A geometric approach to improve spectrum efficiency for cognitive relay networks
A geometric approach to improve spectrum efficiency for cognitive relay networks
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DOI：
10.1109/twc.2010.01.090180
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发表时间：
2010
影响因子：
10.4
通讯作者：
Min Xie;Wei Zhang;Kai‐Kit Wong
中科院分区：
文献类型：
--
作者：
Min Xie;Wei Zhang;Kai‐Kit Wong
认知无线电（CR）可实现动态频谱访问（DSA）。在CR网络（CRN）中，如果出现的信号到噪声和分解比（SNIR）与PUS相比，无牌的认知用户（CUS）可以与许可的主要用户（PU）共享无线电谱。 。在本文中，我们研究了继电器以增强瑞利褪色通道中理想化的二维几何网络的光谱利用。为此，应该使CUS与PU透明，同时本身可以实现可接受的可靠性。基于这些条件，我们首先得出了几何条件，在该条件下，CU可以在脓液处于活跃的情况下在单个跳跃上传播。如果目的地超出了单个跃点的源头，则将使用多跃波继电器用于较短的距离传输。然后，我们提出和分析两种多跳路由策略，称为最近的邻居路由（NNR）和最远的邻居路由（FNR）。在MultiHop继电器中，我们还研究了并发的好处，其中允许多个CUS同时传输以改善端到端（E2E）通道利用率。最后，我们比较有或没有中继的CRN的E2E性能。
Cognitive radio (CR) enables dynamic spectrum access (DSA). In CR networks (CRNs), unlicensed cognitive users (CUs) can share the radio spectrum with the licensed primary users (PUs) if the incurred signal-to-noise-and-interference ratio (SNIR) to the PUs is above a predetermined threshold. In this paper, we investigate the use of relaying to enhance the spectrum utilization of an idealized two-dimensional geometric network in Rayleigh fading channels. To do so, the CUs should be made transparent to the PUs while achieving acceptable reliability themselves. Based on these conditions, we first derive the geometric condition under which CUs could transmit over a single hop with the PUs being active. If the destination is beyond the reach of the source in a single hop, multihop relaying will be used for shorter-distance less-power transmission. Then, we propose and analyze two multihop routing strategies, termed nearest-neighbor routing (NNR) and farthest-neighbor routing (FNR). In multihop relaying, we also study the benefits of concurrency, in which more than one CUs are allowed to transmit at the same time to improve the end-to-end (e2e) channel utilization. Finally, we compare the e2e performance of CRNs with and without relaying.