现有频谱切换信道访问策略主要考虑切换失败概率,而较少考虑认知用户的信道容量。针对这一问题,提出了一种基于切换失败概率和认知用户信道容量联合优化的频谱切换信道访问策略。首先证明了按信噪比降序访问可以得到最大的认知用户信道容量,而按信道平均空闲时间降序访问可以得到最低切换失败概率。接着提出对信道平均空闲时间和信噪比进行排序并加权合并的非参数化处理。最后,按非参数化处理结果降序进行信道访问。结果表明,所提方法能够在切换失败概率接近最低的情况下,使认知用户信道容量提升50%左右。
The available channel visiting strategy for spectrum handoff mainly considers the probability of handoff failure more than the channel capacity. Aiming at the problem, anovel spectrum suitching channel visiting strategy was proposed based on the probability of handoff failure and the channel capacity foins optimixing of secondary user. It was proved that the maximum channel capacity of secondary user can be obtained by visiting the channel in the descending order of the signal to noise ratio(SNR), and the minimum probability of handoff failure couldbe obtained in the descending order of the mean vacant time duration. Then the mean vacant time of channel and SNR for sorting and weighted combination was processed of non-parameterization. At last, the channel was visited in descending order according to the result of non parametric processing. The numerical results show that the proposed method can increase the channel capacity of secondary user by about 50%, while keeping the probability of handoff failure close to the minimum.