论文标题
使用可重新配置的天线具有不完美的感应和渠道估计的机会性认知无线电系统的可实现速率
Achievable Rates of Opportunistic Cognitive Radio Systems Using Reconfigurable Antennas with Imperfect Sensing and Channel Estimation
论文作者
论文摘要
我们考虑了一个机会性的认知无线电系统，其中次级发射器（SUTX）配备了可重构天线（RA）。利用RA的光束转向能力，我们将重点介绍一个基于扇形的频谱传感和数据通信的设计框架。在此框架中，SUTX感知频谱并检测到与主动主要用户（PU）位置相对应的光束。 SUTX还发送训练符号（在数据符号之前），以启用次级接收器（Surx）的通道估计，并选择SUTX-SURX之间的最强光束进行数据传输。在存在频谱传感和通道估计误差的情况下，我们建立了SUTX-SURX链路可实现的速率的下限，以及由于对与PU的位置相对应的光束的检测不正确以及对数据传输最强的光束的选择不正确而引起的误差。我们制定了一个新颖的约束优化问题，旨在最大程度地提高衍生的可实现的速率下限受试者，以达到平均发射和干扰功率约束。我们优化了空间频谱传感和通道训练的持续时间以及数据符号传输功率。我们的数值结果表明，在优化频谱传感和通道训练持续时间之间，后者对于提供更高的可实现速率更为重要。
We consider an opportunistic cognitive radio (CR) system in which secondary transmitter (SUtx) is equipped with a reconfigurable antenna (RA). Utilizing the beam steering capability of the RA, we regard a design framework for integrated sector-based spectrum sensing and data communication. In this framework, SUtx senses the spectrum and detects the beam corresponding to active primary user's (PU) location. SUtx also sends training symbols (prior to data symbols), to enable channel estimation at secondary receiver (SUrx) and selection of the strongest beam between SUtx-SUrx for data transmission. We establish a lower bound on the achievable rates of SUtx-SUrx link, in the presence of spectrum sensing and channel estimation errors, and errors due to incorrect detection of the beam corresponding to PU's location and incorrect selection of the strongest beam for data transmission. We formulate a novel constrained optimization problem, aiming at maximizing the derived achievable rate lower bound subject to average transmit and interference power constraints. We optimize the durations of spatial spectrum sensing and channel training as well as data symbol transmission power. Our numerical results demonstrate that between optimizing spectrum sensing and channel training durations, the latter is more important for providing higher achievable rates.
