认知无线电多信道下的感知时间优化

主要研究了认知无线电中多信道连续感知结构下,多个感知时隙和单个传输时隙的感知时间优化问题。首先在信道的空闲概率已知的条件下,当信道的信噪比保持不变时,经证明最佳感知时间是存在的;其次在信道的空闲概率未知的条件下,提出了一种单时隙感知时间的次优方法,逐步的计算出来各个时隙中下一个时隙的最优化感知时间。仿真实验证明,提出的方法优于固定感知时间的感知方法,同时降低了算法的复杂度,且在不同的条件下,此方法吞吐量性能接近于理论上的最佳感知时间吞吐量性能,并优于固定感知时间方法的吞吐量。

Sensing Time Optimization in Cognitive Radio with Multiple Channels

The design and the optimization of sensing time in multi-channel sequential sensing for cognitive radio under the multi-channel sensing slots and single transmission slot are investigated and studied. Firstly, under the condition that the channel idle probability is known and that the SNRs （signal-to-noise-ratio） of the channels keep constant, the existence of optimal sensing time could be proved; then under the condition that the channel idle probability is unknown and that the SNR of each channel is equal, a sub-optimal approach of single-slot sensing time is proposed. With this approach, the most optimal sensing time of the next slot in each sensing slot could be calculated step by step. Experiment shows that the proposed approach works better than that of fixed sensing time. Meanwhile the single-slot sensing time could achieve low complexity. Simulation results indicate that the proposed approach could, under different conditions, achieve the performance close to that of the optimal sensing time or ever better performance than that of the fixed sensing time.