Achievable rates in cognitive radio channels
Achievable rates in cognitive radio channels
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DOI：
10.1109/tit.2006.872971
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发表时间：
2006-05-01
影响因子：
2.5
通讯作者：
Tarokh, V
中科院分区：
文献类型：
--
作者：
Devroye, N;Mitran, P;Tarokh, V
认知无线电有望成为传统单频段、单协议无线设备的一种低成本、高灵活性的替代方案。通过感知和适应其环境，这种设备能够填补无线频谱中的空白，并可以显着提高频谱效率。在本文中，认知无线电信道被定义为一个两个发送者，两个接收者的干扰信道中，发送者2获得编码的消息发送者我计划发送。我们考虑两种情况：在基因辅助的认知无线电信道中，非因果地向发送方2呈现发送方1要发送的数据，而在因果认知无线电信道中，因果地获得数据。然后，发送器2处的认知无线电可以选择在相同的信道上同时发送，而不是像传统的认知无线电那样等待空闲信道。我们的主要结果是开发了一个可实现的区域，它结合了Gel'fand-Pinkser编码和干扰信道的可实现区域构造。在加性高斯噪声的情况下，这类似于脏纸编码，一种用于计算高斯多输入多输出（MIMO）广播信道容量的技术。数值评估的区域中的高斯噪声的情况下，进行比较，内界，干扰信道，和外界，修改的高斯MIMO广播信道。结果也扩展到因果关系获得的消息的情况下。
Cognitive radio promises a low-cost, highly flexible alternative to the classic single-frequency band, single-protocol wireless device. By sensing and adapting to its environment, such A device is able to fill voids in the wireless spectrum and can dramatically increase spectral efficiency. In this paper, the cognitive radio channel is defined as a two-sender, two-receiver interference channel in which sender 2 obtains the encoded message sender I plans to transmit. We consider two cases: in the genie-aided cognitive radio channel, sender 2 is noncausally presented the data to be transmitted by sender 1 while in the causal cognitive radio channel, the data is obtained causally. The cognitive radio at sender 2 may then choose to transmit simultaneously over the same channel, as opposed to waiting for an idle channel as is traditional for a cognitive radio. Our main result is the development of an achievable region which combines Gel'fand-Pinkser coding with an achievable region construction for the interference channel. In the additive Gaussian noise case, this resembles dirty-paper coding, a technique used in the computation of the capacity of the Gaussian multiple-input multiple-output (MIMO) broadcast channel. Numerical evaluation of the region in the Gaussian noise case is performed, and compared to an inner bound, the interference channel, and an outer bound, a modified Gaussian MIMO broadcast channel. Results are also extended to the case in which the message is causally obtained.