On cognitive radio networks with opportunistic power control strategies in fading channels
On cognitive radio networks with opportunistic power control strategies in fading channels
复制标题
衰落信道中具有机会功率控制策略的认知无线电网络
DOI：
10.1109/twc.2008.070145
复制
发表时间：
2008-07-01
影响因子：
10.4
通讯作者：
Qiu, Peiliang
中科院分区：
文献类型：
--
作者：
Chen, Yan;Yu, Guanding;Qiu, Peiliang
本文研究了衰落无线信道下的认知无线电系统，提出了一种认知用户的机会功率控制策略，作为保护主用户传输和实现主用户与认知用户频谱共享的一种替代方法。该策略的主要特点是，认知用户通过机会性地调整其发射功率，可以在不降低主用户中断概率的情况下最大化其可达传输速率。与现有的认知协议相比，该协议通常试图保持主用户的瞬时速率不变，从而减轻了认知用户检测和中继主用户消息的负担，并放宽了系统同步要求。分析和仿真了认知用户在所提出的功率控制策略下的可达速率，并考虑了不理想信道估计的影响。一个修改的功率控制策略也被提出来降低我们的策略的估计误差的敏感性。仿真结果验证了该方法的有效性。
In this paper, we consider a cognitive radio system in fading wireless channels and propose an opportunistic power control strategy for the cognitive users, which serves as an alternative way to protect the primary user's transmission and to realize spectrum sharing between the primary user and the cognitive users. The key feature of the proposed strategy is that, via opportunistically adapting its transmit power, the cognitive user can maximize its achievable transmission rate without degrading the outage probability of the primary user. If compared with the existing cognitive protocols, which usually try to keep the instantaneous rate of the primary user unchanged, our strategy relieves the cognitive users from the burden of detecting and relaying the message of the primary user and relaxes the system synchronization requirements. The achievable rate of a cognitive user under the proposed power control strategy is analyzed and simulated, taking into account the impact of imperfect channel estimation. A modified power control strategy is also proposed to reduce the sensitivity of our strategy to the estimation errors. Its effectiveness is verified by the simulations.