Opportunistic spectrum access for energy-constrained cognitive radios
Opportunistic spectrum access for energy-constrained cognitive radios
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DOI：
10.1109/vetecs.2008.363
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发表时间：
2008-05
影响因子：
10.4
通讯作者：
A. Hoang;Ying-Chang Liang;D. Wong;Yonghong Zeng;Rui Zhang
中科院分区：
文献类型：
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作者：
A. Hoang;Ying-Chang Liang;D. Wong;Yonghong Zeng;Rui Zhang
本文考虑这样一种场景，其中次要用户（SU）机会性地访问分配给某个主网络（PN）的信道，该主网络以时隙方式在空闲和活动状态之间切换。在每个时隙开始时，SU可以选择保持空闲或者进行频谱感知来检测PN的状态。如果检测到PN空闲，SU可以进行数据传输。频谱感测会消耗时间和精力，并会导致误报和误检测。目标是针对每个时隙动态决定 SU 是否应该保持空闲或进行感知，如果是，则持续多长时间，以最大化预期奖励。我们将其表述为部分可观察的马尔可夫决策过程，并证明了最优控制策略的重要属性。还提出了复杂度低且性能良好的启发式控制策略。数值结果显示了我们的动态控制方法对于机会频谱访问的显着性能增益。
This paper considers a scenario in which a secondary user (SU) opportunistically accesses a channel allocated to some primary network (PN) that switches between idle and active states in a time-slotted manner. At the beginning of each time slot, SU can choose to stay idle or to carry out spectrum sensing to detect the state of PN. If PN is detected to be idle, SU can carry out data transmission. Spectrum sensing consumes time and energy and introduces false alarms and mis-detections. The objective is to dynamically decide, for each time slot, whether SU should stay idle or carry out sensing, and if so, for how long, to maximize the expected reward. We formulate this as a partially observable Markov decision process and prove important properties of the optimal control policies. Heuristic control policies with low complexity and good performance are also proposed. Numerical results show the significant performance gain of our dynamic control approach for opportunistic spectrum access.