Maximizing Rendezvous Diversity in Rendezvous Protocols for Decentralized Cognitive Radio Networks
Maximizing Rendezvous Diversity in Rendezvous Protocols for Decentralized Cognitive Radio Networks
复制标题
最大化去中心化认知无线电网络交会协议中的交会多样性
DOI：
10.1109/tmc.2012.103
复制
发表时间：
2013-07-01
影响因子：
7.9
通讯作者：
Park, Jung-Min 'Jerry'
中科院分区：
文献类型：
--
作者：
Bian, Kaigui;Park, Jung-Min 'Jerry'
在分散式认知无线电（CR）网络中，在一对通信节点之间建立链路需要无线电在一个公共信道（这种信道称为会合信道）中“会合”以交换控制信息。当未授权（辅助）用户机会性地与授权（主要或现任）用户共享频谱时，给定的会合信道可能由于授权用户信号的出现而变得不可用。理想地，每个节点对应该能够在每个可用信道中会合（即，最大化会合分集），从而使会合失败的可能性最小化。信道跳变（CH）协议已经提出了以前建立成对交会。它们中的一些允许在所有信道上进行成对会合，但需要全局时钟同步，这在分散式网络中可能很难实现。在分散的CR网络中，最大化两两会合分集是一个非常具有挑战性的问题。在本文中，我们提出了一个系统的方法来设计CH协议，最大限度地提高任何节点对的会合分集分散CR网络。由此产生的协议是耐交会失败所造成的外观的主要用户（PU）信号，不需要时钟同步。所提出的方法，称为异步信道跳频（ACH），有两个值得注意的特点：1）任何一对CH节点能够在每个信道上会合，使会合过程是鲁棒的出现的PU信号所造成的中断;和2）一个上界的时间到会合（TTR）保证两个节点之间，即使他们的时钟是异步的。我们提出了两个最佳的ACH设计，最大限度地提高任何一对节点之间的交会分集，并通过分析和仿真结果显示其交会性能。
In decentralized cognitive radio (CR) networks, establishing a link between a pair of communicating nodes requires that the radios "rendezvous" in a common channel-such a channel is called a rendezvous channel-to exchange control information. When unlicensed (secondary) users opportunistically share spectrum with licensed (primary or incumbent) users, a given rendezvous channel may become unavailable due to the appearance of licensed user signals. Ideally, every node pair should be able to rendezvous in every available channel (i.e., maximize the rendezvous diversity) so that the possibility of rendezvous failures is minimized. Channel hopping (CH) protocols have been proposed previously for establishing pairwise rendezvous. Some of them enable pairwise rendezvous over all channels but require global clock synchronization, which may be very difficult to achieve in decentralized networks. Maximizing the pairwise rendezvous diversity in decentralized CR networks is a very challenging problem. In this paper, we present a systematic approach for designing CH protocols that maximize the rendezvous diversity of any node pair in decentralized CR networks. The resulting protocols are resistant to rendezvous failures caused by the appearance of primary user (PU) signals and do not require clock synchronization. The proposed approach, called asynchronous channel hopping (ACH), has two noteworthy features: 1) any pair of CH nodes are able to rendezvous on every channel so that the rendezvous process is robust to disruptions caused by the appearance of PU signals; and 2) an upper bounded time-to-rendezvous (TTR) is guaranteed between the two nodes even if their clocks are asynchronous. We propose two optimal ACH designs that maximize the rendezvous diversity between any pair of nodes and show their rendezvous performance via analytical and simulation results.