多次要用户动态频谱共享模型研究

发布时间：2018-03-04 09:21

本文选题：混合频谱共享　切入点：连续时间马尔科夫链　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着无线设备越来越多,有限且珍贵的频谱资源显得越发不足,传统的频谱固定分配模式弊端越来越明显。已被分配的固定频谱频段中有相当大部分的时间都处于空闲阶段,而很多继续使用频段传输信息的设备却无法使用,这对无线设备以及未来信息社会的发展造成了巨大的影响和限制。传统频谱分配的模式已经不能满足现阶段社会以及科技发展的需要,因此,我们需要用更好的方式来解决频谱匮乏以及利用率不高的问题。现阶段理论上解决频谱匮乏以及频谱利用率不高的方法有很多种。比如使用竞价博弈以提升频谱共享的效率;也可以充分利用TV空白频谱共享,并使用排队论解决共享问题,这是在使用认知无线电探测频谱后再择机接入信道;在认知双向中继网络中实施频谱共享,由一个模拟网络编码策略实现一个二相频谱共享协议。上述三种方法各有千秋。我们采用了另一种简单有效的方法——动态频谱接入网络下混合频谱共享。现在已有使用连续时间马尔科夫链联合overlay与underlay的混合共享方案,该方案降低了主要用户和次要用户动态建模的复杂性。我们从2次要用户网络向3次要用户网络推导,进而扩展到多次要用户网络时该方案的模型。在此我们推导出这些状态的稳定概率并且通过使用香农信道容量计算出上述频谱共享方案的吞吐量。通过比对,得出3次要用户的混合方案吞吐量高于2次要用户的混合方案吞吐量。同时,我们优化该方案,对次要用户引入期望数据速率以分配给次要用户一个访问概率,将得以使该方案可依据情况对系统的公平性做出调节。同时也展示了数字结果以验证调节系统平衡性方案的性能,结果显示当期望数据速率越高,次要用户访问概率越低。
[Abstract]:With the increasing number of wireless devices, limited and precious spectrum resources are becoming more and more inadequate, and the drawbacks of the traditional fixed spectrum allocation mode are becoming more and more obvious. And many of the devices that continue to use the frequency band to transmit information are not available. This has had a great impact on wireless devices and the development of the information society in the future. The traditional mode of spectrum allocation can no longer meet the needs of the current society and the development of science and technology. We need to solve the problem of spectrum scarcity and low efficiency in a better way. There are many ways to solve the problem of spectrum scarcity and low spectrum efficiency in theory at present, such as using bidding game to improve the efficiency of spectrum sharing; We can also make full use of TV blank spectrum sharing, and use queuing theory to solve the problem of sharing. This is to select a machine to access the channel after using cognitive radio to detect spectrum, and to implement spectrum sharing in cognitive bidirectional relay network. A two-phase spectrum sharing protocol is implemented by an analog network coding strategy. The three methods mentioned above have their own advantages and disadvantages. We have adopted another simple and effective method-hybrid spectrum sharing in dynamic spectrum access networks. There is a hybrid sharing scheme using continuous time Markov chain and overlay and underlay. This scheme reduces the complexity of dynamic modeling for primary and secondary users. In this paper, we derive the stability probability of these states and calculate the throughput of the spectrum sharing scheme by using Shannon channel capacity. The hybrid throughput of 3 secondary users is higher than that of 2 secondary users. At the same time, we optimize the scheme by introducing the expected data rate to the secondary users in order to assign a access probability to the secondary users. It will enable the scheme to adjust the fairness of the system according to the situation. At the same time, the digital results are shown to verify the performance of the balancing scheme. The result shows that the lower the access probability of the secondary user is, the higher the expected data rate is.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925

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