变体的VCDC方案，这是一跳，两跳，和约束的VCDC。这些变体基于所采用的本地CCC的数量提供不同的集群大小。我们比较现有的聚类方案的VCDC方案的性能。仿真结果表明，VCDC构造较少的较大规模的集群与适当数量的公共空闲信道，并引入了一个较低的百分比的集群没有共享空闲信道。因此，VCDC在不强制同步的情况下性能更好。
Cognitive radio (CR) networks are expected to offer a huge bandwidth to wireless users through dynamic spectrum access techniques. To realize this new network paradigm, effective distributed coordination schemes to exchange control information without assuming the availability of a prespecified common control channel (CCC) are needed. In this paper, we propose a distributed group-based spectrum-aware coordination scheme for carrier-sense multiple access with collision avoidance (CSMA/CA)-based CR networks, which is called virtual clustering distributed coordination (VCDC). By using a CSMA/CA access mechanism, VCDC allows neighboring CR users with a similar view to spectrum opportunities to asynchronously organize themselves into virtual clusters and coordinate their communications using locally available CCCs. VCDC differs from previous cluster-based schemes in that it exploits the discrete orthogonal frequency-division multiplexing (D-OFDM) technology to reduce neighbor-discovery time and facilitate intercluster communication and broadcasting. Three variants of the VCDC scheme are proposed, which are one-hop, two-hop, and constrained VCDC. These variants provide different cluster size based on the number of adopted local CCCs. We compare the performance of the VCDC scheme with existing clustering schemes. Simulation results show that VCDC constructs fewer larger size clusters with an appropriate number of common idle channels and introduces a lower percentage of clusters with no shared idle channels. Thus, VCDC performs better without imposing synchronization.