Effect of secondary transmission on primary pilot carriers in overlay cognitive radios
Effect of secondary transmission on primary pilot carriers in overlay cognitive radios
复制标题
叠加认知无线电中二次传输对主导频载波的影响
DOI：
10.4108/icst.crowncom.2013.252033
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
R. Jäntti
中科院分区：
文献类型：
--
作者：
Y. Beyene;K. Ruttik;R. Jäntti
认知无线电旨在通过利用有关环境和其他发射机活动的信息来提高频谱效率。它允许访问临时和/或空间上未使用的电视频谱、空白空间或电视传输上的覆盖。在本文中，我们考虑在 DVB-T 覆盖区域、电视黑空间中覆盖认知无线电。我们分析了存在信道估计误差的情况下辅助接收器处的简单顺序干扰消除算法的性能。信道估计质量取决于叠加信号如何干扰主导频。我们比较了两种具有辅助功能的基于正交频分复用的重叠认知无线电方案：1）修改的WLAN帧结构避免了主导频上的辅助传输。 2) 使用所有DVB-T载波的LTE型帧结构。在硬件平台上实现了原型系统，以验证分析结果并研究实施限制。仿真和测量结果表明，主导频上的叠加干扰不会对主接收产生显着影响。然而，与方案(1)不同的是，在方案(2)中，发现辅助接收机处的信号干扰加噪声比受到导频载波上的干扰水平的严重限制。
Cognitive radio aims to increase spectral efficiency by exploiting information about the environment and activity of other transmitters. It allows access to temporary and/or spatially unused TV spectrum, white space, or overlay on the TV transmission. In this paper we consider an overlay cognitive radio in DVB-T coverage area, TV black space. We analyze the performance of a simple sequential interference cancellation algorithm at secondary receiver in presence of channel estimation error. The channel estimation quality depends on how the overlay signal disturbs the primary pilots. We compare two Orthogonal-Frequency Division Multiplexing based overlay cognitive radio schemes having secondary with: 1) modified WLAN frame structure avoiding secondary transmission on primary pilots. 2) LTE-type frame structure that uses all the DVB-T carriers. A prototype system was implemented on hardware platform to validate analytical results and study implementation limitations. Simulation and measurement results show that overlay interference on primary pilots does not have significant impact on primary reception. However, unlike scheme (1), in scheme (2) signal-to-interference plus noise ratio at secondary receiver was found to be severely limited by interference level on pilot carriers.